Cracks are widely found on the surface of structures. Accurate crack detection is important for reducing structural risks. However, cracks have complex morphological features and thin edges, making the detection results incomplete. Moreover, noises such as textures and scratches on the structure’s surface interfere with model detection and lead to false alarms. To address such issues, the Dual-Stream Collaborative and Enhancement Crack Network (DSCE-CrackNet) is proposed to extract the global morphology and local detail features of cracks by combining the advantages of transformer and convolution. Specifically, a Global–Local Collaborative Fusion Module (GLCFM) is designed to eliminate redundant information and adaptively fuse long-range global context with thin local structural features, enabling the model to better distinguish true cracks from background textures and surface scratches that resemble cracks. In addition, a Multi-Scale Feature Enhancement-Based Edge Refinement Module (MERM) is developed to produce multi-scale crack feature maps and enhance edge local information, which sharpens thin crack boundaries and improves the continuity and completeness of segmented crack structures. Extensive experiments involving eleven state-of-the-art methods on five public crack datasets demonstrate the effectiveness and generalization capability of DSCE-CrackNet. On the Crack500 and DeepCrack datasets, DSCE-CrackNet achieves the best overall performance with Dice scores of 70.6% and 83.5%, respectively, yielding improvements of +4.0% and +4.9% over CrackFormer on the same datasets. Competitive and outstanding results are also attained on Rissbilder, CFD, and GAPs384. These quantitative gains confirm that the proposed GLCFM and MERM modules effectively strengthen crack feature representation and suppress background noise in complex structural scenes.
裂缝广泛存在于结构的表面。准确的裂缝检测对降低结构风险具有重要意义。但由于裂纹形态特征复杂，边缘较薄，检测结果不完整。此外，结构表面的纹理和划痕等噪声会干扰模型检测，导致误报。针对这一问题，提出了双流协同增强裂缝网络（DSCE-CrackNet），结合变压器和卷积的优点提取裂缝的全局形态和局部细节特征。具体而言，设计了全局-局部协同融合模块（global - local Collaborative Fusion Module， GLCFM），消除冗余信息，自适应融合远程全局上下文与薄局部结构特征，使模型能够更好地区分真实裂缝与背景纹理和表面划痕。此外，开发了基于多尺度特征增强的边缘细化模块（MERM），生成多尺度裂纹特征图，增强边缘局部信息，从而锐化薄裂纹边界，提高分段裂纹结构的连续性和完整性。在5个公开的裂缝数据集上进行了11种最先进的方法的大量实验，证明了DSCE-CrackNet的有效性和泛化能力。在Crack500和DeepCrack数据集上，DSCE-CrackNet实现了最佳的整体性能，Dice得分分别为70.6%和83.5%，在相同的数据集上比CrackFormer提高了+4.0%和+4.9%。在Rissbilder、CFD和GAPs384上也取得了具有竞争力和突出的结果。这些定量增益证实了所提出的GLCFM和MERM模块在复杂结构场景中有效地增强了裂纹特征表示并抑制了背景噪声。
{"title":"DSCE-CrackNet: On combining collaborative feature fusion and edge refinement for automatic crack segmentation","authors":"Xin Guo, Wenzhong Tang, Shuai Wang, Xiaolei Qu, Yuwei Duan, Bowei Wang","doi":"10.1016/j.jobe.2026.115212","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115212","url":null,"abstract":"Cracks are widely found on the surface of structures. Accurate crack detection is important for reducing structural risks. However, cracks have complex morphological features and thin edges, making the detection results incomplete. Moreover, noises such as textures and scratches on the structure’s surface interfere with model detection and lead to false alarms. To address such issues, the <ce:bold>D</ce:bold>ual-<ce:bold>S</ce:bold>tream <ce:bold>C</ce:bold>ollaborative and <ce:bold>E</ce:bold>nhancement <ce:bold>Crack Net</ce:bold>work (<ce:bold>DSCE-CrackNet</ce:bold>) is proposed to extract the global morphology and local detail features of cracks by <ce:bold>combining the advantages of transformer and convolution</ce:bold>. Specifically, a <ce:bold>Global–Local Collaborative Fusion Module</ce:bold> (GLCFM) is designed to eliminate redundant information and adaptively fuse long-range global context with thin local structural features, enabling the model to better distinguish true cracks from background textures and surface scratches that resemble cracks. In addition, a <ce:bold>Multi-Scale Feature Enhancement-Based Edge Refinement Module</ce:bold> (MERM) is developed to produce multi-scale crack feature maps and enhance edge local information, which sharpens thin crack boundaries and improves the continuity and completeness of segmented crack structures. Extensive experiments involving eleven state-of-the-art methods on five public crack datasets demonstrate the effectiveness and generalization capability of DSCE-CrackNet. On the Crack500 and DeepCrack datasets, DSCE-CrackNet achieves the best overall performance with Dice scores of 70.6% and 83.5%, respectively, yielding improvements of +4.0% and +4.9% over CrackFormer on the same datasets. Competitive and outstanding results are also attained on Rissbilder, CFD, and GAPs384. These quantitative gains confirm that the proposed GLCFM and MERM modules effectively strengthen crack feature representation and suppress background noise in complex structural scenes.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956836","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 : 2026-01-09DOI: 10.1016/j.jobe.2026.115267
Zhiyuan Xia , Zhenqi Li , Youzhen Fang , Baijian Tang , Gang Xu , Huiyuan Shi , Yiran Li
Lateral stiffness is a key indicator of the lateral resistance capacity of high-rise buildings, and shear walls are one kind of the primary means to enhance the lateral stiffness. Given the favorable shear performance demonstrated by composite shear walls, a novel embedded-perforated-steel concrete composite shear wall (ECCSW) was proposed herein. Through quasi-static experiment and finite element numerical simulation, the effects of different constraint conditions and perforation configurations including orthogonal, staggered, and perpendicular-to-diagonal under constant perforation rate on the shear performance of the ECCSW were systematically investigated. The results indicated that the numerical model can effectively validate the failure mode and load capacity observed in the experiments. The specimens primarily exhibited a shear-dominated failure mode, with cracks forming along diagonal and parallel directions on the concrete panel surface before progressively propagating to crushing and spalling. The specimens with four-side connection outperformed those with opposite-side connection in load capacity and initial stiffness where the stiffness degradation was slower and reflects superior collaborative performance. The influence of perforation configuration on load capacity of specimens was primarily significant after the yielding. The specimen with staggered configuration exhibited the highest load capacity and relatively good ductility. Based on the application of the existing formulas, the shear resistance capacity of the ECCSW was effectively evaluated with enough safety margin.
