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2024 | Book

Technologies for Sustainable Buildings and Infrastructure

Select Proceedings of SIIOC 2023

Editors: B. R. Jayalekshmi, K. S. Nanjunda Rao, G. S. Pavan

Publisher: Springer Nature Singapore

Book Series : Lecture Notes in Civil Engineering

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About this book

This book presents select proceedings of the International Conference on Sustainable Infrastructure: Innovations, Challenges and Opportunities 2023 (SIIOC 2023). The topics covered include behavior of masonry and RC buildings under earthquakes, performance of concrete, bricks and blocks manufactured with non-organic industrial wastes, bamboo for construction, composites for construction, and finite element simulations on buildings and special structures. The book presents various facets of experiments to characterize the properties of construction materials and intricacies involved in performing finite element simulations to assess the behavior of buildings under seismic and wind loading conditions. The book serves as a resource material for budding researchers and industry professionals interested in developing solutions for sustainable building habitats.

Table of Contents

Frontmatter
Effect of Infills with Realistic Openings on the Seismic Performance of Gravity Load-Designed RC Buildings

Unreinforced Masonry Infills (URM) are essential part of Reinforced Concrete (RC) buildings, serve as external claddings and internal partition walls. These infills are often ignored in structural analysis, considered as non-structural elements as they don’t take part in sustaining gravity loads acting on the building. However, infills do take part under lateral loading due to earthquake, and imparts significant lateral strength and stiffness to the building even with realistic openings for doors and windows, thereby ignoring infills in structural assessment lead to inaccurate conclusions. Gravity Load Designed (GLD) buildings are still existing in India, even in high seismic zones, and need realistic performance assessment in order to mitigate their collapse, and formulating strengthening measures for these buildings. In the present study, effect of infills on the seismic response of gravity Load Designed mid-rise (4-story) buildings have been examined through nonlinear static analysis. It is observed that ignoring infills in the structural analysis predicts ductile behavior of GLD building, which contradicts after simulation of infills considering realistic openings due to doors and windows. The shear force demand in columns that gets enhanced due to lateral action of infill strut exceeds shear capacity of non-seismically designed RC columns resulting brittle failure of columns. GLD buildings may undergo collapse in higher seismic zones but can sustain in lower seismic zones depicting reasonable seismic performance.

P. L. Kurmi, Neeraj Kumar, Deepa Telang
Positioning and Quantification of Cracks by Sensors Using Algorithms

A crack or other type of damage causes a sharp discontinuity in the rotational displacement curve of a load-bearing structure. However, if the beam is not sufficiently loaded or the crack depth is very small, the discontinuity may be impossible to detect using conventional methods. To understand cracks in concrete, important parameters such as characteristic length, fracture energy, and critical crack width are used. In this project, the crack width is estimated as either crack mouth opening displacement (CMOD/COD) or crack tip opening displacement (CTOD). This project involves early detection of cracks by sensors and quantification of the cracks with help of algorithms. For the testing, three basic structural members, i.e., concrete cubes, beams, and T-beam are used. Internal cracks are detected by ultrasonic sensors with the help of IoT. A GPS module will be used for finding the position of the cracks and GSM module going to send the SMS to the phone whenever the cracks are formed. To quantify the cracks and show the position of the cracks, algorithms are used. Therefore, to monitor the damages at the early stage thereby avoiding the degradation of the structure, we are proposing a regular monitoring system.

S. L. Arpitha Gowda, H. Ananya, B. Pradeep Kumar, D. L. Chethan, P. Advith Gowda, K. Mahantesh, K. S. Sugam
Structural Damage Detection in Double-Tapered Steel Beam Using Modal Strain Energy Method

Structural failures can be prevented by appropriate retrofitting techniques provided if the damage was detected at the early stage. Toward this end, this paper presents a damage detection procedure for double-tapered beams using modal strain energy (MSE) method. The beam is modeled using 2D plane stress element in OPENSEES software. Enhanced quad elements are used for discretizing the tapered beam. The damage is induced in the selected elements by reducing the modulus of elasticity in the beam. The first twenty-five mode shapes are extracted for both undamaged and damaged beams. The extracted natural frequencies of the undamaged double-tapered cantilever beam are compared with the classical approach reported in Mabie and Rogers (1972). The obtained natural frequencies are in agreement with the results reported in the literature. The extracted mode shapes of undamaged and damaged beams were utilized in the MSE method to detect and quantify the single and multiple damaged scenarios. MATLAB code is prepared to estimate the damage index using MSE method. The results indicate that, MSE method is efficient in detecting the damaged elements in beam.

Siddesha Hanumanthappa, A. S. Sinchana, Pavan Kumar Emani
Rheological and Mechanical Properties of Self-Compacting Concrete with Partial Replacement of Marble Slurry and Fly Ash

Continuous increase in the marble waste production and high carbon emission of the cement affects the environment. The use of marble waste in concrete as replacement of fine aggregate and the substitution of cement with supplementary cementitious material (i.e., fly ash) reduces the carbon emission and cost of concrete and promotes sustainable growth. The paper investigates the effect of partial replacement of marble slurry with natural fine aggregates and fly ash as supplementary cementitious material (SCM) on the rheological and mechanical properties of self-compacting concrete. The workability of self-compacting concrete was measured through slump flow, V-funnel, and L-box. The hardened property includes compressive strength under the curing of 7 and 28 days with a target strength of 25 MPa. A set of concrete mixes was considered for finding the optimum mixes through the basic fresh properties. Rheological parameters like yield stress and plastic viscosity were evaluated for the critical mixes. The mixes that validate the linear and nonlinear relations of flow were evaluated by studying the Bingham and modified Bingham model. Polycarboxylate Ether (PCE)-based superplasticizer (SP) was added to disperse the agglomerated cement and marble slurry (MS) particles to reduce the higher demand of water to binder (w/b) ratio. The PCE based SP contains inbuilt viscosity modifying agent (VMA) to control the static segregation of mixes. The influence of thixotropy under static and dynamic conditions describes the nature of interparticle bonding. The paper validates the critical flow path that a concrete mix follows through parametric evaluation at an optimum w/b ratio so that the mixes behave like pumpable concrete, along with reduced formwork pressure at the site.

Piyush Verma, Rajesh Kumar, Snigdhajit Mukherjee, Mahesh Sharma
Thermo-Mechanical Behaviour of Lightweight Precast Sandwich Panels Incorporating Solid Waste—An Experimental Investigation

Precast concrete sandwich panels (PCSPs) are lightweight, prefabricated composites consisting of two basalt fibre-reinforced concrete wythes and expanded polystyrene (EPS). EPS as a thermal insulation layer is used to improve the energy efficiency in buildings. The combination along with basalt fibre connectors was used in the preparation of PCSPs to realize the composite action and also enhance thermal resistance. The prime aim of the study was to develop load bearing PCSPs by utilizing stone waste and thereby investigation of its structural and thermal performance. Various properties of the raw materials such as chemical composition and particle size distribution were investigated. The samples were put through a number of tests including the thermal resistivity test and the three-point bending test. The panels' load vs. mid-span deflection relationships, crack patterns and failure mechanisms were determined. The findings indicated that the panel specimens had adequate flexural strength and thermal resistivity.

Shubham Semwal, Abhilasha Prajapati, Rajesh Kumar, Sachin Kumar, Shahnavaz Khan, R. Siva Chidambaram, Gunjan Joshi, Rajni Lakhani
Ground Granulated Blast Furnace Slag as a Potential Binder in the Geopolymeric Concrete—A Review

This review article represents the activities of the potential behaviour of ground granulated blast furnace slag (GGBFS) as a different backfilling material in the concrete. The current study considers the effects of sodium hydroxide (NaOH) concentration and percentage of GGBFS. The outcomes stipulate that the products and strengths generated from the reaction depend on the NaOH concentration and different types of basic materials. The property of fresh concrete, i.e. the slump values increase as the increment in GGBFS. The compressive strength increases due to the addition of GGBFS with a required proportion. The microstructural (SEM) analysis shows a denser structure due to the increase in GGBFS and NaOH concentration. This current review paper suggests the potential use of GGBFS in GPC, considering the enhancement of strength and microstructural characteristics.

Siba Sankar Chanda, Shyamal Guchhait
Effect of Reinforced Concrete Beams with Circular Opening in Flexural and Shear Zone

Reinforced concrete beams often incorporate transverse openings to accommodate various utility services such as air-conditioning pipes, fire safety lines, internet cables, and electrical wires. However, the introduction of these openings results in a notable reduction in the stiffness and ultimate load capacity of the beams, primarily due to heightened stress concentrations near the openings. This research focuses on RC concrete beams with circular openings of varying diameters at flexure and shear locations. Utilizing ANSYS software, the study employs multilinear isotropic concrete material models and bilinear inelastic steel material models to analyze the nonlinear behavior through the finite element method. The investigation specifically explores the effects of different opening diameters and their locations within the beams. Circular openings with varying diameters are assessed at both the middle and quarter span section of the beam. The impact of different openings is examined through load–deflection plots, crack patterns, and stress distribution evaluations. Additionally, a finite element convergence study is conducted to determine an optimal mesh density, while time stepping is employed to estimate the ultimate load. The research aims to assess the ultimate load capacity and failure modes resulting from different opening diameters, considering both flexure and shear locations. Notably, the study reveals that increasing the diameter of the beam opening to half of the overall beam depth significantly diminishes the ultimate load capacity compared to an equivalent solid beam, particularly in the quarter-section opening. The findings contribute valuable insights for the development of design rules for reinforced concrete members with openings. A comprehensive three-dimensional nonlinear finite element analysis using ANSYS simulations further enhances the understanding of the structural behavior in real-world scenarios.

Chirag KaPatel, Ruthvik Sheth
Numerical Investigation on Fire Resistance of Restrained Q690 High-Strength Steel Beams

High-strength steels (HSS) possess wide applications in framed structures because of its superior performance. Current design codes including EN 1993-1-2, CECS200 and ASCE consider the reduced material property of HSS by providing reduction factors for yield strength and elastic modulus with respect to mild steel at elevated temperature. Hence it is imperative to study the mechanical properties of HSS at elevated temperatures. Axial and rotational restraints cause steel beams that are restrained to behave differently than beams that are unrestrained. The fire resistance of constrained beams at high temperatures was found to be improved by catenary action. This paper provides a numerical analysis of the fire behaviour of restrained Q690 beams. A parametric study was conducted using ANSYS® software. The parameters considered were web aspect ratio, perforations, axial restraint stiffness ratio and load ratio. The effect of perforations was studied considering size of opening and spacing of opening. An increase in axial restraint stiffness from 0.3 to 1 increased the axial force developed in the beam by 121%. The deflection of beams was found significantly high for higher load ratios and hence the beams entered early runaway deflection. Influence of parameters on yield temperature, axial force and catenary action were studied and are presented in this paper.

