Pub Date : 2026-02-10DOI: 10.1016/j.jobe.2026.115556
Zhu Zhang, Eryu Zhu, Bin Wang, Chunqi Zhu, Jiacheng Li, Wenchao Cai
As a typical multiphase composite material, the initial pore defects in concrete cannot be ignored. To evaluate the impact of initial defects on concrete structures, this study investigates it through experimental and numerical methods. Expanded polystyrene (EPS) beads are firstly used to quantitatively fabricate initial pore defects within the concrete, and their environmental benefits during the construction process are evaluated. Then, based on the stress concentration effect induced by initial pore defects, a prediction model for the mechanical properties of concrete is established. In addition, a voxel-updating method based on int mark is employed to delineate the geometric characteristics of the four-phase material of concrete. Finally, a numerical method is proposed to reveal the damage evolution process in the meso-structure of concrete containing initial pore defects. The results indicate that as porosity increases, the reduction in the effective strength of concrete specimens is greater than the reduction in elastic modulus. And the degree of damage in the specimens decreases with increasing porosity. Moreover, the results from the prediction models and numerical simulations are consistent with experimental results. Environmentally, carbon reduction benefits can be achieved by using recycled EPS beads to prepare concrete structures, which enhances the synergy between optimized structural design and environmental benefits.
{"title":"Influence of initial pore defects on mechanical properties and environmental benefits of concrete: Experimental and numerical study","authors":"Zhu Zhang, Eryu Zhu, Bin Wang, Chunqi Zhu, Jiacheng Li, Wenchao Cai","doi":"10.1016/j.jobe.2026.115556","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115556","url":null,"abstract":"As a typical multiphase composite material, the initial pore defects in concrete cannot be ignored. To evaluate the impact of initial defects on concrete structures, this study investigates it through experimental and numerical methods. Expanded polystyrene (EPS) beads are firstly used to quantitatively fabricate initial pore defects within the concrete, and their environmental benefits during the construction process are evaluated. Then, based on the stress concentration effect induced by initial pore defects, a prediction model for the mechanical properties of concrete is established. In addition, a voxel-updating method based on int mark is employed to delineate the geometric characteristics of the four-phase material of concrete. Finally, a numerical method is proposed to reveal the damage evolution process in the meso-structure of concrete containing initial pore defects. The results indicate that as porosity increases, the reduction in the effective strength of concrete specimens is greater than the reduction in elastic modulus. And the degree of damage in the specimens decreases with increasing porosity. Moreover, the results from the prediction models and numerical simulations are consistent with experimental results. Environmentally, carbon reduction benefits can be achieved by using recycled EPS beads to prepare concrete structures, which enhances the synergy between optimized structural design and environmental benefits.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"93 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-10DOI: 10.1016/j.jobe.2026.115481
Xuezhong LI, Zhuguo LI
As natural aggregate resources become increasingly scarce, recycling wastes as aggregates in cementitious materials provides an environmentally sustainable alternative. This study investigates the influence of three low-density waste materials—clinker ash (CA), incineration bottom ash (IBA), and recycled fine aggregate (RFA)—as partial replacements (0–100%) for natural sand on the mechanical strength and carbonation resistance of FA/BFS-based geopolymer (GP) mortars. Five types of alkali activator (AA) solutions with varying sodium silicate/sodium hydroxide ratios were employed to evaluate the effects of activator composition on material performance. Furthermore, sodium aluminate (AN) surface treatment were performed to enhance carbonation resistance. The relationships between strength and carbonation behavior were examined, and microscopic observations using scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS) and phase characterization through X-ray diffraction (XRD) were performed. The obtained results show that the porous nature of CA and IBA reduces compressive and flexural strengths, whereas strength loss is negligible when the replacement ratio of sea sand is ≤ 20%. The AN surface treatment significantly improved carbonation resistance by densifying the geopolymer matrix and refining the interfacial transition zone (ITZ). The study demonstrates that combining waste-derived fine aggregates with optimized replacement ratio, AA, and AN surface treatment offers a novel and effective approach for producing geopolymer materials with enhanced performance and sustainability.