{"title":"Shear performance of a novel composite shear wall considering the influence of constraint conditions and perforation configurations","authors":"Zhiyuan Xia , Zhenqi Li , Youzhen Fang , Baijian Tang , Gang Xu , Huiyuan Shi , Yiran Li","doi":"10.1016/j.jobe.2026.115267","DOIUrl":"10.1016/j.jobe.2026.115267","url":null,"abstract":"<div><div>Lateral stiffness is a key indicator of the lateral resistance capacity of high-rise buildings, and shear walls are one kind of the primary means to enhance the lateral stiffness. Given the favorable shear performance demonstrated by composite shear walls, a novel embedded-perforated-steel concrete composite shear wall (ECCSW) was proposed herein. Through quasi-static experiment and finite element numerical simulation, the effects of different constraint conditions and perforation configurations including orthogonal, staggered, and perpendicular-to-diagonal under constant perforation rate on the shear performance of the ECCSW were systematically investigated. The results indicated that the numerical model can effectively validate the failure mode and load capacity observed in the experiments. The specimens primarily exhibited a shear-dominated failure mode, with cracks forming along diagonal and parallel directions on the concrete panel surface before progressively propagating to crushing and spalling. The specimens with four-side connection outperformed those with opposite-side connection in load capacity and initial stiffness where the stiffness degradation was slower and reflects superior collaborative performance. The influence of perforation configuration on load capacity of specimens was primarily significant after the yielding. The specimen with staggered configuration exhibited the highest load capacity and relatively good ductility. Based on the application of the existing formulas, the shear resistance capacity of the ECCSW was effectively evaluated with enough safety margin.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"119 ","pages":"Article 115267"},"PeriodicalIF":7.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940454","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 : 2026-01-09DOI: 10.1016/j.jobe.2026.115263
Fan-Qin Meng, G. Charles Clifton
Simplified analytical compartment fire models, such as the Parametric fire model, the BFD model, and the iBMB model, are widely used in research and engineering practice. However, their validation remains inconsistent, with limited transparency and inadequate documentation of verification against experimental data. To address this gap, a systematic thermal data selection framework was developed first to ensure that the experimental thermal data collected could be used to predict the structural response accurately. Subsequently, a quantitative assessment of the three analytical models was conducted on maximum temperature and protected steel element temperature prediction, through the discussion on parameters of fuel load energy densities, opening factors, and thermal boundary conditions. Comparisons between analytical predictions and experimental results indicated that all three models provided reliable estimates of maximum gas temperatures, with average prediction-to-experiment ratios of 0.98 for BFD, 1.09 for iBMB, and 1.02 for PRM. The predictions for protected steel temperatures showed greater deviations, leading to conservative design results. Sensitivity analyses revealed that the accuracy of protected steel temperature predictions, determined by the experimental and analytical fire curves, is highly influenced by ventilation conditions and high FLED. To enhance the robustness of these analytical models and validate their applicability across the full intended range, further research involving larger floor areas and higher fire load densities should be conducted in the future.