S. Nehna, B. Rajeevan
Effect of Pier and Deck Flexibility on the Behavior of Isolated Integral Bridge Under Far and Near-Fault Earthquake

The effect of the flexibility of the bridge on the seismic response of the base isolation of the integral bridge is studied. For the study, flexibility of deck and pier were considered separately. The pier height and length of the middle span were varied to consider flexibility of pier and deck, respectively. For the seismic analysis, suit of both far and near-fault earthquakes was used. Nonlinear dynamic analysis was conducted using one-component and two-component time histories of both far-fault and near-fault earthquakes. For the earthquake loading on the bridges, the direction of major component of the time history was aligned along the length of the bridge. Various response parameters were considered which include the bending moment (BM) in the longitudinal girder about major axis, BM of in the pier about major and minor axis, and displacement of the deck in longitudinal direction. As the study is intended to investigate the effect of flexibility on the isolation of the integral bridge, the responses of isolated bridges were normalized with the corresponding fixed base bridges. From the results, it was noted that pier flexibility affects greatly the isolation effect.

Kedar Kumbhojkar
Topology Optimization of Concrete Beam Using Higher Order Finite Elements

Topology optimizations are based on the principle of eliminating solid material to ensure the efficiency of the design with an adequate amount of material. The optimized topology of a structure, the solution should have a clear distinction between solid and void that can be manufactured. The example problem taken in the present study for comparison is modeled with three different finite elements and optimized using three element updating algorithm. The Optimality Criteria (OC) method, Bidirectional evolutionary structural optimization (BESO) method, and Method of moving asymptotes (MMA) algorithm are used to update elements. Minimum compliance topology optimization with a prescribed volume fraction has been adopted for this study. The purpose of using higher-order elements is to check whether it change the optimum layout of the structure. Shape functions of higher-order elements can be derived by extra nodes on the sides of the linear element. BESO algorithm with 4-noded elements shows the fastest convergence with the least time. MMA algorithm with 9-noded elements takes the maximum computation time. Higher-order elements take a greater number of iterations to converge. The convergence history of different finite elements using the BESO algorithm has been checked. The optimum layout of structure in OC and MMA is almost similar in all order finite elements. Optimum topology using BESO method is similar for 8 and 9-noded elements. The fastest converged BESO algorithm shows a slight difference in optimum topology for higher-order elements. Solutions to optimization problems are simulated with a filter and without applying the filter. Higher-order elements extract the layout with less checkerboard pattern without a filter.

V. R. Resmy, C. Rajasekaran
Comparative Study of Pile Supported Wharf Structure Including Soil Structure Interaction Effects Using Nonlinear Static Pushover Analysis

Ports and harbors are considered as lifeline structures because of the significant role they play in transporting people and cargos cost effectively. A large number of important ports are located in active seismic regions worldwide. Currently in India, no guideline is available for seismic design of Port structures and hence performance analysis of such structures becomes essential. A typical pile supported wharf at Mundra Port, Gujarat (Latitude: 22º43′88″ N, Longitude: 69º42′34″ E) is selected for the study (Shah and Shah in J Struct Eng 43:235–246, 2016). In this study, analysis and design of existing pile supported wharf structure for different loads and load combination using depth of pile fixity and with considering linear spring as per IS code. Capacity curves are derived for an existing pile supported wharf with considering depth of pile fixity as per IS code guideline and using nonlinear soil spring model using p–y, t–z, and q–z curve. The wharf is modeled using nonlinear platform along with soil structure interaction. Pushover analysis is performed to obtain its capacity curve with nonlinear plastic hinge formation. Based on the peak responses of the piles, PIANC has recommended qualitative criteria to judge the degree of damage to a pile supported wharf. But quantitatively, PIANC does not specify the bound for each damage state. Hence upper bounds of the damage states I, II, and III are based on the sequence of plasticity development in the pushover process (Shah and Shah, Int J Res Eng Technol 7(6):16–27, 2018). It is observed that without considering soil structure interaction, results are overestimate based on design and capacity curve.

Jayesh Prajapati, Rutvik Sheth, Bharat Shah
Analytical Study of Low-Speed Open Circuit Wind Tunnel Using Ansys Fluent

Wind is an omnipresent natural element with which the structures must be in harmony during normal winds and also gusts. Civil engineering structures are stationary with respect to the ground. However, they are moving bodies with respect to the air. Thus, it becomes imperative for civil engineers to obtain wind pressure acting on a structure at various points of interest which has to be incorporated in the structural design. For simple geometry, one could infer the values offered in the respective national standards. However, for complex geometry one must resort to obtaining the values using open/closed circuit low speed wind tunnels. This study presents the dimensioning principles involved in an open circuit low speed wind tunnel and the bluff body to be introduced, various possible configurations of an open circuit low speed wind tunnel based on parametric study and an analysis performed using Ansys®—Fluent for a bluff body introduced in the wind tunnel. Ansys®—Fluent allows the user to realize the potential of obtaining results on a scale model even before physical model testing, thus, saving time and cost involved in physical testing of models. Obtaining precise results and using them in design will economize the structure and render sustainability. Static and dynamic pressure acting on the bluff body and the velocity of wind at various points of interest along the length of the wind tunnel are the findings of this analytical study.

V. A. Rohin Ashvij, N. C. Balaji
The Failure Behaviour of Concrete Cubes in Compression

Concrete is a mixture of cement, fine aggregate, coarse aggregate, water and sometimes they use admixtures. After the concrete cube is cast and cured, the compression strength of the concrete is tested for 7, 14, and 28 days. The failure behaviour of concrete cubes depends on the type of material used, such as cement, aggregates, and so on. This study explains the concrete cube failure behaviour and what the reasons are for it. The failure behaviour differs for different cube sizes and shapes, and the failure of a concrete cube indicates whether the obtained failure is satisfactory or not. The actual failure of the concrete cube is an hourglass failure; failures other than hourglass failure are due to eccentric loading, flaws in the testing apparatus, human errors, and so on. Concrete cubes can fail in a variety of ways, such as crushing, tensile cracks, edge failure, surface cracks, and so on. Moreover, failure may occur in the aggregates or interface of the concrete matrix. However, in this study, the failure behaviour observed differs for different cubes due to various factors influencing it.

H. Girish, N. C. Balaji
Dynamic Analysis of Pile Foundations Under Liquefiable Soil

A Pile foundation, a type of deep foundation, is a slender column or long cylinder composed of materials such as concrete or steel, holds the structure and transfers the load at a specified depth through end bearing or skin friction. The pile foundations fail when subjected to lateral forces coming from earthquake motions. The time-history analysis is done to a 10-storey moment frame resisting frame system with piled-raft foundation under liquefiable soil. The displacement and acceleration responses are drawn out from analytical study using FE software ETABS 18.0.2. An attempt is made in this study to analyze the behavior of pile foundations under liquefiable soil when subjected to different strong motions and for different methods of spring constants assigned to piles. The results extracted from the time-history analysis at critical location of piled raft. From the present study it is concluded that structures constructed under liquefiable soils are vulnerable to high magnitude earthquakes and pile foundations are necessary to maintain the overall stability of the structure.

Abhishek Pujar, B. O. Naveen, T. M. Swaroop
Comparison of Flexural Performance by FEM Evaluation of Reinforced Concrete Beam Strengthened by Natural-Synthetic Hybrid FRP

Synthetic fiber-reinforced polymers have been widely used in the construction industry for retrofitting purposes. However, due to their high carbon emissions in the manufacturing process, a need for investigating the efficacy of natural fiber-reinforced polymers in strengthening concrete structural elements is needed. In this paper, the ANSYS material designer module is utilized to evaluate composite material properties from the mechanical properties of fibers and matrix components. Using the obtained composite parameters from this module, an experimental test from the literature was simulated, and the results were validated. For a constant fiber volume fraction, similar composite models are evaluated using experimental data from tensile testing of natural fibers (sisal, hemp, kenaf) and synthetic fibers (carbon, glass). The numerical modeling of stack up is done in ABAQUS software with the intention to replace 50% synthetic fibers with natural fibers. A reference beam with no strengthening and 11 additional beams with a combination of natural and synthetic fibers are modeled and compared.

Tanvesh Dabholkar, M. Harikumar
A Deep Learning Approach for Structural Health Monitoring of Wind Turbine Using CNN Algorithm

Renewable wind energy is generated by constructing wind turbines, which aim to provide economical, reliable, and environmentally friendly energy sources. The blade of a wind turbine is really important. If it gets damaged, it can cause a big breakdown. This damage is a major reason for the turbine to fail. Hence, detecting and addressing any damage to the blade as early as possible is advantageous. This research aims to create a deep learning technique that relies on data analysis to detect and monitor any damage in wind turbine blades using vibrational analysis. This study involved the use of ANSYS 2022 R2 software to generate a NACA 63-412 profile, and its accuracy was confirmed by comparing it with finding from a previous study. According to numerical simulations, the proposed method can identify two types of damage in wind turbine blades: (i) crack in the blade and (ii) loosening of bolts in the turbine. Acceleration data was gathered from various locations on the structure, while it was subjected to impact loading, and this data was analyzed in the frequency domain using the Fast Fourier Transform (FFT) technique, both in its healthy and unhealthy conditions. After the acceleration time-histories data were collected, they were transformed into scalogram images. These images were then used for the Convolutional Neural Network algorithm to classify and identify any damage present. With the deep learning technique, it is possible to accurately differentiate between healthy and various types of damage conditions with high accuracy. This demonstrates its effectiveness as an automation tool for Wind Turbine Structural Health Monitoring (SHM).

Nisha Saharan, Pardeep Kumar, Joy Pal
Geopolymer Fly Ash Fine Aggregate as a Partial Replacement to M-Sand in Mortar

Environmental sustainability is a paramount concern worldwide, and addressing issues such as the depletion of river sand and the underutilization of fly ash has become imperative. India, in particular, disposes of a staggering 38 million tons of fly ash annually. This study focuses on harnessing the potential of fly ash through the development of Geopolymer Fly Ash Fine Aggregate (GFAFA) and its incorporation into mortar as a fine aggregate. Various characteristics of GFAFA including particle size distribution, specific gravity and surface morphology are analyzed to assess its suitability as a construction material. The particle size distribution analysis demonstrates that GFAFA falls within the prescribed limits suitable for mortar usage. Moreover, the specific gravity of GFAFA is 2.1, presenting a notable contrast to the specific gravity of M-sand (2.68). Field Emission Scanning Electron Microscopy (FESEM) image of GFAFA corroborates the presence of surface porosity and unreacted fly ash particles. The study investigates the effects of partial replacement of M-sand with GFAFA on mortar properties, such as unit weight and compressive strength. The results indicate that a 30% replacement of M-sand with GFAFA yields the highest compressive strength, suggesting this as the optimal substitution ratio in mortar mixtures.

K. P. Rusna, V. G. Kalpana
Geopolymer Concrete—Advancements, Challenges and Future Prospects

The major crisis facing today’s world is scarcity of resources and global warming. The most widely used infrastructure development material is cement concrete. The production of cement concrete is highly energy and resource intensive and it emits a lot of greenhouse gases to the atmosphere. Geopolymer concrete (GPC) can address the above issues effectively. In geopolymer concrete, alkali-activated aluminosilicate is used as binding material and the source material used is any industrial wastes which are rich in alumina and silica. In this paper, an attempt has been made to review the manufacture of ambient-cured GPC from various industrial waste. Properties such as mechanical, microstructural and durability were reviewed. A discussion about geopolymerisation process, mix design, different source materials, properties affecting performance of GPC, curing conditions and the effect of elevated temperature on GPC was also carried out. Recent developments like alternate binders and nanotechnology in the field of GPC were also considered. It is reported that ambient-cured GPC possess comparable mechanical properties compared to normal concrete. Alkaline to binder ratio, molarity of solution, curing conditions, workability, etc., play a major role in the development of mechanical properties. Overall, this state-of-the-art paper provides a comprehensive overview of geopolymer concrete, highlighting its advantages, challenges and future prospects.

