Journal of building engineering最新文献_第10页

Effect of shrinkage reducing additives on the interfacial properties of alkali-activated modified recycled aggregate 减缩助剂对碱活化改性再生骨料界面性能的影响

IF 7.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115463

Jifei Cui , Lei Bao , Feng Xie , Liang Chen , Mei Yan Bai , Gui Li , Bixuan Yang , Yu Zheng

Alkali-activated materials (AAMs) provide a promising green alternative for recycled concrete aggregates (RCA) surface pretreatment, which are essential for sustainable construction. However, the high shrinkage of AAMs poses a critical challenge to the modified interfacial transition zone of RCA. This study investigates the effects of shrinkage-reducing additives (MgO, CaO and PPG) on the properties of recycled concrete powder-based alkali-activated (AASFR) pastes, and their efficacy in enhancing the interfacial performance of RCA. Shrinkage-reducing additives on the mechanical properties, drying shrinkage, and microstructural of AASFR pastes are investigated. The interfacial bonding performance is analyzed using BSE imaging and nanoindentation. Results demonstrate that 4% MgO yields the best mechanical and interfacial behavior, forming the narrowest new interfacial transition zone (NITZ) and the highest elastic modulus. In comparison, 3% CaO provides a cost-effective solution with significant shrinkage reduction but offers limited long-term strength and interfacial improvement. Although the addition of PPG significantly mitigates drying shrinkage by reducing the pore solution surface tension, it leads to increased porosity and a reduction in compressive strength, presenting a moderate compromise in enhancing the mechanical properties of NITZ. The performance-cost-emissions trade-off analysis identifies MgO-modified paste as optimal for high-performance situation, while CaO-modified paste serves as the most cost-effective sustainable solution. This study provides the first comparative study of these three additive types on the modified interfacial micromechanics of RCA in an alkali-activated system, and focuses on the interfacial micromechanics of alkali-activated modified materials and proposing a comprehensive evaluation method that combines nanoindentation characterization with environmental impact and economic cost. This study provides practical insights for optimizing alkali-activated RCA modification technologies, highlighting the critical role of additive selection in modified interfacial microstructure and practical applications.

碱活化材料（AAMs）为再生混凝土骨料（RCA）表面预处理提供了一种有前途的绿色替代方案，这对可持续建筑至关重要。然而，AAMs的高收缩率对改性RCA的界面过渡区提出了严峻的挑战。研究了还原剂MgO、CaO和PPG对再生混凝土粉基碱活化（AASFR）膏体性能的影响，以及它们提高RCA界面性能的效果。研究了减缩剂对AASFR膏体力学性能、干燥收缩率和显微组织的影响。利用BSE成像和纳米压痕分析了界面键合性能。结果表明，4% MgO的力学性能和界面性能最好，形成了最窄的新界面过渡区（NITZ）和最高的弹性模量。相比之下，3% CaO提供了一种具有成本效益的解决方案，显著降低了收缩率，但长期强度和界面改善有限。虽然PPG的加入通过降低孔隙溶液表面张力来显著减轻干燥收缩，但它会导致孔隙率增加和抗压强度降低，在提高NITZ的机械性能方面表现出适度的妥协。性能-成本-排放权衡分析表明，mgo改性膏体是高性能情况下的最佳选择，而cao改性膏体是最具成本效益的可持续解决方案。本研究首次对碱活化体系中三种添加剂对改性RCA界面微观力学性能的影响进行了对比研究，重点研究了碱活化改性材料的界面微观力学性能，并提出了一种将纳米压痕表征与环境影响和经济成本相结合的综合评价方法。本研究为优化碱活化RCA改性技术提供了实践见解，突出了添加剂选择在改性界面微观结构和实际应用中的关键作用。

{"title":"Effect of shrinkage reducing additives on the interfacial properties of alkali-activated modified recycled aggregate","authors":"Jifei Cui , Lei Bao , Feng Xie , Liang Chen , Mei Yan Bai , Gui Li , Bixuan Yang , Yu Zheng","doi":"10.1016/j.jobe.2026.115463","DOIUrl":"10.1016/j.jobe.2026.115463","url":null,"abstract":"<div><div>Alkali-activated materials (AAMs) provide a promising green alternative for recycled concrete aggregates (RCA) surface pretreatment, which are essential for sustainable construction. However, the high shrinkage of AAMs poses a critical challenge to the modified interfacial transition zone of RCA. This study investigates the effects of shrinkage-reducing additives (MgO, CaO and PPG) on the properties of recycled concrete powder-based alkali-activated (AASFR) pastes, and their efficacy in enhancing the interfacial performance of RCA. Shrinkage-reducing additives on the mechanical properties, drying shrinkage, and microstructural of AASFR pastes are investigated. The interfacial bonding performance is analyzed using BSE imaging and nanoindentation. Results demonstrate that 4% MgO yields the best mechanical and interfacial behavior, forming the narrowest new interfacial transition zone (NITZ) and the highest elastic modulus. In comparison, 3% CaO provides a cost-effective solution with significant shrinkage reduction but offers limited long-term strength and interfacial improvement. Although the addition of PPG significantly mitigates drying shrinkage by reducing the pore solution surface tension, it leads to increased porosity and a reduction in compressive strength, presenting a moderate compromise in enhancing the mechanical properties of NITZ. The performance-cost-emissions trade-off analysis identifies MgO-modified paste as optimal for high-performance situation, while CaO-modified paste serves as the most cost-effective sustainable solution. This study provides the first comparative study of these three additive types on the modified interfacial micromechanics of RCA in an alkali-activated system, and focuses on the interfacial micromechanics of alkali-activated modified materials and proposing a comprehensive evaluation method that combines nanoindentation characterization with environmental impact and economic cost. This study provides practical insights for optimizing alkali-activated RCA modification technologies, highlighting the critical role of additive selection in modified interfacial microstructure and practical applications.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 ","pages":"Article 115463"},"PeriodicalIF":7.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095867","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}

引用次数: 0

Seismic performance of CFRP-strengthened prefabricated plant fiber-magnesium oxychloride cement composites frame structures under bidirectional shaking table tests cfrp增强预制植物纤维-氯氧镁水泥复合材料框架结构双向振动台试验抗震性能

IF 6.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115624

Mingliang Wang, Huagang Zhang, Qiang Fang, Pengye Gu, Qinzheng Wang, Penggang Tian