{"title":"A critical assessment of compartment fire models through quantitative analysis of recent large-scale experiments","authors":"Fan-Qin Meng, G. Charles Clifton","doi":"10.1016/j.jobe.2026.115263","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115263","url":null,"abstract":"Simplified analytical compartment fire models, such as the Parametric fire model, the BFD model, and the iBMB model, are widely used in research and engineering practice. However, their validation remains inconsistent, with limited transparency and inadequate documentation of verification against experimental data. To address this gap, a systematic thermal data selection framework was developed first to ensure that the experimental thermal data collected could be used to predict the structural response accurately. Subsequently, a quantitative assessment of the three analytical models was conducted on maximum temperature and protected steel element temperature prediction, through the discussion on parameters of fuel load energy densities, opening factors, and thermal boundary conditions. Comparisons between analytical predictions and experimental results indicated that all three models provided reliable estimates of maximum gas temperatures, with average prediction-to-experiment ratios of 0.98 for BFD, 1.09 for iBMB, and 1.02 for PRM. The predictions for protected steel temperatures showed greater deviations, leading to conservative design results. Sensitivity analyses revealed that the accuracy of protected steel temperature predictions, determined by the experimental and analytical fire curves, is highly influenced by ventilation conditions and high FLED. To enhance the robustness of these analytical models and validate their applicability across the full intended range, further research involving larger floor areas and higher fire load densities should be conducted in the future.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"81 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956809","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 : 2026-01-09DOI: 10.1016/j.jobe.2026.115245
Weina Xu, Yunsheng Zhang, Qiliang Wang, Yu Zhang, Xi Wang
With the depletion of natural sand and the tightening of environmental regulations, manufactured sand (MS) has emerged as a sustainable alternative owing to its controllable availability and environmentally benign production. However, the stone powder inherent in MS have been found to significantly influence the hydration kinetics and volumetric deformation behavior of concrete. These effects increase risk of early-age cracking, thereby compromising the structural durability and service performance. Existing early-age cracking prediction models have primarily been developed for natural sand concrete based on idealized material parameters and theoretical assumptions, which limits the accurate prediction of stress evolution and cracking risk in manufactured sand concrete (MSC). To obtain key parameters related to early-age cracking in the studied MSC system, a series of experiments were conducted on mixtures with varying tuff stone powder (TP) contents, including hydration heat measurement, internal humidity monitoring, capillary pressure measurement, early-age mechanical properties testing, and thermal stress testing. Key parameters were extracted by fitting the experimental data, including hydration reaction parameters, the “time-zero,” humidity reduction induced by cement hydration, moisture transfer coefficient, coefficient of thermal expansion (CTE), stress relaxation coefficient, and early-age mechanical parameters. Based on these parameters, a coupled hydro–thermo–hygro–constraint model was developed for MSC. Calibration and validation were conducted only within the investigated material-source and mix-proportion domain, wherein the degree of hydration serves as the primary state variable to simulate the evolution of stress and strain. Furthermore, a reliability-based cracking risk index was proposed to quantitatively assess the early-age cracking risk, providing a theoretical foundation for crack control strategies in MSC structures.
{"title":"Experimentally calibrated multi-field model for early-age cracking risk prediction in manufactured sand concrete","authors":"Weina Xu, Yunsheng Zhang, Qiliang Wang, Yu Zhang, Xi Wang","doi":"10.1016/j.jobe.2026.115245","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115245","url":null,"abstract":"With the depletion of natural sand and the tightening of environmental regulations, manufactured sand (MS) has emerged as a sustainable alternative owing to its controllable availability and environmentally benign production. However, the stone powder inherent in MS have been found to significantly influence the hydration kinetics and volumetric deformation behavior of concrete. These effects increase risk of early-age cracking, thereby compromising the structural durability and service performance. Existing early-age cracking prediction models have primarily been developed for natural sand concrete based on idealized material parameters and theoretical assumptions, which limits the accurate prediction of stress evolution and cracking risk in manufactured sand concrete (MSC). To obtain key parameters related to early-age cracking in the studied MSC system, a series of experiments were conducted on mixtures with varying tuff stone powder (TP) contents, including hydration heat measurement, internal humidity monitoring, capillary pressure measurement, early-age mechanical properties testing, and thermal stress testing. Key parameters were extracted by fitting the experimental data, including hydration reaction parameters, the “time-zero,” humidity reduction induced by cement hydration, moisture transfer coefficient, coefficient of thermal expansion (CTE), stress relaxation coefficient, and early-age mechanical parameters. Based on these parameters, a coupled hydro–thermo–hygro–constraint model was developed for MSC. Calibration and validation were conducted only within the investigated material-source and mix-proportion domain, wherein the degree of hydration serves as the primary state variable to simulate the evolution of stress and strain. Furthermore, a reliability-based cracking risk index was proposed to quantitatively assess the early-age cracking risk, providing a theoretical foundation for crack control strategies in MSC structures.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"259 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956811","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 : 2026-01-09DOI: 10.1016/j.jobe.2026.115243
Song Ran , Shulai Guo , Guihou Ran , Jingcong Deng , Wenjian Huang , Gege Chen , Junjie Yuan , Zhengwu Jiang , Qing Chen
Balancing workability and mechanical performance remains a key challenge in high water-to-binder ratio cementitious grouts, largely due to the adverse effects of excessive carboxyl groups in admixtures on cement hydration and strength development. This study addresses the issue by reducing copolymer carboxyl density. Hydrolysis-resistant acrylic acid/N,N-Dimethylacrylamide (AA/DMAA) copolymers with carboxyl densities from 25 % to 75 % were synthesized and tested at dosages of 0.10 %, 0.25 %, and 0.50 wt% for their effects on grout workability, hydration, and strength. The lowest density (25 %) maintained high flowability and low bleeding while improving anti-washout performance (turbidity 94 NTU at 0.50 wt%, 17.5 % higher than the high-density group (75 %)). In contrast, high carboxyl density increased stability but significantly retarded hydration and reduced workability. FTIR, zeta potential, total organic carbon, and calorimetry revealed that carboxyl groups interact with cement particles and Ca2+, promoting adsorption-flocculation that influences stability and early hydration kinetics. At the optimal 0.25 wt% dosage, the low-density copolymer formed effective Ca2+ adsorption, maintained workability, and avoided the severe hydration peak delay and setting time extension seen in high-density copolymers. TG/DTG, XRD, and mercury intrusion porosimetry (MIP) analysis confirmed that low-density copolymer promoted hydration product formation, refined pores, and enhanced compactness, leading to an 11.1 % increase in 28-day compressive strength over the control group. This work offers an effective approach and technical reference for balancing performance in high water-to-binder ratio cementitious grouts for engineering applications.