R. Panchami, S. Deepa Raj
Vulnerability and Sensitivity Assessment of RC Structure with Uncertainity in Material Properties

The importance of uncertainties in material properties for building behavior needs to be brought into focus because the reliability and robustness of behavior predictions under uncertainty have not been well recognized. The assessment of seismic risk of structures is subjected to uncertainty, and therefore material properties need to be considered. The seismic susceptibility of structures (RC) varies considerably due to uncertainties in material strengths developed by construction procedures. To address this, performance-based analysis and designs are being intensively researched, evaluating the variability in material strengths and their specific effects on seismic susceptibility through fragility estimates and tornado diagram analysis. The results show that the variations in material thickness affect the structural response in a significant way. The parameters used to comprehend the structural response have shown that changes in material strength must be vigilantly well thought-out.

L. K. Ashwini, M. Keshavamurthy, C. M. Ravikumar
Mitigation Methods to Control Traffic-Induced Vibration on Mono-Column Structure

Due to the swift development of urbanisation through mega infrastructure projects and also due to the development of multipurpose vehicles, it is extremely important to support long-term subsidies in metropolitan cities. Many buildings have been built near railway bridges, subway and high-traffic roads. Transportation-based vehicle interaction with buildings will induce ground vibrations that affect the long-lasting properties of these structures. These induced vibrations are passed through the soil media. It includes a variety of trenches, such as trenches of different depths, open trenches and even a completely filled type of trench with different materials that can be used to dampen vibrations. Soil regions are modelled on multiple levels, and the load model is set through a series of successive moving loads. Then, a parametric model of the structure of a single column is performed. The performance of different parameters can be identified based on the distance of the trenches, the depth and the level of vibration attenuation.

K. S. Shiva Kumar, M. N. Shashank, B. K. Tarun Kumar, S. Karthik, H. J. Pallavi
An Intrinsic Smart Self-Sensing Paver Block Using Carbon Nano-Black

Urbanisation has a significant impact on road pavements due to various factors such as heavy vehicular loads, high traffic volume, climate change, temperature variation, and further more. These factors contribute to the distress of road surfaces, resulting in the need for frequent maintenance and services. This study focuses on the development of a smart self-sensing paver block with enhanced strength, durability, and the incorporation of self-sensing technology through the infusion of carbon nano-black into the existing paver block. The use of carbon black as a filler material enhances the mechanical properties and strengthens the bond between materials. Its high carbon content and graphitic nature also contribute to improved conductivity and structural health monitoring capabilities. This study utilises strength tests and four-probe method tests to analyse the material’s structural and sensing performance. The study analysis revealed that the incorporation of carbon nano-black in an appropriate ratio resulted in a significant increase in strength, approximately by 21%. The addition of 5% carbon black resulted in improved sensing performance when applied with loading. The analysis of the results indicates that the identified issues can be resolved through the use of a carbon-infused paver block. The proposed solution focuses on enhancing the wear and tear resistance of block against the heavy vehicular and to withstand sudden impact loads. The cost analysis demonstrates the effective fabrication of economically viable carbon-infused paver blocks with enhanced durability and sensing abilities. The cost is nearly comparable to that of conventional paver blocks.

Ramachandran Kousalya, V. Ponmalar
Seismic Response of Elevated Cylindrical Water Tank with Lead Rubber Bearing Isolation System

The frequency and severity of high-magnitude earthquakes are on the rise, resulting in significant human casualties and infrastructure damage worldwide. The land in India is also vulnerable to earthquakes to the extent of almost 60%. The primary purpose of elevated liquid storage tanks is to distribute drinking water, provide relief in the event of fires, and store water during catastrophic earthquakes. Under the influence of earthquakes, these structures need to be designed crack free. The utilization of seismic isolation is a proven and efficient approach for addressing various seismic design issues. By implementing a seismic base isolator, a structure can be shielded from ground movement, thereby reducing its susceptibility to earthquake damage. In this study, a nonlinear time history analysis was conducted using the structural analysis software SAP2000 to investigate the seismic response of water storage tanks both with and without base isolation. In the present study, base isolation is carried out by using a lead rubber bearing (LRB) isolator which is proportioned by adopting the existing design procedure developed for structures on plain ground. To evaluate the impact of ground motion fluctuations on the response of both fixed base and base-isolated structures, analysis has been conducted using three distinct past ground motions. Response parameters such as base shear, base moment, storey displacement, hoop stress, and bending moment on the tank wall are reported. Results indicate that the LRB isolation system can reduce various responses by 75–95%.

Gino Baby, Glory Joseph
Modelling and Analysis of Plates Under Simulated Damage Using FEM

Structures undergo damages over time due to various reasons. Early detection of the damages saves the structure from being operationally deficient and/or experiencing failure during its service life. The literature suggests that a damage acts as a source of acoustic emission (AE) whereby the emitted acoustic waves propagate through the structure. AE sensors placed at selected locations of the structure can capture the AE waves, which can be further processed to detect the damage. However, the first step towards such detection is to understand the behaviour of the structure/structural components under a known damage. Plate is a very common structural component having a simple geometry. Accordingly, the present work makes an effort to study the response of plates under a known damage through numerical modelling using finite element method (FEM). Responses are obtained at the plate centre, which corresponds to an AE sensor for different locations of the damage. The damage is simulated by using a suitable mathematical function. In order to compare the numerically obtained results with experimental outputs, which is obtained in terms of voltage, the sensor also needs to be modelled. Therefore, the present FE model integrates the plate along with the AE sensor mounted on it. The modelling is carried out using ABAQUS software, and the obtained results are further processed through MATLAB for the purpose of filtering. The final results from the present FE model are compared with the corresponding results from experimentation which is carried out in-house in laboratory. The performance of the FE model is found to be satisfactory.

Radhe Yassung, Parikshit Roy, Neetika Saha, Pijush Topdar
Localization of AE Source in Plates Using ANN Approach: An Experimental Investigation

Structures are prone to damage, and detecting them early is extremely important for taking corrective measures. It is understood from the literature that the location of damage acts as an acoustic emission (AE) source. Acoustic signals emitted from the source are captured by AE sensors and then analyzed to detect the source. Effective localization of AE source using conventional methods of signal analysis depends on detecting the actual arrival time of the AE waves at the sensors, use of appropriate material property, concept of relevant signal processing techniques, etc. In this context, artificial neural network (ANN) technique is very promising. While the effectiveness of ANN depends on data of good quality and quantity, use of an established ANN model is very simple. In light of the above, the present study makes an effort to develop an ANN model for prediction of AE source location in a plate. For developing the ANN model, adequate data are collected through extensive experimentation with aluminum plate in the laboratory setup, where pencil lead break (PLB) is used as an AE source and a single AE sensor is utilized. Relevant signal features are extracted from each signal and used as the inputs to the model whereas distance between the source and the sensor is taken as output. The trained model is then tested with another set of experimental data. The results of the AE source locations, predicted by the model, are found to be very encouraging when compared with the actual location of the source.

Bhanu Kiran Gudipati, Tamal Kundu, Neetika saha, Parikshit Roy, Pijush Topdar
Graphene Reinforcement in Cementitious Materials: A Comprehensive Review of Mechanical and Durability Properties

Graphene is a two-dimensional allotrope of carbon with unique properties like high strength, thermal and electrical conductivity, and a large surface area. Recently, researchers have been investigating the use of graphene in cementitious materials to improve their mechanical and durability properties. Significant enhancements in the mechanical characteristics like compressive, tensile, flexural, and bond strength have been observed by adding small concentrations of graphene. Furthermore, graphene provides an impermeable layer that protects reinforcing rebars from corrosion. The increase in strength depends on the high aspect ratio, uniform dispersion, and excellent interfacial bonding between graphene and the matrix, and increased crack resistance. In this review, we provide a comprehensive overview of the fundamentals and applications of graphene and summarize the impacts of incorporating graphene oxide on the mechanical and durability characteristics of cementitious materials.

Malaiappan Sindhu Muthu, Mallikarjun Perumalla
Experimental Investigation of Mechanical and Failure Analysis of Banana Stem Fibre in Concrete

The primary goal of the study was to perform research using natural fibres in grade M40 concrete to investigate the mechanical behaviour and flexural failure analysis of beam elements. Fibre-reinforced concrete is the fastest-developing concrete in construction techniques and is greatly used in all structural systems. To enhance sustainable development and introduce natural materials in concrete, the addition of banana fibre was studied. In this study, M40-grade concrete was used to improve sustainability and the performance of the concrete. By incorporating banana fibre into the concrete mix, the researchers may have aimed to reduce the environmental impact of the concrete by introducing a renewable and biodegradable material and also improve the performance of the concrete by reinforcing it with natural fibres. Flexural failure occurs in concrete due to the yielding of steel and the development of cracks in beams. Hence, using the fibres in concrete reduces cracks and shrinkage by improving flexural behaviour. The dosage of banana fibre varies from 0.25%, 0.5%, 0.75%, and 1%, respectively, and the aspect ratio of 40 mm of the banana fibre used in the M40 grade. The experimental results show that the compressive strength increases when banana fibre dosage decreases, and the targeted strength for flexural behaviour is achieved at 1% of banana stem fibre used in concrete. This is due to the fibre tensile action added to the concrete in quantity.

Pooja Damodaran, Lakshmi Thangasamy, Arivukkarasu Dhanapal
Durability Study on Ultra-High Performance Fiber-Reinforced Concrete

Ultra-high-performance concrete (UHPC) stands out as a superior alternative to conventional concrete due to its remarkable enhancements in compressive strength, ductility, tensile strength, and overall lifespan. In present research study, we meticulously formulated three trial mixtures, utilizing locally available materials such as cement, ground granulated blast furnace slag (GGBFS), micro-silica fume (MS), M-sand, quartz powder (QP), water, steel fibers, and chemical admixtures. The investigation delved into rheological parameters to assess the fresh concrete's characteristics and compressive, split tensile, and flexural strength to evaluate the attributes of the hardened concrete. The results of this study illuminate a direct correlation between increased binder content and heightened compressive strength. Additionally, the combination of a low water-to-cement (w/c) ratio, coupled with optimal particle packing, substantially enhances UHPC's durability by fortifying its resistance against moisture infiltration and deleterious ions like chlorides and sulfates. Microstructural analysis unveiled the formation of crucial compounds such as calcium–silicate–hydrate (C–S–H), calcium hydroxide (CH), ettringite, and a resilient interfacial zone characterized by a tightly knit fiber matrix. These findings underscore the promise of UHPC as a viable solution for critical applications where structural integrity and longevity are of paramount concern. In conclusion, this study sheds light on the transformative potential of UHPC, demonstrating its ability to bolster structural performance, mitigate environmental degradation, and extend the service life of concrete structures.

