The 1st International Conference on Net-Zero Built Environment

Concrete three-dimensional (3D) printing technology has the potential to significantly reduce on-site labour activities, as 3D-printed concrete eliminates the need for formwork. However, challenges persist in ensuring the quality and strength of 3D-printed concrete. One of the factors likely to impact its strength is the fluctuation of the water-to-binder ratio (w/b) during the printing process. In contrast to traditional cast-in-place concrete, where the mix is prepared at the factory with a fixed water-to-binder ratio, 3D-printed concrete is continuously mixed from a dry mix during printing. The amount of water added to the dry mix is routinely adjusted by the printer operator to maintain optimal consistency. This adjustment affects the water-to-binder ratio, leading to variations in concrete strength. This chapter investigates the extent to which the consistency and strength of 3D-printed mortar may vary while remaining printable using an industrial-scale concrete printer. Using the same dry mix, we observed a difference of approximately 15% in the mean strength for samples cast at the 3D printing site on two different dates. Additionally, there was about a 20% difference in the strength between the thickest and thinnest printable consistencies mixed in the laboratory. This variation must be considered when determining the design strength of 3D-printed concrete.

This research aims to design and develop a proof-of-concept system for three-dimensional (3D) printing of fly ash-based geopolymer materials. The primary focus of this research was designing and creating a 3D printer capable of printing straight multi-layered geopolymer walls. The geopolymer mixture consists of fly ash, an industrial waste by-product, sand, sodium silicate, sodium hydroxide, and water. Through the controlled application of AC voltage, the natural resistance of the geopolymer causes heat generation through a phenomenon known as ohmic heating. This heating method rapidly cures the geopolymer in as little as five (5) minutes based on volume. Several off-the-shelf 3D printer designs were studied to understand the working principle, and ultimately, the final design was developed based on the necessary design criteria. This design allowed the printer to extrude geopolymer through a rotating auger assembly. Parallel copper electrodes mounted at the end of the extruder allow AC voltage to apply through the uncured geopolymer and heat it as it is extruded. Following many trials, the developed printer provided proof of concept for a viable electrically heated rapid-setting geopolymer 3D-printed wall. This design effectively demonstrates that with further development, the 3D printing of geopolymer can potentially serve as an eco-friendly alternative to 3D-printed concrete.

Life-cycle assessment (LCA) stands as a vital tool in gauging the environmental impacts of building endeavors. Extending LCA to emerging research practices like advanced digital manufacturing of bio-based materials becomes pivotal for refining materials, appraising outcomes, and steering architecture toward sustainable development and circularity goals. To outline the main obstacles and to provide a potential methodology, the chapter presents two cases of application of LCA to digital fabrication with bio-based materials in experimental research practice. The application is framed within the ISO and EU standards for LCA and is tested through an ex-post “cradle to construction” analysis of two European Research Council (ERC) funded projects developed by the Center for Information Technology in Architecture (CITA) at the Royal Danish Academy. Specifically, a product LCA is performed for bio-polymeric composited 3D robotic fabrication using a novel collagen-based 3D print material, and a comparative LCA is carried out for Glulam manufacturing optimization connecting data from the timbers source in the forest and sawmill with its design and fabrication. In both cases, the prototypes assembly and exhibition are covered by the analysis. The unavailability of data, difficulties in standard protocols adaptation, and material and energy flows tracing in the research process emerge as the main barriers and contribute to aggravate the analysis’s uncertainty. The chapter shows how to manage such uncertainties via sensitivity analysis to evaluate design options according to different impact scenarios. The knowledge established and the methodology outlined in this research could be useful for researchers, designers and industry in the implementation of sustainable digital fabrication processes and new construction materials.

There are different ways to reduce the CO2 amounts emitted from concrete production, e.g., carbon capture during the cement production, application of low-clinker binders, or changing the structural design strategies to decrease the total consumption of overall materials. Another vital approach is to foster the application of locally available resources, which does not require a significant amount of energy for the production and transport, and which could be used as cementitious materials without compromising the properties of the concrete. Biochar, produced by pyrolysis, is a potentially promising material for improving the sustainability of cementitious materials as it can sequester CO2 and can be made widely available. However, its use in concrete is limited due to negative effects on concrete properties at dosages that can have a significant effect on the carbon footprint. These effects depend on the source of raw biomass and pyrolysis conditions. Biochar’s high porosity leads to the absorption of mixing water, altering the water to cement ratio and rheology. Superplasticizers can help adjust this, but at the cost of longer setting times. High levels of biochar also reduce the mechanical properties of cement-based materials. Currently, the maximum replacement of cement with biochar without compromising mechanical properties is 5–10%. However, to increase the CO2 reduction potential, the content of biochar in cement-based materials must be increased. The current paper suggests possible strategies to promote the use of biochar in cementitious materials to increase its CO2 reduction potential and pave the way to net-zero concrete technologies.

This research delves into the integration of economically sustainable materials—Portland limestone cement (PLC) and recycled glass powder (GP)—into ultra-high-performance concrete (UHPC) formulations. The emphasis is on mitigating UHPC’s reliance on high-cost, high content of cement, and proprietary additives, which elevate both the expense and environmental impact of infrastructure projects. By evaluating the effects of PLC and GP on the structural performance of UHPC, the study aims to provide affordable, locally sourced, and customizable options. This study investigates the enhancement of UHPC by testing six mortar mixes that contrast the use of ordinary Portland cement (OPC) with the more sustainable PLC, enriched with silica fume (SF) and recycled glass powder. The introduction of glass powder notably increased UHPC’s compressive strength, and PLC mixes showed enhanced early strength and reduced shrinkage. This underscores the potential of PLC and recycled glass for making UHPC more sustainable, while highlighting their beneficial roles in enhancing structural properties, marking a stride toward more eco-friendly construction materials.

This study focuses on reducing the CO2-eq footprint of ultra-high-performance concrete (UHPC) by substituting Portland cement with alternative binders. Three types of cement types which are pre-accepted in the standard EN 197 were used: CEM I with >95% ordinary Portland cement (OPC), CEM II with 30% ground-granulated blast-furnace slag (GGBS), and CEM II with 70% GGBS. Fresh state consistency, compressive strength, and flexural tensile strength were evaluated, in addition to a comparison of CO2-eq footprints. Results showed that while the compressive strength was brought to the same level for all three mixes when curing at elevated temperatures for a short period, significant reductions in CO2-eq emissions were achieved: up to 60% for UHPC excluding steel fibers and 40% when including 2 vol.% micro steel fibers. The study also highlighted the potential for further improving strength properties by reducing water content in mixes with higher GGBS content. Overall, this research underscores the potential to reduce the environmental impact of UHPC through incorporating alternative materials in UHPC production that are already pre-accepted for industrial use.

This chapter investigates the potential of lightweight ultra-high-performance concrete (LUHPC) with a focus on its application in sustainable construction. The objectives encompassed an analysis of LUHPC’s workability, heat of hydration, autogenous shrinkage, and carbon footprint through a multidisciplinary approach. Methodologically, an extensive review of existing literature was conducted, consolidating findings from experimental investigations. Key findings elucidate that the integration of lightweight aggregates (LWAs) positively impacts LUHPC’s workability by reducing water demand and enhancing particle movement. Moreover, LWAs facilitate internal curing, mitigating autogenous shrinkage, and improving hydration degree. The utilization of supplementary cementitious materials (SCMs) and sustainable additives further reduces LUHPC’s carbon footprint, manifesting notable reductions in carbon dioxide (CO2) emissions and energy consumption. These findings underscore LUHPC’s potential for sustainable construction practices, offering structures that are both lighter and stronger with a diminished environmental impact. The findings of this study indicate emerging opportunities for improving the utilization of LUHPC mixtures in construction projects, focusing on promoting workability, durability, and environmental sustainability.

Over the past decades, ground granulated blast furnace slag (GGBS) has been extensively used as a replacement for cement in concrete production to mitigate cement carbon emissions. Hence, a substantial portion of the hydrated cement paste discarded at the end of a concrete’s lifespan could contain a certain quantity of GGBS. This study aims to investigate the feasibility of using hydrated cement paste containing 30% GGBS (BSCP) in cementitious binders via moisture carbonation treatment. The changes in the microstructure of BSCP before and after carbonation are analyzed using thermogravimetry-differential thermal analysis (TG-DTG), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) techniques. The carbonated BSCP (CBSCP) is then used to substitute a part of cement (0%, 15%, and 30% by mass), and the flowability and compressive strength of the blended CBSCP-cement paste are examined at 3, 7, and 28 days. The results show that carbonation can significantly alter the microstructure of BSCP by forming calcium carbonate crystals and consuming a significant amount of calcium hydroxide. Consequently, the inclusion of CBSCP in new cement paste results in a reduction in flowability and enhancement of early-age strength. Overall, it can be concluded that carbonated BSCP can be utilized as an emerging binder up to 30% in cement-based materials, without significantly compromising the later-age strength.

This study assesses the performance of metakaolin (MK)-based alkali-activated geopolymers as potential materials for underwater applications. Mortars were formulated using gradually higher sand volumes, which resulted in binder-to-sand ratios varying from 1:3 to 1:1.85 and 1:0.8. The alkali-activated solution (AAS) was produced using sodium silicate and sodium hydroxide. The AAS was adjusted to achieve a flow of 16 and 22 ± 1 cm while the setting times, plastic viscosity, washout loss, and 28-day compressive strengths were determined. Generally, an increase in AAS content prolonged setting time, while washout loss increased with higher sand content. Mortars with lower flowability exhibited higher resistance to washout, attributed to higher viscosity and stickiness of the matrix. The compressive strengths of mortars cast in dry or underwater conditions ranged between 23.4–54.1 MPa and 12.7–28.3 MPa, respectively; the residual strengths varied from 50.5% to 75.6%, mainly depending on the AAS-to-binder ratio.

Calcium sulphoaluminate (CSA) cements have proven to be a viable alternative to ordinary Portland cement (OPC) due to their advantageous attributes such as reduced CO2 emissions and lower energy requirements during their production. These qualities contribute to ongoing efforts to advance sustainable practices and materials in the construction industry. With a focus on promoting the circular economy, sustainability, and improving the performance of building materials, municipal solid waste incineration fly ashes (MSWI FA) have been considered as a potential material to use within the construction sector. In this research, several CSA clinkers were produced using MSWI FA as raw material in the raw meal formulation. Substitutions of 10%, 20%, 30%, and 40% of the raw meal were evaluated at 1250°C, identifying their effect on the development of cementitious phases by XRD and TG-DSC and their hydration kinetic using isothermal microcalorimetry. Also, some effects from trace elements and chloride compounds present in MSWI FA during the CSA clinkering process were identified. The contribution of calcium from the ashes allows us to reduce the amount of natural raw material necessary for the formulation of the clinker, in addition to providing some compounds that act as fluxes, lowering the burning temperature and thus the energy consumption for the production of the clinker. The social contribution to communities that incinerate urban solid waste is also highlighted by taking advantage of the waste that is generated.

The study used electric arc furnace oxidizing slag (EAFOS) to substitute natural fine aggregates. However, EAFOS replacement may cause volumetric instability. Therefore, a cement, fly ash, or slag layer was coated with EAFOS as a precoated technique. Then, the effect of EAFOS on engineering properties was investigated, and the optimum amount of EAFOS was identified. The amount of coated binders was set at 20%, 25%, 30%, 35%, and 40% of the weight of EAFOS, and the water-to-binder ratio (w/b) of the coated binders was fixed at 0.50 to 0.20. The proportion of EAFOS replacing fine aggregates was 10%, 20%, 30%, 40%, and 50%, and the w/b of the mortar was fixed at 0.55. The results showed that the proportion of precoated binder was 30% of the EAFOS and the w/b was 0.30. Curing time was up to 28 days, and slag was the appropriate precoated binder. Maximum compressive strengths of mortars made with precoated EAFOS were 42.94 and 56.96 MPa at 7 and 28 days (40% replacement for fine aggregates). The maximum compressive strengths of specimens without coated EAFOS were 36.67 and 47.55 MPa at 7 and 28 days (the identical replacement). The drying shrinkage of 40% precoated slag specimens was 0.054% at 7 days and 0.074% at 28 days. The appearance of the specimens did not reveal any abnormality after 28 days of immersion in water at 70 °C. The precoated technique adopted in this study can be used as a stabilization procedure for replacing natural fine aggregates with EAFOS.

Achieving net-zero construction is curial for construction sector to mitigate the effects of climate change. Using alkali-activated materials (AAM) to replace the carbon intensive ordinary Portland cement (OPC) in concrete has attracted many researchers’ attention in the past years. However, several problems are associated with AAM, such as lower early age mechanical strength. This paper aimed to investigate the early days effects of graphene on hydration mechanism of Na2CO3-activated granulated blast-furnace slag (GGBS) concrete. Graphene dosages ranging from 0.005% to 0.02% (of slag weight) were considered in this study. The compressive strength of GGBS concrete was measured at 3 days. Samples were cured under ambient room temperature around 20 ± 3 °C. Results indicated the incorporation of graphene could increase the compressive strength up to 33%. To understand the changes on the microstructure level, various microstructure technics were performed on 3-day curing samples to provide a comprehensive understanding of the microstructure elements. X-ray diffraction (XRD) was employed to identify the composition and crystallinity of different phases. Overall, the higher gain in early-day strength of concrete and the shortened setting times are mainly due to the nucleation effect of graphene which was revealed by the much denser and compact microstructure, as shown in the SEM images.

During the past two decades, exploiting the metabolic processes (urease activity) of some microorganisms that lead to the precipitation of calcium carbonate (CaCO3) as a sustainable solution for producing self-healing cementitious materials in the construction industry has gained significant interest. Despite extensive efforts for experimental characterization of the effect of various influential factors such as the type of bacteria, urea and calcium concentration, temperature, and pH of the environment governing this phenomenon, the numerical modeling of this biochemical process has not advanced substantially due to its complexity and intertwined involved parameters. Among these influential parameters, pH is of considerable importance, as the initial pH level has an immediate effect on the urease activity of the bacteria, which subsequently affects the rate at which calcium carbonate precipitates. Additionally, during the CaCO3 precipitation process, pH fluctuates due to the production of by-products, such as ammonium, altering continuously the velocity of the bacteria’s urease activity.This chapter presents a numerical modeling for the CaCO3 precipitation by urease activity of Sporosarcina pasteurii via COMSOL Multiphysics®. The model considers the influence of calcium and urea concentrations and the initial pH level along with pH variations resulting from the production of by-products throughout the process. The model’s ability to predict CaCO3 content and the final pH level is assessed by comparing the computational results with experimental data from existing literature. Finally, a parametric analysis investigating the impact of the initial pH on the anticipated ultimate pH is presented.

The continuous increase in demand for cement in the construction industry critically contributes directly to the global carbon dioxide (CO2) emission. Hence, numerous attempts are being made to reduce CO2 emissions in conjunction with cement production, named as low-carbon cement. This has boosted the enthusiasm for searching for alternatives, specifically supplementary cementitious materials (SCM) that are considered the most environmental and economical friendly method for mitigating CO2 emissions associated with the cement-based construction industry. The purpose of this study is to investigate silicon manganese slag (SiMn slag), a by-product of the metal industry as a sustainable alternative for partial replacements with traditional cement. An experimental investigation was conducted utilizing SiMn slag, primarily focusing on evaluating the compressive strength at 3, 7, 14, and 28 days for both binary and ternary sets of binders, the latter being coupled with ground granulated blast furnace slag. The study has investigated the different replacement levels of cement with SiMn slag up to 90% while maintaining water to binder ratio at 0.35. The microstructure and mineralogical analyses of the prepared hardened binders have been conducted using scanning electron microscopy (SEM) and X-ray diffraction (XRD) to identify phases, morphological changes, and various reaction products. The results indicate that the investigated binary mixture at 30% and 50% cement replacement levels, as well as the ternary mixture at a 50% cement replacement level, exhibited better compressive strength performances. The study suggests using SiMn slag as a supplementary cementitious material in binary or ternary mixtures, potentially achieving improved compressive strength even with higher levels of cement replacement.

Recognizing climate change’s severity, reducing the construction industry’s greenhouse gas emissions is crucial in material science, architecture, civil engineering, and construction science. Novel bio-based materials like hempcrete are being developed to lessen the environmental impact of construction. Hempcrete, increasingly used in traditional and advanced construction like large-scale 3D printing, is considered carbon-negative due to the biogenic and sequestered carbon of its components. Given the high carbon footprint of Portland cement, hempcrete offers a sustainable alternative for emerging construction technologies. However, hempcrete’s carbon neutrality or negativity depends on the hemp and lime content in the mix. A thorough Life Cycle Assessment (LCA), therefore, becomes important to understand carbon negativity potential of this material. In this paper, we present the results of a cradle-to-gate LCA of hempcrete mixes that have been proposed and examined in empirical studies. The LCA also includes a process-based hybrid cradle-to-gate impact assessment of hemp produced in the United States. The results indicate that the total global warming potential of hemp is roughly −1.72 kgCO2e/kg, and carbon negativity can only be reached with at least 20% of hemp by weight in the hempcrete mix. Findings also show that consideration of carbon absorption of lime binder is essential to reach carbon negativity. Our results further indicate that a balance of carbon negativity and hempcrete’s compressive strength will be more desirable to address both climate change mitigation and adaptation.

In order to meet the new demand for sustainability and lower carbon emissions for concrete, the production and recycling process has to be adapted. Regarding concrete recycling, the main focus in literature and industry is on the reuse of coarse aggregates. However, the recycling of concrete also generates a fine fraction. In this research, the fine fraction with size 0/2 is ground and studied as a partial cement replacement. First of all, the fines were characterized and their physical, chemical and mineralogical properties were determined. Preliminary tests on pastes and mortars with 0%, 5%, 10%, 15%, 20%, 25% and 30% cement replacement, such as isothermal calorimetry and strength tests, were performed. Based on these results, two concrete mixes were made: one reference mix with CEM I as a binder and natural aggregates and a concrete mix with 10% of CEM I replaced by concrete fines and a combination of natural and recycled aggregates. In this second mix, 27.8% of the sand and 100% of the coarse aggregates were replaced by recycled sand and recycled coarse aggregates. The concrete samples were tested on compressive strength, shrinkage and freeze–thaw resistance. The compressive strength of the green concrete was comparable to the strength of the reference concrete after 28, 56 and 90 days of curing. Concrete specimens containing the recycled fines and recycled aggregates had a higher drying shrinkage; however, a lower autogenous shrinkage was measured in comparison to the reference. Regarding durability, the green concrete had a lower freeze–thaw resistance compared to the reference.

This research aims to analyze the physical durability of oyster shells in hydraulic lime-based mortars. Standardized tests were conducted on mortars in fresh and hardened states using molds in the laboratory. The mortars produced were also applied to solid bricks and detached for further testing. The standardized specimens underwent a curing period of 28 days. The detached specimens, representing in-service conditions, also had a 28-day curing time in the laboratory plus accelerated aging curing. Two different types of mortars were investigated: a control group, and a group with a 30% replacement of sand aggregate by oyster shell aggregate. The study revealed distinct behaviors of the mortars in both laboratory and real-world conditions (after curing by accelerated aging, application, and detachment from the substrate). Key properties such as bulk density, open porosity, and water absorption were found to be influenced by actual service conditions. These nuances in behavior may not be readily apparent when studying mortars in standard molds alone. However, examining in-service conditions can provide valuable insights for optimizing dosage and incorporating new materials, thereby contributing to a more sustainable construction industry.

CO2-emissions as the main reason for global warming turn out to be a challenging issue in the twenty-first century. Reduction of CO2-emission in the cement and concrete industry by using low-carbon alternative binders on the one hand and carbon-capturing technique on the other hand is an innovative solution for this purpose. Using carbon-capturing techniques for recycled aggregates also leads to superior mechanical, as well as durability properties. The objective of this research is to assess the carbonation possibility of the aggregates extracted from alkali-activated concrete and its consequences on the concrete made with them. In this study, recycled aggregates extracted from alkali-activated ground granulated blast furnace slag (GGBS) concrete produced with natural and recycled aggregates were carbonated. The CO2-absorption rate and its influence on the properties of aggregates were investigated. Recycled aggregates showed up to 4 wt.% CO2-capturing potential, which can result in up to 40% lower water absorption. Moreover, the effect of carbonated aggregates on the mechanical behavior of concrete made with them was investigated which showed an improvement of mechanical properties.

In recent decades, the world has experienced a surge in extreme environmental events, exacerbated by the ongoing impacts of climate change. Substantial research underscores the role of anthropogenic CO2 emissions as the primary driver behind climate change and global warming. Cement production, constituting roughly 7% of global anthropogenic CO2 emissions, stands as a significant contributor to this issue. Consequently, there has been a growing focus on mitigation strategies within the cement industry, particularly emphasizing the utilization of mineral admixtures. An innovative yet underexplored material for partial cement replacement is iron mining waste rock, a by-product of open-pit mining operations used to extract iron ore deposits. Unlike underground mining, open-pit methods generate larger volumes of waste rock, typically stored in substantial geotechnical structures like piles, pits, or dams. This study conducted physical–chemical, mineralogical, and morphological characterizations on iron mine waste rock. Subsequently, four mortar mixtures were formulated, integrating iron mine waste as a partial substitute for cement (up to 30% by mass), and compared against a reference mortar. The performance assessment encompassed evaluations of fresh mortar properties, compressive strength, and elastic modulus. Findings revealed that the waste rock demonstrates limited pozzolanic activity, primarily functioning as a filler, and its inclusion in mortar enhances the workability of the mixes. However, a marginal reduction in compressive strength (up to 15%) was observed in mortar mixtures where 30% of the cement was replaced by waste rock.

