4th International Conference on Structural Health Monitoring and Engineering Structures (SHM&ES 2025)

Table of Contents

1. Advances in Engineering and Materials

   1. Frontmatter

   2. Hempcrete—A Carbon Negative Material: From Its Performance to Application in Buildings

      Pham Tien Cuong, Hoang Quoc Tuan, Nguyen Gia Bao, Dhiraj Kumar Shah

      Abstract

      We are living in an era where environmental challenges are becoming increasingly urgent, as the pursuit of economic growth continues to accelerate. The construction industry, in particular, significantly contributes to greenhouse gas emissions due to the processes involved in the production, construction, and lifecycle use of building materials. Addressing this issue requires innovative approaches and materials that balance economic and environmental priorities. Hempcrete, a composite material made from hemp shives (the woody core of the hemp plant) and lime, has emerged as a promising solution. It is recognized as a “carbon-negative” material because it absorbs more CO₂ during its lifecycle than it emits. Moreover, hempcrete is derived from natural, renewable resources, making it inherently eco-friendly. This material is not only sustainable but also offers exceptional properties, such as being lightweight, highly soundproof, and providing superior thermal insulation. The application of hempcrete in construction projects represents a forward-thinking approach to green building. This paper delves into the performance characteristics of hempcrete and highlights its multifaceted benefits. Beyond its contributions to environmental protection and energy efficiency, hempcrete can reduce the loads on buildings by replacing traditional masonry materials like burned clay and unburned bricks, it saves the materials like concrete and steel, further promoting sustainability in the construction industry.

   3. Impact of Opening Ratio on the Structural Performance of Reinforced Concrete Frames with Infill Walls

      Phu-Anh-Huy Pham, Cao-Vinh Le, Van-Tien Nguyen

      Abstract

      This study investigates the influence of the wall opening ratio on the structural behavior of reinforced concrete (RC) frames with infill walls (IWs), focusing on the responses of columns, beams, and the first natural period T₁. A finite element model incorporating stiffness degradation and gap elements was developed and validated against experimental results. Numerical analyses were conducted for four wall thicknesses (70, 110, 220, and 330 mm) and opening ratios ranging from 0 to 100%. Results indicate that in columns, lateral displacement (\(\Delta\)) increases significantly with the opening ratio, while bending moment (M) also increases and shear force (Q) decreases—demonstrating internal force redistribution from the IWs to the RC frame. In beams, deflection (f) increases markedly, especially beyond 60% opening ratio, while both M and Q decrease sharply, reflecting reduced wall–beam interaction. Thicker walls lead to smaller deformations and more uniform structural responses. The study also shows that T₁ increases as the opening ratio rises and decreases as wall thickness increases, indicating a reduction in lateral stiffness caused by the infill walls. Based on the results, a 40% opening ratio is recommended as a practical limit to maintain overall structural stability, while reinforcement measures are advised for ratios exceeding 60%. The findings provide a quantitative basis for optimizing the seismic design of RC frames with IWs under lateral loading conditions.

   4. Effects of Circular Web Holes on Shear Strengths of Cold-Formed Steel Channel Sections

      Quoc Anh Vu, Ngoc Hieu Pham

      Abstract

      Holes are typically drilled into cold-formed steel sections to meet the requirements for installing technical systems in buildings. These drilled holes can impact the load-bearing capacity of the sections, a factor that has been studied and incorporated into design standards. In addition to evaluating compression and bending capacities, it’s crucial to also address the effect of these drilled holes on shear strength in design considerations. This paper, therefore, aims to explore how drilling, specifically circular holes, affects the shear strength of a common structural section namely the channel section. The study focuses on widely used sections in the market, with materials and design methods following Australian standards. The findings will help evaluate how the size of circular holes influences the shear strength of channel sections. Additionally, the paper provides recommendations for selecting hole sizes to assist designers in considering the shear strength of perforated sections.

   5. Impact of Dimensions of Flanges and Lips on Shear Strengths of Thin-Walled Steel Channel Sections

      Le Thuy Nguyen, Ngoc Hieu Pham

      Abstract

      Thin-walled steel sections are widely utilized in construction due to their advantageous properties. From a structural perspective, these sections are designed to withstand various forces, including compression, bending, and shear, among others. While the behaviors under compression and bending are well-established within theoretical calculations, the analysis of shear resistance involves a range of different considerations and theories. Historically, shear capacities were traditionally assumed to be considered solely by webs of steel sections although the presence of the lips and flanges also significantly influences the shear strengths of these sectional types. With advancements in linear buckling analysis, the influence of these components on shear strengths of such sections is now being considered. Therefore, this paper will explore the impact of the dimensions of components such as lips and flanges on the shear capacity of cold-formed steel sections with channel shapes. The goal is to provide recommendations for optimizing the shear resistance of these sections.

