Expansive soils pose geotechnical challenges due to their susceptibility to moisture-induced volume changes, resulting in instability and infrastructure deterioration. This study investigates a stabilization system based on geopolymer binder, iron-enriched biochar (IEB), crumb rubber (CR), and textile fiber (TF), with emphasis on damage evolution and durability performance. A sequential experimental procedure was adopted to identify the best-performing IEB dosage and biochar type, followed by stepwise reinforcement selection using CR and TF. Mechanical behavior, curing-age development, and durability were evaluated through laboratory testing. Damage evolution was assessed using AE, DIC, SEM, and Micro-CT to quantify defect evolution, strain localization, and structural changes, while mechanical improvements corresponded to microstructural densification and reduced defect connectivity. Results identified 3
In recent years, significant efforts have been made to improve traffic efficiency in highway systems. Skew bridges are increasingly being constructed; however, they are more vulnerable to seismic damage than straight and curved bridges. The effects of soil–structure interaction (SSI) are an important issue in relation to the seismic response of highway bridges, but its effects on the seismic response of skew bridges have not been sufficiently studied. In this paper, the effects of SSI on the seismic behavior of a typical skew highway bridge under fixed base and SSI conditions are studied via numerical modeling with SAP2000 The SSI effect is modeled using the Berdugo-Novak (BN) equivalent spring model, and the structure is subjected to five earthquake time histories for rocky, medium, and soft soil conditions. The impact of the foundation flexibility on the displacement of the bridge deck, shear force, bending moment, and dynamic properties of the bridge has been systematically studied. The results demonstrate that the SSI has a great impact on the bridge response, with the maximum differences of 44
The increasing demand for sustainable construction materials has accelerated the development of alternative aggregate systems for pervious concrete. This study investigates the performance of fly ash-based pervious geopolymer concrete incorporating engineered synthetic aggregates manufactured from alkali-activated ground granulated blast furnace slag (GGBS). Class F fly ash with 5
The present study investigates the influence of Mangifera indica (mango) seed shell-extracted cellulose, aluminum wire mesh, and Pergularia daemia stem fiber as reinforcements in vinyl ester composites, with a focus on electromagnetic interference (EMI) shielding effectiveness, dielectric behaviour, load-bearing capacity, and tribological properties. The cellulose particle is extracted from Mangifera indica seed shell using thermo chemical process. The vinyl ester matrix, Pergularia daemia stem fiber, and aluminium wire mesh reinforced composite using hand layup method and their performance are evaluated as per ASTM standard. The cellulose extracted from mango seed shells provides a sustainable and filler material, while the aluminum wire mesh enhances EMI shielding by improving the composite’s conductivity. Pergularia daemia stem fiber impart improved mechanical strength and toughness to the composite. The addition of 3 wt
Polypropylene (PP) composites reinforced with recycled jute fibers (JF) have been investigated as sustainable alternatives for applications in reinforced concrete (RC) structures, contributing to waste reuse and circular economy practices. In this study, polymer matrix composites were produced using polypropylene and shredded jute fibers with contents of 20
Accurate prediction of circular slope stability remains challenging because slope failure is controlled by nonlinear interactions among geomaterial strength, slope geometry, pore-water effects, and small case-history datasets. Although many studies have applied boosting models and metaheuristic tuning to geotechnical classification, limited attention has been given to optimized CatBoost (CAT) frameworks that combine multiple optimizers, consistent dataset reporting, rigorous validation, and explainable interpretation. This study addresses this gap by developing a metaheuristic-optimized CAT framework for circular slope stability assessment. The established 221-case benchmark database, comprising 115 stable and 106 failed slopes, was used with six predictors: slope height (H), slope angle (β), unit weight (γ), cohesion (C), internal friction angle (φ), and pore-water pressure ratio (ru). CAT was first benchmarked against Light Gradient Boosting Machine (LGBM), XGBoost (XGB), and conventional Gradient Boosting (GB), and then optimized using Grey Wolf Optimizer (GWO), Artificial Hummingbird Algorithm (AHA), and Potter Optimization Algorithm (POA), with AHA and POA representing less-explored optimizers in slope stability prediction. Among the optimized configurations, CAT-GWO achieved an Accuracy of 0.9333, a stable-class F1-score of 0.9362, a failure sensitivity of 0.9091, a stable-class specificity of 0.9565, a balanced accuracy of 0.9328, and a macro-F1 of 0.9332. Two of the 22 failed slopes were incorrectly classified as stable. Therefore, the results do not demonstrate a reduction in missed failures compared with the baseline CAT model. Shapley Additive Explanations (SHAP) analysis identified φ, γ, and C as the dominant predictors and ru as the least influential variable. The proposed framework offers an accurate, robust, transparent, and interpretable decision-support tool for practical slope stability evaluation.