Freshwater scarcity is expected to become one of the biggest concerns globally, with the construction industry accounting for as much as 30% of global freshwater use over the life cycle of civil infrastructure today. Water management and its potential to practically alleviate water scarcity and increase the sustainability of concrete therefore need more consideration in scientific research. Existing research suggests that non-potable water such as treated domestic wastewater (TDW) could be used to produce structurally sound concrete for the construction industry. Consequently, this research study was conducted as a pilot project to assess the feasibility of utilizing treated domestic water to produce good quality and durable concrete in South Africa. Chemical analyses of the TDW samples, evaluation of the concrete setting time, slump retention and 7-day and 28-day compressive strength tests were performed in the study. While no definitive correlations of using TDW on the setting time and workability of concrete could be deduced, the majority of the recorded effects were surmised to be acceptable for the concrete industry in South Africa. In addition, while using TDW as mixing water delayed the compressive strength development of the concrete samples, the samples still attained sufficient compressive strength at 28 days to pass the stipulations of the standard. The findings of this study show that TDW produces concrete with sufficient workability, setting time, and compressive strength to be used in the local construction industry. However, quality control of the TDW is vital to ensure the consistent production of good quality concrete.

The possibility of achieving auxetic behaviour in conventional materials is currently attracting significant research interests in the form of auxetically enhanced cementitious composites and, especially, in re-entrant honeycomb structures. Most studies on the behaviour of re-entrant steel honeycomb auxetic reinforcement for concrete focus on achieving uniplanar auxetic behaviour perpendicular to the direction of loading. This study focuses on investigating multi-planar auxetic behaviour throughout the composite. The auxetic behaviour was achieved by perforating the steel sheets before making the re-entrant honeycomb structures. The re-entrant honeycomb was fabricated by folding mild steel strips 70 mm wide into a re-entrant profile and welding the strips onto one another. Three types of perforations were investigated, representing three categories of samples: circular perforation, orthogonal elliptic perforations and orthogonal peanut perforations. The perforated samples were compared to the non-perforated re-entrant honeycomb (control) through compression strength tests of the composites. Direct tension tests were also carried out on each steel strip in order to understand their respective stress–strain behaviour. The study demonstrates that perforating the re-entrant honeycomb walls could be a simple method for achieving multi-planar auxetic behaviour in re-entrant steel honeycomb-reinforced cementitious composites.

The process of concrete development requires extensive water use, leading to a scarcity of natural freshwater supplies. It was found that nearly 19% of the overall water is consumed by industrial fields in which the construction field takes the lead. Employing seawater for concrete construction activities could help in protecting vital freshwater supplies when concrete is reinforced by materials such as aluminum, stainless steel, polymer composites or bio-based materials which are less sensitive to seawater. In the present research, seawater is used in place of tap water for mixing and curing of mortar. Different tests such as heat of hydration, compressive strength, flexural strength, electrical resistance and test for water absorption and permeable voids were conducted to evaluate the effectiveness of mortar made with seawater and tap water. The findings of this study show that seawater is a viable option to produce mortar without compromising the properties of mortar. Unreinforced concrete, fiber-reinforced polymer and aluminum-reinforced concrete all offer promising applications when combined with seawater, enhancing their construction potential and sustainability.

Utilization of lightweight concrete results in a reduction in the weight of the structure, leading to lower destructive effects of seismic forces on the building. Additionally, in today’s conditions where more efficient energy use is desired, there is an increasing interest in the use of lightweight concrete facade panels due to their superior performance in terms of heat insulation. It is known that pollutants such as COx and NOx adhere to facades over time, causing pollution and visual deterioration. It was reported that materials with photocatalytic properties are used in concrete elements to prevent such issues. In this context, the use of self-cleaning concrete facades containing materials with photocatalytic properties has become more prevalent in recent years. Among the many semiconductor materials used in the production of self-cleaning concrete, it is understood that the use of TiO2 is more widespread due to the various advantages it offers. On the other hand, it was reported that urbanization is increasing, and the volume of construction waste is rapidly growing, particularly after severe earthquakes. In this context, promoting the use of recycled concrete waste and efficiently disposing of construction and demolition waste are of great importance for the European Green Deal. This study examines the effect of using recycled concrete aggregate on the self-cleaning properties of lightweight concrete mixtures (SCLWC) compressive and flexural strength performance. For this purpose, an SCLWC containing 1% TiO2 and 100% pumice aggregate was prepared. By substituting recycled concrete aggregate with pumice aggregate at 25% and 50% rates, two different SCLWCs with self-cleaning properties were produced. The compressive strength and flexural strength performances of the produced mixtures were examined. It was observed that the increase in pumice aggregate content caused a decrease in both strength performances. It was observed that the increase in pumice aggregate content caused a decrease of up to 53% and 7% in compressive and flexural strength performance, respectively.

The surge in population and urbanization in South Africa has increased construction activities, leading to the generation of a significant amount of construction and demolition waste (C&DW). While a portion of this waste is used in low-grade applications, the rest ends up in landfills. The conventional use of virgin materials persists, contributing to environmental issues such as increased energy usage and CO2 emissions from the mining and transportation of raw materials and the use of cement in concrete production. To promote a circular economy, resource efficiency, and reduced carbon footprint, a shift toward C&DW recycling is imperative. Despite successful international practices, the recycling rate in South Africa still needs to improve. While previous research works have focused mainly on using recycled aggregates (RAs) in structural concrete, this review explores their potential use in the manufacturing of low-strength concrete bricks and blocks, which are essential construction products within the context of housing development in South Africa. The lack of certification and standards for RAs in South Africa has hindered their practical use. Thus, different stakeholders need to take responsibility for investigating and developing quality control procedures to ensure consistency.

Molecular dynamics simulations have been increasingly employed to investigate the mechanical properties of cement hydrates at the nanoscale. This technique deepens the understanding of cement-based materials, yet correlating these nanoscale findings with larger scale experiments remains a challenge, particularly due to scaling effects. This study focuses on the scaling impact on calcium silicate hydrate (C-S-H). Two types of C-S-H models were constructed: one with defective silicate chains and the other without. Each model includes three sub-models of varying sizes. Under uniaxial tension along silicon chain direction, the stress and strain responses were recorded. The results show that at the nanoscale, model correction such as silicon chain breakage has a greater impact on the elastic modulus and tensile strength than model size. Additionally, the stress–strain curve obtained during the tension process needs to be corrected before comparison with stress–strain on other scales. The findings provide crucial insights into the mechanical behavior of C-S-H at the nanoscale and offer a theoretical basis for bridging the gap between nanoscale simulations and larger scale experimental results.

Local clay, characterized, ground, and burnt, was used to partially substitute ordinary Portland cement (OPC) for mortar production. The raw clay burning was optimized to guarantee the lowest possible environmental effect with the highest possible reactivity of the calcined clay Fanja (CCF). The obtained clay pozzolana was used in mortar at (0–30%) proportions to partially replace OPC. The blended mortar was evaluated at fresh and hardened states, including the flow, compressive strength, and durability properties.The findings show a decrease in the mortar’s flow, while the various CCF contents enhanced the compressive strength. Meanwhile, the mortar’s porosity and permeability decreased. The blended CCF mortars showed an impressive resistance to chloride compared to the plain mortar. Apart from its noteworthy mortar’s mechanical and durability performance improvements, the developed cementitious system is more cost-effective and environment-friendly compared to the control. This research advocates for using locally sourced, eco-friendly construction materials, as they enhance building performance and longevity and have minimal adverse effects on the environment and ecosystem.

Supercritical CO2 was utilized to accelerate the carbonation process, altering the microstructure and composition of Portland cement mortar blended with metakaolin. Mortar samples were cured in a high-pressure reactor at 323 K and 15 MPa under supercritical CO2 conditions. The results demonstrate a significant enhancement in both compressive and flexural strength for all carbonated mortar samples treated with supercritical CO2 compared to those subjected to ambient curing conditions. Furthermore, longer reaction times resulted in increased overall CO2 utilization within the mortar matrix, with more pronounced effects observed in samples containing metakaolin. Hydrated mortar samples demonstrated a complex pore system characterized by a substantial presence of small gel pores, alongside large gel and mesopores. Upon exposure to supercritical CO2, SEM micrographs revealed a rougher surface, along with the formation of CaCO3 crystals.Comprehending high-pressure carbonation is vital for several applications, such as carbon capture and storage, improving the properties of recycling concrete, and safely managing toxic elements in construction waste materials.

Ultra-high-performance concrete (UHPC) often faces challenges due to its low water-to-binder ratio. In this case, cement particles will be unable to fully hydrate, resulting in a high degree of initial dimensional instability. As a promising solution, superabsorbent polymers (SAP) and natural zeolite have potential in mitigating shrinkage and achieving self-stressing properties. Despite prior research on strength, shrinkage, and hydration of UHPC, no systematic study has examined the effects of SAP and natural zeolite on porosity and pore structure. To address this gap, a holistic testing program was established in this study to investigate how these materials affect the microstructural properties of UHPC, especially porosity and pore distribution. This included compressive strength, drying shrinkage, and autogenous shrinkage. The hardened mixtures were also characterized using mercury intrusion porosimetry, while nuclear magnetic resonance (NMR) technology was used to evaluate the pore parameters. The results show that UHPC incorporated with zeolite experiences less autogenous shrinkage than SAP due to the internal curing effect of zeolite particles. The compressive strength, however, is reduced attributed to a more porous microstructure. The outcome of this study provided valuable insights into optimizing the balance between durability and mechanical performance, paving the way for more sustainable and cost-effective applications of UHPC in modern construction practices.

Cement manufacturing is one of the widest industries in the world and yet largely contributes to the global CO2 emissions. As a result, introducing low carbon sustainable concrete designs without compromising performance has become one of the greatest challenges over the last few decades. This complexity was majorly caused by heterogeneity of concrete due to the existence of cementitious particles, fibers, or fine filler materials. Further, this multi-scale material heterogeneity of concrete influences the performance of concrete at macro levels and makes it more complicated to understand the hydration behaviors. Macroscale trial and error-based mechanical property testing might not always be the feasible way to find the optimum mix designs, because those techniques cannot quantify the root cause relationship to the microstructure. Therefore, microscale quantitative chemical and mechanical characterizations pave the way for cement to upscale strength from microlevel to structural level using strength homogenization, revealing the compositional characteristics which contributed to the strength variation in any novel cement mix. Since microphase identification is crucial to achieve that task, in this study, energy-dispersive x-ray spectroscopy (EDS) together with scanning electron microscopy (SEM) is used to quantify the hydration of an ultra-high-performance cement paste at microlevel. The image analysis is carried out using the mapping data collected from four different locations of the same cement batch, and the accuracy of the hydration quantification is compared with an independent analytical hydration simulation software, Virtual Cement and Concrete Testing Laboratory (VCCTL) by NIST.

Currently, geopolymers are introduced as sustainable construction materials with high durability performance and lower carbon dioxide emission. This experimental work prepared geopolymer concrete specimens with 30, 40, 50, 60, and 70% of tile ceramic waste powder (TCWPs) as ground blast furnace slag (GBFS) replacement. Then, the natural coarse and fine aggregates, including crushed stone and river sand, were replaced by 10, 20, and 30 vol% of discarded rubber tire crumbs (DRTCs). The effect of TCWPs and DRTCs inclusion on the geopolymer matrix workability, compressive strength, and splitting tensile and flexural strengths are assessed. From the results obtained, it was found that the content of TCWPs and DRTCs significantly influences the proposed geopolymer’s workability. The results show the increasing content of TCWPs as GBFS replacement led to improved concrete workability. However, the utilization of DRTCs as natural aggregate replacements negatively affects slump value and workability, with a trend to decrease with increasing replacement levels. Moreover, the results show an inverse relationship between TCWPs and DRTCs content and strength development of proposed concrete. The loss in strength was found to increase with increasing content of both TCWPs and DRTCs. However, the investigated geopolymer concrete achieved acceptable compressive strength (more than 25 MPa), which can be considered for many applications in construction sectors. It is shown that using TCWPs and DRTCs in geopolymer production can help produce construction materials with reduced environmental impacts, including carbon emissions and landfill problems.

This study investigates the integration of synthetic fibers—polyvinyl alcohol (PVA), alkali-resistant glass (AG), and polypropylene (PP) fibers—into concrete mixes from the perspective of the structural materials’ carbon footprint and progress toward net-zero construction. It scrutinizes these fibers’ production processes, usage, and end-of-life stages, evaluating their CO2 emissions and broader environmental impact within the sustainable construction framework. The study introduces a specific mix design where the fibers above are added at percentages of 0.25% and 0.50% to concrete, with analysis conducted on six beams for each type of fiber. The results demonstrate that while all fibers enhance concrete’s strength and durability, PP fibers exhibit the lowest CO2 emissions, making them the most environmentally advantageous option among the three. This chapter concludes with strategies to optimize synthetic fibers in concrete, advocating for energy-efficient manufacturing and recycled materials. This research enriches the discourse on sustainable construction materials, offering a detailed examination of synthetic fibers’ potential to reduce the environmental impact of the construction industry.

The rapid growth of cities, particularly in developing regions, is driving a significant increase in concrete demand. However, concrete production is a major environmental concern, releasing high levels of carbon dioxide (CO2) due to its dependence on cement. This study investigates the use of class-F fly ash as a partial replacement for cement in self-compacting concrete (SCC) to reduce its environmental impact. Life cycle assessment (LCA) is employed to measure the embodied energy (EE) and global warming potential (GWP) of various fiber-reinforced SCC mixes containing different fly ash replacement ratios. The results emphasize the importance of optimizing the amount of fly ash to achieve a balance between desired mechanical performance and minimized environmental burdens. While the study explores the influence of fiber types, the key finding is that incorporating class-F fly ash demonstrably reduces both GWP and EE in SCC. In conclusion, this study highlights the potential of fly ash as a sustainable alternative in SCC production, promoting eco-friendly construction practices without compromising performance.

Burned clay brick masonry is a commonly used building unit for structures. Improving the earthquake resistance of such structures is vital due to the increase in the occurrence of seismic events globally, affecting larger populations and aging/deterioration of the masonry. Generally, conventional synthetic material-based strengthening techniques are widely used for structures, which is carbon-intensive and not climate-friendly. Therefore, to strengthen brick masonry structures seismically, various techniques for enhancing earthquake resistance using locally available natural fibers are investigated and presented in this study. The use of locally available natural fibers helps in reducing emissions and carbon footprint overall, apart from providing good thermal insulation. In this study, a finite element model of a two-story brick masonry building strengthened with natural fiber-reinforced polymer (FRP) composites subjected to earthquake ground motions is developed. Linear dynamic analysis of the buildings without and with strengthening is performed under uniaxial earthquake ground motion. The dynamic response of the buildings, i.e., peak shear force, acceleration time histories, stress distribution, crack propagation patterns, and overall earthquake resistance of the buildings is compared. An enhancement in the dynamic performance of the building is reported on the adoption of strengthening measures using a variety of natural fiber elements. The flax FRP composite is observed to be the most effective in strengthening the masonry structure under static and seismic load scenarios. The study contributes to proposing sustainable practices in seismic risk mitigation for existing as well as new structures.

This study investigates the integration of electrospun cellulose acetate (CA) microfibers into cementitious composites to enhance the mechanical properties of the resulting composite material. Through systematic experimentation, optimal parameters for electrospinning CA fibers were inspected, and different methods were used to blend electrospun fibers and cement. Some preliminary tests of the mechanical properties indicate a significant increase in the compressive strength of the fiber-reinforced material with respect to the reference non-reinforced material. Incorporating 0.5% CA fibers led to a 15.5% increase in compressive strength compared to the reference sample. This research demonstrates that CA microfiber reinforcement in cement-based materials is promising, highlighting its potential for cost-effective enhancement of mechanical properties.

Lightweight concrete is a popular construction material for its numerous benefits, including reduced weight, improved thermal insulation, and enhanced fire resistance. It can combine with functional additives to regulate moisture properties and improve indoor air quality, making it an ideal choice for walls and roofs. This versatile material not only enhances structural performance but also contributes to better indoor comfort. On the other hand, phase change materials (PCMs) have emerged as an effective solution for reducing energy consumption. However, moisture-related issues, such as condensation and mold growth, remain a concern. Therefore, a comprehensive understanding of the hygrothermal behavior of building materials is essential to mitigate moisture-related risks. This study investigates the potential of glycerin, an affordable PCM, to enhance the hygrothermal performance of lightweight concrete walls. Despite lightweight concrete providing advantageous properties such as low density, high thermal insulation, and sound absorption, they are prone to two significant issues: shrinkage due to gradual water loss and high-water absorption because of their intrinsic porosity. Addressing these challenges, this study explored the application of glycerin as a PCM coating to mitigate the identified drawbacks. The obtained results indicate that a 2 mm layer of glycerin, which was proportionally adjusted to the size of the test specimens in this study, can significantly improve the performance of lightweight concrete. The findings underscore the effectiveness of combining lightweight concrete with an affordable and available PCM choice, presenting a promising energy conservation and sustainable building design solution by minimizing energy consumption and allowing for thinner wall construction.

The impact of climate change has prompted government authorities to implement regulations aimed at reducing energy consumption and CO2 emissions. The construction industry holds a prominent position among the major greenhouse gas emitters, contributing a large amount of global energy consumption. A significant portion of these emissions is attributed to heating. In response to these challenges, the use of biobased materials emerges as a solution. In this context, this study aims to assess the impact of low-carbon binders on the mechanical and thermal properties of biobased insulation materials. Binders such as natural prompt cement and natural air lime CAEB CL 90-S are considered sustainable, low-carbon alternatives. The results highlight that hempcrete (cement/hemp) exhibits enhanced mechanical strength with a 0.80 MPa at 28 days and low thermal conductivity with a value of 0.12 W/(m·k). In comparison, hempcrete with lime exhibits lower mechanical strength (0.4 MPa) and thermal conductivity (0.20 W/(m·k)) at 28 days and flax shives with both binders. In a parallel manner, it is observed that the compressive strength of flax shives, when combined with both binders, is inferior to that of cement/hemp. Simultaneously, the thermal conductivity of flax shives with both binders surpasses that of cement/hemp.

Cement mortar, a fundamental material in construction, requires advancements to enhance its energy efficiency. Phase change materials (PCMs) offer promise in this regard due to their high thermal energy storage capacity. However, challenges persist in integrating PCMs into cement-based materials. Microencapsulated phase change materials (MPCMs) present a solution to these challenges. This study evaluates the impact of MPCMs on the properties of cement mortar with various grades (cement-to-sand ratio of 1:2, 1:3, and 1:4), including mechanical, physical, and thermal characteristics. Through regression analysis, predictive equations are derived to estimate key properties based on the cement-to-sand ratio and MPCM content.

This study reports the experimental investigation of the heat transfer properties of building panels obtained from the post-consume textile waste through an Airlay process in the framework of a research project for the valorization of textile waste in the building sector. The analyzed panels are based on a different kind of textile fabric (mostly polyester, mostly cotton or mixed) and have a different density (low, medium and high). The heat transfer properties were measured through the dynamic methodology of the hot disc, both in laboratory conditions and in a climatic chamber. A good thermal insulation performance was generally observed for all the panels. For a given kind of waste textile, the thermal conductivity was found to increase with density, so that the most performing panels are the low-density ones. Moreover, thermal conductivity was found to increase with relative humidity. For the same density and relative humidity, the thermal conductivity of the cotton-based panels is higher by 26% on average compared to the polyester-based panels.

The exploration and harnessing of thermal energy in geothermal tunnels have gradually emerged as a new research topic. This study employs concrete modified with phase-change materials (PCMs) as a pivotal material for geothermal energy tunnels and introduces a temperature-dependent dual-operation mode. The system, functioning in a dual-operation mode of cooling and storage, facilitates adjustment of the tunnel temperature field and extraction of geothermal energy. A comprehensive multi-field coupled finite element model is established, simulating the energy tunnel with PCMs under the proposed operation. Results demonstrate that the temperature-dependent dual-operation mode effectively maximizes the energy storage capacity of PCMs, leading to an annual increase in energy extraction ranging from 0% to 7.73% as the PCM mass fraction escalates from 0% to 20%. Additionally, a parametric analysis is conducted to evaluate the operational efficacy of the system considering the thermal properties of PCMs. Enhanced performance in heat reduction and energy extraction is observed with narrower phase-change temperature windows, and the PCMs with low latent heat show advantages in energy extraction under this operational mode.