{"title":"Balancing workability, hydration, and strength of high water-to-binder ratio grouting materials via tuning the carboxyl density of acrylamide copolymers","authors":"Song Ran , Shulai Guo , Guihou Ran , Jingcong Deng , Wenjian Huang , Gege Chen , Junjie Yuan , Zhengwu Jiang , Qing Chen","doi":"10.1016/j.jobe.2026.115243","DOIUrl":"10.1016/j.jobe.2026.115243","url":null,"abstract":"<div><div>Balancing workability and mechanical performance remains a key challenge in high water-to-binder ratio cementitious grouts, largely due to the adverse effects of excessive carboxyl groups in admixtures on cement hydration and strength development. This study addresses the issue by reducing copolymer carboxyl density. Hydrolysis-resistant acrylic acid/N,N-Dimethylacrylamide (AA/DMAA) copolymers with carboxyl densities from 25 % to 75 % were synthesized and tested at dosages of 0.10 %, 0.25 %, and 0.50 wt% for their effects on grout workability, hydration, and strength. The lowest density (25 %) maintained high flowability and low bleeding while improving anti-washout performance (turbidity 94 NTU at 0.50 wt%, 17.5 % higher than the high-density group (75 %)). In contrast, high carboxyl density increased stability but significantly retarded hydration and reduced workability. FTIR, zeta potential, total organic carbon, and calorimetry revealed that carboxyl groups interact with cement particles and Ca<sup>2+</sup>, promoting adsorption-flocculation that influences stability and early hydration kinetics. At the optimal 0.25 wt% dosage, the low-density copolymer formed effective Ca<sup>2+</sup> adsorption, maintained workability, and avoided the severe hydration peak delay and setting time extension seen in high-density copolymers. TG/DTG, XRD, and mercury intrusion porosimetry (MIP) analysis confirmed that low-density copolymer promoted hydration product formation, refined pores, and enhanced compactness, leading to an 11.1 % increase in 28-day compressive strength over the control group. This work offers an effective approach and technical reference for balancing performance in high water-to-binder ratio cementitious grouts for engineering applications.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"119 ","pages":"Article 115243"},"PeriodicalIF":7.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956812","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 : 2026-01-09DOI: 10.1016/j.jobe.2026.115255
Seonghyuk Son, Nina Sharp, Dongwoo (Jason) Yeom
This study examined how combined thermal and lighting conditions influence older adults’ perceptual, physiological, and cognitive responses, using baseline-referenced changes as a comparative frame. Twenty-two older adults (mean age = 75.15 years) completed five sessions, including a baseline condition (23 °C, 4000K) and four combinations of two temperatures (18 °C, 28 °C) and two lighting levels (3200K, 5500K). Perceptual responses, including thermal and lighting sensations and preferences, were collected along with physiological and cognitive measures and evaluated relative to the baseline condition. Both thermal sensation and preference shifted significantly with a 5 °C change, while lighting sensation was affected when temperature differed by 10 °C, with 3200K perceived as the warmer lighting condition than 5500K under the same temperature. Changes in sensations and preferences were significantly associated with physiological responses, while associations to cognition were more selective, showing a physiology-to-perception pattern in males and a perception-to-cognition pattern in females. For working memory, perceiving lighting as one step warmer on the Likert scale corresponded to a 26-point decrease in performance. For visual learning and spatial working memory (VOLT), each 1 mm increase in pupil size was associated with a 116-point reduction, and each one-step increase in thermal preference was associated with a 12-point decline. Lighting sensation also indirectly affected VOLT through pupil size, indicating that warmer sensation altered physiology and predicted reduced performance. These findings indicate that perceptual and physiological sensitivities substantially contribute to cognitive variation in older adults, underscoring the importance of designing indoor environments that support sensory and cognitive functioning.