{"title":"Performance of Geopolymer Materials with Low-Density Waste Fine Aggregates and Enhanced Carbonation Resistance through Surface Modification","authors":"Xuezhong LI, Zhuguo LI","doi":"10.1016/j.jobe.2026.115481","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115481","url":null,"abstract":"As natural aggregate resources become increasingly scarce, recycling wastes as aggregates in cementitious materials provides an environmentally sustainable alternative. This study investigates the influence of three low-density waste materials—clinker ash (CA), incineration bottom ash (IBA), and recycled fine aggregate (RFA)—as partial replacements (0–100%) for natural sand on the mechanical strength and carbonation resistance of FA/BFS-based geopolymer (GP) mortars. Five types of alkali activator (AA) solutions with varying sodium silicate/sodium hydroxide ratios were employed to evaluate the effects of activator composition on material performance. Furthermore, sodium aluminate (AN) surface treatment were performed to enhance carbonation resistance. The relationships between strength and carbonation behavior were examined, and microscopic observations using scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM-EDS) and phase characterization through X-ray diffraction (XRD) were performed. The obtained results show that the porous nature of CA and IBA reduces compressive and flexural strengths, whereas strength loss is negligible when the replacement ratio of sea sand is ≤ 20%. The AN surface treatment significantly improved carbonation resistance by densifying the geopolymer matrix and refining the interfacial transition zone (ITZ). The study demonstrates that combining waste-derived fine aggregates with optimized replacement ratio, AA, and AN surface treatment offers a novel and effective approach for producing geopolymer materials with enhanced performance and sustainability.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"42 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-10DOI: 10.1016/j.jobe.2026.115506
Ju-Hyung Kim, Young Hak Lee, Dae-Jin Kim, Jang-Woon Baek
Reinforced concrete (RC) walls are critical components in seismic design, yet predicting their lateral load-displacement relationships is challenging due to limited experimental data and complex design variables, such as reinforcement detailing and geometry. To address these challenges, this study introduces the Energy-Equivalent Neural Network (EENN), an extension of physics-informed neural networks (PINNs) designed for RC wall behavior. By integrating an energy dissipation-based loss function, EENN ensures physical consistency and enhances prediction stability, reducing the coefficient of variation (COV) from 0.75-0.80 (ASCE 41) to 0.29-0.39—a reduction of over 50%. Trained on the SERIES RC Wall Database, EENN outperforms conventional neural networks and captures experimentally and mechanically validated trends, such as revealing that the effectiveness of confinement is highly dependent on failure modes and shows a limited correlation with the deformation capacity. These findings align with observed physical behavior, offering a reliable tool for interpreting complex design variable interactions. The proposed framework provides a robust foundation for advancing seismic design practices by delivering accurate, physics-consistent predictions of RC wall behavior under cyclic loading.
{"title":"Energy-Equivalent Neural Networks for Lateral Load-Displacement Prediction in RC Walls for Seismic Design","authors":"Ju-Hyung Kim, Young Hak Lee, Dae-Jin Kim, Jang-Woon Baek","doi":"10.1016/j.jobe.2026.115506","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115506","url":null,"abstract":"Reinforced concrete (RC) walls are critical components in seismic design, yet predicting their lateral load-displacement relationships is challenging due to limited experimental data and complex design variables, such as reinforcement detailing and geometry. To address these challenges, this study introduces the Energy-Equivalent Neural Network (EENN), an extension of physics-informed neural networks (PINNs) designed for RC wall behavior. By integrating an energy dissipation-based loss function, EENN ensures physical consistency and enhances prediction stability, reducing the coefficient of variation (COV) from 0.75-0.80 (ASCE 41) to 0.29-0.39—a reduction of over 50%. Trained on the SERIES RC Wall Database, EENN outperforms conventional neural networks and captures experimentally and mechanically validated trends, such as revealing that the effectiveness of confinement is highly dependent on failure modes and shows a limited correlation with the deformation capacity. These findings align with observed physical behavior, offering a reliable tool for interpreting complex design variable interactions. The proposed framework provides a robust foundation for advancing seismic design practices by delivering accurate, physics-consistent predictions of RC wall behavior under cyclic loading.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"9 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-10DOI: 10.1016/j.jobe.2026.115584
Jian Yang, Kai Luo, Rui Zhang, Xiangguo Wu, Xilun Ma, Xiaolong Li, Junwei Luo, Shilong Li
This paper addresses the insufficient load-bearing capacity and cracking of concrete bridges caused by aging by investigating the influence of steel fibers on the tensile performance of lightweight ultrahigh-performance concrete (LUHPC). We systematically examined the influence of steel fiber volume fractions on the tensile toughness, first-cracking strength, tensile strength, and peak tensile strain of LUHPC and analyzed its failure mode evolution via uniaxial tensile tests. The results indicate that the failure mode of LUHPC becomes more pronounced with increasing steel fiber volume fraction. As the volume fraction rises from 0% to 3%, the fracture mode transitions from brittle single-crack failure to ductile multi-crack propagation, while the direct tensile toughness first increases and then decreases. The first-cracking strength increases from 2.8 MPa to 5.4 MPa, an improvement of 103.57%; the tensile strength rises from 4.6 MPa to 17.4 MPa, an increase of 278.26%; and the peak tensile strain grows from 750×10-6 to 6086.3×10-6, representing an enhancement of 711.51%. Based on fracture mechanics theory, integrated experimental data, and compiled literature datasets, predictive equations for the first-cracking strength, tensile strength, peak tensile strain, and uniaxial tensile toughening coefficient of steel-fiber-reinforced LUHPC were established. Three axial tensile constitutive models for LUHPC were established. Among them, a damage model developed based on acoustic emission, which correlates the damage factor with a Weibull distribution, effectively characterizes the evolution of the material’s tensile performance. The proposed prediction equations and constitutive models can provide a theoretical basis for the design and application of LUHPC in lightweight, high-durability structures.