The imperative shift toward sustainable construction practices drives the exploration of alternative building materials, among which autoclaved aerated concrete (AAC) is emerging as a promising option. This research focuses on assessing embodied energy throughout the life cycle of residential buildings using a comprehensive life cycle assessment (LCA) methodology. The study specifically investigates AAC masonry as an infill material in reinforced concrete (RC) frame structures, highlighting its eco-friendly attributes.The present study conducts a detailed comparative analysis between RC frame buildings infilled with AAC block masonry and their counterparts using traditional clay brick infill. The assessment covers different life cycle phases, including extraction of raw materials, production, transport, construction, maintenance, and eventual demolition. By using LCA techniques, the embodied energy of both building types is quantified and compared, providing valuable insight into the environmental impact and sustainability of these construction materials.

Ground-source heat pump systems that collect energy from thermal borehole fields can produce heat independent of the outdoor temperature, making them ideal for heating cold climates. To reduce the risk of boreholes freezing due to excessive heat drain, the boreholes must be spaced far enough apart from each other. This requires space on the ground, which can be a great challenge in urban environments with limited plot sizes.This study looks into the potential of using residential waste heat to reduce the space requirements of ground-source heat pump systems while maintaining the long-term borehole field temperatures. In addition to conventional air-to-air ventilation heat recovery during the heating season, ventilation heat was also recovered in summer using a liquid-loop connected to the borehole fields. Similarly, sewage heat recovery was connected to the same loop.Hourly heating demand for a new apartment building in Finland was estimated using the IDA-ICE simulation tool. The various heat recovery schemes were modelled in TRNSYS 18. Two sets of similar simulations were completed: one for a single building case with a small borehole field and another for a block of buildings with a large borehole field. Widely spaced borehole fields were compared to tightly spaced borehole fields, to see how the ground temperatures and heat transfer fluid temperatures change over five years of operation.Without waste heat utilization, the tightly spaced borehole fields suffered from rapid temperature reduction. This problem was exacerbated in the large borehole field, due to having less natural regeneration as a result of a lower surface-to-volume ratio. However, when both ventilation and sewage heat were actively fed into the borehole field over the whole year, the ground temperature levels were stabilized and the fluid outlet temperatures remained above 0 °C.

A previous LCA study on the insulation products has led to some uncertainty on the resulting Environmental Product Declaration (EPD) certification obtained by Hunton Fiber AS in Norway. There are certain themes included in the existing LCA which contain larger uncertainties than others. The bulk of uncertainties are related to allocation of impacts stemming from the phase of extraction and production of raw materials (A1), impacts from the transportation of raw materials (A2) and impacts of different scenarios of waste processing (C3). Goal of this study is to address these uncertainties by investigating (i) different scenarios for allocation of impacts from raw materials (wood chips), (ii) the impact of different modes of transportation of raw materials and (iii) different waste treatment scenarios. A comparative analysis of different LCA scenarios was assessed focused on the product’s impact on climate change and results are taken by the company as useful suggestions for future decisions.

India depends heavily on coal-based thermal power plants for its energy requirements, with as much as 75% of all installed power production capacity sourced from coal-based plants. Although the country is gradually moving towards non-conventional and renewable energy sources, still the dependency on coal-based energy is significant to date. Some recent studies have indicated that by 2030, the country will be in need of more than 1340 MT coal for power generation annually. The average ash production is 33% of coal consumed, which in turn implies that nearly 437 MT of annual ash production. To reduce this disposal problem and the construction cost of engineering structures, pond ash is nowadays encouraged to be widely used as a geotechnical fill material in various infrastructure, in particular highway construction. However, there is significant research gap regarding understanding the behaviour of pond ash, particularly under repetitive cyclic loading, vehicle-induced vibratory loading, and earthquake-induced high-intensity and high-frequency transient loadings. The present study focuses on experimentally investigating the cyclic behaviour of pond ash samples under various confining pressures and strain levels and relative densities. The pond ash sample was collected from the nearby Parichha Thermal Power Plant located in Jhansi town in Uttar Pradesh, India. A series of element-level strain-controlled cyclic simple shear tests have been conducted for this purpose, apart from physical characteristic tests, compaction test, permeability tests, and direct shear tests on pond ash. The dynamic shear modulus was observed to be highly sensitive to the change in confining pressure, showing an increase of about 34% when the confining pressure was increased from 100 kPa to 200 kPa. For subjected to higher strain amplitude, the ash material showed softer behaviour with faster degradation in strength and stiffness and increased vulnerability for liquefaction related failure.

The construction industry is expected to be transformed due to its significant contribution to the consumption of natural resources, emissions, and solid waste. Despite its slow progression in achieving sustainable development goals (SDGs), in recent years, engineers have been adopting several techniques to address sustainability issues. Among the available sustainable construction techniques, the utilization of earthen materials, particularly rammed earth, which has been adapted from historical practices, has attracted significant attention from the public. Notwithstanding being recognized as a sustainable technique, its compressive strength is not on par with certain applicable construction materials, especially concrete. Therefore, its compressive strength remains a controversial issue. In the first place, this study performs a sentiment analysis using an NLP-based tool to assess the public’s comments and sentiments toward implementing sustainable techniques in the construction industry. In the second place, through a bibliometric study, the trends and gaps in rammed earth research are studied. In the third place, this research article employs soft computing methods such as ANN and DT and data science principles so as to predict and analyze the mechanical behavior, particularly compressive strength, of both unstabilized- and stabilized-rammed earth materials. Finally, the results are compared and critically discussed with an emphasis on sustainability. Overall, this article offers valuable insights into gauging public perception of sustainable construction methods such as rammed earth and exploring the practicality of computer-aided modeling for predicting the mechanical behavior of rammed earth mixtures.

Insulation materials are critical for reducing building space heating energy demands and achieving net-zero targets, as well as for improved occupant thermal comfort. However, traditional insulation materials are frequently derived from unsustainable sources, therefore contributing to carbon emissions and environmental degradation. Mycelium-based composites (MBCs), a bio-based material made from mycelium—the filamentous structures of fungi—and an organic substrate, are a sustainable alternative. Thermal characterisation of insulation materials is a vital component of research and development of construction materials and underpins subsequent operational and embodied energy performance evaluation. Transient methods generally permit rapid testing and use of small specimen sizes, which is highly advantageous in material development. However, steady-state methods show more accurate measurements, especially for materials with some heterogeneity. The objective of this study is to identify sources of uncertainty in the thermal characterisation of MBCs, such as the presence of the fungal skin layer, and to seek to mitigate their effect such that reported thermal performance determined from both steady and transient methods could be more meaningfully compared. In this study, we found that, compared to thermal conductivity measured using a Heat Flow Meter (HFM) at 10 °C, the Hot Disk (HD) overestimates thermal conductivity by 40% for samples with the fungal skin on, and 26% for the samples with the skin off. In comparison to the HFM results at 20 °C, the HD overestimates thermal conductivity by 24% for the sample with skin on, and 11% for the sample with skin off.

Morocco aims to decarbonise its cement subsector, responsible for 91% of domestic industrial CO2 emissions. To that end, clinker reduction figures among the main strategies listed in the Nationally Determined Contribution (NDC) put forward by the country in 2021. Clinker reduction can be achieved through its substitution with supplementary cementitious materials (SCMs). One type of SCM widely available in Morocco is marl, abundantly deposited in Moroccan phosphate mines. Valorising phosphate marl as an SCM in cement production will thus reduce cement-related CO2 emissions while bringing an element of circular economy to the table. To estimate the environmental potential of this solution and benchmark it against existing cements, a comparative life cycle assessment (LCA) of ordinary Portland cement (OPC), calcined marl cement (CMC) and limestone calcined clay cement (LC3) has been conducted. The first part of the study is a cradle-to-gate LCA of 1 ton of cement. Results show that CMC and LC3, due to their lower clinker content, respectively emit 22% and 42% less CO2 than OPC. In the second part of the study, durability and compressive strength are quantified and then considered in an upgraded functional unit: 1 ton of cement per MPa per year. Results show that CMC and LC3 this time emit respectively 29% and 70% less CO2 than OPC. A sensitivity analysis of the results to the choice of the impact method was carried out. The disparities between Impact World+ and ReCiPe 2016 illustrate the importance of interpreting LCA results in light of the chosen impact method.

Global warming is strongly affected by the release of various anthropogenic greenhouse gases, in particular CO2, and is still increasing due to the use of fossil fuels, land use, and the consumption and production of goods. Cement production is accountable for approximately 6% of the global anthropogenic CO2 emissions. In this respect, supplementary cementitious materials (SCMs) made from sustainable resources can make a significant contribution to reducing CO2 emissions and mitigating global warming. Biochar typically possesses the necessary properties, such as microstructure, specific surface area and chemical stability, to be used as SCM. The present work reports the reactivity of biochar from pyrolyzed biomass, focusing on screen overflows which consist of green waste, wood waste, and other inorganic waste. Screen overflows from two different composting plants in Germany and different particle size distributions (< 40 μm, 40–125 μm, and 125–250 μm) are investigated using thermogravimetric analysis (TGA) of the R3 test. TGA is conducted after 7, 14, 28, and 56 days. Additionally, the chemical composition is determined using X-ray diffraction (XRD) and particle size distribution. Material from screen overflows was focused purposely in this study due to them being one of the main components being incinerated in waste incineration plants. Therefore, pyrolyzed biochar produced from these screen overflows represents an up-cycling opportunity. Preliminary investigations revealed a moderate reactivity.

To achieve an optimal balance among concrete’s technical properties, environmental impacts, and economic costs, this chapter proposes a three-level ensemble learning framework for concrete strength prediction and then uses NSGA-II and TOPSIS method for multi-objective optimization of strength, cost, and carbon emissions. The results show that stacking and voting methods have better model performance in terms of predicting concrete strength. NSGA-II can effectively obtain Pareto solutions when strength is lower than 50 Mpa, which may be due to limited datasets. A larger concrete mix dataset is necessary to obtain robust optimization results. Future research can focus on incorporation of domain knowledge into machine learning model, a hybrid of MOO algorithms, more interactive Pareto pruning methods based on decision makers’ preferences, etc.

Ultra-high-performance concrete (UHPC) is well known for its exceptional strength and durability in modern construction and bridges. Despite its advantages, traditional UHPC mixes with high cement content can negatively affect the environment through CO2 emissions. This study aims to investigate using low-impact supplementary cementitious materials (SCMs) such as ground granulated blast furnace (GGBF) slag, fly ash, and silica fume as replacements for cement in different ratios in UHPC compositions. A life cycle assessment (LCA) has been conducted to evaluate the environmental impact of these innovative UHPC compositions. The evaluation considers critical variables, including resource allocation, energy sources, raw material procurement distances, and manufacturing processes. Using SCMs in UHPC formulas helps lessen the impact of global warming and aids in mitigating climate change. These results highlight the importance of using new material combinations to promote sustainability in construction, showing ways to adopt more environment-friendly solutions and creating a path toward a more sustainable future in concrete production.

The paper presents selected findings from a combined theoretical and experimental investigation focusing on chemical reactions and strength gain in glass powder (GP) and calcium hydroxide (CH) mixes as a means of achieving more than the current wisdom of ~20% cement replacement with waste glass powder in concrete. The expected chemical reactions between CH (in concrete, CH is available as a by-product of cement hydration) and silica (SiO2) present in GP were first theoretically established using mole concept theory. The theoretically obtained results were then used to determine an appropriate CH and GP mix ratio for the CH–GP test specimens. The strength gain in CH–GP specimens with time was determined using compression tests, and the formation of strength contributing compound calcium–silicate–hydrate (C–S–H) was determined using X-ray diffraction (XRD) experiments. The compression test results showed CH–GP specimens possessed noticeable compressive strength, and the XRD results confirmed the formation of C–S–H. The results of both compression test and XRD analysis show the major strength imparting compounds in CH–GP specimens formed at later stages (i.e., after 28 days) of curing.

Buildings consume nearly one-sixth of the total global fresh water for its construction and operational activities in addition to roughly 48% of global energy supply. It is prudent to ensure that designers and engineers make decisions based on not only the embodied energy (EE) and carbon (EC) but also the embodied water (EW) of construction materials. Steel, particularly structural steel, is an integral part of buildings that finds its use as a key structural material. However, the steel-making process is quite water intensive. In other words, the steel manufacturing process has a high embodied water footprint. In this paper, we examine how high-strength low-alloy (HSLA) steel can help reduce the embodied water footprint of a building structure. An input–output-based hybrid (IOH) model is used to estimate the total EW of buildings with vanadium microalloyed high-strength steel. Two 3-story buildings are modeled with reinforced concrete (RC) and steel structural frames to compare EW footprints. Results show that steel commodity has an EE, EC, and EW of 20,530 MJ/ton, 1790 kgCO2e/ton, and 1956 Gal./ton of steel, respectively. The IOH model is extended to determine the total EW of the two buildings. Results show that use of vanadium microalloyed high-strength steel instead of mild steel generates ca. 6% savings in EW, EE, and EC for a structural steel-framed building and ca. 14% savings in EW, and ca. 24% savings in EE and EC for a reinforced concrete-framed building. This underscores the significance of the role of HSLA steel in reducing the embodied water demand of building construction and highlights the importance of design decision-making based on EE and EW to achieve net-zero structures.

Increased attention toward a sustainable built environment has driven the construction industry to utilize new materials such as bio-based materials and composites as an alternative to conventional materials. Timber concrete composite (TCC) structural members address performance challenges of timber construction, offering improved stiffness, sound insulation, fire resistance, and reduced deflection and floor vibration compared to timber elements. Moreover, TCC structures are lighter and have a lower carbon footprint than conventional reinforced concrete elements. Extensive research has been conducted to identify the structural and economic viabilities of TCC. Nevertheless, there is a demand for comprehensive understanding of the environmental impacts of TCC. LCA method is currently being used as an effective tool for evaluating the environmental impacts of alternative building materials. In this study, a systematic investigation on peer-reviewed studies on LCA of TCC elements is performed. It is found that a holistic LCA or life cycle inventory (LCI) study of TCC is not available yet and the studies vary in scope, system boundaries, data sources and indicators in the LCA. The system boundary was set as cradle-to-gate in most studies due to a lack of sufficient data regarding the end-of-life phase. Particularly, there is limited information on the material disposal impacts that will occur some decades later, and the carbon storage potential of timber is often overlooked. In the future, additional studies need to be conducted to comprehensively assess the entire cradle-to-grave cycle to understand the potential environmental impacts of using TCC.

Porous asphalt is a road material that allows rainwater to infiltrate through the top layer of a road in an effort to handle stormwater on the spot rather than through drainage piping and infrastructure. Good design of porous asphalt requires understanding the relationship between porosity, permeability, as well as durability. In this work, the pore space is modelled via imaging and digital construction of the total and connected pore space. Then, the infiltration behaviour through the pore space is simulated via lattice Boltzmann modelling, which allows for the calculation of saturated-permeability values. Spatial coarsening tests are performed to assess its impact on permeability results. It is in understanding the top-to-bottom connected pores that the permeability of the asphalt can be better assessed, leading to improved design of porous asphalt.

This study presents a new approach to asphalt material analysis, utilising deep generative learning techniques to generate asphalt microstructures from a limited set of micro-CT images. Recognising the critical influence of porosity variation and vertical distribution on the performance and durability of pavement structures, our research focuses on reconstructing the porous microstructure of asphalt. This deep learning-based method enables the rapid creation of new three-dimensional (3D) volumes with controllable porosity profiles, which can be used for material design, simulations and characterisation.We conduct a comparative analysis between the generated volumes and the original micro-CT images. This approach aims to validate the generated dataset’s accuracy and assess the effectiveness of our method. Our findings indicate that generative deep learning can rapidly generate new representative 3D microstructures with properties that match the real dataset. This advancement provides a new framework for future explorations into developing more durable and efficient pavement systems.Through the integration of generative deep learning methods with micro-CT imaging techniques, this paper introduces a fresh perspective on the design and analysis of asphalt materials. The developed framework can also be extended to other types of microstructures and properties which can offer a powerful and flexible method in the field of material science and civil engineering.

Photocatalysis in building envelopes can reduce air pollution, further providing surfaces with antimicrobial and self-cleaning effects. However, conventional photocatalysts have drawbacks, like environmentally unfriendly industrial production processes, UV-restricted light absorption, and human health concerns. So, this chapter reviewed photocatalysts synthesized following a green route in several research fields, relying on the wide availability of sea waste. The final goal was to assess if the construction sector already encompasses the topic and provide experimental paths to preserve renders with marine-based photocatalysts and enhance their resilience under climate change. The final sample had 64 papers, in which algae, shells, fish waste, and other marine materials were bio-sources. Indoor air pollution was the closest topic to buildings, addressed by three papers but without direct applications, and no papers have tested bio-photocatalysts in façades. Titanium, zinc, and silver were the most common metals combined with the biomaterials. A lack of toxicity and life cycle assessments prevented a comprehensive environmental discussion.

The global imperative to transition towards sustainable and energy-efficient practices has brought to the forefront the need for innovative solutions and strategies within the construction industry, a major contributor to energy-related emissions. With over a third of global emissions stemming from the built environment, the construction sector, particularly in extreme exposures, faces unique challenges. Reinforced Concrete (RC) structures in chloride-laden environments are especially vulnerable to rapid deterioration. The integration of binders such as fly ash and slag, as well as blended cements, has been suggested in international and local codes as a relief to this problem. Despite these preventive strategies, insufficient concrete cover often undermines these efforts, resulting in severe degradation of RC structures in regions like Bangladesh where performance-based rebar cover design is not available in local codes. Once an RC structure reaches a limit state of spalling due to rebar corrosion, it often necessitates concrete patchworks to ensure continued service. However, such patchworks are often not only expensive but also energy intensive due to further utilization of concrete, resulting higher-than-anticipated lifetime CO2 emissions. This study shows the effectiveness of concrete cover as a strategy in reducing the carbon footprint of marine RC construction from the perspective of Bangladesh. Few commonly practiced concrete mixes in Bangladesh have been investigated for durability parameters, exploring the integration of environmentally friendly supplementary binders such as fly ash and slag. To assess the impact of various rebar covers in combination with binder types on the lifecycle CO2 emission of RC structures, a probabilistic approach utilizing Monte Carlo Simulation is employed. This allowed for a comprehensive evaluation of the service life of structures built with different mixes, emphasizing the critical role of concrete cover practices in reducing the frequency of repair works and associated energy-intensive CO2 emissions.

Corrosion can have several detrimental effects on bridges, impacting both the structural integrity and long-term durability of the infrastructure. The risk of corrosion for structures like bridges can vary depending on several factors, and different elements of a bridge may be exposed to different levels of risk. In addition to humidity and rainfall, which elevate the risk of corrosion, another contributing factor is road salt, commonly employed for de-icing roads in cold-climate regions during winter. Proper corrosion protection measures, including coatings, cathodic protection, and material selection, can help extend the service life of bridge structures and ensure their safety and durability over time. A risk assessment was performed to evaluate the risk of corrosion of different components of bridges in Oslo, Norway, based on visual inspection data registered in the Brutus online system. The Brutus system, specifically developed for bridge maintenance in Norway, has recorded various information about the bridges. This information encompasses various details, including geometry, construction year, location, material type, and bridge type. In this study, bridges under the maintenance responsibility of the Oslo municipality were classified according to their material type and construction year. Afterward, the level of corrosion damage to each component and its possible consequences were evaluated. The study pinpointed components of bridges exhibiting corrosion damage and categorized the Oslo region according to the corrosion risk index. Finally, preventive measures were suggested to decrease the corrosion risk of bridges.

The carbon emissions of future reinforced concrete structures need to be considered throughout their entire life cycle to meet CO2 reduction targets. This is critical for structures exposed to aggressive environments, such as chloride, due to the increased risk of reinforcement corrosion. Premature degradation caused by steel corrosion leads to significant repairs, increasing both the CO2 footprint and also the costs of the structure over its service life. This work proposes a design framework that integrates the laboratory performance concept consigned in the new Eurocode 2 and Sustainability Assessment. The framework’s applicability is demonstrated through a case study inspired by an existing structure. By employing a multi-criteria decision-making method, the proposed framework concurrently considers environmental impact and cost, facilitating the selection of the most balanced alternative in terms of environmental reduction objectives and budget constraints. The results show that appropriately selecting the Exposure Resistance Class leads to more cost-effective and environmentally friendly structures.

Concrete repair and rehabilitation are vital disciplines in structural and civil engineering, given the age of concrete infrastructure and the need to extend its service life. Most repair projects involve removing deteriorated or damaged concrete, followed by applying a patch repair mortar or bonded overlay. These repairs are typically done with proprietary repair materials of very high strength exceeding 40 MPa, which is related to the general misconception that the high strength of cementitious materials correlates with high quality and structural contribution. However, the performance of concrete repairs deteriorates with the increasing strength of the repair material, which is related to an increasing tendency to crack and debond. Furthermore, repair patches commonly do not contribute to the load-bearing behaviour of the structure, mainly because of creep and shrinkage of the repair mortar. This paper discusses common misconceptions around the ‘structural repair’ of concrete members and the related adverse effects regarding sustainability costs. Recommendations for rational and more sustainable repair approaches are presented.