The plant fiber-magnesium oxychloride cement composites (PF-MOC) are a low-carbon and sustainable building material. Existing studies have primarily focused on the material properties and component-level performance of PF-MOC under static or quasi-static loading, while its system-level dynamic response to seismic excitation remains unclear. Therefore, a 1:3-scale, two-story single-span PF-MOC frame structure strengthened with CFRP was designed and tested through shaking table tests. Ground motions were selected from the El Centro and Taft earthquake records, with both unidirectional and bidirectional seismic inputs considered. The dynamic characteristics, acceleration and displacement responses, and shear force distribution of the frame were measured and analyzed. The results show that as the peak ground acceleration (PGA) increased from 0.05 g to 0.85 g, the fundamental frequencies in the X- and Y-directions decreased by 18.47% and 7.90%, respectively. The overall acceleration amplification factor (AAF) generally decreased with increasing PGA, although localized increases were observed at higher excitation levels due to period lengthening and coupling with the response spectrum peak. The maximum inter-story drift ratios reached 1/769 and 1/83 at PGAs of 0.1 g and 0.62 g, respectively, and the maximum base shear force reached 11.62 kN. Overall, the results indicate that CFRP-strengthened prefabricated PF-MOC frame structures exhibit stable system-level dynamic behavior, providing experimental evidence for their seismic assessment and potential engineering applications.

植物纤维-氯氧镁水泥复合材料（PF-MOC）是一种低碳可持续建筑材料。现有的研究主要集中在静态或准静态载荷下PF-MOC的材料性能和构件级性能，而其在地震激励下的系统级动力响应尚不清楚。为此，设计了一种1:3比例CFRP加固两层单跨PF-MOC框架结构，并进行了振动台试验。从埃尔森特罗和塔夫脱地震记录中选择了地面运动，考虑了单向和双向地震输入。对框架的动力特性、加速度和位移响应以及剪力分布进行了测量和分析。结果表明，当峰值地加速度从0.05 g增加到0.85 g时，X和y方向的基频分别下降了18.47%和7.90%。随着PGA的增加，整体加速度放大因子（AAF）普遍降低，但在较高的激励水平下，由于周期延长和与响应谱峰的耦合，局部增加。在PGAs为0.1 g和0.62 g时，最大层间位移比分别为1/769和1/83，最大基底剪力为11.62 kN。结果表明，cfrp加固预制PF-MOC框架结构具有稳定的系统级动力性能，为其抗震评价和潜在的工程应用提供了实验依据。

{"title":"Seismic performance of CFRP-strengthened prefabricated plant fiber-magnesium oxychloride cement composites frame structures under bidirectional shaking table tests","authors":"Mingliang Wang, Huagang Zhang, Qiang Fang, Pengye Gu, Qinzheng Wang, Penggang Tian","doi":"10.1016/j.jobe.2026.115624","DOIUrl":"https://doi.org/10.1016/j.jobe.2026.115624","url":null,"abstract":"The plant fiber-magnesium oxychloride cement composites (PF-MOC) are a low-carbon and sustainable building material. Existing studies have primarily focused on the material properties and component-level performance of PF-MOC under static or quasi-static loading, while its system-level dynamic response to seismic excitation remains unclear. Therefore, a 1:3-scale, two-story single-span PF-MOC frame structure strengthened with CFRP was designed and tested through shaking table tests. Ground motions were selected from the El Centro and Taft earthquake records, with both unidirectional and bidirectional seismic inputs considered. The dynamic characteristics, acceleration and displacement responses, and shear force distribution of the frame were measured and analyzed. The results show that as the peak ground acceleration (PGA) increased from 0.05 g to 0.85 g, the fundamental frequencies in the X- and Y-directions decreased by 18.47% and 7.90%, respectively. The overall acceleration amplification factor (AAF) generally decreased with increasing PGA, although localized increases were observed at higher excitation levels due to period lengthening and coupling with the response spectrum peak. The maximum inter-story drift ratios reached 1/769 and 1/83 at PGAs of 0.1 g and 0.62 g, respectively, and the maximum base shear force reached 11.62 kN. Overall, the results indicate that CFRP-strengthened prefabricated PF-MOC frame structures exhibit stable system-level dynamic behavior, providing experimental evidence for their seismic assessment and potential engineering applications.","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"3 1","pages":""},"PeriodicalIF":6.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146209559","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}

引用次数: 0

Study on the concurrent wind fire spread model of dry and wet aged fir 干湿老杉木同期风火蔓延模型研究

IF 7.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115419

Jingyu Zhao , Hanqi Ming , Jiajia Song , Xingyu Shuai , Yanni Zhang , Jun Deng , Yihe Liu

Ancient buildings contain a large number of inclined timber components and are exposed to the natural environment for long periods. Consequently, the wood materials undergo ageing, which alters their fire spread behaviour. In this study, fir, which is commonly used in ancient buildings, was selected as the research object. Fir specimens with different dry and wet ageing degrees were prepared using an artificially accelerated ageing method. The variation trends of their thermophysical properties were investigated, and an experimental system for measuring fire spread parameters was self-developed to analyse the fire spread process of dry and wet aged fir under different inclination angles. The results show that dry and wet ageing enhances the overall heat transfer capacity of fir, and the specific heat capacity is strongly correlated with the ageing degree. Increasing the inclination angle promotes flame attachment to the surface and increases the fire spread rate, while the correlation between the gas-solid phase temperature and the ageing degree becomes weaker. Under horizontal conditions, fir with a higher ageing degree exhibits smaller fluctuations in the flame angle, and the fire spread rate gradually tends to stabilize. The calculations indicate that dry and wet aged fir behaves as a thermally thin material. Based on the thermally thin assumption and a convection-dominated heat feedback mechanism, a theoretical concurrent wind fire spread model of dry and wet aged fir under horizontal and inclined conditions was established and further corrected, providing a theoretical basis for the monitoring and assessment of fire risk of timber components in ancient buildings.