{"title":"Tensile performance and uniaxial tensile toughness of lightweight ultrahigh-performance concrete: Acoustic emission monitoring and meso-discrete analysis","authors":"Jian Yang, Kai Luo, Rui Zhang, Xiangguo Wu, Xilun Ma, Xiaolong Li, Junwei Luo, Shilong Li","doi":"10.1016/j.jobe.2026.115584","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115584","url":null,"abstract":"This paper addresses the insufficient load-bearing capacity and cracking of concrete bridges caused by aging by investigating the influence of steel fibers on the tensile performance of lightweight ultrahigh-performance concrete (LUHPC). We systematically examined the influence of steel fiber volume fractions on the tensile toughness, first-cracking strength, tensile strength, and peak tensile strain of LUHPC and analyzed its failure mode evolution via uniaxial tensile tests. The results indicate that the failure mode of LUHPC becomes more pronounced with increasing steel fiber volume fraction. As the volume fraction rises from 0% to 3%, the fracture mode transitions from brittle single-crack failure to ductile multi-crack propagation, while the direct tensile toughness first increases and then decreases. The first-cracking strength increases from 2.8 MPa to 5.4 MPa, an improvement of 103.57%; the tensile strength rises from 4.6 MPa to 17.4 MPa, an increase of 278.26%; and the peak tensile strain grows from 750×10<ce:sup loc=\"post\">-6</ce:sup> to 6086.3×10<ce:sup loc=\"post\">-6</ce:sup>, representing an enhancement of 711.51%. Based on fracture mechanics theory, integrated experimental data, and compiled literature datasets, predictive equations for the first-cracking strength, tensile strength, peak tensile strain, and uniaxial tensile toughening coefficient of steel-fiber-reinforced LUHPC were established. Three axial tensile constitutive models for LUHPC were established. Among them, a damage model developed based on acoustic emission, which correlates the damage factor with a Weibull distribution, effectively characterizes the evolution of the material’s tensile performance. The proposed prediction equations and constitutive models can provide a theoretical basis for the design and application of LUHPC in lightweight, high-durability structures.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"89 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-10DOI: 10.1016/j.jobe.2026.115595
Muhammad Akbar Caronge, Nevy Sandra, Jati Sunaryati, M.W. Tjaronge, Muhammad Anshari Caronge, Kazuaki Nishimura, Nurul Hudaya
This study investigates the feasibility of valorizing Sulawesian ferronickel slag (FNS) powder as a supplementary cementitious material (SCM) for sustainable mortar production. Ordinary Portland cement (OPC) was partially replaced with FNS at levels of 0–35% (at interval of 5%) by weight, and mixtures were evaluated for fresh density, consistency, setting time, compressive strength, strength activity index (SAI), ultrasonic pulse velocity (UPV), microstructure, and life cycle assessment (LCA). Results showed that consistency slightly decreased with higher FNS substitution, while setting times increased proportionally, with each 1% replacement extending the initial and final setting times by 1.5 and 2.6 minutes, respectively. Fresh density declined linearly from 2366.67 kg/m3 (control) to 2048.53 kg/m3 (35% FNS), representing a 13.45% reduction. Compressive strength remained comparable to the control up to 10% replacement, achieving 28.07 MPa versus 28.27 MPa at 28 days. Beyond 15%, strength decreased, with 35% FNS yielding only 22.06 MPa at 90 days (>30% reduction). The SAI confirmed SCM suitability at 5–10% FNS, meeting pozzolanic material thresholds with values of 99–102%. At these levels, pozzolanic contributions reached up to 11.23% at 7 days. UPV demonstrated strong correlations with compressive strength (R2 = 0.95) and density (R2 = 0.98), with the 10% FNS mix maintaining high matrix compactness (3928 m/s at 28 days). SEM images supported these results, showing refined pores and dense hydration products at 10% FNS, but porous, heterogeneous structures at 30%. LCA revealed that embodied energy reductions from 3751.01 MJ (control) to 2708.02 MJ (35% FNS), and GWP declines from 488.55 kgCO2-eq to 335.35 kgCO2-eq, indicating energy and emission savings of 27.78% and 31.39%, respectively. The sustainability index and economic index both identified 10% FNS as the optimum dosage, combining mechanical stability, minimized environmental impact, and the lowest cost-efficiency ratio of 3.46 $/m3/MPa.
