2031 research outputs found
Sort by
Predicting the UCS of Industrial Byproduct-Based CLSM Using Machine Learning and Experiments
No full textThis study investigated the development of sustainable Controlled Low Strength Material (CLSM) using industrial by-products pond ash, fly ash, and red mud as alternatives to conventional concrete constituents. This research employs a dual methodology: comprehensive experimental testing aligned with ASTM standards and the implementation of advanced machine learning (ML) techniques to predict the unconfined compressive strength (UCS) of CLSM mixes. Experimental datasets, generated through the variation of key material and mix design parameters, were utilized to train ensemble-based supervised ML models, including ADAboost, XGBoost, gradient boosting machine (GBM), and random forest (RF). A comparative performance evaluation was conducted, and the XGBoost model emerged as the most accurate predictor, achieving R² values of 0.969 for training and 0.933 for testing, surpassing GBM, ADAboost, and RF across multiple performance indicators. The optimal model was subsequently embedded into a graphical user interface (GUI) for UCS prediction. A sensitivity analysis based on the XGBoost model revealed that cement, water, and curing age were the most influential parameters affecting UCS, with cement exhibiting the highest impact value of 0.86 and a relative contribution of 19%. These findings emphasize the significance of these variables in strength development and mix optimization. The integration of experimental validation with predictive modeling not only advances the understanding of CLSM behavior but also underscores the utility of ML in the formulation of sustainable construction materials. This research supports the beneficial reuse of industrial waste, aligns with environmental sustainability goals, and provides an efficient and reliable tool for CLSM mix design
Adaptive Stilt Housing and Socio-Ecological Resilience in Coastal Settlements Under Urbanization Pressure
No full textThe water-based settlement of Cambayya, Makassar, represents a spatial adaptation by coastal communities facing urbanization, land scarcity, and dynamic marine conditions. High population density has driven the organic growth of informal stilt housing over coastal waters. This study examines spatial adaptation strategies that foster socio-ecological resilience in densely populated coastal environments. Utilizing a mixed-methods approach within a constructivist paradigm, the research combines spatial analysis, participatory observation, field surveys, interviews, and socio-ecological data interpretation. The findings reveal key adaptive responses, including the conversion of underfloor stilt areas into domestic space, the use of hybrid timber-concrete structures, and horizontal expansion into shallow waters. While adaptive, these practices exacerbate ecological degradation, such as tidal flooding, pollution, and inadequate sanitation. The study highlights the need for inclusive, sustainable spatial planning and proposes an innovative strategy: integrating stilt housing with waterfront development and cultural seascape tourism. This approach not only enhances resilience but also unlocks economic potential—estimated at over IDR 3.5 billion annually—through heritage-based ecotourism and creative industries. The study contributes a context-sensitive, community-driven spatial model for resilient coastal urbanism, positioning Cambayya as a reference for sustainable development in similar tropical coastal settlements
GPR-Driven Geomechanical Modeling and Drill-Blast Optimization for Enhanced Efficiency in Open-Pit Gold Mining
Get PDFThis study seeks to raise the operational efficiency and economic return of the Vasilkovskoye open-pit gold mine by integrating real-time ground-penetrating-radar (GPR) monitoring, geomechanical modeling, and digital optimization of drilling-and-blasting parameters. Continuous GPR scanning identified hazardous fracture zones that were subsequently characterized in DIPS and RS2 to model slope stability, while ShotPlus-based blast simulations and OrePro 3D displacement modeling guided the redesign of hole spacing, charge distribution, and delay timing. Fragmentation quality was verified with high-resolution photogrammetry and correlated to blast design through statistical analysis; a comparative techno-economic assessment quantified cost and dilution differentials between conventional and optimized schemes. The integrated workflow established a robust predictive link between blast geometry and fragment size, reducing oversize generation by 17% and ore dilution by 9%, while increasing gold grade in mill feed from 0.84 g t⁻¹ to 0.94 g t⁻¹. GPR-informed hazard mapping eliminated unplanned wall failures, and the revised pattern lowered specific explosive consumption without compromising fragmentation, cutting total unit costs by 8%. Unlike previous studies that treat slope stability and blasting as separate tasks, this study couples deformation dynamics with blast design in a single digital loop, offering a transferable framework for automation-ready, risk-aware mine planning at complex geological sites
Evaluating the Role of Polymer Concrete in Enhancing Long-Term Performance and Reducing Early Age Cracking