Concrete, hailed for its widespread utility in construction, faces intrinsic challenges, primarily its vulnerability to cracking and subsequent degradation. This chapter reviews the evolving landscape of self-healing concrete strategies, spotlighting autogenous, and autonomous healing methodologies while focusing on the emerging electrodeposition technology. The exploration distinguishes autogenous self-repair, which relies on natural processes like continuous hydration and calcium carbonate formation, from autonomous approaches, which employ engineered additives for immediate crack intervention. Detailed insights into autogenous healing mechanisms unravel the role of continuous hydration and calcium carbonate formation in sealing microcracks, albeit with inconsistent outcomes. Limitations in achieving consistent autogenous healing have propelled research into autonomous methods. Notably, electrodeposition technology emerges as a frontrunner, utilizing controlled currents and engineered compounds to fill cracks and shield the concrete from deterioration. This chapter emphasizes electrodeposition’s efficacy, showcasing studies demonstrating its ability to seal cracks of varying widths by depositing compounds like ZnO, Mg(OH)2, and CaCO3. Parameters like current density and immersion solutions significantly influence its efficiency. While promising, the universal application of electrodeposition remains under research, urging further exploration to refine parameters, broaden applicability, and bolster reinforced concrete’s durability. This review encapsulates critical facets of self-healing concrete, particularly highlighting electrodeposition’s potential and ongoing challenges. It aims to pave the way for enhanced concrete resilience and sustainability in construction practices.

Modeling drying shrinkage presents significant challenges due to the complexity and multitude of contributing parameters. This study provides detailed insights into the input requirements and predictive capabilities of established models by leveraging various datasets from the NU-ITI database. Initially, the performance of a shrinkage model was evaluated. The data for a machine learning random forest model included eight variables, interpreted through SHapley Additive exPlanations (SHAP), which elucidates the most influential inputs. However, the partial dependency graphs yielded minimal information on their relative impacts. This research demonstrates that enhancements in the random forest model’s predictive accuracy improved shrinkage predictions by 25%. This advancement significantly mitigates potential deviations in anticipated strains and stresses. The findings from this comprehensive analysis facilitate the selection and prediction of drying shrinkage, focusing on the most critical factors to ensure the highest accuracy.

The construction industry in Bangladesh is actively pursuing the goal of preserving the equilibrium between the amount of greenhouse gases (GHGs) produced and expelled from the atmosphere. An ideal way to reduce CO2 emissions from concrete production is the utilization of industrial by-products like class F fly ash, slag, etc. as supplementary cementitious materials (SCMs). On the other hand, reducing the life cycle cost (LCC) through the extension of service life could also be an effective way to reduce the overall carbon footprint of any RC infrastructure, particularly in saline exposure. Higher service life ensures lesser repair work for a corroded marine RC element and eventually results in reduced CO2 emission in the lifetime. Therefore, it is evident that producing concrete with proper proportions of SCMs and other mix parameters to achieve the desired service life can reduce both the initial and long-term carbon emission potential of an RC structure in saline exposures. With this end in view, a case study is presented where concrete mixes have been prepared using different binder types (both customized and commercially available composite blends) for a particular design strength commonly used in Bangladesh. The service life and repair frequency of an RC element made of considered concrete mixes have been predicted through the electrical resistivity of the mixes. LIFE-365 software has been used for the analysis. It has been found that commercially available CEM III and the blended mix of CEM I with 30% slag plus 20% fly ash exhibited prolonged corrosion initiation time, least repair requirements during the service life of 100 -years and consequently, lower LCC and overall CO2 emissions as compared to other mixes used. The outcome of the study thus necessitates the inclusion of required policies and guidelines in local construction supply chains and practices to reduce embodied carbon of RC construction.

To reduce the emission of greenhouse gases within the building industry, effort must be put into reducing waste and converting reclaimed materials towards reuse. Within the Netherlands, discarded wood is incinerated for energy generation, releasing the carbon that has been captured during growth. To extend the lifetime and the carbon storage duration and, consequently, improve the environmental performance of “wood waste,” re-use is desired. Hence, the production and structural performance of cross-laminated timber (CLT) made of current wood waste were explored in this study. Single-use pallets were collected and manually disassembled with all fasteners removed. The wood was then finger-jointed, edge-glued, planed, and fabricated into 1.2 × 3 m CLT. In total eight CLT panels were made with different layups, of which three were used in this work. Mechanical testing indicated the potential of the created elements, showing similar performances to new CLT. While the bending tests suffered due to some manufacturing problems, planar shear tests showed good performances, similar to new CLT.

Given the considerable number of concrete structures either damaged or nearing the end of their lifespan, it becomes crucial to undertake substantial repairs. This is essential not only to address existing deterioration but also to ensure the preservation and prolonged durability of these structures. This study aims to explore the usability of innovative concretes in the repair of damaged reinforced concrete structures. However, these repairs must be executed in an environment-friendly manner. Therefore, the envisioned characteristics aimed to develop highly fluid concretes comprised of readily available natural ingredients or sourced from recycled materials. In pursuit of this goal, the developed concretes draw inspiration from the principles of self-compacting concrete. Fluidity has been boosted by limiting aggregate diameters (Dmax = 5 mm), reducing the proportion of gravel, and increasing the proportion of sand. The resulting concrete was designated as Self-Compacting Sand Concrete (SCSC). Three distinct formulations of SCSC concrete were devised: SCSC-LF, enriched with limestone fillers; SCSC-Pr, incorporating natural perlite; and SCSC-Pz, featuring natural pozzolan. The substrates were constructed using standard vibrated concrete of ordinary class (OC). The repair success of composites, consisting of an OC substrate and a layer of SCSC, was evaluated under tensile stress. The results are highly promising, demonstrating the efficacy of concrete-reinforced composite (SCSC) systems in effectively repairing damaged concrete structures.

This paper presents a comprehensive multicriteria performance index analysis to find the most suitable screed composite to be used in flooring applications. The mechanical and durability properties and the economic and environmental impact of various screed mixes were considered. The screed composites were prepared by varying the mix design parameters, including the binder (cementitious and geopolymeric), fine aggregates (crushed sand or dune sand), solution-to-binder ratio, and binder-to-aggregate ratio. Compared to cementitious mixes, geopolymer screeds demonstrated higher production costs but remained competitive in terms of cost per unit strength and durability–cost relationship. Geopolymer screeds also exhibited lower global warming potential values, highlighting their environmental advantage over cementitious counterparts. Upon synergic consideration of the examined response criteria, the multicriteria performance index analysis showed that geopolymer screeds produced with crushed sand demonstrated superior performance among the different screed mixes for category A types of screeds. At the same time, cement-based mix produced with crushed limestone performed the best as a category B type of screed. However, the geopolymer screed produced with a binder-to-crushed sand ratio of 1:7 was superior to all category B screed mixes when cost and environmental impact were considered solely.

A novel system utilising steel-fibre reinforced concrete (SFRSSC) has been developed and implemented in projects in the recent years for structures such as ground-based slabs and ground-level elevated slabs on piles among others. Being that the system is chemically prestressing the concrete, this compressive self-stress can be used to significantly decrease the thickness of the structures while maintaining their load bearing capacity yet decreasing the materials used and lowering the emissions caused by making the said structures. Recently, a comparative full-scale testing has been conducted to compare the impact of the chemical self-stress on the load bearing capacity of a supposed ground-level slab on piles when looked in a comparison with a more traditional steel fibre reinforced concrete slab in a practically identical situation. This document shall shed light on the possibilities of reducing the CO2 emissions via usage of SFRSSC when compared to other existing more traditional construction systems. The full-scale tests revealed that the SFRSSC slab could bear approximately 30% higher loading while maintaining 30% lower deflections and exhibiting lower number of cracking. This, in turn, allows for making SFRSSC slabs significantly thinner, thus reducing the emissions caused by the extraction of raw materials, transportation of the said materials, production of the concrete and production of the structure itself.

The advancement of geopolymer concrete technology presents a sustainable solution to address the challenges associated with the significant carbon footprint of the construction industry. This research uses machine learning methods to predict the compressive strength of fly ash-based geopolymer concrete using a wide range of experimental results. Furthermore, the effect of different features, including the components of fly ash-based geopolymer concrete, alkaline activator, and other additives, was investigated utilizing Shapley values technique. The results show that both XGBoost and linear regression models can predict the compressive strength of the studied dataset with acceptable accuracy. In XGBoost approach, R2 values for the train and test data were obtained 0.98 and 0.86, respectively, which leads to more accurate results than linear regression method. Additionally, based on the results, MgO is regarded as the most influential factor in compressive strength compared to other investigated features. Furthermore, the concentration of the alkaline activator, NaOH, positively impacts the target value.

This study explores the properties of lightweight concrete incorporating slag and steel fibers. Cubic and cylindrical specimens were created with varying fiber percentages (0%, 1.5%, and 3%) and slag replacements (0%, 10%, 20%, 30%, and 40%). The samples underwent testing for compressive strength at 7, 28, and 90 days, tensile strength at 28 and 90 days, and water absorption at 28 and 90 days. Results indicate an enhancement in both compressive and tensile strength with a 20% slag replacement in all specimens. Additionally, an inverse correlation is observed between overhead percentage and water absorption, where an increase in overhead corresponds to a decrease in water absorption. Despite no substantial impact on compressive strength, the incorporation of waste steel fibers consistently improves tensile strength across all fiber percentages. This study underscores the potential of these eco-friendly additives in promoting environmentally conscious construction practices, aligning with the principles of sustainable development in the concrete industry.

Global CO2 emissions from cement production represent a major challenge on the path towards a future of net zero emissions. Concrete represents 5–8% of the total global CO2 emissions while remaining a critical building material globally. It is imperative to find low-emissions solutions that can reduce the environmental impacts by finding new mixtures and binders for cement production, which are the main contributing factor for emissions from concrete. Alternative concrete binders are being developed, and one such binder is geopolymer cement. Geopolymer cement is made by mixing industrial wastes with an alkaline solution, such as sodium or potassium hydroxide. This cement can be produced from waste can completely replace ordinary Portland cement in concrete. In Norway, the company Saferock is developing a new geopolymer cement which utilises mine tailings from ilmenite production combined with potassium hydroxide. In the region of Sokndal, Norway, more than 100 million of tons of easily accessible mine tailings are available for Saferock to use for producing geopolymer cement. The Saferock concrete is expected to reduce emissions compared to normal concrete, but to what extent is unknown. Thus, the purpose of this study is to evaluate the environmental impacts of Saferock’s geopolymer cement by using life cycle assessment (LCA) to quantify the emissions from the Saferock production process. The results of this LCA study show that the geopolymer concrete analysed had a 57% reduction of CO2 emissions from branch standard B35 concrete and a 22% reduction according to Norwegian Concrete Association Low Carbon A standard, but that potassium hydroxide accounts for 90% of the emissions.

This study investigates the integration of recycled concrete aggregate (RCA) in landfill cover systems as a sustainable alternative to natural aggregates. The research primarily examines the interaction of RCA with geomembranes by determining the interface friction angle between RCA drainage layers and geomembranes through large-scale direct shear testing. A Finite Element Method (FEM) model of a municipal solid waste landfill in Este, Italy, was developed and validated against the analytical two-wedge theory for veneer shear failure in layered systems. The results demonstrate that RCA outperforms traditional aggregates as a drainage layer material. It also highlights the limitations of commercial FEM software in identifying weak interfaces in landfill cover systems.

Material development science in the construction industry is saddled with the responsibility of seeking alternative materials that can alleviate the reliance on virgin resources, reduce the energy use associated with building material production, mitigate the pollution associated with the disposal of building materials, and ultimately foster a more sustainable environment. In recent years, fibre-reinforced polymer composites have garnered attention across diverse sectors like automobiles, consumer products, transportation, packaging, and construction. However, bio-based alternatives to these composites offer a promising avenue towards creating more environment-friendly building materials. This paper explores the practical applications of bio-based polymer composites in non-structural contexts, such as building panels, partitions, facades, and structural applications, including internal and external reinforcement. It examines the benefits and challenges inherent in these applications, drawing insights from a comprehensive review of research in the field. Through this review, the paper sheds light on the potential of bio-based polymer composites in developing more sustainable construction materials, providing a pathway towards a greener and more sustainable built environment.

Governments around the world are aiming for net-zero carbon emissions by 2050. To drive broader decarbonization efforts, the building industry is challenged by the mission to reduce embodied carbon emissions, which stem from building materials and systems. Most efforts in buildings are focused on operational energy, but up to 80% of a building’s emissions occur before use and occupancy, from extraction to construction phases. These emissions are irreversible and contribute around 11% of global carbon emissions. This study emphasizes the need to prioritize the decarbonization of conventional building materials during production using low carbon constituents to mitigate associated environmental impact. Quantitative data analysis and reviews have identified alternative low-carbon options for possible application in mix design. Examples include substituting general use (GU) Portland cement with Portland limestone cement, using supplementary cementitious materials (SCMs) to reduce cement content, and utilizing low-carbon concrete masonry units. Achieving net-zero embodied carbon requires promoting circular bio-based products and reducing conventional materials’ carbon throughout their life cycle. At material level analysis, this is possible not only by promoting the use of circular bio-based materials but also by purposefully reducing the embodied carbon of conventional building materials throughout their life cycle, as well as communicating the best practices as lessons learnt to promote broader adoption by the architecture, construction and engineering (ACE) industry. However, collaboration among designers, contractors, and manufacturers is essential. This study provides a preliminary pathway to overall decarbonization efforts, understanding that conventional, existing building materials will play a significant role in attaining the net-zero commitments of the future built environment.

In the development of low-emission concretes the focus has been on the reduction of carbon footprint by using supplementary cementitious materials (SCMs). However, the resistance against chloride ingress may vary considerably among the different types of SCM concretes. For concrete structures exposed to chloride-induced corrosion, the resistance against chloride penetration is decisive in determining the service life of the structures. This paper presents calculations of CO2 emissions (Global Warming Potentials—GWPs) from two road culvert solutions, a concrete culvert with two types of low-carbon concretes and a steel pipe culvert. It was found that the main source of the emissions came from the production of concrete and steel materials. The importance of including service life as a parameter in the assessment of CO2 emissions from concrete infrastructures is demonstrated through the chloride ingress simulations of four different SCM concretes. Based on Fick’s second law of diffusion, the service life for a reinforced concrete structure can be twice as long by using concrete with 20% fly ash and 4% silica fume than by using concrete with 35% fly ash. The GWP from concrete is typically given per volume unit. However, a more appropriate unit for LCA of concrete infrastructure should be to include service life and strength parameters in the GWP calculations.

Construction and demolition waste (CDW) is defined as non-hazardous waste produced during the construction, repair and rehabilitation, or demolition of infrastructure. While only 19% of the CDW produced in South Africa has been reported to be diverted annually, during the same period, up to 40% of the CDW produced in the Western Cape province of South Africa was beneficiated to be reused or recycled. This discrepancy is due to a shift in local government legislation and implementation thereof which, in turn, has encouraged a change in the behaviours of waste management and built environment professionals. This paper aims to review and contrast the waste management legislation and policies of South African local and national governments, as well as the waste management practices used at landfills and recycling facilities, and the quality and uses of materials produced at these facilities from CDW in various parts of the country.

Recycling industrial waste into construction materials is becoming a fundamental strategy, offering a hopeful path toward sustainable construction practices. This study focuses on the innovative reuse of end-of-service wood and crumb rubber to develop environmentally favorable materials. Their high availability, lightweight properties, and high-energy absorption capacity make them highly suitable as additives in masonry unit production. Furthermore, using them with sustainable binding material, such as geopolymer, enhances the overall sustainability of the masonry, facilitating rapid strength development and enhancing durability while providing increased protection against fire and weathering. The study involved the development of an optimal mix design, which can potentially be used for the production of load-bearing and non-load-bearing masonry units. This was achieved by examining various proportions of wood, as well as combinations of wood and rubber, using a partial–factorial experimental design. The results show that wood-to-binder ratios ranging from 0.2 to 0.4 can potentially be used for the production of wood–geopolymer masonry units. Additionally, a ratio of 0.3 (with 50% wood and 50% rubber) was identified as potentially suitable for producing wood and rubber-based units.

The construction industry is responsible for a considerable share of the carbon emissions annually. Despite the wide body of literature addressing the embodied carbon of superstructures, limited attention is given to the embodied carbon of substructures. This research introduces an optimization algorithm to minimize the embodied carbon of deep foundations. The algorithm is used to optimize and then compare the embodied carbon of concrete, timber, and steel piles at different pile capacities. Results show that for clay soils and low pile capacities, timber piles are the least emitting compared to other materials, while steel piles are the highest emitting. The algorithm is then applied to a case study in London clay and demonstrated embodied carbon savings of up to 76% compared to current pile designs showing a high potential to reduce the embodied carbon and achieve the net-zero future goal in the construction industry.

Achieving net-zero emissions by 2050 is driving innovation across the construction industry. Within the industry, there is no component in greater need for change than concrete. The carbon emissions associated with concrete production could be reduced if radical changes to the industry took place. Calcined clay is a growing area of research interest, with its value in LC3 concrete showing great potential. Research beyond concrete-based applications, however, is sparse. This chapter will review the reactivity of calcined clays and assess their suitability as pozzolanic materials. The high reactivity potential of kaolinite is well established across literature; however, the reactivity of low-grade excavation waste comprising 2:1 clay minerals is underexplored. This study thereby assesses the chemical properties and reactivity potential of waste clays and therefore their potential as a polymer. Isothermal calorimetry and bound water R3 tests confirmed that certain excavation wastes exhibit similarities to pure 2:1 minerals like bentonite. While kaolinite is preferred, moderate to high proportions of 2:1 minerals demonstrate potential as supplementary cementitious materials. The novelty of this research is that pozzolanic waste will be applied within earth, rather than concrete. The lower strength requirements of earthen structures alongside typically poor durability properties will be examined in future studies. This study of chemical performance within earthen applications will further demonstrate the value of calcined clay, an abundant yet low-carbon material, thereby facilitating the industry’s transition towards net-zero.

Life Cycle Assessment (LCA) is an essential tool for quantifying the environmental burdens of products and processes, critical for advancing sustainability goals. Central to the effectiveness of LCA is the Life Cycle Inventory (LCI) phase, which requires reliable data to reflect the environmental footprint of products accurately. However, LCA practitioners often encounter data gaps that can compromise the assessment’s accuracy. To address this, we explore the integration of Machine Learning (ML) to enhance LCA data quality, particularly in the LCI stages B to D, which focus on product use, end-of-life, and beyond-life phases. This chapter introduces a novel framework that leverages ML to overcome LCI data challenges, emphasizing reducing the embodied carbon of construction products. We extract existing data from the Environment Product Declaration online library and apply natural language processing to interpret this unstructured data. Subsequently, we employ a random forest algorithm, a robust ensemble tree-based ML method, to refine the data analysis. We present a pilot study that validates the feasibility of our ML-enhanced framework. The incorporation of ML addresses the voluminous data in LCA. It augments the analytical capacity, thereby improving the precision and reliability of both LCI and Life Cycle Impact Assessment (LCIA) datasets. Consequently, our approach yields higher quality LCA outcomes, offering a more reliable basis for environmental impact evaluation. In summary, the successful application of ML in this research bridges the critical data gap in LCI for construction products, paving the way for a more sustainable industry through improved accuracy in environmental impact assessments and more informed decision-making in green product innovation.

This case study addresses the reutilization of building elements, encompassing the mapping of reusable components during the demolition phase and their reintegration in the refurbishment project Grensen 9b, an office building in Oslo, Norway. Grensen 9b project has the ambition to achieve BREEAM-NOR v6.0 certification at least at the “Very Good” level as well as reducing the CO2eq-emissions from building materials by 93% compared to a new build. The research investigates how these practices can impact sustainable development within the building industry through realizing efforts that have a high transferability to the rest of the built environment. Particularly, focus is also with the reduction of greenhouse gas emissions and resource management in a life cycle perspective. Through a practical project analysis, current research uncovers the essential steps involved in identifying and preserving elements that can be reused. This process not only mitigates the environmental repercussions of demolition but also diminishes the demand for new materials, consequently reducing the associated carbon footprint. Efforts made to design for future reuse will also be mapped. Such practices hold great potential in the overarching mission of curtailing carbon emissions and aligning with the broader objectives of climate change mitigation and resource optimization. Moreover, this study explores the practical challenges, feasibility, and best practices associated with reusing building elements, and designing for future reuse, making it a valuable resource.