{"title":"Valorization of Sulawesian Ferronickel Slag Powder for Cementitious Materials: Feasibility and Sustainability Assessment","authors":"Muhammad Akbar Caronge, Nevy Sandra, Jati Sunaryati, M.W. Tjaronge, Muhammad Anshari Caronge, Kazuaki Nishimura, Nurul Hudaya","doi":"10.1016/j.jobe.2026.115595","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115595","url":null,"abstract":"This study investigates the feasibility of valorizing Sulawesian ferronickel slag (FNS) powder as a supplementary cementitious material (SCM) for sustainable mortar production. Ordinary Portland cement (OPC) was partially replaced with FNS at levels of 0–35% (at interval of 5%) by weight, and mixtures were evaluated for fresh density, consistency, setting time, compressive strength, strength activity index (SAI), ultrasonic pulse velocity (UPV), microstructure, and life cycle assessment (LCA). Results showed that consistency slightly decreased with higher FNS substitution, while setting times increased proportionally, with each 1% replacement extending the initial and final setting times by 1.5 and 2.6 minutes, respectively. Fresh density declined linearly from 2366.67 kg/m<ce:sup loc=\"post\">3</ce:sup> (control) to 2048.53 kg/m<ce:sup loc=\"post\">3</ce:sup> (35% FNS), representing a 13.45% reduction. Compressive strength remained comparable to the control up to 10% replacement, achieving 28.07 MPa versus 28.27 MPa at 28 days. Beyond 15%, strength decreased, with 35% FNS yielding only 22.06 MPa at 90 days (>30% reduction). The SAI confirmed SCM suitability at 5–10% FNS, meeting pozzolanic material thresholds with values of 99–102%. At these levels, pozzolanic contributions reached up to 11.23% at 7 days. UPV demonstrated strong correlations with compressive strength (R<ce:sup loc=\"post\">2</ce:sup> = 0.95) and density (R<ce:sup loc=\"post\">2</ce:sup> = 0.98), with the 10% FNS mix maintaining high matrix compactness (3928 m/s at 28 days). SEM images supported these results, showing refined pores and dense hydration products at 10% FNS, but porous, heterogeneous structures at 30%. LCA revealed that embodied energy reductions from 3751.01 MJ (control) to 2708.02 MJ (35% FNS), and GWP declines from 488.55 kgCO<ce:inf loc=\"post\">2</ce:inf>-eq to 335.35 kgCO<ce:inf loc=\"post\">2</ce:inf>-eq, indicating energy and emission savings of 27.78% and 31.39%, respectively. The sustainability index and economic index both identified 10% FNS as the optimum dosage, combining mechanical stability, minimized environmental impact, and the lowest cost-efficiency ratio of 3.46 $/m<ce:sup loc=\"post\">3</ce:sup>/MPa.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"1 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-09DOI: 10.1016/j.jobe.2026.115568
Aron Berhanu Degefa, Woldeamanuel Minwuye Mesfin, Hyeong-Ki Kim, Solmoi Park
This study presents a methodology for durability-based design using machine learning (ML) models to predict chloride resistance and service life in blended concrete. Key ML models—Gaussian Process Regression (GPR), Series Neural Networks (SNN), and ensemble methods—were employed to estimate chloride migration and diffusion coefficients for concrete containing slag, fly ash, and silica fume. GPR and SNN models achieved the highest accuracy across datasets, with each model demonstrating optimal performance in specific chloride exposure conditions. The ML models’ predictions aligned conservatively with experimental data and fib Model Code 2010 values, reinforcing their reliability. Probabilistic simulations revealed that ML-predicted migration coefficients significantly influence service life estimates, particularly for slag and fly ash binders. The findings suggest that pretrained ML models can support early-stage durability assessments, supplementing traditional design methods when experimental data are limited.