The convergence of self-compacting geopolymer concrete (SCGC) and 3D concrete printing (3DCP) represents one of the most compelling frontiers in sustainable construction technology. While SCGC has established itself as a credible low-carbon alternative to ordinary Portland cement (OPC) concrete offering excellent workability, durability, and mechanical performance. Its application within extrusion-based additive manufacturing introduces a fundamentally different set of demands that have received comparatively limited systematic attention. This paper provides a focused review of the current state of knowledge on SCGC as a feedstock material for 3DCP, examining the rheological requirements unique to the printing environment, the challenges of adapting traditional SCGC mix design for printability, and the mechanical and durability consequences of the layer-by-layer deposition process. Key issues including open time management, thixotropy control, interlayer bond strength, anisotropy, and shrinkage at print interfaces are discussed in depth. The role of binder selection, activator chemistry, fiber reinforcement, and nano-additives in producing print-ready geopolymer mixes is also assessed. The review indicates that achieving an optimal balance between pumpability, extrudability, and buildability remains the primary challenge in developing printable SCGC. Fly ash–slag blended binders and advanced additives show considerable potential for enhancing printing performance, whereas interlayer bond degradation, mechanical anisotropy, and the lack of standardized printability assessment methods continue to limit practical implementation. Overall, the review identifies the development of standardized printability evaluation methods, optimization of SCGC mix designs, enhancement of interlayer performance, and comprehensive long-term durability assessment as key priorities for advancing the practical adoption of SCGC in large-scale 3D concrete printing.
Operating bridges involves significant economic, social, and environmental impacts. Therefore, ensuring the sustainable maintenance of these vital structures throughout their life cycle must be carefully examined. This paper provides an analytical review of 51 manuscripts on sustainable bridge maintenance published in Scopus and Web of Science from 2000 to 2025. The search inquiry covers at least 4 of the 7 key sustainability themes. The novelty of this paper lies in developing an original classification system to evaluate targeted manuscripts: Case Studies and/or Comparative Assessment and Analyses (CS), Framework and Methodology Development (FM), Theoretical Models and General Practices (TM), Review (R). Using this system, the paper identifies targeted, in-depth gaps in sustainable bridge maintenance and provides a roadmap of future research. The results reveal a discrepancy between theoretical development and the practical implementation of Life Cycle Assessment (LCA) in real-world bridges, as well as an imbalance in material and technological coverage, with concrete bridges receiving more attention. Moreover, multi-criteria decision-making (MCDM) in sustainable bridge maintenance remains far less investigated than in sustainable bridge design. The developed roadmap is a valuable resource that underscores the urgency of implementing LCA in steel–concrete bridges and of initiating element-oriented sustainability analysis in the short term.
The construction industry is a major driver of global development, yet it also contributes substantially to environmental degradation through the energy-intensive production of Ordinary Portland Cement (OPC). To reduce the carbon footprint of concrete and lessen pressure on natural resources, the incorporation of supplementary cementitious materials (SCMs) has become an important strategy for sustainable infrastructure. This study presents a comprehensive experimental investigation and practical mix-design optimization framework for 126 concrete specimens representing 108 unique concrete mix designs incorporating Fly Ash (FA) and Ground Granulated Blast-Furnace Slag (GGBS) as partial clinker replacements, with particular attention to the Bangladeshi construction context. Using locally sourced materials, including Sylhet sand, local sand, and crushed stone aggregates, 126 concrete specimens were tested, comprising 36 OPC control mixes, 36 fly ash blends, and 54 GGBS blends, across three water-to-binder (w/b) ratios (0.4, 0.5, and 0.6) and binder contents ranging from 350 to 500 kg/m3. The program included standardized testing of workability, 28-day compressive strength, and material characterization through chemical and physical analysis. The results showed that 20
Bitumen modification is an effective method to improve the performance of the pavement under heavy traffic and harsh environmental conditions. Among the various modification techniques available, the combined use of polymers and nanomaterials has gained increasing attention in recent years. Thus, in this research, the binder was modified using 5.5
Uncontrolled intersections operating under heterogeneous mixed-traffic conditions constitute a substantial component of transportation networks in semi-urban regions of India. Conventional Level of Service (LOS) assessment methods primarily rely on operational traffic measures and do not explicitly account for user perceptions of service quality. This study investigates the relationship between perception-based and operational LOS at semi-urban uncontrolled intersections through an integrated behavioral and traffic-performance assessment framework. Data were collected from thirteen uncontrolled intersections located across eight Indian cities. A combined stated-preference and revealed-preference survey was administered to 5,050 motorized drivers to obtain perception-related information, while GPS-enabled probe vehicle surveys were conducted to measure operational variables including travel time, speed, and delay. Boruta feature selection and Random Forest analysis were employed to identify significant explanatory variables. Functional Neural Network (FNN) and Multi-Gene Genetic Programming (MGGP) models were developed to estimate latent traveler satisfaction scores, whereas Kernelized Type-2 Fuzzy C-Means (KT2FCM) clustering was applied to derive operational LOS categories from service-delay observations. The analysis identified service delay, volume-to-capacity ratio, parking demand, conflicting traffic flow, travel speed, heavy-vehicle proportion, land-use characteristics, and driver age as significant determinants of perceived service quality. The final calibrated FNN model achieved an adjusted-R2 of 0.908, compared with 0.901 for the final calibrated MGGP model. Comparative analysis indicated differences between perception-derived LOS thresholds and delay-based operational LOS classifications across several study intersections. The findings suggest that operational traffic performance and user-perceived service quality represent related but distinct dimensions of intersection service assessment. The proposed framework provides a basis for examining LOS under heterogeneous mixed-traffic conditions using both operational and driver behavioral indicators.