Circular strategies of prolonging and closing resource flows within the economy hold the potential of avoiding greenhouse gas emissions and reducing other environmental impacts. There are several circularity indexing systems that account for material circularity in buildings. However, there is a lack of harmonized benchmarking systems, meaning that circular buildings are mostly compared with alternatives of their own design. This study addresses these research gaps by exploring a mass-based circularity indexing system and identifying current and future references for the circularity performance of buildings, for use in FutureBuilt, a Norwegian green building innovation programme. The FutureBuilt Circularity Index system rates a building’s circularity performance between 0% and 100%. The indexing system discerns between materials and masses used during construction, and materials available at the end of life of the building. A weighting system is introduced to emphasize the importance of reusing materials at the highest level of functional quality, and to emphasize the importance of current resource circularity versus circularity at the building’s end of life. The circularity index is tested on four Norwegian buildings that have a high focus on circularity, achieving indexing levels from 44% to 69%. A mixed methods approach using statistics, environmental product declarations, and interviews is applied to establish the reference baseline for Norwegian buildings (i.e. 7% circularity) and scenarios for future circularity in 2050 (from 35% to 80% circularity). Actors in the Norwegian construction industry can evaluate the level of ambition for circular buildings by using this novel indexing system and benchmarking approach, which can also be adopted to other national or regional contexts.

Today, the role of the construction sector is fundamental to mitigating climate change, especially given the potential of innovations introduced during the Industrial Revolution. The Internet of Things (IoT), together with Internet-enabling technologies, has developed and spread even in the architecture, engineering, and construction (AEC) sector, though with some differences in purposes and objectives. However, especially in the field of heritage buildings, a gap in the definition of cultural heritage (CH) and the one in the concept of smartness need to be bridged. This chapter aims to identify specific innovative approaches for CH, through an analysis of a literature review and best practices related to the different applications of the aforementioned technologies, to develop a roadmap toward new perspectives against climate change while increasing the smartness of the heritage environment.

The realization of energy efficiency targets in Europe requires renovation of 30 million buildings by 2050. Compared to new building constructions, there is currently very limited research-based knowledge concerning the challenges and solutions of achieving energy efficiency in renovation through the lens of the project delivery process. Hence, this study aims to fill this knowledge gap through a qualitative study, involving project professionals representing clients, designers, general contractors, building services contractors, and maintenance experts. To do so, 21 semi-structured interviews were conducted, and the extracted data were analyzed through thematic and content analysis methods. The findings reveal that high investment cost and an uncertain payback period for replacing the old energy system together with insufficient space for new building services systems and building protection issues for façade renovation seem to be the most critical challenges. Regarding the enablers, the interviewees frequently mentioned a competent maintenance workforce, practice-oriented training and education for maintenance and operation staff, and detailed as well as purposeful measurement/metering of energy consumption for achieving energy efficiency in building renovation projects. The findings highlight the significance of investing in people and technological solutions for realizing energy efficiency through building renovation.

In Europe, where buildings are responsible for about 36% of total greenhouse gas emissions, largely due to their operational energy use, addressing climate change necessitates reducing buildings’ energy consumption, particularly for climatization. Despite its energy demands, climatization is crucial for a healthy indoor environment. Thus, efforts to enhance climatization efficiency must aim to both lower energy use and preserve indoor comfort.This research explores resilience of a hybrid ventilation strategy in a mixed-mode office building in a cold climate. The study evaluates the energy performance of two ventilation strategies—full mechanical ventilation and hybrid ventilation—under future conditions relative to contemporary scenarios. Two distinct emission scenarios, RCP 4.5 (mid-emission) and RCP 8.5 (high emission), are considered, spanning three periods: near future, far future, and a reference period.Oslo, the capital of Norway, serves as the selected case study because it exemplifies a relatively large city by Nordic standards, situated in a cold and humid continental climate. Weather data were compiled in accordance with EN ISO 15927-4 standards, using a 30-year period for reference. Subsequently, the Perez model was applied to separate global radiation into its direct and diffuse elements. Following this, simulations of the indoor climate and energy requirements were conducted using IDA ICE.The results indicate that adopting hybrid ventilation can lead to energy savings of up to 40% in scenarios of high emissions during the far future. This efficiency gain is primarily attributed to an extension of the window opening period, which is approximately 6% longer than the baseline period. Such an increase in window opening duration notably contributes to the reduction of indoor CO2 levels, as illustrated by the case of Norway. These findings emphasize the critical role of incorporating passive design solutions, like hybrid ventilation through window openings, into both architectural design and urban planning practices in cold climates.

Buildings account for a significant proportion of the total energy consumption in the global energy sector, with a value of about 40% of the total energy consumption and greenhouse gas emissions, and studying building energy can play a crucial role in shaping sustainable development goals (SDGs). Interest in achieving net-zero and positive-energy buildings has been growing in recent years. Recent research publications to this day exhibit a lack of focus on net-zero-energy buildings (NZEBs); a more comprehensive literature would include the challenges and opportunities of such buildings. For this reason, this chapter aims to provide a comprehensive up-to-date review of the recent progress, challenges, and opportunities in constructing net-zero-energy buildings in tropical climates.The findings show that the opportunities for constructing net-zero-energy buildings in tropical climates include, but are not limited to, the availability of solar energy, government policies and incentives promoting NZEBs, monetary benefits from increasing the demand for energy-efficient buildings, creating employment opportunities in research and development, reducing operational energy costs, and decreasing the carbon emissions of buildings. On the other hand, the challenges to constructing NZEBs in tropical climates are their high initial costs, regulations and policies, technological barriers to developing energy-efficient materials that are both cost-effective and readily available, connecting net-zero-energy buildings to smart grids, environmental and socioeconomic concerns, occupant behavior, and retrofitting existing buildings.

With global concern about climate change on the rise, environmental certification of buildings with BREEAM Nor will provide a holistic evaluation on the sustainability of buildings, especially in Norway. When it comes to optimizing energy performance and indoor climate, a paradox often exists. This paradox becomes even more challenging in the context of educational buildings, where it can be difficult to achieve both optimal indoor climate and passive house standards due to potential negative impacts on energy performance, particularly with regard to energy use for cooling. In this study, energy performance and indoor climate are assessed in a pilot project (the school project: one of Norway’s most environmentally friendly schools). The connection between energy supply solutions, building envelope, and technical details will be elucidated. The study underscores the importance of post-occupancy evaluation to compare a building’s projected performance with its actual outcomes. This process helps identify gaps and discrepancies, allowing for adjustments to meet intended energy efficiency and environmental goals. This paper is partly based on a bachelor’s project by three bachelor’s students from Oslo Metropolitan University.

In the current complexity of the design process, it is important to clarify the information flow for the creation of smart architectures. This clarity ensures coherence at each design scale, up to the definition of construction elements that make them effectively realizable and manageable throughout their entire life cycle. This paper presents a definition of sustainable metamodules using homogeneous sets of smartness indicators to support the design workflow. It specifically focuses on façades with a transparent base skin that can be digitalized through a BIM-based approach, promoting interoperability and multidisciplinary control.In analyzing present societal demands and the features of smart architectures, a range of smartness indicators will be established as parameters that contemporary architecture should consider to be classified as smart. The information cores formed by the combination of the predetermined parameters and feasible design solutions will be stated at every level of design detail.Following BIM regulations and leveraging the customization capabilities of open-format files (IFC), the earlier identified metamodules will be stated at various Levels of Detail (LOD), crafting suitable property sets within a BIM authoring software. This process will generate a structured matrix capable of supporting designers’ decisions in the realization of smart architectures.

The stakeholders in various industries focus on developing innovative preventions to increase environmental, economic, and social sustainability to tackle the negative impacts of climate change. Hence, the interest in transitioning from a linear to a circular model has gained momentum in the last decade. The circular economy (CE), therefore, has attracted the construction industry stakeholders to adopt the sustainable model based on the CE principles because it is the most resource-consuming and waste-producing industry. Recycling the materials and construction and demolition waste, reusing the building components, renovating and refurbishing the buildings, adapting circular building design principles, innovating for a regenerative built environment, developing circular supply chains, and enabling circular business models are the core topics to ground this new model. However, the more perspectives, the more challenging the transition. Therefore, circular transition in the construction industry becomes compelling since it has complex and distributed collaborations due to its nature. Although the number of studies has increased, the circular construction industry from the stakeholder perspective still needs to be explored. Within this point of view, this study aims to present a new framework developed to increase stakeholder collaboration for circular transition at micro, meso, and macro-scales. It approaches the micro-scale for materials, meso-scale for buildings, and macro-scale for cities. Besides, it considers the construction industry target groups determined by the European Commission to demonstrate the circular building design principles. The research obtains data by literature review, maps the findings at micro, meso, and macro-scales, and employs natural language processing (NLP) to analyze the CE strategies. Followingly, it constructs thirty-seven success factors to treat the strategies obtained by NLP. Consequently, the REVERT framework based on six dimensions and thirty-seven success factors is introduced to consider stakeholder collaboration for circular transformation in the construction industry.

It is known that the built environment is one of the largest contributors to greenhouse gas emissions. In the building sectors, significant efforts have been made to reduce emission associated with energy use in buildings and construction materials. However, the process related to integrated technical building installations (ITB) is not well addressed. The study includes a case study for zero-emission educational building. By examining case studies, best practices, and emerging problems, this research sheds light on the transformative power of integrated technical building installations in optimizing energy efficiency and consequently reducing carbon footprints. The findings underscore the need for a multidisciplinary approach, collaboration among stakeholders, and the integration of best practices in the realization of zero-emission buildings should be applied at the very beginning of building process.

Urban heat islands (UHIs) in the built environment are becoming alarmingly severe, calling for urgent climate change mitigation measures. Common data collection and data-driven analysis protocols are needed to efficiently study this phenomenon across different urban areas. The emerging low-cost sensing systems and weather data crowdsourcing are showing a great potential to support these efforts. This study explores the spatial patterns of UHIs in the city of Oslo, Norway, as similar studies in northern European cities are still too scarce. It leverages the available weather data from municipal stations and crowdsourced weather observations with high spatial resolution (over 2800 stations in the area) to characterize the phenomenon at city scale. The results show that Oslo is affected by UHIs, with its intensity reaching up to 5.5° in some districts. They also suggest that in particular conditions the spatial distribution of UHIs does not always follow the typical pattern, i.e., higher temperatures in downtown and more urbanized areas, and lower temperatures in less dense areas with more open and green spaces. Occasional negative UHIs intensity values were also captured. These effects may be the result of the strong influence of weather phenomena and topography. The findings in this study indicate the need for careful consideration of the underlying local conditions to better understand UHIs drivers and develop more targeted urban planning policies and mitigation strategies. Therefore, future studies should delve into the links between UHIs intensity and urban form characteristics.

Urbanisation is growing rapidly with global population and economic growth. Significant action is required to find possible solutions to reduce greenhouse gas (GHG) emissions from new physical structures and supporting infrastructure, such as transport, water and energy networks, enabling urban planners and engineers to decarbonise the built environment to achieve a net zero emission (NZE) target by 2050. Life cycle assessment (LCA) plays a pivotal role in decarbonising the built environment as it helps identify materials, construction processes, design, and end use energy technologies significantly increasing the carbon footprint of the built environment and extending the influence of urban heat island (UHI) impacts. This paper will present a comprehensive LCA framework to calculate the GHG emissions associated with a modern central business district (CBD), including trade, commerce, and service industries, to help identify the hotspots contributing significantly to GHG emissions in a city and the possible decarbonising pathways to encourage NZE development. This framework could then be used to assess the potential for emissions management in city development and urban planning. The system boundary of the LCA will consider all stages from raw materials procurement up to the delivery of the aforementioned services. All the main urban infrastructure systems, including the transportation system, construction, energy and water supply networks and waste management systems, will be considered in the life cycle assessment process. Traffic congestion, population mobility, the urban heat island effect and landscape issues will be considered as these are also factors accelerating the increase of GHG emissions. In using this suggested LCA framework, we can then develop the green engineering solutions required to help the urban planning process develop a potential decarbonisation roadmap towards NZE targets for our cities.

This study presents an investigation on implementing student active learning in a civil engineering course dealing with concrete as a building material. The primary objective was to enhance student engagement and learning outcomes through the integration of a variety of activities. A key anticipated learning outcome of this course was an understanding of sustainability issues, including the greenhouse gas emissions associated with the materials. Increasing student awareness of the environmental impacts associated with material selection for building applications can empower future experts to make informed choices that contribute to sustainability and net-zero construction. In this paper, the performance of the students in the course after implementing flipped classroom and selected student active learning methods with a focus on student awareness on consequences and environmental impacts of choice of the material is discussed. Selection and modification of the research methods were conducted by considering existing literature, own experience, communication with colleagues, and students’ feedback. The main activities include multiple choice questions before attending the physical classroom, laboratory-based project assignments with pre-recorded video guidelines, as well as quizzes and discussions during the physical classroom by using a digital learning platform. The learning outcomes were assessed by collecting the feedback from student activities during the course, as well as project report and the final exam. The results show that the selected student active learning approaches enhanced student motivation and their reflection on learning outcomes in the course. The student’s reflection on the environmental impacts of the materials and the way to reduce them was significantly improved due to conducting a lab-based project as a course assignment as well as the planned discussion arrangements.

Urgent needs to mitigate climate change and reduce waste generation require collaborations between sectors. We examine the impacts of the potential recycling of ashes from the incineration of urban waste streams such as municipal solid waste, sewage sludge, and biomass within the construction sector. We perform material flow analysis to estimate the flows and stocks of ashes to identify underutilized waste streams. In this study, we use a multi-objective optimization model at the regional level (country level) to estimate optimal scenarios for urban waste recycling in the construction sector, with a focus on minimizing CO2 eq. emissions and costs. We combine geographic information systems and life cycle assessment (LCA) to examine the configurations of optimal supply chain networks, including direct symbiosis between waste producers and construction material manufacturers, as well as centralized waste recycling plants with recovery of valuable substances. We apply the proposed methodology to a case of sewage sludge recycling and phosphorus recovery in Denmark. Results show that recycling of sewage sludge ashes as supplementary cementitious materials with mineral recovery can bring up to 69% lower CO2 eq. emissions compared to business-as-usual ash landfilling and production of conventional cement construction materials and fertilizers. The methodology can be further applied to assess impacts with potential urban waste recycling in different regions. The results can provide indications to policymakers to encourage the establishment of new urban-industrial collaborations, promote sustainable waste management practices, and advance the goals of a circular economy.

Building construction has a profound impact on economic, social and environmental sustainability. The transformation of building construction towards reaching the United Nations sustainability goals will necessitate a transformation of project delivery models (PDMs) in construction projects. Successful management of uncertainty is essential for a project to reach its goals. Sustainable transformation is increasing the complexity and need for innovation in construction projects, and complex projects have a relatively high tendency to fail in reaching their goals. Collaborative project delivery models (CDMs) are considered particularly suitable for complex projects with high uncertainty and need for innovation. A CDM can be divided into contractual, organizational and cultural elements. The relationship between CDM elements, uncertainty and sustainability is insufficiently understood. This chapter seeks to fill the research gap by examining experiences from five large European collaborative projects studied in two longitudinal multiple-case studies carried out in cooperation with two of the largest project owners in the Norwegian construction industry. Experiences from the five case projects demonstrate how CDM elements facilitate early and joint management of opportunities and risks in a way which can advance both economic, social and environmental sustainability. For a CDM to successfully contribute to the advancement of sustainability, its elements must be selected and implemented in ways that ensure the recruitment, incentivization and organization of suppliers and personnel with competence and commitment to create a collaborative culture aimed at achieving sustainability goals. Social, political and market uncertainty in the front-end greatly impacts the ability of the client to select and implement such a CDM. In future research, it is recommended to study in detail how collaboration towards sustainability goals can be integrated into CDM elements and to carry out comparative quantitative studies on how projects with various forms of such integration perform economically, socially and environmentally.

Climate-change-imposed challenges in the form of heightened frequency and intensity of weather events exert additional pressure on securing the imperative continuous and reliable power supply, leading to increased power outages. This research proposes a comprehensive framework for enhancing the resilience of electric power networks (EPNs) through reliability-based risk assessment, promoting predictions and proactive decisions. The presented research discusses weather phenomena, their association with climate change, and their projected impacts. The numerical weather prediction model, WRF 3.4.1, with a 4 km resolution cell grid, gives a more accurate projection of high winds’ frequency and intensity. The simulation period from 2086 to 2099 is based on a reference control period spanning from 2000 to 2013, with adjustments made to background conditions using climate model output consistent with projections for the late century, a pseudo-global warming (PGW) technique. The presented research focuses on the wooden power distribution poles. The reliability assessment approach employs fragility development and analysis against wind scenarios through advanced modeling techniques and statistical analysis used to mimic historical and projected wind scenarios and to allow numerous factors on both the demand and capacity sides and their inherent uncertainties to be considered. The annual probability of failure is obtained by performing a mathematical convolution of the fragility and the hazard curves, showing the reflection of the effects of climate change on the annual probability of failure. Scaling these results to a system-level resilience assessment will facilitate the flexible energy design strategies integration and allow smoother net-zero standards incorporation and adaptation to the changing environmental conditions. This understanding will allow the decision-makers to evaluate the critical locations within a distribution line and plan to address the vulnerabilities by hardening the assets or implementing modern microgrid techniques or distributed energy resource integration.

The chapter focuses on Historical Villages (HVs), a precious segment of European cultural identity heritage characterized by fragile environments that, over the last decade, have experienced a progressive rapid decay.There is an urgent need to develop initiatives aimed at preserving the memory and heritage of past communities and inhabitants.Renovation strategies are crucial in halting the depopulation of HVs, offering a wide-ranging opportunity for a novel approach to conservation and revitalization. This approach has the potential to generate added value, enhance appeal, spur growth, and facilitate transformation in areas grappling with degradation.Moreover, the paper introduces an innovative strategy for decarbonizing HVs known as Energy Communities (ECs): an approach gaining traction across Europe. These communities entail initiating participatory processes through public–private partnerships. The initial section provides a comprehensive overview of the growing concept of ECs in Italy, underscoring their pivotal role in fostering a transition toward economic, technical, and environmental sustainability.Furthermore, the paper examines challenges and opportunities in Italy aimed at preserving the heritage value of HVs and encouraging their historical identity. This involves empowering local inhabitants to spearhead bottom-up initiatives promoting their integral role in building refurbishment, retrofitting, and valorization toward decarbonization objectives.Finally, the paper presents an Italian case study: the CommOn Light Energy Community, which serves as an exemplar of best practices in Italy. It combines community engagement, innovative funding strategies, and a scalable model for national replication, emerging as a benchmark for future endeavors in sustainable energy development and community-driven initiatives.

The topic on how to reduce energy use by close monitoring system, such as Energy Monitoring System (EMS), has attracted more and more interests nowadays. However, there is a noticeable lack of practical case studies illustrating the concrete steps, the potential challenges, and actionable solutions along with the process. This study is based on a pilot project for Vestfold and Telemark County municipality in Norway, aiming to reduce energy use by tracking and analyzing energy consumption patterns on a weekly basis. Deployment of EMS system offers the real-time monitoring capabilities, providing an invaluable tool for energy use optimization. By studying the interactive measurements and illustrating trends through interactive diagrams, EMS system producing relevant results parallelly facilitates precise energy optimization, enhancing sustainability and facilitating the efficiency of energy management. This study underscores the contribution of the EMS system and its practical barriers and their respective resolutions, emphasizing the necessity of these insights toward zero carbon footprint and energy-efficient future. Notably, the close monitoring and optimization of energy usage in this case study culminated in savings of 9.8 million Norwegian kroner in 2022.

Positive energy districts (PEDs) are central in the global transition toward sustainable, decentralized, and self-sufficient energy systems. Energy transformation taking place locally in cities may trigger broader sustainability transitions (STs) toward PED ecosystems at macro level. The work adopts a service ecosystems perspective to tackle the complexity of STs in the energy sector. The work builds a conceptual framework intended to support the transition and renewal of PED service ecosystems at a micro- and meso levels and uses illustrative case examples from a PED located in Espoo, Finland. The framework is intended to map the interdependencies between different actors in commercializing PED service ecosystems, and acts as a transformational tool for the public and private organizations to address change in PEDs. The framework concretizes the value propositions, actor roles, resource integration, and monetization mechanisms, as well as the transformation enablers, challenges, and long-term impacts. Additionally, the goal of the framework is to help municipalities to understand their roles in strengthening the institutional and social enablers for the local energy transformation with clear regulatory frameworks, incentive mechanisms, long-term political commitment, and vision. Overall, the study supports our understanding on the underlying mechanisms in the paradigm change toward sustainable energy systems.

Railway trains are an efficient mode of transportation for passengers and goods in large quantities. The planning of railway lines, however, needs to take the complex terrain into account. For areas with land parcels separated by wide and deep water bodies, the railway connection is even more challenging. Submerged floating tunnels (SFTs), on the other hand, become an appealing option to connect the separated land parcels. They utilize the natural water buoyancy to support the weight and payloads of the structure and traffic. They have a much lower dependency on the seabed conditions as opposed to their bottom-founded counterparts. They are also submerged at a certain depth below the water surface, which reduces the wave loads acting on the structure and provides a navigation clearance for passing vessels. Owing to the numerous advantages of such structural systems, they have attracted interest among both researchers and engineers. However, the research on the use of such transport infrastructure for safe and comfortable train travel is limited. In this paper, the dynamic responses of a train traveling across an SFT subjected to wave loads are examined. The SFT is modeled as a slender beam according to the Euler–Bernoulli beam theory. The hydrodynamic responses of the SFT subjected to various wave conditions are analyzed using SIMA/RIFLEX. Then, the responses are extracted as input to a train model idealized as a multi-body system for the calculation of the vehicle dynamics. This study aims to propose a computationally efficient method for the evaluation of the safety and comfort of train travel inside an SFT in an environmentally exposed location. Results show that travel rides inside SFTs are generally good under the normal design operational conditions. When the sea conditions are rough, limiting the operational train speeds may be necessary as the vertical acceleration is approaching 0.6 m/s2. Under extreme sea conditions, the SFTs should be closed to traffic.