{"title":"Machine Learning-Driven Prediction of Chloride Resistance and Service Life Estimation in Blended Cement Concrete","authors":"Aron Berhanu Degefa, Woldeamanuel Minwuye Mesfin, Hyeong-Ki Kim, Solmoi Park","doi":"10.1016/j.jobe.2026.115568","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115568","url":null,"abstract":"This study presents a methodology for durability-based design using machine learning (ML) models to predict chloride resistance and service life in blended concrete. Key ML models—Gaussian Process Regression (GPR), Series Neural Networks (SNN), and ensemble methods—were employed to estimate chloride migration and diffusion coefficients for concrete containing slag, fly ash, and silica fume. GPR and SNN models achieved the highest accuracy across datasets, with each model demonstrating optimal performance in specific chloride exposure conditions. The ML models’ predictions aligned conservatively with experimental data and <ce:italic>fib</ce:italic> Model Code 2010 values, reinforcing their reliability. Probabilistic simulations revealed that ML-predicted migration coefficients significantly influence service life estimates, particularly for slag and fly ash binders. The findings suggest that pretrained ML models can support early-stage durability assessments, supplementing traditional design methods when experimental data are limited.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"7 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-09DOI: 10.1016/j.jobe.2026.115497
Salah Almazmumi, Carlos Jimenez-Bescos, John S. Owen, John Kaiser Calautit
Single-sided ventilation (SSV) in multi-storey buildings often suffers from limited flow penetration, strong directional dependence, and floor-to-floor imbalance. This study investigates a façade-integrated Wall Windcatcher (WWC) system designed to overcome these limitations by combining a low-level supply inlet and a high-level exhaust outlet on the same façade, connected by an external vertical duct. A computational fluid dynamics (CFD) framework was first validated against atmospheric boundary layer wind-tunnel measurements using a baseline WWC geometry, which then served as the reference model for a systematic parametric analysis of geometric modifications and contextual factors based on a steady-state RANS (k–ε RNG) approach. Design variants were tested across wind angles from 0° to 180° to capture windward, oblique, perpendicular, and leeward exposures. For the k–ε RNG model, agreement in pressure coefficients (Cp) for WWC cases yielded MAPE = 5.6% (0° wind angle), 4.6% (45°), and 6.8% (90°), respectively, confirming the accuracy of the CFD framework for subsequent analysis. Three design parameters were tested individually and in combination: (i) transitions before each outlet, (ii) enlarged outlet size, and (iii) a thin inlet plane. Transitions reduced junction losses and improved vertical continuity, enlarged outlets strengthened upper-storey extraction but could suppress ground-floor intake at high obliquity, and the inlet plane provided the largest single improvement under oblique winds. The fully integrated design (COC2: inlet plane + transitions + enlarged outlet) achieved the highest and most uniform velocities, with up to 2–3× higher performance than the baseline and measurable improvements even under leeward winds. Increasing building height (to four and five storeys) enhanced mid- and upper-floor ventilation without significantly penalising lower levels. Urban-canyon simulations showed that wider street-to-building ratios improved windward and side-zone performance, while leeward zones remained limited by wake shielding. The results demonstrate that a retrofit-focused WWC can outperform SSV when inlet capture (inlet plane), duct continuity (transitions), and outlet discharge are optimised together. The findings provide practical guidance for passive ventilation design, and the development of modular façade retrofit systems for multi-storey buildings.