S. Kavya, A. Sanjay Raj
Performance of Plain Concrete Column Confined with Cold-Formed Steel Subjected to Axial Compression

Thin gauge sheets of cold-formed steel are commonly utilized in non-structural elements such as pre-engineering buildings, roofing sheets, and frames. An investigation to explore the potential use in structural aspect of these steel sections in civil engineering as the confinement material for the column is conferred through this report. The main intention of this investigation is to study the effect of confinement of cold-formed steel lipped channel built-up tubular column in filled with concrete. For this an experiment study was carried out for 12 columns of height 500 mm having the square cross-section of side 140 mm filled with two different grades of infilling material M30 and M40 were cast. Out of 12 columns 6 number of columns were confined with connected channel-lipped sections of thickness 2 mm each, and another 6 number of columns were unconfined specimens. The aspect ratio of depth to width is 1.0, and the depth-to-plate thickness ratio for the confinement steel is 70. These columns were tested on a 2000 kN capacity universal testing machine under axial compression. The parameters including ultimate bearing capacity, axial shortening, load vs deflection curve, ductility index, failure pattern of the concrete columns was studied. The study showcased that the ultimate bearing capacity is improved with the addition of the confinement material. The effect of M40 grade concrete is prominent in unconfined specimens when it is compared to confined specimens. The confinement restricts the axial shortening of the column specimens due to its triaxial effect on the infilled concrete. Crushing failure of the concrete is more prominent in case of the unconfined specimens as compared to confined one. The prediction of EC4 is in good agreement to the experimental results, whereas AISC overestimates the strength.

Venkat Raj Konam, Pranoy Roy, Amiya K. Samanta
Dynamics Analysis of Steel Framed Structure Under Different Damage Scenarios

Bridges, buildings, dams, and pipelines are just a few examples of the complex engineering systems that sustain a society's economic stability and quality of life. These systems’ proper inspection, monitoring, and maintenance become more crucial as they get older and degrade. In such case the probability of occurrence of damage is high. The early identification of structural damage is vital to avoid structural failure in case of extreme loading conditions, which undetected can result in catastrophic conditions. Hence, there is a need for assessment and study of behavior of the damaged structural elements or structures as whole in order to increase the safety and serviceability of any structure and to maintain structural integrity for longer period of time. This study aims to investigate the effect of damage location and severity in beams and columns of a multistory steel structure. Different damage scenarios, i.e., reduction in cross sectional area, stiffness, and Young’s modulus are considered to introduce damage at different locations in beams and columns. In order to predict the critical location and severity of damage, modal analysis is carried out to find the dynamic behavior of damaged structures. The natural frequency and time periods are considered as dynamic response parameters. Further, lateral load analysis, i.e., equivalent static method is performed as per IS 1893 (Part-1): 2016 code provisions. From the results, it has been observed that there is a change in the natural frequency, member forces, and lateral displacements of the structural system with the introduction of damage of certain severity and at particular location.

Mahalaxmi S. Sunagar, B. O. Naveen, K. Jayanth
Estimation of High-Frequency Spectral Decay Parameter in a High-Rise Building for Evaluation of Kinematic Soil-Structure Interaction

The seismic response of buildings founded on soft soil is significantly affected by soil-structure interaction. Kinematic soil-structure interaction represents the variation between foundation input motion and free field due to high-frequency filtering of the seismic waves by the structure. High-frequency spectral parameter (κ) proposed by Anderson and Hough in (Bull Seismol Lett Am 74:1963–1993, 1984) is used to describe the shape of the Fourier amplitude spectrum in the high-frequency range. κ parameter has been studied extensively and used in several applications like ground motion simulations and the generation of synthetic accelerograms. In the present study, seismic records of a well instrumented 14-storeyed building, the Hollywood Storage Building with concrete pile foundation on Class D Deep Alluvium soil, are used to determine the high-frequency parameter κ for the free field and basement motions using the classic method proposed by Anderson and Hugh in (Bull Seismol Lett Am 74:1963–1993, 1984). κ is estimated based on the S-wave portion of the accelerograms. The computation of κ is done across four strong motions having magnitudes greater than 4, recorded by the building. Comparison of κ values indicates variations between free field and basement motions. Regression equations have also been developed to relate κ to magnitude and source to site distance. The variation between free field and basement motion in the fitted regression curves is also analysed to identify the effect of kinematic soil-structure interaction.

N. J. Radhika Nair, B. R. Jayalekshmi
Meshfree Methods in Computational Mechanics—State of the Art

The finite element method (FEM) has widespread use in solving problems in computational mechanics and applied sciences. However, researchers continue to develop and implement new numerical methods to solve problems that involve complex geometry, material non-linearity, and fracture mechanisms, including crack formation and propagation with moving and discontinuous boundaries. Meshfree methods have seen a significant increase in their application to solve partial differential equations (PDE). These methods involve modelling and solving procedures that depends on a cloud of nodes or points for geometry representation and discretization. In the field of computational fracture mechanics, the meshfree nature of meshfree methods has gained considerable attention for modelling two-dimensional and three-dimensional crack growth. While FEM uses interpolation methods to formulate shape functions, meshfree approaches use approximation methods. This review aims to examine the developments, utility, limitations, and potential for refinements of meshfree techniques.

Kichu Paul, K. S. Babu Narayan
A Comparative Study of Data-Driven Models for Shear Strength Prediction of FRP-RC Beam Using Machine Learning Techniques

Nowadays machine learning techniques are effectively used as a means of resolving issues in civil and structural engineering. Accurately evaluating the shear strength of a reinforced concrete beam with fibre reinforced polymer (FRP) is crucial to ensure a secure design and effectively assess its performance. However, the accuracy of the predictions made by current shear models is generally constrained by the use of a limited database and complex parameters. The aim of this study is to create a model based on machine learning techniques that can predict the shear strength of reinforced concrete beams containing fibre reinforced polymer bars, both with and without stirrups, by utilizing data-driven approaches. A comprehensive database of 491 shear strength tests on FRP beams was collected from the public literature for developing framework’s training and testing sets. In order to prepare the data for machine learning algorithms, exploratory data analysis (EDA) has been carried out to investigate the correlation and identify collinearity between several independent parameters. Further, different models for linear regression, decision tree regression, random forest regression, gradient boost, and XGBoost have been developed for prediction of shear strength based on twelve different independent parameters and dependent output parameters. Root mean square error (RMSE), R2 score, and mean absolute error (MAE) are used to check the performance of all the models, and the best model is chosen for forecasting the shear strength of FRP reinforced concrete beam.

Manish Shankarlal Jangid, B. R. Jayalekshmi
Dynamic Response Analysis of Fluid Storage Tanks Using Coupled Acoustic-Structural Approach

Industrial fluid storage tanks are exposed to significant damage in earthquakes and cause the destruction of life and property. The seismic response of fixed-supported, three-dimensional rectangular rigid and flexible fluid storage tanks is analyzed using the finite element method. In this study, the fluid storage tanks are examined by utilizing coupled acoustic-structural (CAS) models. The convective displacement behaviors of rectangular liquid tanks are studied numerically under harmonic and earthquake excitations. The tank fluid–structure interaction (FSI) performance is studied by applying CAS methodology. Convective displacement, convective pressure component, impulsive pressure component, and total hydrodynamic pressures are analyzed for square and rectangular liquid storage tanks, and it is found that rectangular fluid storage tanks have more sloshing displacement and impulsive pressure component compared to square liquid storage tanks.

P. Giridhar, Pranitha Jogi, B. R. Jayalekshmi
Nonlinear Seismic Response Analysis of Mid-rise RC Buildings Founded on Soft Soil

Multi-storeyed RC structures have become a significant part of modern construction. Damages induced by earthquake excitations on RC structures depend not only on the structural behaviour of the superstructure but also depend on the type of foundation and soil on which the structure is founded. The present study aims to understand the impact of soil-structure interaction on the seismic response of mid-rise RC buildings. Nonlinear static pushover analysis of RC frame buildings having 4 and 6 storeys has been conducted considering fixed base condition and flexible base. The effect of SSI is analysed by creating 3D building models using finite element software considering the SSI between the building model and the soil on which the building is founded. The nonlinear behaviour of the building components is incorporated in modelling using the concrete damaged plasticity model by defining the compression and tension damage parameters. The consideration of nonlinearity of soil and structure is found to alter the system’s dynamic characteristics by an increase in the natural period. The pushover analysis results indicate a comparable variation of the force–displacement curves for the building models with and without considering SSI and show an increase in the lateral displacement value while considering the SSI effect. The results presented in this study illustrate the inefficiency of fixed base modelling in assessing the dynamic response of mid-rise RC buildings by highlighting the disparity in the fundamental time period and flexibility of the building under the effect of SSI.

Merin Mathews, B. R. Jayalekshmi, Katta Venkataramana
Vulnerability Assessment of RC Building by Incremental Dynamic Analysis Approach

Vulnerability assessment of existing RC building subjected to earthquake excitations can be used as an effective tool for understanding the seismic response of building. Incremental dynamic analysis (IDA) offers an efficient method to nonlinear dynamic structural analyses for accurate estimation of seismic performance of structures under earthquake ground motions. This study summarizes the evaluation of fragility curves for a reinforced concrete frame structure using incremental dynamic analysis approach considering variability of ground motion. A detailed review of literature on incremental dynamic analysis and fragility curve is presented. The detailed model of two-story RC building is generated, and nonlinear time history analysis is performed to assess the performance under seismic excitation. The variation in ground motion is considered by using three sets of earthquake data to evaluate response of the structure and IDA curves are obtained. These curves are then operated by fragility evaluation procedure to obtain fragility curves at different damage limit states. From the fragility curves, prediction on the probability of exceedance of different damage states under seismic excitations is made.

Shreyansh N. Rawal, Merin Mathews, B. R. Jayalekshmi
Numerical Analysis of Base Isolated Liquid Storage Tanks

Liquid storage tanks behave in a different manner as compared to any other type of structure when subjected to a dynamic loading, wherein the motions of lower and upper liquid are non-identical in nature. The upper liquid mass is named convective mass, which is responsible for sloshing and subsequent damage to the tank. Base isolation is an effective method in seismic response reduction of structures. Laminated rubber bearings (LRB) and lead core rubber bearings (LCRB) are used as effective base isolators for seismic response reduction across the globe. The current study deals with the reduction of hydrodynamic pressures induced due to seismic action in square and rectangular flexible tanks when isolated with LRB and LCRB. The transient analysis of 3D ground supported base isolated tanks subjected to El Centro and Northridge ground motions is performed using FE software. The coupled acoustic structural approach is employed in order to incorporate the fluid–structure-interaction effects. Variation of convective displacement is assumed according to a linear wave theory. It is found that a considerable reduction in impulsive pressures and sloshing is achieved by employing a lead core rubber bearing system.

Pranitha Jogi, B. R. Jayalekshmi
Performance of Alternate Superplasticizers on Performance of Self-compacting Geopolymer Mortars—An Experimental Study

Geopolymer binders are the best alternatives to Ordinary Portland cement in the view of carbon impact on the environment. The effect of addition of different types of superplasticizers (SPs) on the flow and compressive strengths of a class of self-compacting geopolymeric mortar (SCGM) mixes is investigated in the present study. Three different kinds of SPs, namely modified Polycarboxylate Ether (MPCE), Polycarboxylate Ether (PCE), and Sulfonated Naphthalene Formaldehyde (SNF), were used in the production of SCGM with varying proportions at 1, 1.5, and 2% by weight of the binder. Results revealed that modified PCE-based SP showed better results in flow and compressive strength (CS) in comparison to PCE and SNF-based SPs. However, an increase in the dosage of SP had less/adverse effect on the flow properties. A maximum slump flow of 270 mm was observed for a modified PCE-based SP at 1.5% dosage, while the highest CS of 34 MPa was observed at 1.5% dosage of the same SP. Scanning electron microscope (SEM) analyses were carried out on a few selected SCGM mixes.