古建筑包含大量倾斜的木材构件，长期暴露在自然环境中。因此，木材材料经历老化，这改变了他们的火势蔓延行为。本研究选择古建筑中常用的杉木作为研究对象。采用人工加速老化法制备了不同干湿老化程度的杉木标本。研究了其热物性的变化趋势，自行研制了一套测量火灾蔓延参数的实验系统，分析了不同倾角下干湿两种老化杉木的火灾蔓延过程。结果表明：干湿老化增强了杉木的整体换热能力，比热容量与老化程度密切相关；倾斜角的增大促进了火焰对表面的附着，增大了火势的蔓延速度，而气固相温度与老化程度的相关性减弱。水平条件下，老化程度越高的杉木火焰角度波动越小，火势蔓延速度逐渐趋于稳定。计算表明，干、湿老化杉木表现为热薄材料。基于热薄假设和对流主导的热反馈机制，建立了水平和倾斜条件下干湿老杉木风火并行传播理论模型，并进行了修正，为古建筑木结构构件火灾风险监测与评估提供了理论依据。

{"title":"Study on the concurrent wind fire spread model of dry and wet aged fir","authors":"Jingyu Zhao , Hanqi Ming , Jiajia Song , Xingyu Shuai , Yanni Zhang , Jun Deng , Yihe Liu","doi":"10.1016/j.jobe.2026.115419","DOIUrl":"10.1016/j.jobe.2026.115419","url":null,"abstract":"<div><div>Ancient buildings contain a large number of inclined timber components and are exposed to the natural environment for long periods. Consequently, the wood materials undergo ageing, which alters their fire spread behaviour. In this study, fir, which is commonly used in ancient buildings, was selected as the research object. Fir specimens with different dry and wet ageing degrees were prepared using an artificially accelerated ageing method. The variation trends of their thermophysical properties were investigated, and an experimental system for measuring fire spread parameters was self-developed to analyse the fire spread process of dry and wet aged fir under different inclination angles. The results show that dry and wet ageing enhances the overall heat transfer capacity of fir, and the specific heat capacity is strongly correlated with the ageing degree. Increasing the inclination angle promotes flame attachment to the surface and increases the fire spread rate, while the correlation between the gas-solid phase temperature and the ageing degree becomes weaker. Under horizontal conditions, fir with a higher ageing degree exhibits smaller fluctuations in the flame angle, and the fire spread rate gradually tends to stabilize. The calculations indicate that dry and wet aged fir behaves as a thermally thin material. Based on the thermally thin assumption and a convection-dominated heat feedback mechanism, a theoretical concurrent wind fire spread model of dry and wet aged fir under horizontal and inclined conditions was established and further corrected, providing a theoretical basis for the monitoring and assessment of fire risk of timber components in ancient buildings.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 ","pages":"Article 115419"},"PeriodicalIF":7.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089300","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}

引用次数: 0

Kilogram-scale synthesis of phase-pure clinker phases with hydration reactivity benchmarks and CO2 emissions constraints for machine-learning-assisted low-carbon clinker design 千克级合成具有水化反应性基准和二氧化碳排放限制的相纯熟料相，用于机器学习辅助的低碳熟料设计

IF 7.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115395

Munan Zhai, Jiayuan Ye, Xuehong Ren, Wensheng Zhang

Decarbonizing cement production is essential for sustainable construction materials, and clinker manufacturing accounts for the majority of CO₂ emissions in the cement sector. Therefore, designing next-generation low-carbon clinker systems is a promising strategy to reduce CO₂ emissions. Machine-learning-assisted clinker design could accelerate the development of low-carbon clinker systems, but progress is limited by the lack of high-quality, accessible data. To address this gap, (i) a critical review of existing clinker phases, (ii) kilogram-scale synthesis of representative phase-pure clinker phases and their degree of hydration (DoH) and compressive strength development as hydration-reactivity benchmarks, and (iii) quantification of the CO₂ emissions attributable to each phase-pure clinker phase were conducted. Eleven phase-pure clinker phases were synthesized at the kilogram scale and were systematically characterized for their DoH and compressive strength development. These phases were selected for their high hydration reactivity or intrinsically lower CO₂ emissions. Theoretical CO₂ emissions were estimated as the sum of raw-material-derived emissions and fuel-derived emissions. The CO₂ emissions of clinker phases enable explicit environmental constraints in clinker design. Overall, this work demonstrates reproducible routes to produce multiple phase-pure clinker phases at the kilogram scale, providing ample feedstock for high-throughput experiments. It also establishes benchmarks for hydration reactivity and constraints on CO₂ emissions, enabling machine-learning-assisted inverse design of novel low-carbon clinkers. These advances lay a foundation for accelerating the data-driven discovery of next-generation clinker and contribute to developing more sustainable cementitious materials.

脱碳水泥生产对可持续建筑材料至关重要，熟料生产占水泥行业二氧化碳排放的大部分。因此，设计下一代低碳熟料系统是一种很有前途的减少二氧化碳排放的策略。机器学习辅助熟料设计可以加速低碳熟料系统的发展，但由于缺乏高质量、可访问的数据，进展受到限制。为了解决这一差距，(i)对现有熟料相进行了批判性审查，（ii）以公斤级为基准合成了具有代表性的相-纯熟料相及其水化程度（DoH）和抗压强度的发展，以及（iii）量化了每个相-纯熟料相的二氧化碳排放量。在千克级合成了11相纯熟料，并对其DoH和抗压强度发展进行了系统表征。选择这些相是因为它们具有较高的水化反应活性或本质上较低的二氧化碳排放量。理论二氧化碳排放量被估计为原料衍生排放和燃料衍生排放的总和。熟料相的二氧化碳排放在熟料设计中具有明确的环境约束。总的来说，这项工作展示了在公斤级生产多相纯熟料相的可重复路线，为高通量实验提供了充足的原料。它还建立了水合反应性和二氧化碳排放限制的基准，使新型低碳熟料的机器学习辅助逆设计成为可能。这些进展为加速下一代熟料的数据驱动发现奠定了基础，并有助于开发更可持续的胶凝材料。