   6. Numerical Simulation of Combustion Kinetics for Thermal Degradation in Laminated Veneer Lumber (LVL) Under Fire Exposure

      T. T. Tran, T. B. Q. Vu, Thi-Thanh-Hoa Nguyen, Viet-Phuong Nguyen

      Abstract

      This research presents a detailed numerical simulation of combustion kinetics and thermal decomposition characteristics of Laminated Veneer Lumber (LVL) when subjected to fire conditions. A comprehensive finite element modeling framework is implemented to simulate heat transfer and predict the progression of material degradation in LVL structures exposed to elevated temperatures. The study incorporates advanced kinetic reaction models to accurately depict the complex thermal decomposition processes, providing insight into structural behavior and fire performance of engineered wood materials.

   7. Modelling of Timber-to-Timber Composite Beam Using Welded-Through Wood Dowels

      N. Hong Son, T. Trong Tuan, N. Le Thuy, L. Huu Thanh, N. G. Huy

      Abstract

      This study investigates the structural behavior of timber-to-timber composite beams connected using welded-through wood dowels, a novel fastening technique that enhances compatibility and sustainability compared to traditional metal connectors. Full-scale two-layer timber beams were fabricated and subjected to four-point bending tests to assess flexural performance, stiffness, and load distribution. Each specimen consisted of solid wood boards joined with 56 welded dowels, evenly spaced along the beam span. A corresponding finite element model was developed using Abaqus, exploiting geometric symmetry to improve computational efficiency. Two models were compared: a dowel-connected beam and an unjointed reference beam. Orthotropic material properties were assigned to simulate the anisotropic behavior of spruce timber, with fictitious vertical dowels adjusted for oblique orientation through local material rotation. The model incorporated detailed contact interactions and boundary conditions to replicate the physical test setup accurately. Results demonstrate that welded-through dowels significantly enhance shear transfer between timber layers, increasing global stiffness and improving structural integrity. Load–deflection curves from both experimental and numerical models confirm the effectiveness of the dowel system in achieving partial to near-full composite action. These findings suggest that welded-through dowels are a viable solution for sustainable, high-performance timber composites in structural applications.

   8. Ground Granulated Blast Furnace Slag and Fly Ash in Cement with Ultra-Low Clinker Content

      Hong Thi Luu, Mai Thanh Pham, Cham Thi Trinh, Amir Mirzaattari

      Abstract

      This paper presents research conducted into cement production with an extremely low clinker content. Hoang Thach Portland clinker was used at a dosage of less than 10% by mass. Fly ash and ground granulated blast furnace slag (GGBFS) were utilized in varying proportion, with slag content ranging from 60 to 90% and fly ash content from 10 to 30%. The results show that all samples exhibited acceptable consistency and setting times. More importantly, the cement containing 90% GGBFS, 9.6% clinker and 0.4% gypsum demonstrated good compressive strength. Its compressive strength, at 28 days of age, exceeded 30 MPa, equivalent to 60% of that of conventional cement containing 96% clinker. Another mix comprising 80% GGBFS and 10% fly ash achieved a compressive strength of nearly 28 MPa, which represented 54% of the control sample’s strength. In conclusion, it is feasible to produce cement with ultra-low clinker content using ground granulated blast furnace slag and fly ash.

   9. Strengthening Old Post-tensioned Concrete Beams Using External FRP Sheets

      Phuong Phan-Vu, Dinh Trung Nghia Pham

      Abstract

      The efficacy of externally bonded fibre-reinforced polymer (FRP) systems for reinforcing old unbonded post-tensioned concrete (UPC) beams remains unexplored. This experimental research aims to address this gap. The experiment involved four UPC beams, i.e., one new beam and three old beams (aged more than 6.5 years). External FRP sheets proved effective in restoring the deteriorated functionality of the old UPC beams and improving their performance. By resisting tensile stresses and increasing flexural stiffness, FRP reinforcement significantly improved the old beams’ behaviour in terms of deflection and load-carrying capacity. The FRP-strengthened old beams outperformed the new beam, especially in the ultimate stage.