Gundupalli Bhanu Prakash, Kaku Mahendra, Lankireddy Tanush, M. C. Narasimhan
Shear Strength Characteristics of One-Part Alkali Activated Concrete Mixes—A DOE Approach

Utilization of one-part alkali-activated concrete (OPAAC) mixes is an advantageous option for large-scale construction applications. In the present investigation, the main objective was to investigate the shear strength characteristics of OPAAC mixes that were made using GGBFS and fly ash as precursors and sodium meta-silicate as solid activator. Taguchi’s DOE approach has been used to reduce the experimental effort and to find the optimum parameters. An initial set of nine OPAAC mixes was identified based on an L-9 array, with three representative levels considered for each of three principal mix parameters and experiments were conducted to test their compressive and shear strengths. The test results revealed that the OPAAC mixes exhibited 28-day compressive strength values ranging from 55 to 70 MPa, with shear strengths varying in the range of 8.5–12.67 MPa. Multi-linear regression equations were then developed to predict the 28-day compressive and shear strengths using MINITAB 21 statistical software. The predictions of these were verified by conducting actual strength experiments on a new set of three verification mixes. Further, additionally, a generalized correlation was developed to predict the 28-day shear strength of OPAAC mixes based on the known 28-day compressive strength. Again, an examination of microstructures was carried out through the utilization of FESEM analysis, to get a general appreciation of the microstructure (morphology) and elemental composition using EDX analysis of these mixes. The outcomes of this study are anticipated to promote the extensive adoption of environmentally friendly and sustainable materials within the construction industry. The findings of this study are anticipated to promote the extensive adoption of environmentally friendly and sustainable materials in the construction industry.

Kaku Mahendra, Gundupalli Bhanu Prakash, Shreyas Shetty, Mattur C. Narasimhan
Determination of Effective Properties of Masonry Using FEA-Based Homogenization Approach

Masonry is a widely used construction method. Masonry is typically heterogeneous in nature, consisting of bricks and mortar joints with varying mechanical properties. Thus, masonry will behave like a composite material with orthotropic material characteristics. However, the material heterogeneity of masonry will be ignored in the analysis of masonry structures, assuming it is a homogeneous, isotropic element, which is not true and leads to incorrect assessment. Thus, it is necessary to predict the orthotropic properties of masonry for the accurate assessment of masonry structures. On the other hand, predicting such orthotropic characteristics of masonry becomes a complex task, due to the presence of material heterogeneity. Therefore, researchers adopted numerical homogenization methods to assess the orthotropic properties of masonry. In this study, the FEA-based homogenization method is proposed to predict the orthotropic properties of masonry. Toward this direction, a small periodic part called the repetitive unit cell (RUC) of the English bond masonry prism available in the literature study is considered and modeled in ABAQUS software for the homogenization process. The constituents of RUC are modeled as a continuum element with linear and isotropic behavior. A series of linear stress analyses of RUC has been conducted using six-far field unit strains. The effective orthotropic properties of masonry can be predicted using the stress–strain relationship obtained from the linear stress analysis of masonry RUC. Finally, the results obtained from the numerical homogenization process are validated with the experimental results available in the literature study.

Santoshgouda Honnalli, G. S. Pavan
Pseudo-Dynamic Analysis of Gravity Masonry Dams

According to USGS estimates, approximately 5 million earthquakes occur annually, of which 1 million are felt. In the north-eastern and north-western regions of India, where the Indo-Australian plate is subducted beneath the Eurasian plate, seismic activity is extremely high. In addition to the immediate damage, an earthquake can cause minor vulnerabilities that lead to future crises. Safety of important infrastructure like dams, bridges, tunnels, elevated structures, and nuclear power plants under earthquake ground motion is critical. In the past 50 years, seismic analysis of dams has attracted considerable research interest. In this study, a pseudo-dynamic analysis of non-overflowing section of a masonry gravity dam is conducted. Invoking plane-strain condition, a 2D model of the dam is developed in Abaqus software. The dam is modeled using four node rectangular elements. The loads at various levels along the dam's height are computed for the fundamental, higher, and static modes. The effects of hydrodynamic forces acting on the dam are also incorporated. The loads are applied separately, and stress analysis is performed. Stress values are combined using the SRSS method, these stresses are compared to the material's strength properties, and the risk factor is evaluated. A comparison of the stresses obtained from FEM model and stresses obtained by considering beam idealization is also presented in this work.

S. Shalini, Malyala Ajay Kumar, G. S. Pavan
Microstructure Characterization and Effective Elastic Properties of Carbon/Carbon Composites

In this research, the effective elastic properties of C/C composites are evaluated using FEA-based homogenization technique. The FEA-based homogenization procedure is carried out by generating a Representative Volume Element (RVE). The features in the microstructure are observed with the help of Scanning Electron Microscopy (SEM) images. A detailed study on the SEM images of C/C composites is carried out. The microstructure of C/C composite consists of carbon fibers and carbon matrix. The details obtained from the microstructure are used to generate the RVE of the C/C composite. Random Sequential Adsorption (RSA) algorithm is employed to insert the carbon fibers inside the RVE model. Periodic boundary conditions are imposed on the RVE model, and six different far-field strains are applied on the RVE. For each case of far-field strains, the effective response of the RVE model is evaluated. The effective elastic properties of C/C composites are obtained by combining the volume-averaged stresses of the RVE for each case of far-field strains. The results from the numerical study are compared with those from the Mori–Tanaka method.

O. S. Vishnu, G. S. Pavan
Deconvolution of Earthquake Ground Motions for Dynamic Analysis of Masonry Gravity Dams

The present study aims at deconvolution of earthquake ground motions pertaining to dynamic analysis of masonry gravity dams. Deconvolution is a process that can be used to remove the effects of these distortions and obtain the actual ground motion. Dynamic analysis of masonry gravity dams incorporating soil-structure interaction requires the application of earthquake motion to the base of the foundation. Soil strata up to a depth of three times the height of the dam is generally included in the dam analysis. Deconvolution procedure is performed in this study for different types of earthquake ground motions and different types of soil strata present beneath the dam. In order to perform deconvolution, frequency domain approach is considered. In this frequency domain approach, the recorded ground motion data is first transformed into the frequency domain using a Fast Fourier Transform (FFT). The response at dam-foundation interface is also transformed into the frequency domain, and the two spectra are divided point-by-point. This procedure is repeated until reasonable accuracy is achieved. The deconvolved signal is then transformed back into the time domain using the inverse Fourier transform. This study provides an overview of the deconvolution of seismic ground motion using a frequency domain approach and highlights its importance in seismic research and engineering applications. Also, the importance of performing deconvolution of ground motions is assessed with respect to different types of soil strata lying underneath the dam.

Udit Singhal, G. S. Pavan
Strength and Durability Properties of Early Cement-Soil Mortar

Looking back at history can inspire new construction technologies and methodologies. Our ancestors used earth as a primary building material, and from prehistoric times, they adopted clever yet simple construction techniques. Mud, which is widely available locally, is a valuable material due to its flexibility in processing and energy efficiency. Mud has been used for construction in India and elsewhere for a long time, and even today, mud wall construction is common in rural parts of India. Although mud is prone to degradation from rain and wind, it is a reliable material with advantages such as affordability, abundance, and good fire resistance. For low-rise and low-cost buildings, mud remains a dependable material. Researchers have discovered methods to enhance mud's quality and durability through stabilization processes to overcome the disadvantages of pure mud construction. In this study, durability aspects of cement-sand-soil mortar are explored. Soil with varying ranges of clay content is considered. Different amounts of cement content are added to obtain different proportions of cement-sand-soil mortar. Durability aspects of mortar that are explored by conducting tests like workability, compressive strength, sulfate-resistance test, acid resistance test, drying shrinkage test, and water absorption test are determined for cement-soil mortar and compared with cement mortar.

Kallem Surya Teja, G. S. Pavan
Detection and Visualization of Corroded Surfaces Using Machine Learning

The use of artificial intelligence in asset management greatly assists the industry and structural health monitoring systems. Using machine learning techniques for asset inspections can increase safety, reduce access costs, provide objective classification, and improve digital asset management systems. The detection and visualization of corrosion from digital images present significant advantages like automation, access to remote locations, mitigation of risk of inspectors, cost savings, and detecting speed. This paper used deep learning convolutional neural networks to build simple corrosion detection models and used an extreme gradient boosting algorithm to visualize the corroded surfaces. A large dataset of 1900 images with corrosion and without corrosion was collected using web scraping techniques and labeled accordingly. Training a deep learning model requires massive and high-resolution image datasets and intensive image labeling to approach high-level accuracy. The results and findings will improve the development of deep learning models for detecting and visualizing specific features on corroded surfaces.

B. J. Shrivathsa, R. Dhanya, D. Meghana Nayak, G. S. Pavan
An Element-Free Galerkin (EFG) Meshless Solution for Static Analysis of FGM Plates Resting on Elastic Foundation

An element free Galerkin (EFG) meshless solution method is presented in this paper to illustrate the bending response of FGM plates resting on Winkler–Pasternak elastic foundations. A power law distribution is used to govern the gradation of material properties through the plate thickness. To check the validity of the theory and formulations, the obtained results are compared with the previous results. Comparison studies reveal that the results of the proposed solution method is more accurate and yield faster results than other methods. Parametric studies are performed to show the influences of elastic foundation coefficients and power law index on the deflection of FGM plates.

N. Indu, K. P. Afsal, K. Swaminathan
Vibration Analysis of FGM Plates Resting on Elastic Foundation in Thermal Environment Using Element-Free Galerkin (EFG) Meshless Solution

The present paper deals with the effect of temperature on the vibration characteristics of functionally graded plates resting on two-parameter elastic foundations. The temperature-dependent mechanical properties of the plates are assumed to vary through thickness. The present solutions are derived using an element-free Galerkin (EFG) meshless method. Using the EFG solution method, the numerical results are presented and compared with those available in the literature. Results show that the foundation stiffness, temperature, and other parameters have a significant influence on the vibration response of functionally graded plates resting on elastic foundation.

K. P. Afsal, N. Indu, K. Swaminathan
Seismic Fragility Estimates Through Time History Method and Re-entrant Corner Buildings with Soil Structure Interaction

The subject of this study is reentrant corner irregularity. Through the use of nonlinear time history analysis, this study compares a building with re-entrant corners to a structure with a regular plan configuration. Five alternative models examined in the current study are regular (R) building with a square-shaped plan, and four irregular structures, each having a C, L, T, and + shaped plan. Nonlinear dynamic (time history) analysis has been performed on the models for three earthquake data of varying magnitude and pseudo spectral acceleration is compared. Further, fragility curves were also developed to study the variation in the performance levels of all the models for different support conditions (fixed support, hard soil, medium soil, soft soil). Re-entrant corner structures experience greater displacement and more susceptible to seismic damage when compared with regular buildings.