{"title":"Kilogram-scale synthesis of phase-pure clinker phases with hydration reactivity benchmarks and CO2 emissions constraints for machine-learning-assisted low-carbon clinker design","authors":"Munan Zhai, Jiayuan Ye, Xuehong Ren, Wensheng Zhang","doi":"10.1016/j.jobe.2026.115395","DOIUrl":"10.1016/j.jobe.2026.115395","url":null,"abstract":"<div><div>Decarbonizing cement production is essential for sustainable construction materials, and clinker manufacturing accounts for the majority of CO<sub>2</sub> emissions in the cement sector. Therefore, designing next-generation low-carbon clinker systems is a promising strategy to reduce CO<sub>2</sub> emissions. Machine-learning-assisted clinker design could accelerate the development of low-carbon clinker systems, but progress is limited by the lack of high-quality, accessible data. To address this gap, (i) a critical review of existing clinker phases, (ii) kilogram-scale synthesis of representative phase-pure clinker phases and their degree of hydration (<em>DoH</em>) and compressive strength development as hydration-reactivity benchmarks, and (iii) quantification of the CO<sub>2</sub> emissions attributable to each phase-pure clinker phase were conducted. Eleven phase-pure clinker phases were synthesized at the kilogram scale and were systematically characterized for their <em>DoH</em> and compressive strength development. These phases were selected for their high hydration reactivity or intrinsically lower CO<sub>2</sub> emissions. Theoretical CO<sub>2</sub> emissions were estimated as the sum of raw-material-derived emissions and fuel-derived emissions. The CO<sub>2</sub> emissions of clinker phases enable explicit environmental constraints in clinker design. Overall, this work demonstrates reproducible routes to produce multiple phase-pure clinker phases at the kilogram scale, providing ample feedstock for high-throughput experiments. It also establishes benchmarks for hydration reactivity and constraints on CO<sub>2</sub> emissions, enabling machine-learning-assisted inverse design of novel low-carbon clinkers. These advances lay a foundation for accelerating the data-driven discovery of next-generation clinker and contribute to developing more sustainable cementitious materials.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 ","pages":"Article 115395"},"PeriodicalIF":7.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146089308","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}

引用次数: 0

Cold-pressed artificial aggregate for sustainable buildings fabricated from multi-source construction waste 用多源建筑垃圾制造可持续建筑的冷压人工骨料

IF 7.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115496

Yanshuai Wang, Zhenyu Zhu, Biqin Dong, Rongxin Peng

Construction and demolition waste (CDW), an unavoidable byproduct of global urbanization, leads to environmental degradation and resource depletion. To address this challenge, a cold-pressing method was utilized to transform multi-source construction waste recycled powder (MCWRP) into artificial aggregates for sustainable buildings. Ground granulated blast furnace slag (GGBS) was incorporated as a reactive micro-filler to enhance aggregate properties. The effects of varying cement and GGBS contents on cold-pressed MCWRP-based artificial aggregates (MCWAAs) were assessed through single-particle crushing strength, apparent density, and water absorption tests. Microstructural characterization was performed using X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and low-field nuclear magnetic resonance (LF-NMR). Results indicate that MCWAAs achieved a 28-day crushing strength of up to 3.3 MPa, an apparent density of 1882.3 kg/m³, and a water absorption rate of 10.8%, demonstrating their practical applicability. SEM analysis revealed that compaction pressure and hydration products densified the initially loose MCWRP structure. However, MCWAAs prepared with cement alone exhibited porous microstructures due to the coarse particle size of MCWRP. The incorporation of GGBS significantly refined the microstructure, reducing porosity to 11.48%. TGA and LF-NMR confirmed that higher GGBS content enhanced C-S-H gel formation, refined pore structure, and increased aggregate compactness. Consequently, MCWAAs exhibited improved strength and density with reduced water absorption, which offers a scalable, automated solution for the efficient reuse of CDW and other solid residues.

建筑拆迁垃圾是全球城市化进程中不可避免的副产品，造成环境恶化和资源枯竭。为了应对这一挑战，采用冷压方法将多源建筑垃圾再生粉末（MCWRP）转化为可持续建筑的人工骨料。为提高骨料性能，采用磨粒型高炉矿渣（GGBS）作为活性微填料。通过单颗粒抗压强度、表观密度和吸水率测试，评估不同水泥和GGBS含量对冷压mcwrp人工骨料（MCWAAs）的影响。采用x射线衍射（XRD）、热重分析（TGA）、扫描电镜能谱（SEM-EDS）和低场核磁共振（LF-NMR）进行了微观结构表征。结果表明，MCWAAs的28天破碎强度可达3.3 MPa，表观密度为1882.3 kg/m3，吸水率为10.8%，具有一定的实用性。SEM分析表明，压实压力和水化产物使MCWRP初始松散的结构致密化。然而，由于MCWRP的粒径较大，仅用水泥制备的MCWAAs表现出多孔的微观结构。GGBS的加入显著细化了显微组织，孔隙率降至11.48%。TGA和LF-NMR证实，较高的GGBS含量增强了C-S-H凝胶的形成，改善了孔隙结构，增加了聚集体的致密性。因此，MCWAAs表现出更高的强度和密度，同时减少了吸水率，这为CDW和其他固体残留物的有效再利用提供了可扩展的自动化解决方案。

{"title":"Cold-pressed artificial aggregate for sustainable buildings fabricated from multi-source construction waste","authors":"Yanshuai Wang, Zhenyu Zhu, Biqin Dong, Rongxin Peng","doi":"10.1016/j.jobe.2026.115496","DOIUrl":"10.1016/j.jobe.2026.115496","url":null,"abstract":"<div><div>Construction and demolition waste (CDW), an unavoidable byproduct of global urbanization, leads to environmental degradation and resource depletion. To address this challenge, a cold-pressing method was utilized to transform multi-source construction waste recycled powder (MCWRP) into artificial aggregates for sustainable buildings. Ground granulated blast furnace slag (GGBS) was incorporated as a reactive micro-filler to enhance aggregate properties. The effects of varying cement and GGBS contents on cold-pressed MCWRP-based artificial aggregates (MCWAAs) were assessed through single-particle crushing strength, apparent density, and water absorption tests. Microstructural characterization was performed using X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and low-field nuclear magnetic resonance (LF-NMR). Results indicate that MCWAAs achieved a 28-day crushing strength of up to 3.3 MPa, an apparent density of 1882.3 kg/m<sup>3</sup>, and a water absorption rate of 10.8%, demonstrating their practical applicability. SEM analysis revealed that compaction pressure and hydration products densified the initially loose MCWRP structure. However, MCWAAs prepared with cement alone exhibited porous microstructures due to the coarse particle size of MCWRP. The incorporation of GGBS significantly refined the microstructure, reducing porosity to 11.48%. TGA and LF-NMR confirmed that higher GGBS content enhanced C-S-H gel formation, refined pore structure, and increased aggregate compactness. Consequently, MCWAAs exhibited improved strength and density with reduced water absorption, which offers a scalable, automated solution for the efficient reuse of CDW and other solid residues.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 ","pages":"Article 115496"},"PeriodicalIF":7.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095860","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}

引用次数: 0

Influence of rubber substitution rate and cement content on the mechanical and permeability performance of high-content rubberized sand concrete 橡胶取代率和水泥掺量对高掺量橡胶砂混凝土力学性能和渗透性能的影响