No full textThis study evaluates the potential of polymer concrete (PC) to reduce early-age cracking and improve long-term durability compared to traditional Portland cement concrete (PCC). It investigates the effect of varying polymer-to-aggregate ratios (5%-20%) on mechanical properties, early-age cracking, and durability under extreme environmental conditions, including freeze-thaw cycles, high temperatures, and chemical exposure. Experimental tests were conducted to measure compressive strength, flexural strength, fracture toughness, and durability of PC under accelerated aging conditions. The methodology involved mixing epoxy resin with selected aggregates to create different PC formulations. Tests such as restrained shrinkage, freeze-thaw, sulfuric acid immersion, and high-temperature exposure simulated real-world conditions. Results showed that PC with 15%-20% polymer content reduced early-age cracking by up to 56%, increased compressive strength by 28%, and exhibited superior resistance to freeze-thaw cycles and chemical degradation compared to PCC. The main contribution of this study is a comprehensive comparison between PC and PCC under accelerated aging, providing insights into the optimal polymer-to-aggregate ratio for maximizing performance and durability. These findings underscore the potential of polymer concrete as a durable, long-lasting material for high-performance infrastructure, especially in harsh environments. The research suggests that PC could extend the service life of concrete structures, lower maintenance costs, and offer a more sustainable alternative to traditional concrete
Experimental and Numerical Study on Seismic Performance of Batter Pile Groups in Loose Sand: No subtitle
Get PDFPile foundations are critical for maintaining structural integrity under seismic loading, and batter piles, being inclined elements, offer enhanced resistance to combined vertical and lateral forces compared to conventional vertical piles. The objective of this study is to investigate the seismic performance of negative and positive batter pile groups in loose sand. The research employed experimental and numerical approaches: shaking table tests were conducted on 3×3 pile groups embedded in sand with a relative density of 31.2%, subjected to the El Centro and Kobe earthquakes, while finite element modeling was performed to validate the experimental outcomes. The analysis compared the responses of piles with batter angles of -5°, 0°, and +5° in terms of lateral displacement, vertical displacement, and acceleration. Findings revealed that negative battering substantially amplifies pile group displacements, as demonstrated by a 22.085% increase in maximum lateral displacement and a 23.061% rise in vertical displacement for the El Centro motion when the batter angle shifted from 0° to -5°. Conversely, positive battering reduced displacements by up to 4.765%. The novelty of this work lies in experimentally and numerically quantifying the seismic drawbacks of negative battered piles, thereby providing new insights for optimizing pile group design in seismic regions
Performance Evaluation of Semi-Precast Reinforced Concrete Slabs Under Flexural Load
Get PDFThis study aims to evaluate the flexural performance of semi-precast reinforced concrete slabs incorporating steel lattice girders as internal reinforcement. The objective is to investigate the influence of geometric and material parameters such as precast slab thickness, lattice girder height, top chord diameter, concrete compressive strength, and the addition of steel or glass fibers on overall flexural capacity and deformation behavior. Thus, previous studies have shown that replacing conventional cast-in-situ slabs with semi-precast systems can reduce total construction costs by 43–70%. Thirteen semi-precast slabs and one control slab were tested under four-point bending, and a nonlinear finite element model was developed in ABAQUS to simulate the experimental response. The analysis focused on load–deflection behavior, strain distribution, and failure modes. Results indicated that increasing slab thickness and chord diameter enhanced stiffness and load-bearing capacity, while higher concrete strength and fiber reinforcement improved crack control and reduced deflection. The FEM model demonstrated strong agreement with experimental results, validating its reliability for predicting structural performance. This study extends previous research by integrating a broad experimental parameter range with a validated ABAQUS finite element model, providing new insights into the structural optimization and cost efficiency of semi-precast slab systems. The proposed semi-precast system exhibited ductile behavior and achieved savings in formwork and labor cost compared with conventional flat slabs, offering a practical and sustainable alternative for efficient concrete construction
Insights Into the Load-Carrying Mechanism and Interactive Effects of Dissimilar Piles in Cushioned Piled Rafts