   10. Investigation of Local Buckling Loads of Cold-Formed Steel Channel Sections with Eccentric Web Holes Under Compression

       Van Thanh Thinh, Ngoc Hieu Pham, Ngoc Thang Nguyen, Le Thuy Nguyen

       Abstract

       Thin-walled steel sections with perforations are widely used for technical installation requirements, but their structural capacities are reduced due to the presence of perforations. These reductions are addressed in the American Specification through the Direct Strength Method (DSM), a modern approach for designing cold-formed steel sections. The DSM allows for the prediction of strengths of perforated sections by utilising elastic buckling loads, with this analysis being a necessary component for its application. Currently, design guidelines apply to thin-walled sections with concentric web holes, and elastic buckling analyses are typically based on this configuration. Web holes, however, are often drilled eccentrically due to technical constraints; and this can alter the strengths and behaviors of such steel members. This paper therefore investigates the impact of eccentric web holes on local buckling loads of thin-walled sections due to compression. The THIN-WALL-2 software package will be used for the elastic buckling analysis. The investigated results will demonstrate the reduction in local buckling loads for sections with eccentric holes compared to concentric ones. This will be the foundation for further research to provide design recommendations.

   11. Energy Consumption Comparison Using 6D BIM Tool: A Case Study of a 2-Storey House in Hanoi, Vietnam

       Tran-Hieu Nguyen, Do Thi Mai Dung

       Abstract

       6D Building Information Modeling (BIM) enhances energy-efficient design by integrating advanced energy analysis into building models. This study employs TerMus PLUS, a 6D BIM tool, to assess energy consumption in a typical 2-storey residential house in Hanoi, northern Vietnam. In more detail, a parametric study examines the impact of key design parameters, including exterior and interior wall materials and thickness, painting color, window type, and window area, on the building’s energy performance. Using Hanoi’s hot-humid climate data, energy simulations were conducted to compare various design configurations. The results identify painting color, window type and window area as the most influential factors in reducing energy consumption. The findings offer practical recommendations for optimizing residential designs in Vietnam’s tropical climate. This study highlights the potential of 6D BIM tools like TerMus PLUS to support sustainable design, providing architects and engineers with accurate forecasts of building energy consumption, thereby providing optimal design options.

   12. An Investigation on the Multi-storey Building’s the Modal Vibration Using Low-Cost Sensor Based on Frequency Domain Decomposition

       Vinh Nguyen-Quang, Hung Nguyen-Quoc, Linh Huynh-Cong, Toan Pham-Bao

       Abstract

       Modal Analysis (MA) techniques are considered to have made significant contributions in modern fields, including aerospace, mechanical, and civil engineering, especially in the Structural Health Monitoring (SHM). The main task of MA is to perform analysis based on measurement data such as vibration responses and desired outputs suitable for condition monitoring objectives based on vibration features. In this study, the modal vibration modes of a multi-storey building model were experimentally investigated and analyzed using the Frequency Domain Analysis technique (FDD). The multi-storey building model is modeled into Multiple Degree of Freedom (MDOF) systems with generalized coordinates in the lateral direction along with theoretical dynamic parameters for the purpose of determining the initial natural frequencies by the eigenvalue method. Experimental measurements are utilized to identify the modal frequencies, which are then compared to theoretical results. Experiments are conducted using Low-Cost Sensors MPU6050 in conjunction with a cost-effective Arduino system designed for simplicity and cost-effectiveness while ensuring reliable results. Consequently, the FDD technique is utilized to determine the vibration characteristics as modal parameters. The results from FDD are integrated with the Stabilization Diagram (SD) and compared with the theoretical problem to evaluate the sensor’s and the model’s reliability.

   13. An Enhanced Algorithm for Segmenting Point Clouds into Clusters Based on Euclidean Distance

       Tran Thanh Ha, Van Vy, Nguyen Quang Tan

       Abstract

       This paper introduces an enhanced algorithm for segmenting point clouds into clusters based on Euclidean distance. By considering Euclidean distance— a simple and powerful geometric measure—we introduce a new method that not only outperforms previous methods in segmentation accuracy but also handles the scale sensitivity issue of existing Euclidean distance-based work. Our experiments demonstrate that our improved algorithm has a greater ability to accurately segment complex point cloud data, representing significant progress in the algorithm and the application of the field. By exploring segmentation process’s different approaches and presenting an advanced algorithm, this paper makes a contribution to the evolution of point cloud processing, providing valuable knowledge and tools for both researchers and practitioners. Results demonstrate that the performance of clustering is enhanced by the proposed algorithm as opposed to the other algorithms.