IF 7.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115469

Xiancheng Mei , Junjie Zeng , Zhen Cui , Hao Sheng , Qian Sheng , Jian Chen , Yanshuang Yang , Hao Yan

To address the pollution caused by waste tires and break through the bottleneck of difficult coordinated regulation of mechanical and impermeability properties of high-rubber-content rubberized sand concrete (HRC-RSC) in underground and water conservancy projects, this study designed five groups of specimens with different rubber substitution ratios (R) and cement contents (C). Through a progressive testing sequence of macroscopic mechanical testing, permeability and impermeability characterization, and microscopic mechanism analysis, the regulation laws of R and C on material properties were revealed. The macroscopic mechanical testing results show that the increase in R leads to a decrease in compressive strength, the volume deformation shifts from “compression-expansion” to “continuous compression”. The increase in C increases the compressive strength, and when the C is 50%, the specimen shows typical brittle failure. The permeability characterization results show the permeability changes non-monotonically with the R. The specimen with R = 50% has the highest permeability coefficient. And the confining pressure exerts a reducing effect on the permeability coefficient of HRC-RSC. Meanwhile, the microscopic mechanism analysis results show that microscopic interface defects are the core medium for performance regulation. The increase in R disrupts the continuity of the cement matrix, leading to a significant increase in porosity. The increase in specimen C can improve the compactness of the cement matrix, reduce porosity, and mitigate crack development. Based on the mechanical-permeability synergistic coefficient (K) and coupling criteria (K ≥ 0.4 for good synergy), the R50-C40 mix proportion is recommended for the buffer layer in underground projects, and the R70-C40 and R50-C30 mix proportions are recommended for high-confining-pressure impermeability.

为解决废旧轮胎污染问题，突破地下水利工程中高含胶砂混凝土（HRC-RSC）力学性能与抗渗性能难以协调调节的瓶颈，本研究设计了5组不同橡胶替代比(R)和水泥掺量(C)的试件。通过宏观力学试验、透气性和抗渗性表征、微观机理分析等一系列试验，揭示了R和C对材料性能的调节规律。宏观力学试验结果表明，R的增大导致材料抗压强度降低，体积变形由“压缩-膨胀”转变为“连续压缩”。C的增加使试样抗压强度增加，当C为50%时，试样呈现典型的脆性破坏。渗透率表征结果表明，渗透率随R的变化呈非单调变化，当R = 50%时渗透率系数最高。围压对HRC-RSC的渗透系数有降低作用。同时，微观机理分析结果表明，微观界面缺陷是性能调控的核心介质。R的增加破坏了水泥基质的连续性，导致孔隙度显著增加。试样C含量的增加可以提高水泥基体的密实度，降低孔隙率，减缓裂缝的发展。根据力学-渗透协同系数(K)和耦合准则（K≥0.4为协同良好），地下工程缓冲层推荐采用R50-C40配合比，高围压防渗建议采用R70-C40和R50-C30配合比。

{"title":"Influence of rubber substitution rate and cement content on the mechanical and permeability performance of high-content rubberized sand concrete","authors":"Xiancheng Mei , Junjie Zeng , Zhen Cui , Hao Sheng , Qian Sheng , Jian Chen , Yanshuang Yang , Hao Yan","doi":"10.1016/j.jobe.2026.115469","DOIUrl":"10.1016/j.jobe.2026.115469","url":null,"abstract":"<div><div>To address the pollution caused by waste tires and break through the bottleneck of difficult coordinated regulation of mechanical and impermeability properties of high-rubber-content rubberized sand concrete (HRC-RSC) in underground and water conservancy projects, this study designed five groups of specimens with different rubber substitution ratios (R) and cement contents (C). Through a progressive testing sequence of macroscopic mechanical testing, permeability and impermeability characterization, and microscopic mechanism analysis, the regulation laws of R and C on material properties were revealed. The macroscopic mechanical testing results show that the increase in R leads to a decrease in compressive strength, the volume deformation shifts from “compression-expansion” to “continuous compression”. The increase in C increases the compressive strength, and when the C is 50%, the specimen shows typical brittle failure. The permeability characterization results show the permeability changes non-monotonically with the R. The specimen with R = 50% has the highest permeability coefficient. And the confining pressure exerts a reducing effect on the permeability coefficient of HRC-RSC. Meanwhile, the microscopic mechanism analysis results show that microscopic interface defects are the core medium for performance regulation. The increase in R disrupts the continuity of the cement matrix, leading to a significant increase in porosity. The increase in specimen C can improve the compactness of the cement matrix, reduce porosity, and mitigate crack development. Based on the mechanical-permeability synergistic coefficient (<em>K</em>) and coupling criteria (<em>K</em> ≥ 0.4 for good synergy), the R50-C40 mix proportion is recommended for the buffer layer in underground projects, and the R70-C40 and R50-C30 mix proportions are recommended for high-confining-pressure impermeability.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 ","pages":"Article 115469"},"PeriodicalIF":7.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095862","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}

引用次数: 0

Axial compressive behavior and stress-strain model of CFRP-UHPC composite-strengthened concrete columns CFRP-UHPC复合加固混凝土柱轴压特性及应力-应变模型

IF 7.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115501

Qiang Wang , Shiping Guo , Geng Chen , Chunling Lu

To mitigate brittle failure in UHPC-strengthened concrete columns caused by core concrete expansion under axial compression, this study adopts a CFRP-UHPC composite strengthening approach. To investigate the axial compressive behavior and stress-strain models of CFRP-UHPC composite-strengthened concrete columns, uniaxial compression tests were conducted on 3 plain concrete columns, 9 CFRP-strengthened columns, 9 UHPC-strengthened columns, and 27 CFRP-UHPC composite-strengthened columns. The effects of CFRP layers and UHPC thickness on the axial compressive behavior of the core concrete were systematically examined. The results demonstrate that, compared to UHPC-only strengthening, composite-strengthened specimens exhibit a 10%–16.4% enhancement in initial stiffness due to the CFRP-UHPC synergistic confinement effect. The ultimate capacity increase significantly exceeds the additive effect of individual strengthening methods, with specimen CUF-20-4 achieving an ultimate capacity enhancement of 431.28%; Under identical UHPC thickness, the composite-strengthened specimens exhibited bearing capacity increases of 11.9%∼60.8% and ductility improvements of 4.18%∼16.73% with increasing CFRP layers, while the initial stiffness remained virtually constant. For specimens with identical CFRP layers, an increase in UHPC thickness enhanced the bearing capacity by 12.20%∼61.54% and initial stiffness by 3.43%∼7.64%, while ductility exhibited a marginal decline. Furthermore, the failure mechanisms of CFRP-UHPC composite-strengthened columns were proposed based on experimental phenomena and material strains. Based on the ultimate stress-strain formulation for confined concrete proposed by Xiao et al., coefficients in the formula were calibrated to develop an ultimate stress-strain model for CFRP-UHPC composite-strengthened columns. Stress-strain models for low and high confinement ratios were established, with predicted curves demonstrating strong agreement with experimental results.