{"title":"Baseline-referenced changes in older adults’ perceptual, physiological, and cognitive functions under thermal and lighting conditions","authors":"Seonghyuk Son, Nina Sharp, Dongwoo (Jason) Yeom","doi":"10.1016/j.jobe.2026.115255","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115255","url":null,"abstract":"This study examined how combined thermal and lighting conditions influence older adults’ perceptual, physiological, and cognitive responses, using baseline-referenced changes as a comparative frame. Twenty-two older adults (mean age = 75.15 years) completed five sessions, including a baseline condition (23 °C, 4000K) and four combinations of two temperatures (18 °C, 28 °C) and two lighting levels (3200K, 5500K). Perceptual responses, including thermal and lighting sensations and preferences, were collected along with physiological and cognitive measures and evaluated relative to the baseline condition. Both thermal sensation and preference shifted significantly with a 5 °C change, while lighting sensation was affected when temperature differed by 10 °C, with 3200K perceived as the warmer lighting condition than 5500K under the same temperature. Changes in sensations and preferences were significantly associated with physiological responses, while associations to cognition were more selective, showing a physiology-to-perception pattern in males and a perception-to-cognition pattern in females. For working memory, perceiving lighting as one step warmer on the Likert scale corresponded to a 26-point decrease in performance. For visual learning and spatial working memory (VOLT), each 1 mm increase in pupil size was associated with a 116-point reduction, and each one-step increase in thermal preference was associated with a 12-point decline. Lighting sensation also indirectly affected VOLT through pupil size, indicating that warmer sensation altered physiology and predicted reduced performance. These findings indicate that perceptual and physiological sensitivities substantially contribute to cognitive variation in older adults, underscoring the importance of designing indoor environments that support sensory and cognitive functioning.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"32 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956810","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}
The application of nanomaterials provides new approaches to improve the chloride ion corrosion resistance of concrete. This study aims to explore the mechanism by which nanomaterials enhance the durability of concrete in chloride-rich environments and establish a time-dependent lifespan prediction model that comprehensively considers nanomaterial parameters and concrete degradation effects. The research measured the apparent chloride ion diffusion coefficients of ordinary Portland cement (OPC) and nanomodified concretes (nano-SiO2 (NS), nano-Fe3O4 (NF), and nano-TiO2 (NT)) at 28 days through non-steady-state chloride ion diffusion tests (RCM). Combined with artificial seawater immersion simulations, it tracks chloride ion transport patterns over the full aging period (91–365 days). Based on experimental data, an improved Fick's second law lifespan prediction model was ultimately constructed. And, XRD, thermogravimetric analysis (TG), and SEM-EDS were employed to reveal microscopic mechanisms. The results indicate: 1) The ranking of the chloride ion penetration resistance of the three nanomaterials is NT > NS > NF. Under the best condition, the apparent diffusion coefficients of NS, NF, and NT are 3.59 × 10−12, 4.20 × 10−12, and 2.87 × 10−12 m2 s−1, respectively, which are 49.95 %, 41.50 %, and 60.02 % lower than OPC. The apparent diffusion coefficient shows a trend of "first decreasing and then increasing" with the dosage and particle size. The optimal parameters are a dosage of 5 % and a particle size of 10 nm. 2) The full-ageing period diffusion coefficients exhibit a trend of "sharp decline from 28d to 90d (average reduction of 60 %)→stabilization after 270d", with the NT group having the highest aging decay factor m (0.418–0.561). 3) Lifespan predictions show: when the protection layer thickness of NT-modified concrete increases from 40 mm to 65 mm, the lifespan rises from 2.96 years to 27.03 years (an 813.18 % increase). Mechanistic analysis reveals: NS, NF, and NT can promote cement hydration through the "nucleation effect," consuming C2S and C3S to form C-S-H gel. NT exhibits a significantly higher mass loss rate than the NS and NF groups due to its abundant surface hydroxyl groups. SEM reveals that the interface transition zone (ITZ) of the NT group has only a small number of closed pores, with dense C-S-H gel. EDS spectra show a uniform distribution of Ti with Ca and Si, resulting in a more compact structure. While the ITZ of the NS group is less dense, the NF group is relatively loose. This study provides a quantitative reference for the durability design of concrete structures in chloride-rich environments.
{"title":"Durability enhancement mechanism and service life prediction model of nano-modified concrete for buildings in chloride-rich environments","authors":"Penglong Zhao, Zheng Si, Lingzhi Huang, Yanlan He, Yulong Zhang, Xiaorui Liu, Renlong Wang","doi":"10.1016/j.jobe.2025.115164","DOIUrl":"https://doi.org/10.1016/j.jobe.2025.115164","url":null,"abstract":"The application of nanomaterials provides new approaches to improve the chloride ion corrosion resistance of concrete. This study aims to explore the mechanism by which nanomaterials enhance the durability of concrete in chloride-rich environments and establish a time-dependent lifespan prediction model that comprehensively considers nanomaterial parameters and concrete degradation effects. The research measured the apparent chloride ion diffusion coefficients of ordinary Portland cement (OPC) and nanomodified concretes (nano-SiO<ce:inf loc=\"post\">2</ce:inf> (NS), nano-Fe<ce:inf loc=\"post\">3</ce:inf>O<ce:inf loc=\"post\">4</ce:inf> (NF), and nano-TiO<ce:inf loc=\"post\">2</ce:inf> (NT)) at 28 days through non-steady-state chloride ion diffusion tests (RCM). Combined with artificial seawater immersion simulations, it tracks chloride ion transport patterns over the full aging period (91–365 days). Based on experimental data, an improved Fick's second law lifespan prediction model was ultimately constructed. And, XRD, thermogravimetric analysis (TG), and SEM-EDS were employed to reveal microscopic mechanisms. The results indicate: 1) The ranking of the chloride ion penetration resistance of the three nanomaterials is NT > NS > NF. Under the best condition, the apparent diffusion coefficients of NS, NF, and NT are 3.59 × 10<ce:sup loc=\"post\">−12</ce:sup>, 4.20 × 10<ce:sup loc=\"post\">−12</ce:sup>, and 2.87 × 10<ce:sup loc=\"post\">−12</ce:sup> m<ce:sup loc=\"post\">2</ce:sup> s<ce:sup loc=\"post\">−1</ce:sup>, respectively, which are 49.95 %, 41.50 %, and 60.02 % lower than OPC. The apparent diffusion coefficient shows a trend of \"first decreasing and then increasing\" with the dosage and particle size. The optimal parameters are a dosage of 5 % and a particle size of 10 nm. 2) The full-ageing period diffusion coefficients exhibit a trend of \"sharp decline from 28d to 90d (average reduction of 60 %)→stabilization after 270d\", with the NT group having the highest aging decay factor m (0.418–0.561). 