Positive Energy Districts (PEDs) represent innovative place-based strategic approaches aimed at advancing our climate goals within the built environment. PEDs are increasingly recognized as a vital component in the journey toward achieving climate neutrality and fostering smart cities. Success in deploying PEDs necessitates holistic consideration of political, social, environmental, procedural, economic, technological, and contextual factors, involving shifting constellations of stakeholders. Achieving human-centric PEDs requires a transdisciplinary collaboration and a cocreation approach, bridging gaps between the public sector, business sector, research and technology sector, and end users. Many emerging studies have recognized that the main challenge of deploying PEDs pertains to silo thinking and suboptimal governance systems. This exploratory chapter aims to delve into the governance structures and functions in the deployment of a PED project. The chapter adopts a single-case study approach focused on a Sustainable Plus Energy Neighborhood (SPEN) in the specific context of Salzburg, Austria. Our objective is to map the structure of the governance network and their interactions for knowledge and resource exchange in the deployment of PEDs. Our findings challenge the adequacy of both total rational planning and incremental planning approaches in addressing the complexities inherent in neighborhood-scale projects like GNICE SPEN in Salzburg. Our study underscores the importance of recognizing the limitations of traditional planning paradigms and advocating for more adaptive and inclusive approaches to governance. The contribution of this chapter is to refine the structural-functionalism model for empirical investigations of governance models, particularly in the context of PEDs.

Multifaceted challenges spanning the entire building’s lifecycle hinder energy efficiency in renovation projects. Despite regulatory frameworks for buildings’ renovation, operation and commissioning at both EU and national levels, numerous buildings fall short of energy performance targets. This persistent energy performance gap stems from decision-making processes across the building lifecycle, necessitating a comprehensive approach to practical solutions.Notably, modern hybrid energy systems and complex building automation demand meticulous attention to ensure optimal functionality.In Finland, current commissioning guidelines cover the design and planning phases but do not adequately address the construction and usage phases. In addition, the lack of training and motivation among managers and experts involved in energy renovation projects hinders data-driven insights.To address this issue, the study examines obstacles that face current energy renovation projects, such as measurement inaccuracies, data limitations, fault diagnostic methods, compliance issues, and practical impediments. The research involved a literature review and expert interviews.Initial findings reveal significant challenges investigators face when assessing energy efficiency in real-world scenarios. Measurement inaccuracies, data limitations, and practical impediments like compliance issues and fault diagnostic methods were identified as significant obstacles. Analysis of energy efficiency indicators used for building performance evaluation indicates a wide range of metrics employed. However, quantification in practical applications varies, posing challenges to establishing consistent evaluation standards.These preliminary results highlight the complexity and multifaceted nature of energy efficiency challenges in building renovations. Early exploration of risk management practices for hybrid energy systems emphasises the need for a specific model addressing design and deployment risks. Insights from international practices are being gathered to propose effective risk management strategies tailored to the Finnish construction field.

Energy conservation measures (ECMs), also referred to as interventions, are a set of actions intended to enhance energy efficiency or conserve energy consumption. When implementing an intervention in a building or a set of buildings, the actual energy savings cannot be directly quantified. Alternately, savings are calculated by comparing the energy consumption before and after interventions while adjusting to condition changes. Based on the literature, systematic approaches for determining the true impact of an investment in energy efficiency are collectively referred to as measurement and verification (M&V) methods, supported by a well-established set of guidelines, directives, and protocols, e.g. International Performance Measurement and Verification Protocol (IPMVP).Therefore, the paper proposes a methodology based on the available M&V methods to validate, quantify, monitor, and report the achieved energy savings with large-scale aggregated during an operational year. It is designed to integrate and consolidate the available information and provide insights to validate the impact of the energy consumption optimisation strategy. The method describes all the steps, from gathering the data to feature selection to model selection and saving quantification and performance evaluation.The proposed methodology’s practical application is demonstrated through its testing on Danish residential buildings in the Municipality of Aalborg. A shared adjusted baseline model is constructed per cluster of buildings to predict post-intervention energy consumption. The results show that the method reduces the computational effort of calculating the energy consumption of a series of buildings separately and delivers reliable predictions, underscoring its practical value.

This chapter presents a framework for inspecting and assessing bridge structures utilizing unmanned aerial vehicles (UAVs), photogrammetry software, and artificial intelligence (AI) capabilities. The approach aims to generate precise 3D digital twins of bridges to enable accurate remote inspections and decision-making for maintenance. The framework involves collecting high-resolution image data of bridges using drones. The optimal distance between the drone and the bridge is evaluated to balance the captured details with operational safety. The images are then processed through software packages to generate 3D models. An AI algorithm was implemented to automatically detect defects like potholes and cracks in the 3D models through semantic segmentation. The measurement tools validated the accurate scaling of defect dimensions. This innovative app roach enables swift, safe, and thorough remote bridge inspections using devices connected to a main server. The generated 3D models with AI-detected defects provide comprehensive multi-dimensional visualization to inform maintenance decisions, transforming conventional practices.

Circular economy principles can be applied to the construction sector to reduce use of resources, energy consumption and wastes. Bio-based construction materials are particularly suitable to circular building design. Advantages of bio-based materials include: (1) a renewable supply chain, (2) often fast-growing, (3) recyclable or used as fertilisers/compost and (4) can sequester carbon. In this paper, the design of three circular bio-based wall panels is presented. The three panels were designed to be disassembled, and innovative bio-based materials, such as mycelium, sheep’s wool and cellulose were implemented in the walls. The wall assemblies were tested in a large environmental chamber to assess whether the panels achieved high insulating performances. Monitoring results showed that the three panels have excellent thermal properties. In parallel, life cycle assessment (LCA) of the bio-based construction materials applied in the three panels was undertaken to assess the sustainability and circularity of the selected materials. LCA results showed that some of the materials, such as sheep’s wool and flax, do have a low carbon footprint. However, there are uncertainties around the carbon footprint of other bio-based materials (e.g. fungi-based products), as information on the manufacturing process and associated emissions are not always available. This paper provides an overview of the applicability, advantages and challenges of innovative and sustainable technologies in buildings to achieve net-zero targets and to apply circular economy model of construction in buildings.

Addressing greenhouse gas emissions in the built environment is crucial due to its significant contribution to the total equivalent CO2 emissions. Recent efforts have primarily focused on enhancing energy efficiency, resulting in notable reductions in energy consumption. However, the next phase of decarbonization in the building sector is increasingly emphasizing the use of materials with lower embodied energy and CO2. A novel hybrid unitized façade (HUF) system has been developed, specifically designed for cold climates, that integrates aluminium and timber. This study aims to assess the carbon footprint of the HUF system, where timber is used to partially replace high-embodied-energy aluminium frame. For this, a comprehensive cradle-to-grave life cycle assessment using One Click LCA, combined with a building energy tool that incorporates future weather data, is employed. This assessment includes the materials and quantities involved in constructing a HUF unit, incorporating their specific environmental product declarations. The study explores two strategies for long-term sustainability: (i) examining the impact of retrofitting the façade system elements in accordance with their respective service life and (ii) examining the impact of a complete retrofit of the façade system at 30 years. This evaluation will be conducted for a generic office building model in Oslo. The study aims to contribute to sustainable practices in the building sector, offering insights for policy and industry, particularly in the context of climate change mitigation. The global warming potential for HUF unit in Oslo is 129 kg CO2e/m2 for scenario RCP 4.5 and 128 kg CO2e/m2 for RCP 8.5.

Ultra-high-performance concrete (UHPC) is known to exhibit superior performance compared to conventional concrete. The applications of UHPC within structural engineering have been largely focused on its behavior under conventional loads. While the behavior of UHPC structural members has been thoroughly investigated under conventional loads, a literature gap exists regarding its application as a protective system against windborne debris impact. It is important to note that windborne debris stands as a primary cause of damage to building envelopes during severe wind events like tornadoes and hurricanes. In this study, the performance of UHPC wall panels was investigated under direct impact loads due to the representative debris projectiles as prescribed by various building codes. Full-scale finite element (FE) models were developed within the framework of LS-Dyna. Further FE studies into the performance of various UHPC walls panels under windborne debris impact were conducted using rigorously calibrated FE models. In this study, four UHPC walls of thicknesses 76.2, 101.4, 152.6, and 203.2 mm were studied against the windborne debris impact of both lumber and pipe projects. To study the effect of impact velocities, several impact scenarios with velocities ranging from 10 to 70 m/s were developed. This holistic matrix of simulations helped characterize various response measures, such as the type and extent of damage, in the UHPC wall panels individually and in comparison, with their normal-strength concrete (NSC) counterparts. This comprehensive array of simulations assisted in characterizing various response metrics, including the nature and extent of damage in UHPC walls. Based on the outcome of the simulations, the thicknesses required for the UHPC and NSC wall panels to stop the missile from perforation were determined. Further, embodied carbon contributions of the UHPC and NSC walls that could stop the windborne debris missile were estimated. A comparison of embodied carbon contribution and potential amount of concrete saved from this study provided additional insights for analysis and design purposes.

Shear walls are fundamental structural elements within mid- and high-rise buildings, mitigating lateral forces such as wind and seismic forces. In recent years, numerous research endeavors have emerged, focusing on the integration of non-conventional materials such as ultra-high-performance concrete (UHPC) into shear wall construction, as alternatives to conventional materials. Despite the known strength-increasing benefits, there were questions regarding the design requirements, structural performance characteristics, and sustainability of this novel type of shear wall. This study aims to assess the benefits of employing UHPC, in contrast to conventional materials like normal strength concrete (NSC). The analysis consisted of a nonlinear static (pushover) analysis applied to two verified finite element models representing conventional and nonconventional materials. The results indicate that UHPC outperforms its counterpart in damage tolerance and load-bearing capacity. Additionally, an assessment was conducted to determine if increasing the thickness of the NSC shear wall could reach UHPC's performance. The results confirmed that even with enhanced thickness, NSC lagged significantly behind UHPC in performance metrics, thus offering a reliable material choice for structural applications that involve extreme loading effects.

The reuse and recycling of timber are crucial for a circular economy, but barriers like insufficient information and concerns about material quality hinder their industrial-scale implementation. Uncertainty about mechanical properties often leads to downcycling and CO2 release. Circular practices involve cascading reuse of timber, but downcycling occurs at each step, leading to waste. To maintain carbon storage, reclaimed timber should be used with maximum integrity, like in load-bearing beams. Non-destructive assessment methods for reclaimed timber face challenges due to variations in origin, age, and wear conditions. X-ray computed tomography (CT) scanning in conjunction with computational mechanics provides a means to structurally assess wood based on its internal density distribution. In this paper, a modelling pipeline is proposed using CT-based finite element analysis to assess the quality of reclaimed timber elements. The pipeline is part of an ongoing investigation where timber stiffness and strength are evaluated both destructively and non-destructively using various measurement modalities. Accurate non-destructive assessment of the mechanical properties of reclaimed timber could optimize its use and enable repeated reuse. In subsequent research, the pipeline will be validated and simplified to aim for practical application.

Burnt bricks are a predominant material in constructions in India and many other countries globally. The inherent resilience and longevity of brick structures make them suitable for repair and further strengthening. Several procedures are already in practice for the preservation and enhancement of seismic performance in existing masonry structures. One notable method, rooted in history and now under exploration, is the semiconfinement of existing masonry structures with horizontal and vertical reinforced concrete (RC) elements. This method exhibits all the characteristics of an effective retrofitting technique. Most importantly, it has been found to improve ductility and showcase enhanced seismic performance. In this context, two existing masonry constructions at the Structural Engineering Laboratory of IIT Kanpur are considered. These structures, having undergone cyclic testing, include one without any reinforcement (or control masonry) and the other retrofitted with semiconfining horizontal and vertical RC elements (strengthened masonry or retrofitted masonry). Both structures experienced crack formation during testing, with distinct characteristics reflecting their unique structural behaviors. These cracks were sealed using grouting, requiring minimal material and a “light” application. The primary objective of this study is to assess the behavior of these repaired buildings through condition assessment techniques and subsequent testing. For this purpose, accelerometers were installed at various locations, and Experimental Modal Analysis (EMA) was considered by shaker tests. The assessment of dynamic behavior in these structures will facilitate further studies on retrofitting the control masonry and enhancing the scheme of retrofitting or strengthening for improved performance.

The reuse of structural timber has emerged as a promising opportunity in Norway with significant potential to shape the future of construction projects. This sustainable initiative decreases waste and contributes to carbon sequestration, eventually reducing the environmental impact. This chapter focuses on the development of procedures for quality documentation related to the reuse of load-bearing building components and elements made of timber. Recent legislative changes have opened the door to such practices, but the challenge lies in the practical preparation of the necessary documentation to meet regulatory requirements. In this chapter, we have created a detailed flowchart to help navigate the process of reusing structural timber. The flowchart was conceptualized based on a literature study, a document study, and a series of semi-structured interviews with participants from the Norwegian construction industry. This research highlights the flowchart’s alignment with circular economy principles, leading to reductions in waste generation and energy consumption associated with timber production. These findings establish the importance of accurate documentation as an important step towards achieving the goal of reducing the construction industry’s environmental impact and carbon footprint.

Timber is widely recognized as a construction material of choice, owing to its numerous advantages, including its sustainability and abundance in large parts of the world. Although timber is frequently employed by the construction industry for buildings, its usage in modern bridge structures has remained limited. This research investigates the structural performance of cross-laminated timber (CLT) decks for bridge applications. For this purpose, CLT deck made of Douglas Fir North was fabricated to full-scale but with some reduced width dimensions. The deck was then tested under static and fatigue loading conditions. The experiments evaluated various structural response features, including the bending stiffness, interlaminar properties between the panels, and elongation characteristics from the applied vertical forces, representing heavy vehicular loads equivalent to the design loads expected on a typical short-span bridge. The results demonstrate the promising performance of CLT decks, exhibiting excellent structural performance compared to design standards. Overall, this research addresses a knowledge gap by providing valuable information for CLT bridge deck design and optimization, addressing the lack of modeling guides, and offering recommendations to meet standard requirements. Moreover, it emphasizes the environmental benefits of using timber sourced from sustainable sources, which is feasible in areas that have an abundance of such resources.

The harmonious integration of wood and concrete in facade elements represents a breakthrough in construction, offering a synergistic combination of their respective properties. The reduction of greenhouse gas emissions in the field of building emphasizes the need for developing structures including more wood. The facade elements including wood as a structural component will also reduce the thermal insulation of the walls.The bonding between the two materials not only guarantees resistance to environmental and mechanical stresses but also minimizes the risk of premature deterioration, even though it can accede a lot of advantages, this method needs to be studied, particularly in the case of wood–concrete facades. Analysis of the mechanical response to thermal load becomes an essential aspect in the design of glued wood–concrete facades. When a facade is subjected to thermal loading with a difference between internal and external walls, the materials of which it is composed, such as wood and concrete, may react in different ways due to their different coefficients of thermal expansion, these materials can expand or contract at distinct rates in response to a temperature change. This dimensional variation can lead to stress concentration at the interface, which can affect bond quality. This research presents in detail the experimental results of wood–concrete façade panels and aims to understand the thermal responses and expansions induced by a thermal gradient applied to façade panels. It also involved targeted heating of the concrete and cooling of the wood to create a controlled thermal gradient. The results were analyzed in terms of temperature variations observed on the facade surface, as well as thermal expansion measurements taken on both the wood and concrete sections. These observations revealed distinct behaviors between the two materials in response to thermal variations, underlining the importance of judicious design to ensure the stability and durability of composite façade panels.

Mitigating vulnerabilities of cultural heritage assets prevents damage from extreme weather, encourages sustainable restoration practices that cut carbon emissions, and yields long-term cost savings, all while conserving the legacy of historical constructions. Developing a precise numerical model that closely simulates the actual structure is a crucial component of a vulnerability assessment methodology. The objective of this study is to present a finite element (FE) model updating of a historical masonry arch with a corner tower in Rhodes, Greece. The Naillac tower, as part of the medieval city of Rhodes, is recognized as a UNESCO World Heritage site. Three-dimensional (3D) documentation was conducted using digital cameras, 3D laser scanners, drones, and total stations. These tools were chosen for their effectiveness in capturing the intricate architecture of the structure while expediting the documentation process. A 3D dense point cloud was generated, forming the basis for the subsequent development of a 3D FE model. On the other hand, operational modal analysis (OMA) was conducted based on the ambient vibration testing (AVT) data using accelerometer sensors to define the frequency values and corresponding mode shapes of the structure. The material properties of the FE model are calibrated to match the modal properties of the FE model with those recorded experimentally. Finally, the updated mechanical properties of the stone masonry for different parts of the structure were presented. Significant variations exist between the calibrated material properties and those assumed from empirical equations, underscoring the necessity for model calibration based on OMA.

This article presents the results of mechanical testing and structural analysis of the glulam frame supporting novel external façade envelope elements made of aluminium, glass, and insulation. The glulam frame forms the basic structural support for the new modular hybrid façade system, an industrial product designed by STATICUS company with an aim at reducing environmental impact. The ultimate and serviceability limit states are considered to assess the durability of the design in terms of possible deformations affecting air and moisture tightness as well as the level of stresses leading to potential damage accumulations and fatigue. The analysis combines the horizontal environmental loads, that is, wind loads over 4 years of real wind speed data in 2021–2023 together with the permanent self-weight loads for the representative mid-rise building in different characteristic coastal locations in Norway: Oslo, Trondheim, and Tromsø. The constructed load models are applied to the geometrically non-linear numerical mechanical model of the glulam frame. Explicit modelling of the screw connections in the frame was validated by static mechanical testing in a laboratory set-up. Continuum elements with an orthotropic material model are used for wood. The stress level in reference to the ultimate strength was established for all wind loads and characteristic failure mode was identified as local compression perpendicular to grain in the screw connection. The mechanical fatigue life of the glulam frame is estimated at a minimum of 32 years (Tromsø) and a maximum of over 100 years (Oslo, Trondheim) based on the calculated stress level and real expected number of cycles of loading over the service life.

Glass fiber-reinforced polymer (GFRP) bars have been used as a viable environment-friendly alternative to the steel reinforcement in bridge decks. The GFRP bars have comparable structural performance while providing a non-corrosive option for corrosion-prone-reinforced concrete bridge decks. This study presents the results of the performance evaluation of two similar bridge decks, one reinforced with GFRP bars and the other one reinforced with steel bars. The two bridges were instrumented using several vibrating wire strain gauges to collect their long-term data over time in response to the seasonal temperature changes. The GFRP bars were also tested in the lab to extract their stress–strain behavior and compare their mechanical properties to those of the conventional steel. Finally, the two bridge decks were compared in terms of economical characteristics through a set of life-cycle cost analysis based on the initial cost, bridge deck reconstruction, and also repair and rehabilitation costs during the service life of the bridges. The study revealed no concerning difference between the structural performance of a GFRP-reinforced and a steel-reinforced bridge decks, showing that GFRP bars could be used as a viable alternative material in bridge decks.

The presented research study investigates the structural behaviour and performance of a hybrid timber–concrete floor system. These hybrid systems have been proven to contribute to the reduction of the carbon footprint during the construction of a building. In the current paper, a series of numerical analysis have been conducted. A reference numerical model has been created based on a test specimen from the international literature, and the test results have been used for the calibration and validation of the numerical model. The hybrid floor system consists of a set of glulam beams that are connected to a concrete slab. The flexural strength and the deflection of the system under a four-point bending test configuration have been determined. Moreover, several parameters of the system such as the thickness of the concrete slab, the strength class of the glulam beams, and changing the load placement are further investigated to provide a better insight into the response of the system under examination. The numerical results have been assessed and depict that hybrid timber–concrete systems are a sustainable and efficient alternative to traditional steel-concrete floor systems.

Seismic risk associated with the hilly and mountainous region of the Indian Himalayas is immensely high owing to a combination of the extremely high seismicity of the region and the vulnerability of the irregular buildings constructed on sloping terrain. Scientific studies on the seismic vulnerability of such buildings are performed on either bare frame or fully infilled buildings without considering openings in the infill panels for doors and windows. However, presence of openings plays an important role in the overall seismic performance. The present study aims to understand the effects of openings on the dynamic properties of unreinforced masonry (URM) infilled RC buildings constructed on sloping terrains such as the modal properties and fundamental period of vibration. Various opening ratios are considered as per construction practices in India, and the dynamic properties are compared with those of fully infilled buildings. A comparison of dynamic properties revealed that the period of vibration increases and the modal participation ratio corresponding to the fundamental mode of vibration decreases with an increase in the opening ratio. The displacement at the roof of the buildings was also found to increase with an increase in the opening ratio and the maximum displacement was found to be 25–63% higher as compared to fully infilled buildings depending on the opening ratio. Non-linear dynamic analysis has been performed to identify and compare key structural parameters responsible for the collapse of hill buildings with varying opening ratios.