为了减轻轴压作用下核心混凝土膨胀引起的uhpc加固混凝土柱脆性破坏，本研究采用CFRP-UHPC复合加固方法。为了研究CFRP-UHPC复合增强混凝土柱的轴压特性和应力-应变模型，对3根素混凝土柱、9根cfrp -加固柱、9根uhpc -加固柱和27根CFRP-UHPC复合增强柱进行了单轴压缩试验。系统研究了CFRP层数和UHPC厚度对核心混凝土轴压性能的影响。结果表明，与单纯uhpc加固相比，复合材料加固试件由于CFRP-UHPC的协同约束效应，初始刚度提高了10% ~ 16.4%。试验结果表明，CUF-20-4试件的极限承载力提高幅度达到431.28%；在相同UHPC厚度下，随着CFRP层数的增加，复合材料加固试件的承载力提高11.9% ~ 60.8%，延性提高4.18% ~ 16.73%，而初始刚度基本保持不变。对于相同CFRP层数的试件，增加UHPC厚度可使承载力提高12.20% ~ 61.54%，初始刚度提高3.43% ~ 7.64%，但延性略有下降。基于试验现象和材料应变，提出了CFRP-UHPC复合加固柱的破坏机理。基于Xiao等人提出的约束混凝土极限应力-应变公式，对公式中的系数进行校正，建立了CFRP-UHPC复合加固柱的极限应力-应变模型。建立了低约束比和高约束比下的应力-应变模型，预测曲线与实验结果吻合较好。

{"title":"Axial compressive behavior and stress-strain model of CFRP-UHPC composite-strengthened concrete columns","authors":"Qiang Wang , Shiping Guo , Geng Chen , Chunling Lu","doi":"10.1016/j.jobe.2026.115501","DOIUrl":"10.1016/j.jobe.2026.115501","url":null,"abstract":"<div><div>To mitigate brittle failure in UHPC-strengthened concrete columns caused by core concrete expansion under axial compression, this study adopts a CFRP-UHPC composite strengthening approach. To investigate the axial compressive behavior and stress-strain models of CFRP-UHPC composite-strengthened concrete columns, uniaxial compression tests were conducted on 3 plain concrete columns, 9 CFRP-strengthened columns, 9 UHPC-strengthened columns, and 27 CFRP-UHPC composite-strengthened columns. The effects of CFRP layers and UHPC thickness on the axial compressive behavior of the core concrete were systematically examined. The results demonstrate that, compared to UHPC-only strengthening, composite-strengthened specimens exhibit a 10%–16.4% enhancement in initial stiffness due to the CFRP-UHPC synergistic confinement effect. The ultimate capacity increase significantly exceeds the additive effect of individual strengthening methods, with specimen CUF-20-4 achieving an ultimate capacity enhancement of 431.28%; Under identical UHPC thickness, the composite-strengthened specimens exhibited bearing capacity increases of 11.9%∼60.8% and ductility improvements of 4.18%∼16.73% with increasing CFRP layers, while the initial stiffness remained virtually constant. For specimens with identical CFRP layers, an increase in UHPC thickness enhanced the bearing capacity by 12.20%∼61.54% and initial stiffness by 3.43%∼7.64%, while ductility exhibited a marginal decline. Furthermore, the failure mechanisms of CFRP-UHPC composite-strengthened columns were proposed based on experimental phenomena and material strains. Based on the ultimate stress-strain formulation for confined concrete proposed by Xiao et al., coefficients in the formula were calibrated to develop an ultimate stress-strain model for CFRP-UHPC composite-strengthened columns. Stress-strain models for low and high confinement ratios were established, with predicted curves demonstrating strong agreement with experimental results.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 ","pages":"Article 115501"},"PeriodicalIF":7.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110213","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}

引用次数: 0

Energy-independent crack repair of cement mortar using externally bonded corrosion-induced shape-memory fibers 用外粘接腐蚀诱导形状记忆纤维修补水泥砂浆的能量无关裂缝

IF 7.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115504

Ziguo Wang, Shaotao Ma, Yuyan Sun, Zhenghu Zhang, Haocheng Zhang

Autonomous crack repair is essential for extending the service life of marine concrete structures, where conventional repair methods are often difficult and costly to implement. This study investigates the external application of corrosion-induced shape-memory fibers (CSFs) for self-repairing cracks in cement mortar under seawater conditions. Accelerated corrosion tests examined the effects of prestress level, initial crack width, and corrosion duration. Results showed that CSFs achieved average crack closure ratios of 40.00% for fine cracks (0.09–0.20 mm), 91.19% for medium cracks (0.70–1 mm), and 88.48% for wide cracks (1–1.25 mm) within 3 h of accelerated corrosion, with the average residual crack widths reduced to 0.072 mm, 0.075 mm, and 0.133 mm, respectively. Notably, the majority of closure occurred within the first hour, followed by a declined closure rate as the corrosion process slowed. Microscopy and XRD confirmed robust anchorage and effective stress transfer, enabling mechanical crack closure via a corrosion-triggered mechanism. The system provides an energy-independent, adaptable solution for autonomous repair in corrosive environments.