3) Lifespan predictions show: when the protection layer thickness of NT-modified concrete increases from 40 mm to 65 mm, the lifespan rises from 2.96 years to 27.03 years (an 813.18 % increase). Mechanistic analysis reveals: NS, NF, and NT can promote cement hydration through the \"nucleation effect,\" consuming C<ce:inf loc=\"post\">2</ce:inf>S and C<ce:inf loc=\"post\">3</ce:inf>S to form C-S-H gel. NT exhibits a significantly higher mass loss rate than the NS and NF groups due to its abundant surface hydroxyl groups. SEM reveals that the interface transition zone (ITZ) of the NT group has only a small number of closed pores, with dense C-S-H gel. EDS spectra show a uniform distribution of Ti with Ca and Si, resulting in a more compact structure. While the ITZ of the NS group is less dense, the NF group is relatively loose. This study provides a quantitative reference for the durability design of concrete structures in chloride-rich environments.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"2 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956837","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 : 2026-01-09DOI: 10.1016/j.jobe.2026.115246
Matthew Zhi Yeon Ting, Wei Yuan, Xinlei Sun, Mingqian Yang, Yaolin Yi
Cement-based structures constructed in boreholes and excavation sites are often exposed to residual drilling polymers, significantly impairing cement performance. The type and concentration of polymer contaminants determine the extent of these effects. This study investigates therefore the influence of various hydrophilic polymers, including polyacrylamide (PA), xanthan gum (XG), carboxymethyl cellulose (CMC), and polyanionic cellulose (PAC), at dosages ranging from 0.1% to 1% on cement hydration, mechanical strength, pore characteristics, and microstructure. The results showed that PA, CMC, PAC, and XG reduced compressive strength by up to 88%, 45%, 36%, and 34%, respectively, over 3–90 days of curing. PA and CMC increased permeable porosity to 22% and 20.9%, compared to 19.6% in the control, whereas XG and PAC exhibited reduced permeable porosity of 18.4% and 18.9%, respectively. Despite partial pore filling by polymer gels, all polymer-containing specimens exhibited retarded hydration. Adsorption analysis revealed an increasing adsorption tendency in the order of PAC, XG, CMC, and PA, leading to formation of barrier layers that impeded clinker hydration. This inhibitory was intensified by the high organic content and functional groups of amide and carboxyl, inducing complexation. Early-age calorimetry and later-age phase analysis confirmed reduced hydration heat and suppressed formation of hydrate phases. Microstructural examination identified interfacial cracking between hydration products and polymer-rich regions. Finally, mitigation strategies were proposed to enhance cement performance under polymer-contaminated conditions.
{"title":"Influence of hydrophilic polymers contamination on hydration, hardened properties, and microstructure of cement paste","authors":"Matthew Zhi Yeon Ting, Wei Yuan, Xinlei Sun, Mingqian Yang, Yaolin Yi","doi":"10.1016/j.jobe.2026.115246","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115246","url":null,"abstract":"Cement-based structures constructed in boreholes and excavation sites are often exposed to residual drilling polymers, significantly impairing cement performance. The type and concentration of polymer contaminants determine the extent of these effects. This study investigates therefore the influence of various hydrophilic polymers, including polyacrylamide (PA), xanthan gum (XG), carboxymethyl cellulose (CMC), and polyanionic cellulose (PAC), at dosages ranging from 0.1% to 1% on cement hydration, mechanical strength, pore characteristics, and microstructure. The results showed that PA, CMC, PAC, and XG reduced compressive strength by up to 88%, 45%, 36%, and 34%, respectively, over 3–90 days of curing. PA and CMC increased permeable porosity to 22% and 20.9%, compared to 19.6% in the control, whereas XG and PAC exhibited reduced permeable porosity of 18.4% and 18.9%, respectively. Despite partial pore filling by polymer gels, all polymer-containing specimens exhibited retarded hydration. Adsorption analysis revealed an increasing adsorption tendency in the order of PAC, XG, CMC, and PA, leading to formation of barrier layers that impeded clinker hydration. This inhibitory was intensified by the high organic content and functional groups of amide and carboxyl, inducing complexation. Early-age calorimetry and later-age phase analysis confirmed reduced hydration heat and suppressed formation of hydrate phases. Microstructural examination identified interfacial cracking between hydration products and polymer-rich regions. Finally, mitigation strategies were proposed to enhance cement performance under polymer-contaminated conditions.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"187 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956808","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 : 2026-01-09DOI: 10.1016/j.jobe.2026.115230
Negin Aalami, Tariq Maqsood, Muhammed A. Bhuiyan, Mahdieh Abravesh, Guomin Zhang
Current design practice for operable façades increasingly recognises the role of cavity spaces as thermal buffer zones for external louvre systems. This study experimentally and numerically investigates the integration of a low-cost bio-based phase change material (PCM) into these cavities to enhance the performance of operable building skins. The work focuses on how the number and three-dimensional placement of PCM units affect cavity air temperature and cooling energy demand. A prototype operable double-skin façade with cylindrical bio-PCM components was tested under controlled heating and cooling cycles, and the measured PCM properties were implemented in an EnergyPlus model using the Conduction Finite Difference (ConFD) algorithm within a 3D parametric workflow. Results show that optimal performance is achieved when four PCM are installed in the lower, windward front region of the cavity, coinciding with the operable opening and closest to the solar-exposed outer skin. Among the tested configurations, the module with a 0.3 m × 0.3 m × 0.1 m cavity and four circular PCM units delivered the strongest thermal response, reducing the maximum cavity temperature by up to 2 °C and introducing a pronounced thermal lag. When deployed in a reference office model across five Australian coastal climates, this optimised configuration reduced the average cooling energy use intensity by 20.18 % compared with scenarios without PCM. These findings demonstrate that strategically placing bio-based PCM in operable façade cavities can provide meaningful peak-temperature attenuation and cooling energy savings, particularly in warm and hot coastal climates. The results offer practical guidance on PCM quantity and placement for adaptive, energy-efficient façade design.