{"title":"Parametric Evaluation of a Façade-Integrated Natural Ventilation System for Multi-Storey Buildings","authors":"Salah Almazmumi, Carlos Jimenez-Bescos, John S. Owen, John Kaiser Calautit","doi":"10.1016/j.jobe.2026.115497","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115497","url":null,"abstract":"Single-sided ventilation (SSV) in multi-storey buildings often suffers from limited flow penetration, strong directional dependence, and floor-to-floor imbalance. This study investigates a façade-integrated Wall Windcatcher (WWC) system designed to overcome these limitations by combining a low-level supply inlet and a high-level exhaust outlet on the same façade, connected by an external vertical duct. A computational fluid dynamics (CFD) framework was first validated against atmospheric boundary layer wind-tunnel measurements using a baseline WWC geometry, which then served as the reference model for a systematic parametric analysis of geometric modifications and contextual factors based on a steady-state RANS (k–ε RNG) approach. Design variants were tested across wind angles from 0° to 180° to capture windward, oblique, perpendicular, and leeward exposures. For the k–ε RNG model, agreement in pressure coefficients (C<ce:inf loc=\"post\">p</ce:inf>) for WWC cases yielded MAPE = 5.6% (0° wind angle), 4.6% (45°), and 6.8% (90°), respectively, confirming the accuracy of the CFD framework for subsequent analysis. Three design parameters were tested individually and in combination: (i) transitions before each outlet, (ii) enlarged outlet size, and (iii) a thin inlet plane. Transitions reduced junction losses and improved vertical continuity, enlarged outlets strengthened upper-storey extraction but could suppress ground-floor intake at high obliquity, and the inlet plane provided the largest single improvement under oblique winds. The fully integrated design (COC2: inlet plane + transitions + enlarged outlet) achieved the highest and most uniform velocities, with up to 2–3× higher performance than the baseline and measurable improvements even under leeward winds. Increasing building height (to four and five storeys) enhanced mid- and upper-floor ventilation without significantly penalising lower levels. Urban-canyon simulations showed that wider street-to-building ratios improved windward and side-zone performance, while leeward zones remained limited by wake shielding. The results demonstrate that a retrofit-focused WWC can outperform SSV when inlet capture (inlet plane), duct continuity (transitions), and outlet discharge are optimised together. The findings provide practical guidance for passive ventilation design, and the development of modular façade retrofit systems for multi-storey buildings.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"51 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-09DOI: 10.1016/j.jobe.2026.115533
Peng Wang, Longbin Yang, Qingxuan Shi, Qiuwei Wang, Chong Rong
This study proposes a novel two-way slab system integrating stay-in-place ultra-high-performance concrete (UHPC) formwork with a cast-in-place reinforced concrete (RC) layer to enhance mechanical performance and construction efficiency through material and structural optimization. Flexural tests were conducted to systematically investigate the effects of UHPC formwork thickness, reinforcement ratio, and interface treatment on the failure modes, load-bearing capacity, and deformation behavior of the slabs. A complementary numerical model was developed and validated to extend the parametric analysis. The experimental results demonstrated that the ribbed interface treatment significantly enhanced the composite action and effectively suppressed interfacial slip. Compared to specimens with bubble-film-embossing and roughened interfaces, the ribbed ones exhibited 12% and 20% higher peak loads, accompanied by 26% and 24% reductions in peak deflection, respectively. An increase in the reinforcement ratio from 0.28% to 0.61% resulted in a 27% increase in both yield and peak loads, but also led to a 60% rise in peak deflection. However, this increase compromised ductility, as indicated by a ductility factor of 5.56 at the reinforcement ratio of 0.61%. Increasing the UHPC formwork thickness from 10 mm to 15 mm enhanced the yield and peak loads by 10% and 8%, respectively, and reduced the peak deflection by 26%. Numerical simulations further indicated that increasing the normal concrete (NC) strength from 30 MPa to 50 MPa enhanced the load-bearing capacity by 16%. Similarly, increasing the UHPC formwork thickness from 10 mm to 40 mm resulted in a 31.37% increase in capacity. Based on the plastic hinge line theory and the principle of virtual work, a method for predicting the ultimate load-bearing capacity under different failure modes was proposed. The predicted values showed a maximum deviation of 15% from the experimental results, with a mean calculated-to-experimental ratio of 0.95, confirming the accuracy of the proposed method.