Conventionally, seismic hazard at a site is represented by a uniform hazard spectrum (UHS), which represents the seismic hazard in terms of spectral ordinates corresponding to a fixed probability of exceedance at all periods of vibration. Alternatively, a hazard curve can be developed for a site corresponding to each spectral period, which provides the probability of exceedance of different amplitudes of spectral ordinates. The hazard curve can be used for the estimation of the collapse risk of a structure in a given life span. Accordingly, if a structure is designed using a standard procedure to yield a standard fragility curve, a design response spectrum can be constructed to achieve a targeted collapse risk of the structure in its life span. The obtained spectrum is designated as a risk-targeted response spectrum (RTRS). Thus, RTRS provides design spectral demand to achieve uniform (targeted) collapse risk across all spectral periods. RTRS depends on the targeted risk value and construction type, given the site’s seismic hazard. The focus of this study is constructing RTRS for masonry structures aiming to enhance their service life and achieve the targeted collapse risk, which will help gain better control over their performance. Also, a comparative study of the UHS corresponding to different locations and RTRS for chosen targeted risk for the northern Himalayan region is performed in this paper. Moreover, the risk values for the masonry structures with varying heights of storey and dynamic parameters are also compared, and the obtained values are compared with the targeted risk value.

Different environmental issues such as carbonation and corrosion due to chloride threaten aging reinforced concrete (RC) bridges that are in service in areas highly prone to corrosion and earthquakes. Significant experimental and numerical efforts have been put into scrutinizing the effect of corrosion on nonlinear behavior of structural elements. With the rapid development of artificial intelligence, useful methods are now provided to allow for the assessment of such bridges without the drawbacks and limitations of the experimental and numerical methods. In this paper, four machine learning (ML) algorithms are employed; linear regression (LR), decision tree (DT), random forest (RF), and XGBoost for data fitting of the models, and Bayesian search is used for optimization of hyperparameters. Numerical models of RC piers with stochastic parameters defining geometry, loading, and materials are built, and the degradation due to corrosion is applied with a randomly determined level of corrosion. Then, the corroded models are nonlinearly analyzed with random ground motions scaled to design-based and maximum credible earthquake spectra, and maximum drift ratios are stored. Using the created database, different ML models are compared to find the most accurate one. R-squared, mean absolute error, mean squared error, and root mean squared error metrics are considered as the criteria for the selection of the most accurate model. LR model with R2 = 0.53, MAE = 0.0026, mean squared error (MSE) = 1.4 × 10−5, and root mean squared error (RMSE) = 0.0036 has the lowest accuracy while XGBoost with R2 = 0.8, MAE = 0.0015, MSE = 5 × 10−6, and RMSE = 0.0028 is the most accurate model. DT and RF models with R2 = 0.7 and R2 = 0.73, respectively, are in between.

The structural design of buildings, bridges and all other civil engineering structures heavily relies on understanding the beam element, particularly its flexural behaviour. This chapter explores both analytical and numerical approaches to predict the flexural behaviour of reinforced concrete beams. Force equilibrium and strain compatibility equations were used for the analytical approach, while ANSYS, a finite element software, was used for the numerical approach. Comprehensive insights into the analysis, from concrete and reinforcing steel material models to mesh sensitivity analysis in the numerical approach, are provided. The analytical and numerical methods used were validated with an experimental case study beam. The load–deflection curve of a reinforced concrete beam obtained from experimental, analytical and numerical approaches is presented and found to have good correlation. The chapter further provides insights into the efficiency and limitations of each method in predicting the beam behaviour. The findings of this study will guide researchers and practitioners in selecting appropriate methodologies for structural analysis problems.

The conventional methods for determining the shear strength parameters of soil, namely cohesion (C) and angle of internal friction (φ), involve time-consuming and expensive machinery. Also, the extraction metal ore processing into metal and machine manufacturing involves a high level of carbon emission. During the operation of these machines a large quantity of electricity is generated in thermal power plants, leading to an indirect increase in the carbon footprint, thus suggesting a need for the adoption of more sustainable practices. This study is aimed at reducing net zero emission by laboratory testing machines by develop a predictive machine-learning model for estimating soil shear strength parameters by utilizing the existing soil data. An artificial neural network (ANN) is one such model inspired by the human brain, with the ability to learn complex patterns and relationships in data. For this, 88 soil samples in all were gathered from the literature that was available. Basic index properties of soil are used as inputs and C, φ are predicted as outputs. A neural network is developed using a Bayesian regularization optimization algorithm. The model developed is evaluated using the root mean squared error, coefficient of determination, and mean absolute error. The efficacy demonstrated by the ANN model ensures reliable predictions, thus promoting the adoption of these predictive models, leading to net zero carbon emissions in the testing field of geotechnical engineering.

This chapter explores a groundbreaking shift in the evaluation of asphalt pavements by investigating the potential of digital twin technology as an alternative to traditional laboratory tests. Focusing on two road sections, namely national road 4 at Gjøvik and E-road 6 at Tretten in Norway, both featuring the same asphalt type Stone mastic asphalt (SMA) 16 PmB, the study conducts a comparative analysis of air voids and resistance to permanent deformation. A total of 12 asphalt samples were extracted, and digital twins were generated utilizing microcomputer tomography alongside a MATLAB script for 3D visualization and analysis.The research method involved validating the digital twin results against outcomes obtained from standardized laboratory tests. The findings suggest that the digital twin approach not only yields accurate assessments of air void quantity and distribution but also provides unique insights into the internal microstructure of asphalt. This transformative methodology presents a promising avenue for the Norwegian Public Roads Administration (NPRA) to enhance efficiency and precision in asphalt quality evaluations, signaling a potential paradigm shift in pavement assessment practices.

Ground-borne vibrations resulting from various civil engineering activities can cause detrimental impacts on the nearby structures. Therefore, past studies have concentrated on developing vibration mitigation techniques. Vibration screening using wave barriers is a widely accepted approach, and continuous research has been ongoing in the last few decades. However, the current solutions to the problem are limited to the use of single trenches, and only limited experimental studies on open and geofoam-infilled have explored the possibilities of utilizing dual trenches. In some practical scenarios, the recommended depth of a single trench is unimplementable; further, no significant work has been observed to find suitable infill materials in screening the vibrations induced due to harmonic loading under dual trench scenarios. Hence, the current study aims to experimentally investigate the potential of dual trenches infilled with sustainable materials to mitigate the vibrations induced due to continuous harmonic loading. The influence of the filling accomplished by two types of material, namely, a softer one like geofoam (G) and a stiffer one like aggregate (A), has been evaluated and compared to the soil. Thereafter, these materials were interchanged in the trenches. The harmonic loading was applied using a Lazan-type mechanical oscillator. The associated vertical particle acceleration due to wave propagation was captured using an accelerometer positioned at a distance of 1 m from the second trench. The results indicate that infilling the first trench with aggregate improves isolation efficacy. Furthermore, the optimal depth required to reach an amplitude reduction ratio of 0.25 was observed as 0.25LR (LR= Rayleigh wavelength) and 0.34LR for the dual trenches filled with aggregate and geofoam (A + G), and geofoam and aggregate (G + A), respectively.

This research investigates the performance of various regression models in predicting critical structural parameters within a plane truss model. The study encompasses linear, second- and third-degree polynomial, and artificial neural network (ANN) regression models, which are evaluated for their accuracy in estimating the maximum displacement, maximum (tensile) stress, and minimum (compressive) stress of the truss under specific loading conditions. The findings unequivocally establish the superiority of the ANN model, showcasing its ability to capture complex nonlinear relationships within the data. Moreover, the research explores the influence of model complexity, demonstrating that the transition from simpler to more intricate models enhances predictive performance. The implications of this study extend to diverse engineering applications, offering insights into the selection of appropriate regression models for structural analysis and design. Beyond improved predictive accuracy, the ANN’s predictions provide potential for reducing computational demands, making them valuable tools in structural optimization and similar contexts. However, the study underscores the importance of cautious interpretation, as certain scenarios may yield outlier predictions. Overall, this research contributes to the understanding of regression modeling in engineering and provides a foundation for informed decision-making in structural analysis and design.

As the bones and muscles of our built environment, engineering structures support all kind of societal activities. However, they consume huge amounts of resources and significantly contribute to impact on our environment. Structural design codes play an important matter in this regard since they regulate the use of materials by use of prescribed decision rules. These relatively simple and generalized rules offer significant potential for improvement. Grounded on risk-based optimization approaches, this paper explores this potential in connection with the design of reinforced concrete floor systems. Assuming a large variety of realistic design situations, representative sets of such members are defined and designed according to the semi-probabilistic safety concept in the Eurocodes. The benefits of a risk-informed structural design compared to the use of these standardized decision rules are demonstrated in terms of material consumption and CO2 emissions.

This study aims to optimize the carbon fiber-reinforced polymer’s (CFRP) arrangements rather than the amount of secondary steel reinforcements for strengthening reinforced concrete (RC) corbels, utilizing finite element (FE) analysis. While previous studies have only examined different types of FRP sheet arrangement in the absence or presence of equal amount of secondary steel reinforcements, this research fills a gap by comparing the effect of different configurations with the Externally Bonded Reinforcement (EBR) installation method and increasing the amount of the secondary steel reinforcements. Verification was conducted using a fully horizontally wrapped strengthened RC corbel with the secondary steel reinforcement. Results indicate that by just differing the arrangements of CFRP sheets, an increase can cause up to 33% in bearing capacity with the same volume of CFRP. However, by increasing the geometrical secondary steel reinforcement ratio (ρsh) from 0.18% of the verified model to 0.33% and 0.52%; the bearing capacity increases by 5.52% and 11.55%, respectively.

This study delves into the ramifications of manufacturing-induced defects, particularly porosities, on the dynamic behavior of functionally graded material (FGM) beams. These defects possess considerable potential to alter the structural integrity and performance of such elements. The principal objective of this investigation is to examine the free vibration properties of FGM beams incorporating porosities. A power-law formulation is employed to delineate the distribution of Young’s modulus across the beam thickness, while Poisson’s ratio is held constant. Diverse configurations of porosity distribution are thoroughly explored, and the fidelity of the proposed model is rigorously evaluated through comparative assessments. Additionally, this research endeavors to elucidate the effects of variations in porosity distribution rate, power-law index, and thickness ratio on the fundamental frequency of the beams.

This chapter presents a comprehensive approach to optimizing steel usage for reducing the environmental impact of building structures, aligned with sustainable development goals. The study focuses on developing the structural design of members with optimization methods to reduce steel usage, leading to lightweight structural systems while minimizing carbon footprints in the built environment. This study identifies optimum cross-sectional dimensions of structural sections to withstand lateral wind loads. For that purpose, a nonlinear programming solver is used. This solver is robust in finding the minimum of a constrained nonlinear multivariate function. The volume of the structural steel is taken as the objective function to ensure sustainability, while two constraints of demand to capacity indices of structural members as a strength condition and inter-story drift ratio as a serviceability constraint are taken to meet performance criteria, such as safety and cost-effectiveness designing process. The results show that this optimized design tool can effectively reduce the weight of structural steel usage, paving the way to achieve both sustainable and resilient buildings.

This chapter explores the significance of intensity measures for flood hazards in assessing the fragility of bridges. Flood hazards pose considerable challenges to bridge infrastructure due to factors such as hydrodynamic forces, scouring, and debris accumulation. The study reviews various methodologies and models used to quantify flood intensity, including hydraulic simulations, empirical equations, and computational fluid dynamics. Despite advancements in modeling techniques, challenges persist, including uncertainties in hazard prediction and gaps between research and practical applications. Importantly, the chapter highlights the need to incorporate climate change considerations into hazard assessments and infrastructure design, given the projected increase in the intensity and frequency of extreme weather events. The absence of climate change in existing studies underscores a critical area for future research and intervention. By integrating advancements in modeling techniques and proactive adaptation strategies, this study’s outcome promotes sustainable infrastructure development and ensures the longevity of bridge structures in the face of evolving environmental conditions.

As an engineering consultancy company involved in large infrastructure projects globally, COWI has the responsibility of recommending the use of materials that are suitable for the projects that match the sustainability ambitions of both client and COWI and, more importantly, that contribute to shaping a sustainable and livable world. This requires us to develop a clear understanding on how to account for the carbon profile of wood as a construction material.This study was thus conducted internally across different departments to determine what methodological choices can provide a solid comparison on the life cycle carbon performance of wood as a primary construction material in large infrastructure. Three different life cycle assessment (LCA) studies were conducted to compare a timber road bridge designed by COWI against a more traditional reinforced concrete design, and differences in the options’ climate impact across the three different methodologies were observed.

Rapid increase in urbanization and mobility demand are rising concerns for the development of sustainable urban areas. Transport infrastructures play a major role in this regard by promoting well-being, social inclusivity, and economic growth. This is true also for road infrastructure. Over the life cycle of a road infrastructure, the operational stage is the longest one and requires continuous maintenance and/or rehabilitation activities to keep the road operating at a satisfactory level of service. Data-driven decisions are essential to assess and evaluate the status of the road network. However, the data-driven decision-making process is not trivial but rather challenging due to the need of balancing multiple road qualities simultaneously. This chapter presents an overview of the road maintenance decision-making process using the Norwegian case as a case study. After presenting a background on monitoring systems and pavement management systems, this chapter focuses on the data-driven decision-making process of the Norwegian national road network. Finally, this chapter discusses the opportunities to better align this decision-making process with the Norwegian transport plan.

Current linear economic road construction and maintenance methods, characterized by significant use of virgin resources and substantial greenhouse gas (GHG) emissions, are in sharp contrast to circular economy (CE) concepts that emphasize resource efficiency and emissions reductions. Despite the considerable energy use, material consumption, and emissions involved in road construction, this sector has been relatively underexplored in CE research. This paper aims to bridge this gap by investigating the transition from linear to circular road infrastructure, focusing particularly on the Norwegian construction industry. The study identifies barriers and drivers to this shift, intending to contribute to the concept of circular road infrastructure. Employing a mixed-methods approach, the research integrates a web-based survey among Norwegian road industry actors, augmented with six semi-structured interviews with diverse stakeholders, to establish a framework of barriers and drivers to CE. The findings suggest that economic, regulatory, and political factors are major barriers to circularity, but these could be transformed into drivers if key conditions are changed.

In the quest to achieve a sustainable built environment, circular construction emerged as an innovative approach to aid towards a quick transition for the resource-intensive construction industry. The successful implementation of circular approaches requires building design for multiple reuse with effective end of life resource recovery plan. Modular construction remains an integral approach for buildings designed for multiple life cycles, and design for disassembly enables the deconstruction and reuse of components at the end of building life cycle. Through a systematic literature review, the study looks at study trends in modular construction and design for disassembly and the various sustainability targets addressed in these studies, as well as the material inputs and indicators used for specific sustainability goals (environmental, economic and social). The study reveals an increase in studies and applications over the years mostly concentrated in Europe and North America which signifies a lack of adequate studies in developing countries with higher levels of infrastructure deficit and high construction demand. Studies largely focus on energy and emission reduction, material circularity and waste reduction with few addressing cost, health and safety and other socio-economic impacts; hence, evaluation of social impacts is largely neglected in most studies. Studies mostly present the use of conventional building materials rather than more sustainable circular materials to reduce raw material inputs and emission outputs. Achieving a sustainable built environment requires the triple bottom line sustainability consideration. Hence, the study proposed a framework to evaluate modular building and design for disassembly with focus on material selection, design and construction strategies as well as end-of-life considerations to support the determination of sustainability viability of multiple lifecycle designs for buildings.

The Architecture, Engineering, and Construction (AEC) sector produces a large sum of the global carbon emissions. Emerging systems and technology, coupled with a rapid modernisation within the construction industry, have been developed as a response to challenges of maintaining sustainable practices and procedures during the whole project life cycle. The technological advancement of Building Information Modelling (BIM) is the focus of this research: to determine its potential to facilitate the adoption of Circular Economy (CE) principles to empower the path towards net-zero carbon within the built environment. The employed research methods include a systematic literature review and a questionnaire survey to collect data from construction professionals on the potentials of using BIM to enhance circularity in the built environment projects. Existing BIM practices for sustainability within the built environment could in this chapter be identified to align with the concept of the CE, which will yield further strategies aiming to maintain the path towards net-zero carbon construction projects in the future. Following the analysis of the data collected, a conceptual framework is developed to demonstrate how BIM features facilitate CE principles and empower sustainability and resource efficiency within construction projects. To achieve the full potential benefits emerging from the BIM utilisation in a CE context, industry professionals and stakeholders should comprehend the acquired BIM knowledge and appliance for sustainable practices. The BIM competencies currently employed by industry professionals could show the current existence of an interconnection between BIM and CE.

The escalating demand for sustainable development, coupled with the urgent need to mitigate the environmental impact of construction practices, has propelled the advancement of structural optimization as a pivotal approach in engineering. This chapter delves into the transformative potential of structural optimization techniques to foster the creation of more sustainable and environment-friendly structural systems. Through the lens of innovative material efficiency, we explore how the strategic use of materials—not merely reducing their quantity but optimizing their application—can lead to structures that uphold or enhance quality, safety, and functionality, while significantly diminishing the environmental footprint of construction activities. We commence with a comprehensive overview of the current state of structural optimization methodologies, including topology, shape, and size optimization, highlighting their relevance and application in the pursuit of sustainability. Furthermore, we discuss the benefits of optimization in structural design, such as the potential to minimize material usage without compromising structural integrity, while also addressing the challenges and limitations inherent in this endeavor.

Artificial Intelligence (AI) is transforming urban planning and design, heralding a new era of sustainability and livability in rapidly expanding cities. By analyzing vast datasets, forecasting future trends, and autonomously executing tasks, AI holds the promise of significantly enhancing urban efficiency and environmental stewardship. Despite its potential, the adoption of AI faces hurdles, including concerns over complexity, privacy, and cost. This article explores the comprehensive impact of AI on urban development, emphasizing its capacity to optimize energy consumption, improve waste management, and streamline public transportation. Central to our discussion is AI’s role in the critical process of evaluating and selecting contractors and suppliers, which is pivotal for integrating sustainable solutions into urban infrastructure. By addressing these challenges, we advocate for a strategic embrace of AI technologies, aiming to unlock their full potential in crafting greener, more resilient cities worldwide. This synthesis aims to clarify the significant contributions of AI in urban development, providing a clear vision for its future role without the distraction of in-text citations.

This chapter assesses the state of practice for institutional-led tactical urbanism as a means of enacting a transition towards active travel in cities. Using an established assessment framework, the chapter reviews 92 academic works covering the use of temporary, tactical and experimental street-space reallocation projects towards the goal of permanently increasing mode-shares of active modes through improved spatial provision. Although significant ground has been made in this area, particularly in response to the opportunity presented by the COVID-19 pandemic, most projects still encounter difficulty in transitioning towards long-term outcomes. Through a focus on planning process and implementation, the chapter identifies common blockages and limitations inherent to orienting short-term interventions towards long-term transformative goals, while identifying potential best practices common to interventions which do achieve long-term replicability. While some causes of failure are contextually dependent—particularly temporally limited funding schemes and variation in local competencies—the chapter proposes that closer attention to strategic factors ordinarily present in traditional planning can improve the viability of measures.

This chapter addresses a gap in the current literature by focusing on retrofit strategies for existing buildings, particularly on an urban scale, located in a temperate weather context. The proposed methodology consists of three steps (Synthetic Stock Generation, Building Stock Dynamics, and Building Stock Assessment) to create an “Archetype Building Information” framework grounded in an Emergy approach. Preliminary findings reveal consistent energy demand behavior among buildings of similar typologies, forming the basis for defining shared patterns. The difference ratio between baseline and recommended energy demands by ASHRAE, while variable, follows a distinct trend across building types. The research aims to develop a comprehensive Building Retrofit Model tailored to the unique challenges and opportunities in Mexico City’s urban context.

The growth of urban areas intensifies the need for sustainable, efficient transportation infrastructure and mobility systems, driving initiatives to enhance infrastructure and public transit while reducing traffic congestion and emissions. By utilizing real-world data, a data-driven approach can provide crucial insights for urban mobility planning and decision-making. This study explores the efficacy of leveraging telecoms data from cellular network signals for studying crowd movement patterns, focusing on Trondheim, Norway. It examines routing reports to understand the spatiotemporal dynamics of various transportation routes and modes. A data preprocessing and feature engineering framework was developed to process raw routing reports for historical analysis. This enabled the examination of geospatial trends and temporal patterns, including a comparative analysis of various transportation modes, along with public transit usage. Specific routes and areas were analyzed in-depth to compare their mobility patterns with the broader city context. The study highlights the potential of cellular network data as a resource for shaping urban transportation and mobility systems. By identifying deficiencies and potential improvements, city planners and stakeholders can foster more sustainable and effective transportation and mobility solutions.