当前的可操作立面设计实践越来越多地认识到空腔空间作为外部卢浮宫系统的热缓冲带的作用。本研究通过实验和数值方法研究了将低成本的生物基相变材料（PCM）集成到这些空腔中，以提高可操作建筑表皮的性能。工作重点是PCM单元的数量和三维放置如何影响腔内空气温度和冷却能量需求。在受控的加热和冷却循环下，测试了具有圆柱形生物PCM组件的可操作双皮肤farade原型，并在三维参数化工作流程中使用传导有限差分（ConFD）算法在EnergyPlus模型中实现了测量的PCM性能。结果表明，当四个PCM安装在腔体的下部迎风前部区域，与可操作开口一致并且最靠近太阳照射的外皮时，性能达到最佳。在测试的配置中，具有0.3 m × 0.3 m × 0.1 m腔体和四个圆形PCM单元的模块提供了最强的热响应，最大腔体温度降低了2°C，并引入了明显的热滞后。当在澳大利亚五个沿海气候的参考办公室模型中部署时，与没有PCM的情况相比，这种优化配置将平均冷却能源使用强度降低了20.18%。这些发现表明，策略性地将生物基PCM放置在可操作的前侧腔中可以提供有意义的峰值温度衰减和冷却节能，特别是在温暖和炎热的沿海气候中。研究结果对自适应节能立面设计中PCM的数量和布局具有实际指导意义。
{"title":"Optimizing bio-based phase change materials in operable façade cavities to enhance cooling energy efficiency","authors":"Negin Aalami, Tariq Maqsood, Muhammed A. Bhuiyan, Mahdieh Abravesh, Guomin Zhang","doi":"10.1016/j.jobe.2026.115230","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115230","url":null,"abstract":"Current design practice for operable façades increasingly recognises the role of cavity spaces as thermal buffer zones for external louvre systems. This study experimentally and numerically investigates the integration of a low-cost bio-based phase change material (PCM) into these cavities to enhance the performance of operable building skins. The work focuses on how the number and three-dimensional placement of PCM units affect cavity air temperature and cooling energy demand. A prototype operable double-skin façade with cylindrical bio-PCM components was tested under controlled heating and cooling cycles, and the measured PCM properties were implemented in an EnergyPlus model using the Conduction Finite Difference (ConFD) algorithm within a 3D parametric workflow. Results show that optimal performance is achieved when four PCM are installed in the lower, windward front region of the cavity, coinciding with the operable opening and closest to the solar-exposed outer skin. Among the tested configurations, the module with a 0.3 m × 0.3 m × 0.1 m cavity and four circular PCM units delivered the strongest thermal response, reducing the maximum cavity temperature by up to 2 °C and introducing a pronounced thermal lag. When deployed in a reference office model across five Australian coastal climates, this optimised configuration reduced the average cooling energy use intensity by 20.18 % compared with scenarios without PCM. These findings demonstrate that strategically placing bio-based PCM in operable façade cavities can provide meaningful peak-temperature attenuation and cooling energy savings, particularly in warm and hot coastal climates. The results offer practical guidance on PCM quantity and placement for adaptive, energy-efficient façade design.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"390 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956835","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 : 2026-01-08DOI: 10.1016/j.jobe.2026.115214
Chunyu Zhang , Rentai Liu , Yue Wang , Yi Song , Mengjun Chen , Mingbin Wang , Lei Wang , Xiuhao Li , Meng Wang
With the rapid development of building materials, higher requirements are put forward for comprehensive performance of cement-based materials. Synergistic modification of various admixtures has become a crucial approach. In this study, the influence of five key factors, including cement-fly ash ratio, water-binder ratio, PTB emulsion content, thickener content, and PVA fiber content, on the rheological properties, fiber dispersion coefficient, mechanical properties, impermeability and porosity are analyzed by orthogonal test and single factor test. The results show that the five variables exhibit varying degrees of influence on different performance characteristics. PVA fiber significantly improves the flexural strength, and PTB emulsion significantly improves the impermeability. The thickener mainly affects the rheological parameters, and has little effect on other properties. There is a correlation between rheological parameters, fiber dispersion coefficient, porosity and macroscopic properties. The five variables further affect the fiber dispersion by affecting the viscosity of the mortar matrix slurry (without PVA fibers). With the increase of the slurry viscosity, the fiber dispersion coefficient increases first and then decreases, showing a quadratic function relationship. When the plastic viscosity of the mortar matrix slurry is between 2.5 Pa s to 3.5 Pa s, the PVA fiber can achieve the best dispersion effect. With the increase of fiber dispersion coefficient, the porosity generally shows a decreasing trend, and the flexural strength, compressive strength and impermeability pressure show an increasing trend. In the design of cement-based materials, the viscosity of the mortar matrix slurry can be adjusted by modifying the thickener content without altering other mixing proportions. This can improve fiber dispersion with minimal impact on other expected performance, thereby reducing porosity and enhancing mechanical strength and impermeability. This study aims to provide regulation strategy for achieving uniform fiber dispersion under multi-variable conditions, while offering theoretical references for enhancing comprehensive performance.