B. M. Ramesh, K. Manjunatha, D. T. Naveenkumar
Unlocking the Potential of Pond Ash as a Game-Changer in Replacing Natural Sand in Concrete

Pond ash, a byproduct of coal-fired thermal power plants, is a promising alternative to natural sand in concrete production. This review paper examines the potential of pond ash as a game-changer in the construction industry by exploring its chemical composition, physical properties and durability. The high silica content of pond ash makes it a suitable replacement for natural sand, with the added benefits of being easily accessible and cost-effective. Furthermore, using pond ash in concrete production can help mitigate the negative environmental impact of coal combustion and reduce the depletion of natural resources. However, several factors must be considered, such as the particle size, shape and surface texture of pond ash, to ensure optimal performance in concrete. This paper highlights the key findings and implications of recent studies on the use of pond ash in concrete, demonstrating its potential to revolutionize the construction industry while promoting sustainable practices.

Mallik Pooja, P. Laxman Kudva, H. K. Sugandhini
Fire Resistance of Concrete with Partial Replacement of Ceramic Waste and Carbon Fiber as Additives

One of the primary hazards that causes catastrophic damage to properties and people’s lives is fire. Although ceramic garbage is deposited on the land, it is a non-biodegradable waste that pollutes the environment. This study is based on the use of industrial waste products such as ceramic sanitary waste to improve the mechanical qualities of concrete that have been exposed to elevated temperatures. An experimental investigation was carried out on cubes, cylinders, and beams to assess compressive strength, split tensile strength, and flexural strength with fractional replacement of fine aggregates with 10, 20, and 30% of ceramic waste and 0, 1, and 2% of carbon fibers as additives at normal and elevated temperature as per ASTM code recommendations and the results shown as a significant improvement. The strength of M30 grade concrete with partial replacement of fine aggregate with ceramic waste up to 30% and carbon additives up to 2% shows an improvement of compressive strength by 17.56% than conventional concrete. It is also observed that normal M30 grade concrete loses its strength by 49.6% when it is exposed to 600 °C and with fractional replacement of fine aggregate by ceramic waste by up to 30% and carbon additives by up to 2% shows the loss of strength is decreased up to 22.67%. It shows that it is the probable substitute solution for the secure discarding of Ceramic waste.

K. N. Narasimha Murthy, P. Nelda Paul, E. M. Beevi Mymoon, H. K. Thejas
The Use of Artificial Neural Network Model to Predict the Compressive Strength of Sustainable Geopolymer Concrete: A Systematic Review

Geopolymer concrete (GPC) is an alternative building material that has gained attention recently as a more environmentally friendly alternative to traditional Portland cement-based concrete. This type of concrete utilizes industrial wastes or agricultural byproduct ashes as the primary source of binder materials, in contrast to traditional Portland cement. GPC is gaining popularity due to the environmental issues related to cement manufacturing. The compressive strength of all concrete composites, including GPC, is a fundamental mechanical characteristic. A novel approach to forecast the compressive strength of GPC is the application of artificial neural networks (ANNs). This review paper aims to introduce artificial neural networks and emphasize their usefulness as a computational technique for modelling complex functional connections among different parameters affecting the compressive strength of GPC. The review paper is structured into three sections. The first section introduces neural networks and their applications as modelling tools. The second section focuses on using neural networks to model GPC made from different source materials. Finally, the third section summarizes the key findings and contributions of the paper, emphasizing the potential of ANNs to revolutionize the design and optimization of geopolymer concrete for more sustainable and eco-friendly construction practices. From the extensive literature review, it is clear that comparing the results derived from ANNs with experimental findings shows excellent agreement, indicating the reliability and robustness of ANNs in estimating the compressive strength of GPC.

Shimol Philip, M. Nidhi
Sustainable Approach on Concrete Pavers with Partial Replacement of Sugarcane Bagasse Ash for Cement and Foundry Sand for Fine Aggregates

The cement is famed worldwide, because of its unique properties, but its use significantly increases the carbon emissions. In the present scenario to fulfil the need of sustainable construction, the scarcity of river sand has been replaced with M-sand and there is a need for such alternative construction material. The present study aims to investigate the influence of sugarcane bagasse ash (SCBA) and foundry sand (FS) as a partial replacement for cement and fine aggregate. SCBA is a waste obtained from sugarcane industries which has the properties like corrosion resistance, chloride resistance due to presence of high silica. FS is a by-product from the production of both ferrous and non-ferrous metal casting industries. The study focuses on manufacture of M30 grade paver blocks for non-traffic condition as per IS 15658:2006. The study was carried out using 12 mm crushed stone, SCBA in the proportions of 0, 5, 10 and 15% by weight of cement and FS at constant proportion of 40% by weight of fine aggregate. Experimental tests like compressive strength test, flexural strength test were conducted on the paver blocks to measure the quality. The test results indicate that at 5% SCBA replacement provides optimum values with water absorption of 4.7%, flexural strength of 6.53 MPa and compressive strength of 46.25 MPa. Thereby, use of above alternatives can significantly reduce the problems with disposal of wastes and are economically feasible. These pavers can also be used for medium-traffic category since the strengths were high and found to be almost 40 MPa.

K. S. Swathi Rani, M. S. Mukesh, M. Nikitha
Development of Translucent Concrete Using Fibreglass Rods and Replacement of a Part of Fine Aggregate by Glass Powder

The innovation of the research proposal rests in developing a new kind of translucent concrete using fibreglass rod material that permits light to penetrate through the concrete, where such a polymer material can be implanted into the concrete as carefully arranged dispersed bars. The major goal is to examine the effectiveness of employing glass fibres as an alternative to optical fibres and to replace some of the fine aggregate with glass powder by examining their mechanical properties. As waste windscreen glass that is difficult to dispose of is transformed into powder to be replaced for some part of fine aggregate, these blocks tend to function as an energy-saving, green building and as an effective disposal of glass waste. As we use sunlight as a source, it results in significant energy savings. The significance of the current study lies in the introduction of cutting-edge structural materials that match the demands of new sustainable building concepts as well as architectural, interior, and structural standards. The strength qualities and amount of light transmission were tested in the current investigation using glass rods spaced 1.67 cm apart. Results demonstrate that the composite does not compromise mechanical criteria when compared with conventional mortar and results in novel concrete features that are consistent with environmental sustainability standards in the field of architectural building.

Ankitha Kumar, B. Prajwal Kumar, S. Jayanth Kumar, Kumara Naika, M. Naveen Nayak
Experimental Study on Recycled Waste Plastic Material in Concrete

The demand and cost of natural aggregates is increasing day by day due to its non-availability. Aggregates are very important for construction projects, however due to maximum consumption they are getting depleted. Hence suitable alternative materials like recycled plastic aggregates made up of purely waste plastic materials are used as a replacement for these natural aggregates. Utilization of these recycled plastic aggregates (RPA) in concrete helps in disposal of plastic waste and thereby helps in conserving the natural resources and the environment. In the current study, recycled plastic coarse aggregates and recycled plastic fine aggregates in varying percentages of 0, 10, 20 and 30% with the addition of bonding agent were used to partially replace the natural coarse aggregates and fine aggregates in the M30 grade concrete mix design. Concrete was subjected to permeability testing as well as strength tests for its compressive, flexural, and split tensile properties. From the test results it is concluded that desired strength results were obtained for 30% replacement of recycled plastic coarse aggregates and 10% replacement of recycled plastic fine aggregates for M30 grade concrete.

T. S. Pavan, M. Jaswanth, B. Yashaswini
Performance Evaluation of Paver Blocks Incorporated with Natural Rubber Latex for Heavy and Very Heavy Traffic Conditions

Paver blocks have almost become a permanent solution in areas where conventional paving systems are failing. Paver blocks are commonly used in residential areas and commercial areas for parking lots, low and medium traffic driveways, etc. Numerous advantages like durability, ease in maintenance, aesthetic appearance, etc., are promoting its application nowadays in pavements with heavy and very heavy traffic conditions. The present study is an investigation to employ natural rubber latex in concrete paver blocks with high and medium cementitious content suitable for heavy and very heavy traffic conditions. Concentrated natural rubber latex (with dry rubber content of 60%) having dosages 0, 0.25, 0.5, 0.75 and 1% by weight of cement was used in the concrete blocks with and without fly ash. The compressive strength, split tensile strength, flexural strength and water absorption of natural rubber latex-modified paver blocks were evaluated to assess the performance and properties. The test results proved that natural rubber latex-modified concrete can enhance the flexural strength, reduce deflection, and improve the durability required for paver blocks, thereby indicating the possibility of its use in field.

Liji Anna Mathew, Glory Joseph
Affordable Solid Block (SB) Using Industrial Waste Fly Ash Binder and Ferrochrome Slag Fine Aggregate

Cement is a strong bonding material produced in all countries. Carbon dioxide (CO2) is emitted as a by-product during the chemical conversion stage of the clinker process in cement production. It ranges from 7 to 10% globally in the initial clinker production. To minimize this emission, the Portland product is replaced by fly ash. As a result, 55% of fly ash and 45% of OPC53 are utilized as a binder. In addition, industrial slag sand is supplanted to diminish the consumption of virgin sand (< 4.75 mm) and 100% of industrial waste ferrochrome slag sand (FS). The slag as fine aggregate replacement enhances the sustainability of the natural resource. The crushed gravel sand (CGS) and FS have a density of 1590 and 1898 kg/m3. The semi-log sieve curve of CGS and FS tends under the zone II sand. The SEM images of materials described the morphological shape and structure under micro-scale. The mixing methodology of solid block (SB) illustrates the precise procedure for hammering and hydraulic vibrating of the machine. The complete FS (100%) replacement mix shows 14% superior compressive strength than the referral block. The water absorption of SB with complete FS has 3.95% on 28 days. The cost of optimum SB is affordable by 9 Indian rupees (INR) per block, and 900 INR is saved by producing 100 blocks. The embodied energy (EE) of FS100 is 52.23% effective than conventional SB. This investigation recommends the SB with FS is innocuous to nature and an effective supplant of CGS.

Nagarajan Manigandan, Vijayan Ponmalar
Experimental Studies on the Mechanical and Durability Properties of Mortar Containing Waste Glass Powder as Partial Replacement of Cement

It is well known that Portland cement production is an energy-intensive industry, being responsible for about 5% of the global anthropogenic carbondioxide emissions worldwide. An important contribution to the sustainability of concrete and cement industries consists of using pozzolanic additions, especially if obtained from waste such as waste glass. In the present study, crushed waste glass was used in mortar as a partial cement replacement (0, 5, 15, 25, 35, and 45%) material to ascertain applicability in concrete. Experimental studies were carried out to determine mechanical properties like compressive strength and split tensile strength and durability properties by immersing mortar in 5% sulphuric acid and hydrochloric acid solution. Experimental results indicate better mechanical properties of mortar with 15% replacement of cement by glass powder. Further, with 15% replacement of cement by glass powder has shown better resistance to sulphuric acid attack and weight loss is comparable to weight loss in normal mortar in sulphuric acid and thus 15% replacement of cement can be considered as optimum dosage of glass powder in concrete. Also, glass powder replacement above 35% have performed poorly in all tests except in tensile strength test.