{"title":"Flexural Behavior and Load-Bearing Capacity of UHPC Stay-in-Place Formwork-RC Two-Way Slabs","authors":"Peng Wang, Longbin Yang, Qingxuan Shi, Qiuwei Wang, Chong Rong","doi":"10.1016/j.jobe.2026.115533","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115533","url":null,"abstract":"This study proposes a novel two-way slab system integrating stay-in-place ultra-high-performance concrete (UHPC) formwork with a cast-in-place reinforced concrete (RC) layer to enhance mechanical performance and construction efficiency through material and structural optimization. Flexural tests were conducted to systematically investigate the effects of UHPC formwork thickness, reinforcement ratio, and interface treatment on the failure modes, load-bearing capacity, and deformation behavior of the slabs. A complementary numerical model was developed and validated to extend the parametric analysis. The experimental results demonstrated that the ribbed interface treatment significantly enhanced the composite action and effectively suppressed interfacial slip. Compared to specimens with bubble-film-embossing and roughened interfaces, the ribbed ones exhibited 12% and 20% higher peak loads, accompanied by 26% and 24% reductions in peak deflection, respectively. An increase in the reinforcement ratio from 0.28% to 0.61% resulted in a 27% increase in both yield and peak loads, but also led to a 60% rise in peak deflection. However, this increase compromised ductility, as indicated by a ductility factor of 5.56 at the reinforcement ratio of 0.61%. Increasing the UHPC formwork thickness from 10 mm to 15 mm enhanced the yield and peak loads by 10% and 8%, respectively, and reduced the peak deflection by 26%. Numerical simulations further indicated that increasing the normal concrete (NC) strength from 30 MPa to 50 MPa enhanced the load-bearing capacity by 16%. Similarly, increasing the UHPC formwork thickness from 10 mm to 40 mm resulted in a 31.37% increase in capacity. Based on the plastic hinge line theory and the principle of virtual work, a method for predicting the ultimate load-bearing capacity under different failure modes was proposed. The predicted values showed a maximum deviation of 15% from the experimental results, with a mean calculated-to-experimental ratio of 0.95, confirming the accuracy of the proposed method.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"108 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Improving the thermal efficiency of building envelopes while maintaining mechanical integrity remains a significant challenge in sustainable construction. Conventional insulation mortars often fail to achieve simultaneous optimization of thermal conductivity, moisture resistance, and strength. This study addresses this gap by developing aerogel-perlite-cement (ACM) composite insulation mortars designed through particle packing optimization and systematically evaluating their thermal, mechanical, and hygric performance, as well as their impact on building energy consumption. Mortars with varying aggregate gradations were designed using the modified Andreasen & Andersen model (distribution moduli q=0.2, 0.3), and a silica aerogel slurry was incorporated into expanded perlite carriers. Compared with conventional cement mortars (CM), optimized ACM samples achieved a 19% reduction in bulk density, an 18% improvement in water resistance, and reduced thermal conductivity to 0.059 W·m-1·K-1, while maintaining acceptable compressive strength (1.49 MPa). The experimental thermal conductivity results were further interpreted using effective medium theory (EMT) in combination with finite-element simulations, which together elucidate the influence of aggregate gradation, interfacial effects, and structural heterogeneity on heat transfer behavior in aerogel-modified mortars. EnergyPlus simulations of a six-story residential building demonstrated that applying a 100 mm ACM insulation layer can reduce annual HVAC energy consumption by 50.9% in cold regions and 33.8% in mixed climates, providing practical insights into climate-adaptive design.
{"title":"Performance-Driven Design of Aerogel-Perlite Cement Mortars: Particle Packing Optimization and Building Energy Assessment","authors":"Shengjie Yao, Yuming Duan, Weiwang Chen, Jiahui Chen, Huanlin Zhang, Longhui Peng, Xiaoxu Wu, Zhi Li","doi":"10.1016/j.jobe.2026.115567","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115567","url":null,"abstract":"Improving the thermal efficiency of building envelopes while maintaining mechanical integrity remains a significant challenge in sustainable construction. Conventional insulation mortars often fail to achieve simultaneous optimization of thermal conductivity, moisture resistance, and strength. This study addresses this gap by developing aerogel-perlite-cement (ACM) composite insulation mortars designed through particle packing optimization and systematically evaluating their thermal, mechanical, and hygric performance, as well as their impact on building energy consumption. Mortars with varying aggregate gradations