自主修补裂缝对于延长海洋混凝土结构的使用寿命至关重要，而传统的修补方法往往难以实施且成本高昂。研究了腐蚀诱导形状记忆纤维（CSFs）在海水条件下自修复水泥砂浆裂缝中的应用。加速腐蚀试验考察了预应力水平、初始裂缝宽度和腐蚀持续时间的影响。结果表明：在加速腐蚀3 h内，细裂纹（0.09 ~ 0.20 mm）、中等裂纹（0.70 ~ 1 mm）和宽裂纹（1 ~ 1.25 mm）的平均裂纹闭合率分别为40.00%、91.19%和88.48%，平均残余裂纹宽度分别减小到0.072 mm、0.075 mm和0.133 mm。值得注意的是，大多数封闭发生在第一个小时内，随后随着腐蚀过程的减慢，封闭率下降。显微镜和x射线衍射（XRD）证实了坚固的锚固和有效的应力传递，可以通过腐蚀触发机制实现机械裂纹关闭。该系统为腐蚀环境中的自动修复提供了一种能源独立、适应性强的解决方案。

{"title":"Energy-independent crack repair of cement mortar using externally bonded corrosion-induced shape-memory fibers","authors":"Ziguo Wang, Shaotao Ma, Yuyan Sun, Zhenghu Zhang, Haocheng Zhang","doi":"10.1016/j.jobe.2026.115504","DOIUrl":"10.1016/j.jobe.2026.115504","url":null,"abstract":"<div><div>Autonomous crack repair is essential for extending the service life of marine concrete structures, where conventional repair methods are often difficult and costly to implement. This study investigates the external application of corrosion-induced shape-memory fibers (CSFs) for self-repairing cracks in cement mortar under seawater conditions. Accelerated corrosion tests examined the effects of prestress level, initial crack width, and corrosion duration. Results showed that CSFs achieved average crack closure ratios of 40.00% for fine cracks (0.09–0.20 mm), 91.19% for medium cracks (0.70–1 mm), and 88.48% for wide cracks (1–1.25 mm) within 3 h of accelerated corrosion, with the average residual crack widths reduced to 0.072 mm, 0.075 mm, and 0.133 mm, respectively. Notably, the majority of closure occurred within the first hour, followed by a declined closure rate as the corrosion process slowed. Microscopy and XRD confirmed robust anchorage and effective stress transfer, enabling mechanical crack closure via a corrosion-triggered mechanism. The system provides an energy-independent, adaptable solution for autonomous repair in corrosive environments.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 ","pages":"Article 115504"},"PeriodicalIF":7.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110229","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}

引用次数: 0

Synthesis and characterization of lightweight foamed geopolymers from iron tailings for energy-efficient construction 节能建筑用铁尾矿轻质泡沫地聚合物的合成与表征

IF 7.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115414

Andreia Santos , Slavka Andrejkovičová , Daniela Řimnáčová , Ivana Perná , Fernando Almeida , Fernando Rocha

Thermal insulation is a critical consideration in building design, as it enhances energy efficiency and contributes significantly to occupant comfort. An effective solution involves using materials that not only prevent/inhibit heat transfer and have sufficient mechanical strength but also have low energy consumption and sustainability. Among the emerging alternatives, foamed geopolymers have shown considerable promise for thermal insulation applications, generally exhibiting lower thermal conductivity coefficients compared to conventional insulating materials.

This study addresses two main aspects: the incorporation of iron tailings into geopolymeric matrices by 10 and 20 % of the weight and the preparation of foamed geopolymers utilizing three different foaming agents: aluminum powder, hydrogen peroxide, and sodium perborate. The iron tailings were used as a supplementary additive to partially replace metakaolin, with the aim of promoting sustainable resource utilization. To evaluate the performance and feasibility of these materials, a series of tests were conducted, including compressive strength analysis, thermal conductivity measurements, and mercury intrusion porosimetry.

The results indicate that the formulations incorporating sodium perborate achieve the lowest thermal conductivity values, ranging from 0.211 to 0.110 W/m·K. However, these samples exhibit relatively low compressive strengths, between 1.5 and 5 MPa. Conversely, geopolymers foamed with aluminum powder demonstrate higher thermal conductivity values, 0.296–0.391 W/m·K, but with significantly improved compressive strengths, reaching up to 13 MPa. Porosity analysis reveals that samples with more heterogeneous pore structures tend to perform better in terms of thermal insulation. The addition of iron tailings improved some characteristics, such as compressive strength.

隔热在建筑设计中是一个重要的考虑因素，因为它提高了能源效率，并显著提高了居住者的舒适度。一个有效的解决方案是使用既能防止/抑制热传递又具有足够机械强度的材料，同时还具有低能耗和可持续性。在新兴的替代品中，泡沫地聚合物在隔热应用中显示出相当大的前景，与传统的绝缘材料相比，通常表现出更低的导热系数。本研究涉及两个主要方面：将铁尾矿以10%和20%的重量掺入地聚合物基质中，并使用三种不同的发泡剂：铝粉、过氧化氢和过硼酸钠制备泡沫地聚合物。以铁尾矿为补充添加剂，部分替代偏高岭土，促进资源的可持续利用。为了评估这些材料的性能和可行性，进行了一系列测试，包括抗压强度分析、导热系数测量和压汞孔隙度测定。结果表明，含过硼酸钠的配方导热系数最低，为0.211 ~ 0.110 W/m·K。然而，这些样品的抗压强度相对较低，在1.5 ~ 5mpa之间。相反，铝粉发泡地聚合物的导热系数更高，为0.296 ~ 0.391 W/m·K，但抗压强度显著提高，最高可达13 MPa。孔隙度分析表明，孔隙结构越不均匀的样品，其保温性能越好。铁尾矿的加入改善了尾矿的抗压强度等性能。

{"title":"Synthesis and characterization of lightweight foamed geopolymers from iron tailings for energy-efficient construction","authors":"Andreia Santos , Slavka Andrejkovičová , Daniela Řimnáčová , Ivana Perná , Fernando Almeida , Fernando Rocha","doi":"10.1016/j.jobe.2026.115414","DOIUrl":"10.1016/j.jobe.2026.115414","url":null,"abstract":"<div><div>Thermal insulation is a critical consideration in building design, as it enhances energy efficiency and contributes significantly to occupant comfort. An effective solution involves using materials that not only prevent/inhibit heat transfer and have sufficient mechanical strength but also have low energy consumption and sustainability. Among the emerging alternatives, foamed geopolymers have shown considerable promise for thermal insulation applications, generally exhibiting lower thermal conductivity coefficients compared to conventional insulating materials.</div><div>This study addresses two main aspects: the incorporation of iron tailings into geopolymeric matrices by 10 and 20 % of the weight and the preparation of foamed geopolymers utilizing three different foaming agents: aluminum powder, hydrogen peroxide, and sodium perborate. The iron tailings were used as a supplementary additive to partially replace metakaolin, with the aim of promoting sustainable resource utilization. To evaluate the performance and feasibility of these materials, a series of tests were conducted, including compressive strength analysis, thermal conductivity measurements, and mercury intrusion porosimetry.</div><div>The results indicate that the formulations incorporating sodium perborate achieve the lowest thermal conductivity values, ranging from 0.211 to 0.110 W/m·K. However, these samples exhibit relatively low compressive strengths, between 1.5 and 5 MPa. Conversely, geopolymers foamed with aluminum powder demonstrate higher thermal conductivity values, 0.296–0.391 W/m·K, but with significantly improved compressive strengths, reaching up to 13 MPa. Porosity analysis reveals that samples with more heterogeneous pore structures tend to perform better in terms of thermal insulation. The addition of iron tailings improved some characteristics, such as compressive strength.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 ","pages":"Article 115414"},"PeriodicalIF":7.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146110255","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}