Chopra Shaurya, Imran Kuttagola, Prashanth M. H.
Recycling of Granulated Blast Furnace Slag as Fine Aggregate in Masonry Mortars

Over the last few decades, Indian iron and steel industries have stockpiled millions of tonnes of ferrous slags which can be explored as construction materials. The use of ferrous slags as aggregates may close the gap in demand and supply of natural aggregates. The present study focusses on exploring a processed form of granulated blast furnace slag as fine aggregate in the mortars and the concrete. In the past, the direct replacement of sand by granulated slag has shown adverse effect on the workability and strength of mortars and concrete mainly due to poor physical and chemical properties. In the present study, the processed form of granulated blast furnace slag (PGBS) has been explored as alternative to natural sand. The study presents a comprehensive physical and chemical characterization of PGBS and a comparative study of properties of PGBS and natural sand. The strength evolution in PGBS-based mortars and the natural sand-based mortars are also presented. The mortars with PGBS show similar strength evolution patterns when compared with the natural sand-based mortars.

Vibha Venkataramu, B. V. Venkatarama Reddy
Performance of Mortar Mixes Using Exfoliated Vermiculite Exposed to High Temperature

For a variety of building and construction applications, mortar mixes are typically produced using fine aggregates, which are being considered one of the most significant cement-based composites. Nowadays, performance evaluation of various types of building materials including mortars under elevated temperatures is receiving more attention by the researchers, especially when it comes to the application level of industrial furnaces and building structures. For a target to achieve better resistance of mortars subjected to high temperatures, addition of thermally stable and porous aggregate may be an alternative. In this study, an attempt has been made to utilize exfoliated vermiculite (EV) as a supplementary material to produce heat-resistant mortar mixes. Different mortar mixes were designed by considering the replacement level of fine aggregate by EV as 5 and 10%. In order to determine the performance of the manufactured mortar mixes, tests on the physical (workability, density), mechanical (compressive strength), and thermal properties of the mortar mixes containing EV are conducted at ambient and elevated temperatures. Ultrasonic pulse velocity test was also conducted to check the quality of the mortar mixes before and after getting exposed to elevated temperatures. Mortar mixes containing EV exhibited excellent strength preservation or poor strength decay rate after exposure to elevated temperatures and also certifies it as a good insulation material.

Shriti Singh, Amiya K. Samanta, Suman Saha
An Experimental Investigation on the Properties of Concrete Using Natural Soil Deposit

A natural soil deposit, named Kaolin having major ingredient kaolinite mineral, is usually mined for centuries and used for multi-purpose applications. In order to increase the sustainability of mortar, numerous studies have focused on alternate materials like kaolin to reduce the consumption of cement. As results, it has drawn a great attention for evaluating its performance in concrete as well. This study focuses on determining the suitability of using the natural soil deposit of kaolin, very fine particle clay, as supplementary cementitious materials (SCMs) in concrete. In this research work, kaolin is planned to be used to manufacture concrete mixes at the level of 10 and 20% in two different ways; one as the replacement of cement by weight and another is addition in concrete by volume of cement. Physical (workability), mechanical (compressive strength, splitting tensile strength and flexural strength), and non-destructive properties (rebound hammer and UPV) were investigated in order to determine the performance of the concrete mixes containing this natural soil deposit of kaolin. Results showed reduction in workability for all the concrete mixtures, Depending on the mixes where kaolin was added by the volume of cement or used as a partial replacement for cement by weight. Weight slightly increased or decreased, respectively, and concrete quality improved, i.e., compaction was good as compared to conventional concrete for the mixtures where kaolin was added as a supplement. All characteristics of the destructive and non-destructive tests showed that the mixture, in which kaolin was used as a 10% addition to the volume of cement, indicated the best results.

Pritam Singh, Suman Saha, Amiya Kr. Samanta
From Brown Earth to Green Bricks—A Critical Analysis of Stabilized Mud Blocks for Sustainable Construction

This paper offers a thorough analysis of stabilized mud blocks (SMBs) as a greener option to conventional building materials. Even though mud has been used for construction for many years, adding stabilizing additives like cement, lime, and fly ash has greatly increased its strength and toughness. Many benefits, including cheap cost, energy efficiency, and low-carbon footprint are provided by these SMBs. This paper discusses the various stabilizing agents, their effect on the properties of SMBs, and the environmental impact of these blocks. It also highlights the need for more research on SMBs as a sustainable material. The constraints and potential for SMBs adoption in low-carbon footprint buildings are also discussed. The review persists by stressing the significance of further research into the long-term performance of these SMBs, as well as their potential for widespread implementation in the construction sector.

A. Kandasamy, P. Priya Rachel, B. Ramesh, Mahmoud A. L. Khazaleh, P. Krishna Kumar
Influence of Materials in the Production of UHPC: A Review

Concrete is a material that is used extensively in construction activities and needs to undergo various sustainability changes to be future-ready as its use increases daily. Ultra-high-performance concrete (UHPC) contains attributes rich in Portland cement (PC), silica fumes (SF), silica sand, superplasticizer, and a significant amount of steel (or) organic fibres that surpass conventional concrete in several ways. UHPC is a relatively recent category of cementitious materials characterized by extremely high strength, ductility, and durability. UHPC reinforced with fibre can be considered a combination of three concrete technologies: self-compacting concrete (SCC), fibre-reinforced concrete (FRC), and high-performance concrete (HPC). According to the previous literature, the maximum water-to-binder ratio of UHPC has been found to be 0.25, indicating that the compressive strength will be ten times more than conventional concrete. This article offers the identification and fundamental principles of materials that could be used to produce UHPC. Although prior studies have addressed this topic, the present work is unique in presenting essential details about materials that have been used till date with different combinations to create UHPC. The review discusses materials’ chemical and physical characteristics and combinations that can be interpreted in the UHPC. The literature shows that steel fibre and SF utilization has shown better results when quantity was restricted to 2 and 25% as it enhances durability and mechanical properties. Prior studies quoted that properties improved by including industrial wastes in varying percentages.

Yash Raj, Khushpreet Singh
A Prospective Review of Alccofine-Based Mortar with Different Nanomaterials—A Performance Evaluation Approach

The construction industry is currently undergoing significant transformation, leading to an increasing inclination toward utilizing sustainable materials to produce high-quality concrete. Economic feasibility and performance play pivotal roles in exploring new alternative materials. Challenges faced in the construction sector have driven the manufacturing of high-strength concrete with improved durability. Extensive research has been conducted on various admixtures in concrete mortars. Among them, alccofine stands out as a promising micro-fine material, and when combined with nanomaterials, they enhance the strength and workability of concrete. The easy mixability of these materials with cement, along with their ultra-fine particles, ensures a smoother surface finish. To comprehensively evaluate the advantages, this review presents an in-depth analysis of alccofine and nanomaterials performance in hardened concrete, specifically focusing on mechanical properties, durability, and strength. The effect of nanomaterials on the characteristics of mortars based on alccofine is also explored. To support the claims made, relevant citations from existing literature are provided, and research gaps are identified, suggesting future directions for further investigation.

Venkatesh Wadki, Chunchu Balarama Krishna
Experimental Investigation on Fiber-Reinforced Concrete with Bagasse Ash as Binder

Utilizing waste materials in concrete provides an environmental disposal option. Due to a rise in infrastructure development, the demand for concrete raw materials has increased rapidly. In the current study, bagasse fiber after sugarcane juice extraction, bagasse ash waste from the sugar industry, and coir fiber from coconut are considered as potential replacements to raw materials. Bagasse ash is substituted with variable percentages, i.e., 5, 10, 15, and 20% of Ordinary Portland Cement, while Sugarcane Bagasse fiber and Coir fiber are added at 0.5, 1.0, 1.5, and 2.0% of Ordinary Portland Cement. Cubes (150 mm *150 mm *150 mm), cylinders (300 mm height, 150 mm diameter), and prisms (500 mm *100 mm *100 mm) were prepared with M30 grade concrete. After curing for 7, 28, and 56 days, mechanical characteristics such as compressive strength, split tensile strength, and flexural strength were determined. Ultrasonic pulse velocity test was considered as a non-destructive testing approach to determine strength of concrete without destructing the specimens and compared with strength values obtained in destructive tests. Durability tests, i.e., acid attack, sorptivity, carbonation, and rapid chloride ion penetration tests were conducted for 90 days cured specimens. As per the experimental findings, adding 15% of Sugarcane bagasse ash and 1.5% of fibers increase the strength properties of concrete. With 15–20% bagasse ash and 1.5–2.0% fiber replacements showed better durability in comparison to conventional concrete. Therefore, bagasse ash, bagasse fiber and coir fibers prove to be sustainable alternative materials in environment-friendly concrete production.

B. J. Panditharadhya, Raviraj H. Mulangi, A. U. Ravi Shankar
Experimental Investigations on Red Soil Stabilized with Ground Granulated Blast Furnace Slag for Pavement Applications

Ground Granulated Blast furnace Slag (GGBS) is the residual product generated during the manufacturing process steel. The storage of untreated slag consumes more open land for storage. The present article discusses the material properties like grain size analysis, consistency limits, specific gravity, maximum dry density, optimum moisture content, unconfined compression strength test, and durability properties of stabilized red soil with ground granulated blast furnace slag (25%) and its probable application as road construction material. Results have shown an increase in UCS (average 75%) values of the stabilized red soil at 0, 7, and 28 days of curing compared with same day cured sample and problems associated with the earthen road construction material is the reduced strength and weathering due to exposure to harmful climatic conditions. Therefore, the prominence has been given to the durability of the stabilized red soil by considering the effect of wetting and drying (W&D) cycles on its weight loss which is within the limits as specified by codes.

B. J. Panditharadhya, S. J. Sowndarya
Assessment of Ionic Composition of Fresh Cement Blends System with Addition of SCMs and Conductive Materials

In this experimental study, an attempt has been made to investigate the effect on the ionic composition of cement system at early age upon the addition of supplementary cementitious materials (SCMs) and conductive additives. The ionic composition of cement system refers to the type and concentration of ionic species and it varies depending on the type of cement and degree of hydration. Cement system containing fly ash, silica fume, and ground granulated blast furnace slag (GGBS) in different proportions were blended to examine the effect of SCMs on the ionic concentration. Apart from SCMs, conductive additives like graphite powder and inorganic salt were also included in the study. The pore solution, formed as a result of the hydration of cement, contains a complex mixture of ions. The ionic conductivity of the pore solution is determined from the concentration of various ionic species. Ionic conductivity is responsible for the electrical, chemical, and mechanical performance of the cement system, and hence, understanding the same is essential. Pore solution is extracted in the early age of the hydrating cement system by centrifugation, and with ion chromatographic technique, the concentrations of ions in the pore solution are determined and the results and discussion are compiled in this paper. From the study, silica fume and magnesium-based salt were observed to be an effective additive in improving the conductivity of the pore solution.