随着建筑材料的快速发展，对水泥基材料的综合性能提出了更高的要求。各种外加剂的协同改性已成为重要的途径。本研究通过正交试验和单因素试验，分析了水泥-粉煤灰比、水胶比、PTB乳化液含量、增稠剂含量、PVA纤维含量等5个关键因素对水泥流变性能、纤维分散系数、力学性能、抗渗性和孔隙率的影响。结果表明，这五个变量对不同的性能特征表现出不同程度的影响。PVA纤维显著提高抗弯强度，PTB乳液显著提高抗渗性能。增稠剂主要影响流变参数，对其他性能影响不大。流变参数、纤维分散系数、孔隙率和宏观性能之间存在相关性。这五个变量通过影响砂浆基质浆体（不含PVA纤维）的粘度进一步影响纤维的分散。随着浆料黏度的增大，纤维分散系数先增大后减小，呈二次函数关系。当砂浆基体浆体的塑性粘度在2.5 ~ 3.5 Pa s之间时，PVA纤维的分散效果最好。随着纤维分散系数的增大，孔隙率总体呈减小趋势，抗折强度、抗压强度和抗渗压力呈增大趋势。在水泥基材料的设计中，可以在不改变其他配比的情况下，通过改变增稠剂的含量来调节砂浆基质浆体的粘度。这可以在对其他预期性能影响最小的情况下改善纤维分散，从而降低孔隙率，提高机械强度和抗渗性。本研究旨在为实现多变量条件下光纤均匀色散提供调控策略，同时为提高综合性能提供理论参考。
{"title":"Influence of multiple factors on fiber dispersion and the correlation between fiber dispersion and multiple properties of cement-based materials","authors":"Chunyu Zhang , Rentai Liu , Yue Wang , Yi Song , Mengjun Chen , Mingbin Wang , Lei Wang , Xiuhao Li , Meng Wang","doi":"10.1016/j.jobe.2026.115214","DOIUrl":"10.1016/j.jobe.2026.115214","url":null,"abstract":"<div><div>With the rapid development of building materials, higher requirements are put forward for comprehensive performance of cement-based materials. Synergistic modification of various admixtures has become a crucial approach. In this study, the influence of five key factors, including cement-fly ash ratio, water-binder ratio, PTB emulsion content, thickener content, and PVA fiber content, on the rheological properties, fiber dispersion coefficient, mechanical properties, impermeability and porosity are analyzed by orthogonal test and single factor test. The results show that the five variables exhibit varying degrees of influence on different performance characteristics. PVA fiber significantly improves the flexural strength, and PTB emulsion significantly improves the impermeability. The thickener mainly affects the rheological parameters, and has little effect on other properties. There is a correlation between rheological parameters, fiber dispersion coefficient, porosity and macroscopic properties. The five variables further affect the fiber dispersion by affecting the viscosity of the mortar matrix slurry (without PVA fibers). With the increase of the slurry viscosity, the fiber dispersion coefficient increases first and then decreases, showing a quadratic function relationship. When the plastic viscosity of the mortar matrix slurry is between 2.5 Pa s to 3.5 Pa s, the PVA fiber can achieve the best dispersion effect. With the increase of fiber dispersion coefficient, the porosity generally shows a decreasing trend, and the flexural strength, compressive strength and impermeability pressure show an increasing trend. In the design of cement-based materials, the viscosity of the mortar matrix slurry can be adjusted by modifying the thickener content without altering other mixing proportions. This can improve fiber dispersion with minimal impact on other expected performance, thereby reducing porosity and enhancing mechanical strength and impermeability. This study aims to provide regulation strategy for achieving uniform fiber dispersion under multi-variable conditions, while offering theoretical references for enhancing comprehensive performance.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"119 ","pages":"Article 115214"},"PeriodicalIF":7.4,"publicationDate":"2026-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940365","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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