Cities of the future will be smarter and data-driven, utilizing digital technologies to shape urban development. Citizen participation lies at the core of these cities and allows individuals and communities to design their cities to best suit their needs, aspirations, and values. While advancement in technology has expanded opportunities for participation, balance in data-driven insight and aspirations of community perspective should be the major focus of these cities for enhancing participation outcomes, which are explored further in this paper.The study is based on the case study of digital participation conducted as a part of the planning process and citizen participation initiative held in the development of Torskeholmen, a coastal area in Grimstad Municipality, Norway. The survey involved 3474 responses (15% of the municipal population) from the citizens through the involvement of innovative strategies and initiatives.This research has studied the information from this substantial citizen digital survey to examine how these methods have affected community engagement, which is discussed and analysed. The results highlight approaches that can enhance citizen participation in urban planning projects. These findings can be used to envision future possibilities for citizen participation and to understand better the complexities, obstacles, and opportunities for enhancing participation through practical experiences.

Complex linear infrastructure projects have a unique characteristic that the construction site moves as the project progresses, necessitating that off-site manufacturing should be mobile. A mobile prefabrication factory is a promising distributed production facility that meets such requirements and offers benefits such as carbon emissions reduction by shortening the distance between the construction site and the off-site prefabrication facility. However, factory relocations introduce significant variability in the distances for transporting materials to the factory and delivering the completed prefabricated elements from the factory to the construction site. This paper presents an integer linear programming model to identify a feasible relocation strategy that reduces the overall transportation carbon emissions. A case study of hyperloop construction, an ultra-high-speed vacuum ground transportation infrastructure, is conducted as a demonstration. The results show that using mobile prefabrication factories to supply linear infrastructure projects can significantly reduce the overall transportation carbon emissions by around 50% compared to the fixed factory scenario. The primary factor to optimize this problem is the total transportation distance of the prefabricated elements. Relocating the mobile factory four to six times aligns with achieving efficient performance in terms of reducing carbon emissions. This analysis offers insights into developing feasible factory relocation strategies for decision-makers in complex linear infrastructure projects.

Kenya is overly affected by the consequences of climate change and struggling to find ways to balance mitigation with the urgent need to meet the country’s infrastructure and housing needs. Traditional concreting methods, such as onsite mixing and manual compaction, are slow, material, water, and labor-intensive. The precast industry therefore offers a competitive alternative in terms of cost and environmental impact. When ordinary Portland cement is used, it is responsible for 80–90% of the carbon footprint of concrete. Hence, there is urgent need to minimize carbon emissions by using supplementary cementitious materials (SCMs) in concrete construction. Since cement factories are mostly located around the city of Nairobi, in other regions, the price of cement increases with transport distance. Precast concrete construction could become a lever for both lower prices and carbon emissions. Clinker reduction can take place at the cement plant or concrete mixing plant. Blending in the cement factory can produce more robust binder qualities but is limited to large SCM supply streams. Blending at the precast plant allows for tailored, smaller, local supply streams from industrial and agricultural by-products. The paper discusses the potential of using artificial intelligence to merge multiple small heterogeneous feed streams from renewable and recyclable resources into large homogeneous feed streams, with a particular focus on the use in precast concrete processing.

In many parts of northeast India, in order to achieve a sustainable infrastructure based on minimal distance and gradient criteria, railway tracks often have to pass through a marshy deposit with significantly poor bearing capacity. Consequently, the laid tracks undergo significant long-term settlements due to creep-induced dissipation of excess pore pressure from the underlying low-permeable soft cohesive deposits, thereby necessitating ground improvement. Among several techniques, a sustainable one has to be decided to ensure long-term unhindered functionality of the adopted methodology. In lieu to this understanding, a case study of the Udaipur railway embankment in Tripura, India, is presented. The embankment, raised over a thick bed of soft soil, suffered extraordinary settlement. Consequently, prefabricated vertical drains (PVDs) were used as a method of ground improvement. In this regard, a plane strain finite element (FE) analysis is carried out for predicting the consolidation settlement due to the staged loading of the embankment and the evolution of excess pore pressure dissipation from the layered substratum improved with PVDs. Mohr–Coulomb (MC) constitutive model is used for representing the embankment and cohesionless layers, while the soft cohesive soils are represented using Soft Soil model. The PVDs are simulated as ideal drains by employing 1D “drain” elements. In contrary to the conventional approach of considering layered horizontal substratum, the importance of considering the realistic undulated substratum is highlighted. It is exhibited that design based on the conventional approach might be insufficient in draining out the pore water in case a basin is formed in an undulating low-permeable layer beneath the designed length of the PVD, thereby elucidating the sustainability in the considered approach.

To address energy transition through a net-zero built environment, significant citizen activation and participation is crucial. The chapter aims to identify the challenges, outline best practices in citizen co-creation based on the results of selected EU H2020 projects, and provide future research directions. Best practices are analysed in three phases. (1) Recruitment Phase: The first phase of engagement encompasses all the moments in which potential users are exposed to information that is relevant to participating in a specific project or programme until the moment in which they sign up. Core success factors for the set-up of a promising recruitment phase will be outlined. (2) Consumer Response Phase: In the second consumer response phase, strategies are directed at initiating and consolidating responses to innovative net-zero projects. This phase starts with the user’s own acts of planning and reflecting on how best to integrate existing into changing and rearranging urban and domestic living perceptions. (3) Persistence Phase: In the third phase (i.e., persistence), engagement strategies seek to maintain interest and continuous involvement in programmes. By prolonging interest and interaction over time, the goal of this phase is to ensure that participation remains sufficiently interesting and comfortable for users, transferring them to ambassadors and multipliers for innovative solutions. The chapter provides a co-creation framework with project insight-based best practice recommendations and proposes a clustering of stakeholders according to a quintuple helix approach and a stepwise phase approach towards the set-up of net-zero built environment projects.

The offshore wind (OW) energy plays a crucial role in the transition to a clean energy future aligned with the European Union’s Green Deal and Net Zero 2050 strategy and Norway’s commitment and contribution to achieving the climate goals. According to the International Energy Agency (IEA), the building- and construction sector represented 39% of energy and process-related CO2 emissions in 2018—of which 11% was related to steel and concrete. This work aims to assess the environmental impact of floating offshore wind turbine (FOWT) structures, comparing steel and concrete hulls through life cycle assessment (LCA). While OW offers a low-carbon alternative to fossil fuels, the manufacturing and transportation of FOWT structures contribute to greenhouse gas (GHG) emissions. We address the knowledge gap in LCA studies for FOWT structures by comparing two scenario objectives, (1) Steel hull, produced in China and shipped to Norway and and (2) Concrete hull, produced and installed near the Norwegian deployment site. We performed a literature review, and LCA study, to find CO2-equivalent emissions per ton, by breaking down the calculations in 30 FOWT units in steel versus concrete, by using material data to perform an assessment resulting in the Global Warming Potential (GWP) stated in tons of CO2e/T. The study reveals the importance of material selection and local production in reducing the environmental impact of FOWT structures, and concrete hulls exhibit significantly lower carbon footprint compared to steel hulls, with calculated emissions of 0.404 tons CO2-equivalent (CO2e) per ton of concrete and 2.76 tons CO2e per ton of steel. The study encourages further research in this area, highlighting the need for transparent data on the embodied carbon of materials and the potential benefits of incorporating recycled materials. By choosing FOWT structures with lower carbon footprints, decision-makers in the OW industry can contribute significantly to achieving the UN SDGs.

This chapter aims to address life cycle management and the levelized cost of energy (LCOE) of floating offshore wind farms from a probabilistic point of view. Understanding and addressing the uncertainty associated with the main parameters that influence the generated energy is essential for studying the life cycle and economic evaluation of offshore wind farms. The estimated global warming potential (GWP) of the wind farm under consideration is 36.5 kg CO2/MWh, which is found to be reasonably competitive compared to other sources of energy. The probabilistic analysis conducted showed that the distribution of LCOE is more influenced by operational expenditure (OPEX) values than by capital expenditure (CAPEX) and decommissioning expenditure (DECEX). This chapter provides general guidance on conducting early-stage probabilistic life cycle economic analysis of floating offshore wind farms.

The industrial revolution has exacerbated climate change on Earth, mostly due to variables such as rising ambient temperatures, increased levels of greenhouse gases in the atmosphere, and the presence of environmental contaminants. To address this issue, it is imperative to promptly embrace sustainable alternatives. Plasterboard technology presents a viable option for promoting sustainable development, given that about 70% of India’s future building stock remains unconstructed by 2030. Plasterboard technology has had a substantial surge in popularity in Western countries in the last several decades. However, in India, the use of this energy-efficient material remains limited owing to a lack of understanding. This research used the eQUEST simulation tool to analyze the energy usage of a hospitality complex across four distinct climate zones in India. Plasterboards not only save energy consumption but also facilitate the efficient execution of the energy conservation building codes (ECBC). The conventional construction material, namely, burned clay brick with a combined thickness of 280 mm (25 mm (plaster) + 230 mm (FCB) + 25 mm (plaster)), has a thermal transmittance of 2.11 W/m2·K, which is somewhat higher than the specified value in the codes. The thermal transmittance of AAC blocks with the same thickness and layer composition is 0.67 W/m2·K. In contrast, the thermal transmittance of plasterboards with a total thickness of 157 mm is 0.37 W/m2·K, which is below the required value of 0.40 W/m2·K specified in the regulations.

Creating climate-neutral, inclusive urban areas demands long-term multi-stakeholder engagement. Concepts such as Positive Energy Districts (PEDs) and Zero Emission Neighbourhoods (ZENs) aim for climate neutrality by producing energy surpluses and fostering attractive living spaces. While there’s significant research on emission reduction in buildings, neighbourhood-scale studies are scarce.This chapter is a case study of the programming of the sustainable transition process of a former harbour area (Nyhavna) in Trondheim, Norway. Approaches applied during the early planning phase are explored, assessing the suitability of these from the perspective of different stakeholders. How does the chosen pathway for the planning process of Nyhavna impact the harbour area’s transformation into an attractive, zero emission neighbourhood? What challenges arise, and which strategies are essential for maintaining high ambitions over time?Six qualitative expert interviews with seven informants of different stakeholder groups were conducted, public text documents were analysed, and participative observation in meetings was carried out.The study highlights several challenges experienced by the informants: Continuous stakeholder involvement is challenging and must be planned for; various planning document and the ownership structure of a neighbourhood can impose barriers to ambitious goals, the hierarchy of goals must be clearly defined, and the roles of stakeholders and their interplay should be clarified. This chapter contributes to understanding factors influencing climate-neutral neighbourhood development and offers practical recommendations based on the Nyhavna case study.

Innovative ways of implementing renewable and distributed energy systems in the urban environment are necessary to reach climate goals. The realization of Positive Energy Districts (PEDs) builds upon the willing participation of multiple stakeholders from both the private and public sectors. Stakeholders contribute to PED initiatives with resources, competencies, and time and can take on various and changing roles; however, they usually have different powers, goals, and interests. Thus, the efforts of actors belonging to different organizations need to be coordinated to reach tangible results within a given timeframe. This article argues that the co-creation processes across multiple stakeholders in PED projects require better knowledge of leadership roles and functions in PED projects. We seek to identify the extent to which leadership in PED projects has been addressed in the existing literature on PEDs via searches with Google Scholar and Scopus. It is found that, although collective governance is regarded as a major challenge, there is a lack of research on how the processes and people in PED development projects are coordinated, including how information is exchanged, responsibilities are distributed, and decisions are taken. To further our knowledge of leadership roles in PED projects, we suggest drawing lessons from strategic management literature and theories and a preliminary framework for studying leadership roles and co-creation processes in PEDs is proposed for future research.

This study investigates the perspectives of engineers on sustainability. The intention is to get an insight on the position of sustainability in the construction industry in Norway. The method involved interviewing ten engineers within different fields of engineering and with varying levels of experience. The questions were regarding their understanding of sustainability, attitudes toward sustainable projects, and their views on sustainability in the construction industry. A diverse individual perspective, with a predominant focus on environmental aspects, was observed. Economic factors and government incentives played an important role in the individual’s sustainable choices. The participants emphasized reducing carbon footprint, energy-efficient buildings, and reuse of materials as important for a sustainable development. In order to achieve a more sustainable development, this report suggests stricter regulations and government incentives, in addition to clearer definitions and collaborative responsibility distributions.

European countries are facing healthcare challenges demanding significant improvements in the efficiency and effectiveness of healthcare delivery. Consequently, primary care is being strengthened by developing new facilities. As the design of healthcare facilities inevitably entails a delicate balance between various needs and requirements (functional, spatial, environmental, etc.), alongside economic constraints, it is important to determine which elements should be prioritised in the design of new primary care facilities. For this reason, building performance evaluation (BPE) has become a critical aspect of the design, construction and operation of buildings. BPE tools may provide a rational basis to guide designers and local public authorities in decision-making and in prioritising design objectives to optimise primary care facility design as well as to verify design quality in post-occupancy phases. The aim of this chapter is to analyse validated evaluation tools for healthcare-built environments to provide a comprehensive understanding of their main characteristics (target audience, aspects investigated, application phases, data collection methods, expected outcomes and impacts), thereby developing a guideline framework to streamline the adaptation or development of tools specifically tailored to primary care facilities.

A relevant approach to limit virgin materials consumption and waste in the construction industry is to use reclaimed construction products. Their sustainability performance depends on various parameters, including the activities needed to reuse them. Currently, the life cycle sustainability assessment (LCSA) of reclaimed products is conducted following various methods and assumptions, which are not always transparently communicated. There is also limited consideration of other sustainability indicators beyond initial cost and greenhouse gas (GHG) emissions. Therefore, we developed a harmonized Excel-based LCSA framework for evaluating and comparing side-by-side the life cycle environmental (LCA), economic (LCC), and social (S-LCA) impacts of reclaimed and new construction products. This chapter presents the LCSA framework and how it can be applied in practice, with the comparative evaluation of a pavement in Oslo, Norway, with new and reclaimed paving stones. The LCSA framework shows it is possible to harmonize the various assessment methods and expand the scope of product assessment from purely GHG emissions to overall sustainability. The results of the pavement assessment show that reuse can bring lower environmental and social impacts, although it currently costs more to the user. The LCSA framework can be tested by experts in one or more life cycle approaches to guide different actors in the reuse value chain (e.g., product resellers and architects).

Society has historically valued labor and resources, including the intermediate and end products produced through them. Discarding these artifacts was seen as squandering valuable effort and resources, and waste was historically an activity to be avoided. This tradition was rapidly lost in many western countries, replaced by a more rapid linear approach whereby materials quickly went from cradle to grave in a linear system or economy. There has been a recent revival of the idea of moving back from this modern linear model, however, with increasing pressures from environmental degradation, climate change, material scarcity, and population growth. The recent resurgence in interest in circularity in Norway is assessed with an eye toward potential pitfalls, based on the past 75 years of modern building methods. How can society expect to move away from the linear approach if the buildings themselves were created within that paradigm?

The United Nations published a report in May 2023 that highlighted circularity concepts in wood construction. They noted a problem of resistance to deconstruction with the intention of reusing wood elements. That resistance is partly due to the perception of the value, or rather lack of value, within the deconstruction process. However, if deconstruction can disassemble a building and recover the wood elements, it has created a valuable commodity. Value engineering principles can be used to analyze a process or service to maximize value. Value engineering has been applied in the construction industry but not to evaluate the deconstruction process. In this study, the value engineering functional analysis is applied to the process of disassembling a building and the recovery of wood and timber for reuse in the construction industry. The Function Analysis System Technique (FAST), a core element of value engineering, is used to identify primary and secondary functions. These functions are mapped onto the typical process used in building disassembly and recovery of wood and timber elements. The result is a process map that shows the contribution of the value-added steps in the process and identifies the non-value-added steps in the process. These results can be used to improve the design of disassembly and recovery processes to ensure the focus of the deconstruction process is on the value-added effort and that resources allocated to non-value-added efforts are minimized.

As a major source and contributor of carbon emissions globally, the construction industry faces challenges in achieving its carbon emission reduction targets. Carbon trading has been established to be a reasonable aid in greenhouse gas mitigation. Current carbon trading systems were originally not developed for the construction industry, and carbon trading system for the construction industry is lacking. The aim of this study is to present the highest level framework of a carbon trading system for the construction industry using systems theory. Systematic literature review methodology was adopted to obtain documents from Scopus which were then synthesized. From the systems theory lens, the carbon trading system for the construction industry is developed comprising input, transformed through process leading to output. Feedback between the output and input is comprised in the system. This study is significant and contributes to the built environment’s climate change mitigation agenda.

The Norwegian innovation and action project SirkTRE is halfway through. In recent years, it has been increasingly recognized that circular wood solutions for construction solutions are often technically feasible; this is particularly underscored by the SirkTRE project (2022–2025). However, the scaling up of these solutions and their interaction with various barriers underscore the necessity of systemic approaches. This chapter delves into selected circular systemic solutions derived from the project. This collaborative autoethnography, drawing insights from observations and reflections on own experiences, takes an evolutionary approach to selected SirkTRE solutions. The case studies within SirkTRE include solutions at the manufacturing level, the architectural product-system level, and the building-site level and strategies engaging municipalities to supply and utilize reclaimed timber in (especially public) buildings. These examples illustrate not only the successes but also the challenges, including how economic, political, technological, and strategic decisions can impact the scaling up/out or ending. To catalyze a true revolution, or ‘circulution’, it is imperative to integrate governance, and business models, to foster interactions in the emerging system.

In the realm of Industry 4.0, the construction sector has witnessed accelerated strides toward circular economy goals. However, a notable deficiency persists in integrated technologies spanning the entire project lifecycle—covering design, construction, renovation, and demolition phases. This inadequacy is particularly pronounced in the seamless tracing and tracking of materials, products, and waste, obstructing effective material flow analysis. This chapter adopts Design Science Research (DSR) as a methodological guide for systematically developing a Digital Information Management System (DIMS) tailored for construction and demolition waste management. This chapter focuses on a detailed exploration of the iterative steps inherent in the DSR process, specifically as applied to DIMS development with the Horizon Europe Project RECONMATIC. Starting with problem awareness and proposal, the chapter identifies existing gaps and challenges in current technologies, proposing a structured approach to address them. Moving to finding proposed solutions and tentative design, potential resolutions to the identified challenges are explored, leading to the formulation of a preliminary DIMS design. Subsequent steps involve building and testing artefacts, creating tangible prototypes, and conducting rigorous testing to validate their functionality. The evaluation and iteration phase follows, subjecting the artefacts to systematic scrutiny against predefined criteria and real-world scenarios. This iterative process refines the DIMS design and functionalities based on evaluation outcomes. Finally, the chapter underscores the importance of communicating results, presenting findings and insights, and developing DIMS for the academic and industry communities. By navigating these steps within the DSR framework, this chapter contributes a systematic, iterative, and methodologically rigorous approach to DIMS development. It strives to create a practical, effective, and sustainable solution aligning with the evolving landscape of Industry 4.0 in the construction industry.

The building construction industry is an old industry with entrenched behaviors and interaction patterns. The European Union (EU) published a study analyzing these behaviors and measuring the application of circular economy to the construction industry in June 2023. This study included a diagram describing the construction industry as a system, but it did not include all elements or fully analyze the system. The discipline of systems thinking is a dynamic analysis that integrates societal forces with industry dynamics to provide a comprehensive description of behaviors within an industry. This study builds on the EU report and creates a causal loop diagram for the construction industry that includes societal and industrial environmental elements. This diagram is analyzed to identify the reinforcing and balancing loops that explain dynamic system behavior and sources of resistance to change. In addition, potentially dysfunctional elements of the system are identified. The study also assesses the recommended changes from the EU report to determine their likely impact on system performance and identifies additional leverage points that should be considered.

Circular construction is a branch of circular economy (CE) that seeks to reduce the environmental impacts in the built environment through intelligent, sustainable, and circular practices. Examples such as design for reuse, use of recycled materials, and regenerative infrastructure are nascent concepts within the construction industry, as most focus is directed towards buildings with less focus given to other forms of infrastructure, especially roads. A pilot project, known as GoGreen, has been developed for a Norwegian highway project, where materials from demolition are recovered and sorted on the construction site and sent for recycling. While construction projects typically recover less than 40% of waste, GoGreen uses careful planning and implementation to recover nearly 100% of waste materials for recycling. In this chapter, we investigate the circular concepts implemented in the Betna-Hesnes highway project to understand if the choices made lead to lower emissions and to help understand the scale and relevance of these actions as part of larger infrastructure projects. Through the use of life cycle assessment (LCA), we have analysed the processes for collecting, sorting, and recycling materials on the Betna-Hesnes project to understand the overall environmental footprint and attempt to quantify the impact of circular activities. The overall environmental benefit from the GoGreen tent was approximately 89 tons of CO2-equivalents saved. The results of this study will be useful for policymakers and actors within the construction industry to give greater insight into what actions can lead to the best environmental outcome and to push the road construction industry towards greater circularity.