Nalla Rakesh Kumar, S. Arjun, T. Palanisamy
Experimental Investigation on GPC with Partial Replacement of Coarse Aggregates by Granite Chips

This paper investigates the properties of concrete on replacement of its content using ground granulated blast furnace slag (GGBS) as a binder and granite chips (GC) as coarse aggregates (CA). GC is rich in Si and Al and is the by-product of granite slabs. The study investigates the performance of GPC on the replacement of CA with different percentage levels of GC. The study aims to find a sustainable solution for their disposal. This experimental investigation was performed to evaluate the strength properties of concrete. GGBS is the binder, and a combination of sodium hydroxide and sodium silicate solution acts as an alkaline activator. The molarity of NaOH is taken as 12 M. The ratio of sodium silicate to sodium hydroxide solution is taken as 2.5. The ratio of an alkaline solution to binder is taken as 0.35 to prepare the M40-grade concrete. Specimens were tested for 3 and 7 days at room temperature. Test results revealed that the strength of GPC increases with the replacement of CA with GC. It was observed that on replacement of 50% of CA with GC there is an 11.5% increase in early strength (3 days) of GPC. Similarly, for 75% and 100% strength observed was 27% and 32.3%. However, after seven days, the increase in strength is marginal. Similar observations can be made in the flexural strength of the concrete also. SEM images were studied for the Elemental analysis of surfaces (EDS). A cost comparison observed that the GPC of M40 grade with GC is 3% economical when it is replaced by 100% granite chips. Considering the carbon footprint of normal concrete production, it is inferred that the use of GPC is a sustainable alternative and replacing CA with GC will also reduce the cost of GPC with increased mechanical properties.

Sameer Yandigeri, M. V. Chitawadagi, Chaitanya Akkannavar, Gurunath Kampli
Effect of Heating and Fluid Saturation on Certain Physico-Mechanical and Fracturing Behaviour of Concrete

Understanding the fracturing characteristics of construction materials under varying environmental conditions is very important in considering the safety of infrastructural facilities for sustainable civil structures. Concrete has been extensively used in construction, and with recent advancements in offshore structures, its strength in adverse conditions is pivotal and hence requires significant attention. This study investigates the variation in the mechanical properties and fracturing behaviour of M25 concrete cubes under different environmental conditions. The cubes were subjected to five different conditions: heating, saturation, and a combination of heating and saturation. Saturation was carried out separately using water and brine solutions. Three cubes were cast for each condition. The physical properties included density and Ultrasonic pulse velocity, followed by mechanical testing for strength. Acoustic emission monitoring was carried out simultaneously along the mechanical testing. Acoustic emission techniques are used to visualize fracturing behaviour of concrete cubes. Fracture thresholds are established to find crack closure and elastic region, and regions of stable crack propagation and unstable crack propagation. The results show that the combination of heating and fluid saturation significantly impacts the physico-mechanical properties of concrete, reducing its compressive strength and increasing its susceptibility to fracture.

Imtiaz Abdul Gafur, Arjun Anilkumar, Abhay Narendranath Parappalli, Vinoth Srinivasan
Feasibility of Integrating BAPV Façade with Vertical Landscaping for a Hostel Building in Tiruchirappalli

As humankind confronts the mounting exigencies of climate change and the urgent imperative to transition toward sustainable energy resources, the ascendance of solar panels has been gathering momentum. Building-Attached Photovoltaic (BAPV) panels, in particular, have emerged as a compelling alternative due to their dual capacity for electricity generation and building envelope utilization. A promising strategy for enhancing the efficiency of BAPV façade panels is through passive cooling by vertical landscaping. This method helps to reduce the panels’ temperature by facilitating evaporation and shading. Consequently, this approach has the potential to substantially increase the panels’ efficiency, lower energy production costs, and contribute to a more sustainable and environmentally friendly method of energy production. This research endeavors to assess the feasibility of integrating BAPV panels in conjunction with passive cooling by vertical landscaping and to generate energy and curtail the carbon footprint of a residential hostel building located in Tiruchirappalli, a warm and humid region. Additionally, the study aims to benchmark the energy performance of the building against the Energy Performance Index (EPI) specified in the Energy Conservation Building Code. Using Autodesk Revit, the buildings are modeled, and solar insolation simulations are conducted to gauge the energy generation potential for the BAPV façade with vertical landscaping. The simulations are executed for all building orientations, and the most efficacious orientation for energy generation and the payback period are identified. The findings of this research furnish practical recommendations for integrating these technologies in fulfilling the energy requirements of the building while upholding economic feasibility.

S. Somesh, S. Soorya, S. Amalan Sigmund Kaushik
Generation of Building Plans Using ML and AI

Designing residential plans requires expertise and time. Traditional methods are prone to errors and are time-consuming. As a result, deep learning-based methods gained popularity in recent years. This research paper proposes a novel approach to generating building and residential plans using VAE and GANs. The project started with a VAE with Dall-e, which imposed more constraints on the output image. However, this led to pixelated images that were difficult to interpret. To overcome this, GANs were used, which required fewer constraints to produce more explicit output images. In GANs, two networks are trained simultaneously, a generator network that produces new samples and a discriminator network that evaluates the quality of the generated samples. Through adversarial training, the generator network learns to produce images that resemble the actual samples. The proposed GAN approach can overpower traditional residential plan design methods, producing accurate and high-resolution plans that are easier to interpret. However, using GANs is challenging, with instability in the training process leading to mode collapse or gradient vanishing. In conclusion, this research demonstrates the potential of deep learning-based methods for generating building or residential plans. The proposed approach using VAE and GANs can reduce the effort and time required to design a residential project, making it a valuable tool for architects and urban planners. However, further research is needed to address the challenges associated with GANs and improve the model's performance.

Aarti Dasari, Kolli Tejesh Kumar Reddy, Donadi Anand Naidu Santhosh Kumar, D. Rakesh, V. Kusuma Shree, B. V. Ramesh, Basavaraj Dhannur
Standardizing LiDAR Surveying Practices for Accurate and Consistent Data Collection: Colorizing Point Clouds

This paper discusses the importance of standardizing LiDAR surveying practices to ensure accurate and consistent data collection and analysis. Light Detection and Ranging (LiDAR) is a remote sensing technology that uses laser pulses to measure distances and create 3D maps of the environment. With the increasing use of LiDAR in various industries, it is crucial to establish standardized procedures for data collection, processing, and reporting. The paper reviews current practices and identifies key areas that require standardization, including data acquisition parameters, quality control. The benefits of standardization include improved data quality and coloring the point cloud which improves visual interpretation. The paper discusses a simplified software algorithm for merging the point cloud and the panoramic image, which uses open-source hardware and software which provides scope for further modification and improvement.

A. S. Vishwas, P. A. Abhijith, Pruthviraj Umesh, K. V. Gangadharan, Sharan Rai
Influence of Grain Size Distribution (GSD) on GGBFS-Based Binary Cement

Increasing demand due to excessive consumption of pure Ordinary Portland Cement over a couple of decades has resulted in the over-exploitation of natural raw materials in cement manufacturing. This has led to increased carbon dioxide emission levels in the air during cement production and concrete making. To counter the fresh air imbalance, it is the necessity of the epoch to shift toward the use of alternate burning fuels and primarily maximize the usage of Supplementary Cementitious Materials (SCMs) either in its natural or artificial form in replacing pure Ordinary Portland Cement (OPC). One of the major factors in maximizing SCM with OPC is the grain size distribution (GSD) of all primary elements. Microstructure, grain packing density, water requirement, rate of hydration, initial and final sets, strength, permeability, workability, and durability of cement and its allied by-products are significantly affected by grain size distribution in the cement medium. This paper deals with the influence of the distribution of grain size on certain major mechanical properties of Ground Granulated Blast Furnace Slag (GGBFS) supplemented binary cement.

Rajan Suresh Kamble, K. G. Guptha
Thermo-structural Analysis of Cryogenic Tank on LNG Carriers

Cryogenic tanks are used to store and transport liquefied gases such as nitrogen, oxygen, and hydrogen. Due to the extreme low temperatures of these liquids, cryogenic tanks require specialized design and analysis to ensure their structural integrity and safety. Thermo-structural analysis is a crucial component of this design process, as it combines the effects of both temperature and structural stresses on the tank. The present study will focus on the thermo-structural analysis of cryogenic tanks, which involves modeling the tank's behavior under thermal and mechanical loads. The analysis involves several steps, including the determination of temperature gradients within the tank, the calculation of thermal stresses resulting from these gradients, and the analysis of mechanical stresses caused by the tank's weight and liquefied cargo loads. The analysis also takes into consideration the properties of the materials used to construct the tank, such as their thermal expansion coefficients and their behavior under stress. The use of advanced simulation software enables engineers to accurately predict the behavior of the tank under different operating conditions, allowing for the optimization of the tank's design and the identification of potential failure points. Overall, the thermo-structural analysis of cryogenic tanks is a complex and critical aspect of their design and operation. By accurately modeling the tank's behavior under various conditions, engineers can ensure its safety and reliability, which are essential for the transportation and storage of liquefied gases.

Binsina Rahmath, K. Sreejith, Anil Kumar Dash, Vishwanath Nagarajan
Thermal Performance of Residential Buildings at Different Locations

The thermal dynamic thermal properties of the building envelop is an important parameter in thermal comfort studies. The present experimental study investigates the thermal performance parameters of the wall envelopes for the residential buildings at from different locations. The study involves actual field measurements of the buildings inside & outside wall surface temperatures. Time lag (TL) and Decrement factor (DF) are the major parameters that are being evaluated for building wall envelopes. The K-type thermocouple (as temperature sensor), integrated with microcontroller (Arduino) is used for acquiring data of measured temperatures from the building envelope. In addition to the temperature sensors, a Micro SD card adapter module (to store the surface temperature data) and a DS3231 RTC module (for date and timekeeping) have been used. As a result, the integrated device forms a low-cost data acquisition system (DAQ). The data is post processed for obtaining the time lag and decrement factor. The result shows that the time lag varies between 4.36 and 6.5 h and the decrement factor lies in the range of 0.213–1.750. These results help in understanding the thermal behavior of the building envelope in residential buildings.

C. K. Himarani, D. S. Harish Gowda, A. R. Keerthanaram, M. V. Jashwanth Gowda, N. C. Balaji
Comparative Study on Prediction of Interfacial Bond Strength of FRP with Concrete Using Machine Learning Methods

As time elapses for a structure its strength decreases over some time but its utility keeps on growing this results in the same time demolition may cost more, for this problem rehabilitation is the solution. One rehabilitation material is Fiber Reinforced Polymer (FRP), binding on structural elements like beams and columns slabs strengthens the existing structure. So, it is necessary to know bond strength but it depends on several factors like FRP properties (Young modulus, thickness, bond length, tensile strength, width of FRP) and concrete block properties (compressive strength and width of concrete specimen). There are empirical equations to determine bond strength but in practice, these are very far from tested data. So, it is necessary to find the relation between FRP bond strength with respect to FRP and concrete properties. In present days, machine learning methods give good results when compared to conventional methods. So, it is necessary to use the best machine learning model to predict bond strength. This study aims to develop a comprehensive database of experimental results from direct shear specimens made of FRP concrete, and an assessment of the effectiveness of four machine learning algorithms including Support vector mechanism, Ridge regression, Lasso regression, and Elastic regression. The study will also develop a new equation for forecasting interfacial bond strength by considering the parameters discovered by the machine learning algorithm with interpretable physical meanings. The results of this study will provide valuable insights into the effectiveness of ML algorithms for predicting interfacial bond strength in FRP-concrete direct shear specimens and offer a new equation for forecasting interfacial bond strength with practical implications.

H. C. Abhiram, T. Palanisamy
Metadata
Title
Technologies for Sustainable Buildings and Infrastructure
Editors
B. R. Jayalekshmi
K. S. Nanjunda Rao
G. S. Pavan
Copyright Year
2024
Publisher
Springer Nature Singapore
Electronic ISBN
978-981-9748-44-0
Print ISBN
978-981-9748-43-3
DOI
https://doi.org/10.1007/978-981-97-4844-0