A combined framework to estimate as well as optimize the durability performance of geopolymer concrete cured in natural environment using a unique Durability Index (DI) and interpretable machine learning is presented in the current study. The eleven mixes C1 to C11 comprising of fly ash–ground granulated blast furnace slag (GGBS)–silica fume (SF) were tested and results were expressed for water absorption—7, 14 and 28 days of curing, rapid chloride permeability (RCPT)− 28 days of curing and sorptivity tests—7, 14 and 28 days of curing. The results showed a considerable drop in permeability-related properties for higher GGBS and SF contents and validated by microstructural analysis. Mix C10 containing higher calcium proportions of 50
This study investigates the stabilization of expansive clay using a binary blend of recycled concrete aggregates (RCA) and waste glass (WG) for sustainable pavement subgrade applications. The novelty of this work lies in the simultaneous use of these two recycled materials, activating a hybrid stabilization mechanism combining mechanical densification, angular particle interlocking, and limited physicochemical interactions that remains insufficiently explored in the literature. An integrated experimental program (Modified Proctor, soaked CBR, oedometer, XRD, FTIR, SEM–EDX) was conducted on four mixtures. The optimal mixture (10
This paper examines the axial behavior of concrete-filled steel tubes (CFSTs) using experimental analysis and multivariable regression modeling. In the first part of the study, nine CFST specimens and three unconfined concrete cylinders were tested under concentric axial loading. This was done in order to assess their load displacement response and identify if and how any enhancement in strength and confinement effects occurs. The tests revealed that due to steel confinement, there was a significant improvement in strength and ductility. In the second part, a large volume of data was compiled from 321 CFST specimens reported in previous studies to develop and assess five regression models for predicting the ultimate load (Nu) and strength index (SI) of CFSTs. The five models were linear, non-linear, pure quadratic, interaction, and full quadratic. The database was randomly divided into training (75
New high-speed trains will be provided in Egypt to compete with existing modes of transport, including conventional trains, airplanes, buses, and shared taxis. To analyze passengers’ responses to these trains, a cross nested mode-choice model was developed for long-distance trips using Biogeme software, based on questionnaire data. These data include passengers’ socio-economic characteristics, stated-preference options, and trip properties for each mode. The sensitivity analysis of the model resulted in raising the accessibility through high-speed access modes . The model was utilized to estimate the value of time, mode share, and future ridership. Social travelers prefer the high-speed trains of cost €3.75 per 100 km. For trips longer than 150 km, a maximum mode share of 45
Stormwater runoff from road surfaces represents a significant source of diffuse pollution and may adversely affect both surface water and groundwater if discharged without adequate treatment. To mitigate these impacts, stormwater management systems combining retention, sedimentation, and infiltration have become an essential component of sustainable road infrastructure. This case study presents the planning, hydraulic design, and field observations of a stormwater protection facility constructed as part of the Wipfing Bypass road project in Upper Austria. The system integrates a gross solids trap, a retention basin, and an infiltration basin for the treatment of road surface runoff. Hydraulic design was performed in accordance with ÖNORM B 2506 and DWA-A 138, using regional extreme rainfall data obtained from the Austrian Hydrographical Service (eHYD, grid point 3163). The adopted 15-min design rainfall intensities were 126 l/(s ha) for the one-year design rainfall event (HQ1) and 244 l/(s ha) for the five-year verification rainfall event (HQ5). Reservoir routing calculations performed using the Sörensen method demonstrated effective peak-flow attenuation, resulting in a maximum retention volume of 318 m3 for the HQ5 event and calculated drainage times of 31.5 h (HQ1) and 43.2 h (HQ5). Qualitative field observations conducted during rainfall events confirmed the expected hydraulic behaviour of the constructed facility, particularly the effective retention of first-flush runoff, sediment accumulation within the gross solids trap, controlled discharge through the monk structure, and gradual infiltration within the downstream basin. Although no long-term hydraulic monitoring data were available, the observations support the practical functionality of the implemented design under operational conditions. The principal contribution of this study is the comprehensive documentation of a full-scale engineering project, covering the complete process from hydrological assessment and hydraulic design to construction details and qualitative field validation. The presented methodology provides a transferable engineering framework for the planning and implementation of comparable stormwater retention–infiltration systems for road infrastructure under similar climatic, geological, and regulatory conditions. The findings offer practical guidance for engineers and infrastructure planners while contributing to the broader implementation of sustainable and climate-resilient stormwater management systems.