Get PDFDisconnecting pile heads from the raft has gained wide application because the gravel and geogrid layers filling the space between them create a more even pressure distribution and reduce differential settlement. However, due to the complexity of modelling the multiple interfaces in the superstructure-foundation-subsoil system, previous findings on load-transfer mechanisms, interaction effects, and group optimization remain incomplete. Moreover, the common analytical approach employed for understanding the load transfer mechanism is the “unit cell’ concept, which cannot fully capture dissimilarity in the group. To address these limitations, this study aims to develop an analytical framework for predicting the load-settlement response of cushioned piled rafts with dissimilar piles. The proposed method simplifies the cushion-pile-soil interaction using a Winkler-type Spring model, while a hyperbolic load-transfer function captures the nonlinear pile-soil behavior. The model was verified against existing experimental and showed close agreement. It successfully captured the load-sharing mechanism, confirming that stiffer, longer, or larger-diameter piles attract a disproportionately higher share of the load. The novelty of this work lies in the establishment of an analytical model based on the principles of dissimilar pile groups but extended to include cushion force transmission, a critical integration that provides a realistic tool for practice
BIM Utilization to Eliminate Claims, Risks, and Improve Productivity in Construction Projects
Get PDFDelays, cost overruns, and disputes have traditionally plagued the construction industry. These issues arise from poor management and the complexities of construction projects. Given this situation, this research sought to identify and quantitatively prioritize the factors leading to claims/disputes, risks, and the construction activity productivity. At the same time, it aimed to measure the extent to which the BIM approach mitigates such factors. A mixed methodological approach was utilized, which included a structured questionnaire survey and two case studies. For quantitative data analysis, advanced techniques and tools of IBM SPSS and AMOS were used, which included mean analysis, Standard Deviation (SD), Relative Importance Index (RII), Confirmatory Factor Analysis (CFA), Exploratory Factor Analysis (EFA), and Structural Equation Modeling (SEM). The findings confirmed the hypothesis of this research, showing BIM implementation directly and substantially improves productivity, as evidenced by the 28% reductions in disputes, 31% in communication efficiency, and 24% in overall productivity. Moreover, SEM results confirmed the existence of positive causal relationships regarding BIM adoption and cost control, schedule compliance, and safe work performance. This study conclusively demonstrates that BIM is a dynamic management approach to enhancing stakeholder coordination, minimizing disputes, and ultimately ensuring project viability
Experimental and Numerical Study of Enlarged-Head Monopile Under Lateral Load in Soft Clay
Get PDFThe behavior of piles and the reaction of soils in contact with structures are crucial aspects of foundation engineering. Laboratory model tests were investigated to evaluate the enhancement of the subgrade modulus for laterally loaded piles with enlarged heads in clay. These tests compared typical piles with enlarged heads in soft clay, considering factors such as the pile slenderness ratio and geometric configurations. The study was expanded by simulating monopiles with and without head enlargements using the numerical program Plaxis 3D. The results highlight the effectiveness of enlarged-head piles, demonstrating a substantial increase in lateral subgrade reaction with adequate head depth. For piles with Lp/Dp = 24, an enlarged head geometry of Le/Lp = 0.4, Δ De/Dp = 1, and an undrained shear strength Cu = 15, the subgrade modulus improved by 200% compared to typical piles. Additionally, for Lp/Dp = 24 piles, the improvement due to enlargement was 1.3 and 2 times for Cu values of 10 and 15 kPa, respectively. These findings emphasize the advantages of using enlarged heads, especially uniform shapes, which are more practical and effective than tapered shapes. The numerical simulations corroborated the experimental results, providing detailed insights into deformation and bending moment variations that are challenging to measure in laboratory tests. Doi: 10.28991/CEJ-2025-011-02-04 Full Text: PD
Analysis and Development of Surface Distress Index Modified Based on Pavement Condition Index Criteria for Pavement Evaluation
Get PDFThe surface distress index (SDI) method has been used in Indonesia to assess road conditions, especially for areas with limited access, inadequate equipment, and limited local resources, which cause inaccuracies in the resulting pavement condition assessment. This research aims to develop a more accurate and efficient pavement condition assessment model based on three types of damage: cracks, potholes, and rutting. To generate accurate SDI values, we adopt and modify the deduct value (DV) curve based on the PCI method to determine the corresponding damage weight and the new road condition assessment. Based on the research results, the three modified SDI damage models showed an average accuracy value of 90%, which means that there is a good match between the models and the conditions on the ground, which is reinforced by the analysis of the mean absolute percentage error (MAPE) and root mean squared error (RMSE) values. In addition, the resulting development includes new assessment criteria and parameters, such as customized DV curve models and specific damage equations, condition index, condition rating, and maintenance types. Which in turn can support more effective and efficient infrastructure management and maintenance. Doi: 10.28991/CEJ-2025-011-01-014 Full Text: PD