引用次数: 0

Study on chloride ion erosion resistance of magnesium-enriched calcined clay cement (MC2-OPC) 富镁煅烧粘土水泥（MC2-OPC）抗氯离子侵蚀性能研究

IF 7.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2026-02-15 DOI: 10.1016/j.jobe.2026.115433

Hongqiang Ma , Hao Fu , Li Wang , Jingjing Feng , Chao Wu

This study investigates the chloride ion erosion resistance of magnesium-enriched calcined clay cement (MC²-OPC). Based on tests including pH value measurement, Cl⁻ concentration determination, XRD, FT-IR, ²⁹Si NMR, MIP, SEM-EDS, and mechanical property testing, the effects of different curing time and sampling depths on the performance of the MC²-OPC system are explored. The research results show that under long-term erosion, the alkaline stability of the MC²-OPC system is superior to that of the pure cement system, and it exhibits better chloride ion erosion resistance than the cement system. The optimal mass ratio of calcined magnesite-clay (MC²) is 3:7, and the most suitable MC² content ranges from 30 % to 45 %. Within 28d of erosion, Cl⁻ attack leads to the decomposition of the gel phase, a reduction in chain length, and an increase in pore volume (especially macropore volume), which results in a decrease in mechanical properties. With the extension of erosion time, the chain length of the gel phase increases, the pore volume decreases, the pore structure is refined, and the mechanical properties are improved. The reactive Al₂O₃ provided by calcined clay reacts with Ca²⁺ (a hydration product of cement) under alkaline conditions to form Friedel's salt, which effectively immobilizes Cl⁻. The maximum formation of Friedel's salt occurs at a depth of 2.5 cm. The MC²-OPC system achieves the enhancement of long-term chloride ion erosion resistance through the synergistic mechanism of alkaline recovery, chemical immobilization, pore optimization, and mechanical strengthening. It provides a high-performance solution for harsh environments such as marine engineering and saline soil in western China.

研究了富镁煅烧粘土水泥（MC2-OPC）的抗氯离子侵蚀性能。通过pH值测定、Cl−浓度测定、XRD、FT-IR、29Si NMR、MIP、SEM-EDS和力学性能测试，探讨了不同固化时间和取样深度对MC2-OPC体系性能的影响。研究结果表明，在长期侵蚀作用下，MC2-OPC体系的碱性稳定性优于纯水泥体系，且表现出比水泥体系更好的抗氯离子侵蚀能力。焙烧镁粘土（MC2）的最佳质量比为3:7，最适宜的MC2含量为30% ~ 45%。在侵蚀28d内，Cl−的侵蚀导致凝胶相分解，链长减小，孔隙体积（尤其是大孔体积）增大，从而导致力学性能下降。随着侵蚀时间的延长，凝胶相链长增加，孔隙体积减小，孔隙结构细化，力学性能得到改善。煅烧粘土提供的活性Al2O3在碱性条件下与钙离子（水泥的水化产物）反应形成弗里德尔盐，有效地固定了Cl−。弗里德尔盐的最大形成发生在2.5厘米的深度。MC2-OPC体系通过碱性回收、化学固定、孔隙优化、机械强化等协同机制，实现了长期抗氯离子侵蚀能力的增强。为中国西部海洋工程、盐碱地等恶劣环境提供高性能解决方案。

{"title":"Study on chloride ion erosion resistance of magnesium-enriched calcined clay cement (MC2-OPC)","authors":"Hongqiang Ma , Hao Fu , Li Wang , Jingjing Feng , Chao Wu","doi":"10.1016/j.jobe.2026.115433","DOIUrl":"10.1016/j.jobe.2026.115433","url":null,"abstract":"<div><div>This study investigates the chloride ion erosion resistance of magnesium-enriched calcined clay cement (MC<sup>2</sup>-OPC). Based on tests including pH value measurement, Cl<sup>−</sup> concentration determination, XRD, FT-IR, <sup>29</sup>Si NMR, MIP, SEM-EDS, and mechanical property testing, the effects of different curing time and sampling depths on the performance of the MC<sup>2</sup>-OPC system are explored. The research results show that under long-term erosion, the alkaline stability of the MC<sup>2</sup>-OPC system is superior to that of the pure cement system, and it exhibits better chloride ion erosion resistance than the cement system. The optimal mass ratio of calcined magnesite-clay (MC<sup>2</sup>) is 3:7, and the most suitable MC<sup>2</sup> content ranges from 30 % to 45 %. Within 28d of erosion, Cl<sup>−</sup> attack leads to the decomposition of the gel phase, a reduction in chain length, and an increase in pore volume (especially macropore volume), which results in a decrease in mechanical properties. With the extension of erosion time, the chain length of the gel phase increases, the pore volume decreases, the pore structure is refined, and the mechanical properties are improved. The reactive Al<sub>2</sub>O<sub>3</sub> provided by calcined clay reacts with Ca<sup>2+</sup> (a hydration product of cement) under alkaline conditions to form Friedel's salt, which effectively immobilizes Cl<sup>−</sup>. The maximum formation of Friedel's salt occurs at a depth of 2.5 cm. The MC<sup>2</sup>-OPC system achieves the enhancement of long-term chloride ion erosion resistance through the synergistic mechanism of alkaline recovery, chemical immobilization, pore optimization, and mechanical strengthening. It provides a high-performance solution for harsh environments such as marine engineering and saline soil in western China.</div></div>","PeriodicalId":15064,"journal":{"name":"Journal of building engineering","volume":"120 ","pages":"Article 115433"},"PeriodicalIF":7.4,"publicationDate":"2026-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146071732","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}

引用次数: 0