   14. Enhancement of Mechanical Performance of Cement Pastes Prepared with Concrete Reclaimed Water Using CO2 Intermixing

       Tuan Minh Ha, Toan-Hiep Luong, Hong-Ba-Thi Dinh

       Abstract

       This study investigates the effects of CO₂ intermixing on the fresh and hardened properties of cement pastes made with concrete reclaimed water. The reclaimed water, sourced from a construction site and stored for 30 days, was used to completely replace potable water in the cement paste preparation. The mixing process involved introducing CO₂ in varying amounts (0–1.2% of total cement weight) into cement pastes made with reclaimed water. Five cement paste formulations were studied: a control sample using potable water and four samples using reclaimed water with different CO₂ doses. The fresh properties of the cement pastes were evaluated through flowability and rheological tests, while the hardened properties were assessed by compressive strength and hydration heat measurements. The results showed that using reclaimed water slightly reduced the flowability of cement pastes, with a notable increase in rheological properties. Higher CO₂ doses intensified this effect due to the accelerated hydration kinetics from carbonation reactions that formed CaCO₃. Hydration heat patterns were similar between samples made with potable and reclaimed water, with 0.3% and 0.6% CO₂ significantly increasing hydration heat, while 1.2% CO₂ reduced it. The compressive strength of samples with 0.3% and 0.6% CO₂ was 10% higher than the control at 28 days. However, the 1.2% CO₂ dose caused a 15% decrease in compressive strength, likely due to hydration inhibition. These findings suggest that CO₂ intermixing can enhance the mechanical properties of cement pastes made with reclaimed water, with optimal CO₂ doses around 0.6%.

   15. A Hybrid Whale Optimization Algorithm Approach for Efficient Bottled Water Distribution

       Van Nam Nguyen, Trong Phuoc Nguyen

       Abstract

       This study aims to construct an optimized distribution schedule for bottled water suppliers. The study introduces the Hybrid Whale Optimization Algorithm (HWA), which integrates three core search mechanisms: migration, priority selection, and prey enrichment, along with opposition-based learning and mutation-crossover methods. Its effectiveness has been validated through evaluations using 23 standard functions and a real-world case study focusing on water distribution in Vietnam. The results show that HWA is a powerful decision support tool that effectively facilitates optimal decision-making processes in water distribution path management.

   16. Microgrid Energy Management with the Sand Cat Swarm Optimization

       Vu Hong Son Pham, Thanh Thien Vo, Van Nam Nguyen, Nghiep Trinh Nguyen Dang

       Abstract

       Microgrid optimization is essential for enhancing economic efficiency, ensuring reliable operation, and integrating renewable energy sources (RESs) into the power grid. However, the variability of renewable generation, fluctuating demand, and dynamic environmental conditions pose significant challenges to conventional optimization methods. This paper proposes an innovative energy management strategy based on the sand cat swarm optimization (SCSO) algorithm. Inspired by the adaptive hunting behavior of sand cats in harsh desert environments, SCSO offers strong robustness in addressing the complex, multi-dimensional, and nonlinear nature of microgrid optimization. The proposed strategy optimizes power allocation among photovoltaic systems (PVs), wind power plants (WPs), and combined heat and power plants (CHPs) to meet hourly demand while accommodating intermittent generation. Simulations on the IEEE 37-node system confirm the algorithm’s superior performance, with notable improvements in energy cost reduction, emission minimization, and renewable energy utilization, outperforming several benchmark optimization methods.

   17. Influence of Sample Shape and Compaction Energy on the Compressive Strength of Slag-RCC Prepared Using the Modified Proctor Test

       Chau-Tuan Le, My Ngoc-Tra Lam, Trong Nghia-Nguyen

       Abstract

       This study examines the compressive strength of roller-compacted concrete (RCC) incorporating ground granulated blast-furnace slag (GGBS) using the modified Proctor compaction method. GGBS replaced cement at four levels: 15, 30, 45, and 60%, producing slag-RCC mixtures. These mixtures were compacted in cylindrical and cubic molds using a Proctor hammer to evaluate the influence of sample shape on compressive strength. Additionally, low and high compaction energy levels were applied to assess their effects. Results showed that the conversion coefficient from cylindrical to cubic specimens was lower for slag-RCC than for conventional RCC. The conversion coefficient decreased with increasing compressive strength, depending on the strength level. Increasing compaction energy by 100% led to approximately a 10% increase in compressive strength, while reducing energy by 50% resulted in a similar 10% decrease.