were designed using the modified Andreasen & Andersen model (distribution moduli <ce:italic>q=0.2, 0.3</ce:italic>), and a silica aerogel slurry was incorporated into expanded perlite carriers. Compared with conventional cement mortars (CM), optimized ACM samples achieved a 19% reduction in bulk density, an 18% improvement in water resistance, and reduced thermal conductivity to 0.059 W·m<ce:sup loc=\"post\">-1</ce:sup>·K<ce:sup loc=\"post\">-1</ce:sup>, while maintaining acceptable compressive strength (1.49 MPa). The experimental thermal conductivity results were further interpreted using effective medium theory (EMT) in combination with finite-element simulations, which together elucidate the influence of aggregate gradation, interfacial effects, and structural heterogeneity on heat transfer behavior in aerogel-modified mortars. EnergyPlus simulations of a six-story residential building demonstrated that applying a 100 mm ACM insulation layer can reduce annual HVAC energy consumption by 50.9% in cold regions and 33.8% in mixed climates, providing practical insights into climate-adaptive design.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"105 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-09DOI: 10.1016/j.jobe.2026.115592
Tae Yong Shin, Seongho Han, Ryong You, Yubin Jun, Jae Hong Kim
Alkali-activated materials have emerged as promising low-carbon alternatives to ordinary Portland cement-based binders; however, their practical application is strictly limited by rapid setting and poor workability. To address these challenges, this study proposes an evaluation methodology combining setting time measurement, cloud point tests for chemical stability, and wide-range rheological analysis. While conventional superplasticizers like polycarboxylate ether (PCE) proved unstable in high-alkaline environments, cloud point tests revealed that polynaphthalene sulfonate (PNS) and butyl acrylate (BA) exhibited superior chemical stability. Notably, BA was identified as a novel and effective dispersant in 3.5 M KOH-activated systems, reducing yield stress of fresh mortar by 33% when combined with an anti-foaming agent. In terms of retardation, 0.06% sodium gluconate (SG) successfully extended the initial setting time to over 5 hours. Furthermore, rheological modeling revealed that replacing 10% of ground granulated blast-furnace slag with fly ash not only reduced viscosity but also enhanced the 28-day compressive strength to 45.0 MPa, surpassing the control sample (43.7 MPa) due to improved particle packing. These findings offer practical guidelines for enhancing the workability of alkali-activated slag mortars through the use of chemically stable admixtures and optimized mineral substitution.
碱活化材料已经成为普通硅酸盐水泥基粘合剂的有前途的低碳替代品；但由于成型速度快、可加工性差，严格限制了其实际应用。为了应对这些挑战，本研究提出了一种结合凝结时间测量、化学稳定性浊点测试和大范围流变分析的评估方法。虽然聚羧酸酯醚（PCE）等传统高效减水剂在高碱性环境中不稳定，但云点测试表明，聚萘磺酸盐（PNS）和丙烯酸丁酯（BA）表现出优异的化学稳定性。值得注意的是，BA在3.5 M koh活化体系中被认为是一种新型有效的分散剂，当与消泡剂结合使用时，可将新鲜砂浆的屈服应力降低33%。在缓凝方面，0.06%的葡萄糖酸钠（SG）成功地将初凝时间延长至5小时以上。此外，流变学模型表明，用粉煤灰代替10%的磨粒高炉渣不仅降低了粘度，而且由于颗粒填料的改善，28天抗压强度提高到45.0 MPa，超过了对照样品（43.7 MPa）。这些发现为通过使用化学稳定的外加剂和优化的矿物替代来提高碱活性矿渣砂浆的和易性提供了实用指南。
{"title":"Rheological Modification of Alkali-Activated Slag Mortar: Roles of Sodium Gluconate Retarder and Dispersants","authors":"Tae Yong Shin, Seongho Han, Ryong You, Yubin Jun, Jae Hong Kim","doi":"10.1016/j.jobe.2026.115592","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115592","url":null,"abstract":"Alkali-activated materials have emerged as promising low-carbon alternatives to ordinary Portland cement-based binders; however, their practical application is strictly limited by rapid setting and poor workability. To address these challenges, this study proposes an evaluation methodology combining setting time measurement, cloud point tests for chemical stability, and wide-range rheological analysis. While conventional superplasticizers like polycarboxylate ether (PCE) proved unstable in high-alkaline environments, cloud point tests revealed that polynaphthalene sulfonate (PNS) and butyl acrylate (BA) exhibited superior chemical stability. Notably, BA was identified as a novel and effective dispersant in 3.5 M KOH-activated systems, reducing yield stress of fresh mortar by 33% when combined with an anti-foaming agent. In terms of retardation, 0.06% sodium gluconate (SG) successfully extended the initial setting time to over 5 hours. Furthermore, rheological modeling revealed that replacing 10% of ground granulated blast-furnace slag with fly ash not only reduced viscosity but also enhanced the 28-day compressive strength to 45.0 MPa, surpassing the control sample (43.7 MPa) due to improved particle packing. These findings offer practical guidelines for enhancing the workability of alkali-activated slag mortars through the use of chemically stable admixtures and optimized mineral substitution.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"46 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146146563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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