Geotechnical slope design has traditionally used deterministic limit-equilibrium formulations and empirical correlations. Uncertainty in soil parameters, groundwater conditions, modelling idealizations, and human decision-making frequently reduces the reliability of deterministic factors of safety. This paper outlines a pragmatic framework for probabilistic slope stability analysis (PSSA) that quantifies soil property uncertainty statistically and propagates it through Monte Carlo simulation to measures of slope performance. The workflow is developed within the GeoStudio SLOPE/W environment with application of Bishop’s simplified method and assuming a circular slip-surface. The analysis is performed on a benchmark slope with and without groundwater effects, along with sensitivity analyses to identify the most influential uncertain parameters. Findings show that (i) the probability of failure cannot be uniquely inferred from the mean factor of safety, (ii) greater variability in parameters raises beyond-critical values of failure probability even with acceptable mean safety and that (iii) uncertainty on cohesion is usually the greatest contributor to critical failures in observed configurations. The findings confirm the need for reliability concepts to serve as complementary to deterministic practice, thereby also enhancing risk-informed design decisions.
To amend the previous gaps in researches on soil–structure interaction (SSI), this study meticulously investigates the effects of considering dense SSI on the seismic performance of tall tubular frames with damped outriggers. Three hybrid structural models consists of tubular frame, shear core and damped outriggers, with varying heights (50, 60 and 70 stories) were designed and simulated by finite element modelling. Evaluations were conducted under two distinct scenarios: one with considering full effects of soil–structure interaction, as in site class C, and another without considring them. Both models were subjected to eleven different far-fault seismic records, with average responses reported. The key seismic responses assessed included peak floor accelerations, inter-story drifts, base shear, structural energy absorption, and natural periods.The main findings indicate that considering SSI leads to a significant reduction in acceleration, base shear, and energy absorbed in the studied structures. In 50, 60 and 70 storey structures, SSI increases the fundamental period by 14.5
This research investigates the performance of steel–concrete composite beams designed with low concrete compressive strength (f'c = 22 MPa). Two different steel materials were used (mild with fy = 275 MPa, and rigid with fy = 410 MPa) to fabricate Inverted-U-shaped connectors, which welded to HEB 140 steel beam. The effect of two-point static loading on the casted beams was evaluated. The experimental findings were substantiated through numerical analysis using ABAQUS. Despite their low concrete strength, these connectors increased the maximum load and failure load by 20
Climate change is progressing at an unprecedented rate, presenting serious challenges to infrastructure resilience. This study investigates the potential impacts of climate-induced increases in flood risk, with a focus on bridge scour, the primary cause of bridge failure in the United States. Understanding and mitigating scour risk is essential for sustainable infrastructure planning and long-term risk management. The influence of climate indicators on the vulnerability of bridges to scour-related damage is evaluated, including changes in flood frequency and magnitude, snowfall and snowmelt trends, precipitation patterns, annual maximum streamflow, three-day peak river flows, and floodplain zones. In this study, a scour vulnerability index is introduced to quantify the vulnerability of bridges to climate change effects. A geographic information system (GIS) based risk assessment framework is developed, integrating data from the National Bridge Inventory (NBI), the Environmental Protection Agency (EPA), projected climate change models, and other geospatial datasets. The climate indicators used to quantify vulnerability are complemented with a physical linkage between hydrological drivers and scour processes using the HEC-18 scour depth prediction. The proposed methodology was implemented for bridges in New York State. It was found that the majority of the scour vulnerable bridges are concentrated within three counties in State. A comparison with the HYRISK model indicated that the majority of climate-vulnerable scour-critical bridges identified by the proposed framework are located within counties classified as high or very high scour risk by HYRISK. The approach presented in this study enables spatial mapping and prioritization of bridges and can be used in planning and management of critical transportation infrastructure in the face of a changing climate and other evolving hydrological conditions.