   18. The Impact of Periodic Tidal Variations on the Stability of Riverbanks

       Yen Hai Tran, Nhut-Nhut Nguyen

       Abstract

       There are many causes leading to riverbank instability and erosion, such as excessive sand exploitation, ship waves, water flow, tidal level, floods, soft ground, human construction activities, etc. In Ho Chi Minh City, where the river system is quite developed and is greatly affected by high tide flooding, the riverbank geology is also strongly affected by tidal fluctuations. The study thus focuses on analyzing the influence of periodic tidal variations on the stability of riverbank slopes. PLAXIS 2D is applied to model riverbank cross- sections with different slopes, from 16° to 55°, under the influence of tidal levels which change over time to assess their influence on displacement, hydraulic gradient and stability coefficient. Consequently, warnings are given about slopes with high risk of erosion. These slopes are compared with observed erosion slopes to check the reliability of modeling. The findings contribute to improving erosion prediction methods by demonstrating how repeated tidal fluctuations can induce progressive weakening of the riverbank structure. These insights have practical implications for the design of riverbank protection systems in estuarine and coastal river environments where tidal actions are prominent.

   19. Determination of Wind Load on High-Rise Buildings by Wind Tunnel Test in Vietnam

       Nguyen Le Thuy, Vu Thanh Trung, Nguyen Hong Son

       Abstract

       As buildings in Vietnam become increasingly taller and more architecturally complex, the application of current Vietnamese and international wind loading standards has proven inadequate in many design scenarios. In response, wind tunnel testing has gained prominence as a modern and effective method for accurately determining wind loads in structural design. This technique not only enhances the reliability of wind load assessments but also contributes to improved design efficiency and reduced construction costs. Typically, wind loads determined through wind tunnel testing are 20–30% lower than those estimated using conventional code-based methods. This paper presents a comprehensive review of wind tunnel testing applications carried out over the past decade at the Vietnam Institute for Building Science and Technology.

   20. Silica Effects on Properties of Portland Cement Used in Oil Well Construction

       Hong Thi Luu, Hieu Duy Nguyen, Mai Thanh Pham, Amir Mirzaattari

       Abstract

       This paper presents the finding of a study investigating the effects of silica additive on certain properties of Hoang Thach Portland cement and evaluates its suitability for oil well construction at a depth of 1000 m. In this study, silica was added to the cement in varying proportions from 0 to 25% by mass. The results indicate that as the silica content increased, the water requirement of the mixtures gradually rose, while the slurry density slightly declined. At a curing temperature of 52 °C, both the initial and final setting times of the cement paste decreased, and the 1-day compressive strength of the hardened samples increased sharply. Notably, sample M3, containing 15% silica, achieved the highest compressive strength, 1.28 MPa—approximately three times higher than that of the reference sample. However, under standard conditions, the strength of silica-modified samples dropped significantly. These results suggest that Hoang Thach Portland cement, when combined with an appropriate amount of silica, can be effectively used in oil well construction.

   21. Steel Slag as a Sustainable Substitute in Concrete

       Van Nam Nguyen, Phuoc Trong Nguyen

       Abstract

       This study investigates the feasibility of using steel slag (SS) as a sustainable alternative in concrete by partially replacing cement, coarse, and fine aggregates. Three concrete mixes were designed: M1 (control), M2 (SS as coarse aggregate), and M3 (SS powder and fly ash replacing cement). Workability tests showed SS aggregates reduced slump retention due to their porous structure, while FA in M3 improved it. SS accelerated cement setting, with M2 setting faster than M1, while M3 had a slightly delayed setting due to FA. Strength tests revealed similar compressive strengths among all mixes at 90 days, with M2 enhancing flexural strength by 12.7%. SEM analysis confirmed improved microstructure in M3, with a dense C-S–H gel network reducing voids and cracks. These findings highlight SS’s potential as a viable replacement material in sustainable concrete production.