Cement & concrete composites最新文献_第4页

Wind-driven carbonation process of steel slag under low moisture content 低含水率钢渣风动碳化过程研究

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2026-01-02 DOI: 10.1016/j.cemconcomp.2026.106462

Kuizhou Liu , Slyvester Yew Wang Chai , Xilai Jiang , Tung-Chai Ling

To address the significant water demand associated with conventional wet carbonation, this study proposes a wind-driven or suspension technique for steel slag (SS) carbonation under low moisture conditions. The results demonstrate that wind-suspended carbonation (WSC) requires only 2–3 % of the water used in wet carbonation, while achieving approximately 85 % of its carbonation level. Importantly, the low moisture environment leads to the formation of calcium carbonate (CC) with lower crystallinity and a reduced formation of the polymerized silica-rich phases compared to the conventional wet carbonation. These changes favor the formation of higher amounts of hemicarboaluminate and monocarboaluminate, resulting in a denser microstructure and improved mechanical strength of the cementitious material. Additionally, the in-situ formation of CC on the surface and its aggregation into larger particle sizes under low moisture condition carbonation (WSC route) enhances the fluidity of the cement paste, showing an increase of 12 % when the WSC SS replaces 15 % of cement. In contrast, the use of raw and wet carbonated SS decreases the fluidity of the pastes by 13 % and 16 %, respectively.

为了解决与传统湿碳化相关的大量水需求，本研究提出了一种在低湿度条件下进行钢渣（SS）碳化的风力驱动或悬浮技术。结果表明，风悬浮碳化（WSC）只需要湿碳化所用的2 - 3%的水，而达到其碳化水平的约85%。重要的是，与传统的湿碳化相比，低水分环境导致碳酸钙（CC）结晶度较低，聚合富硅相的形成减少。这些变化有利于形成大量的半碳铝酸盐和单碳铝酸盐，从而形成更致密的微观结构，提高胶凝材料的机械强度。此外，在低水分条件下碳化（WSC路线），CC在水泥浆体表面的原位形成并聚集成更大的颗粒，提高了水泥浆体的流动性，当WSC SS取代15%的水泥时，流动性提高了12%。相比之下，使用生的和湿的碳化SS分别使膏体的流动性降低了13%和16%。

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引用次数: 0

Scientific basis and industrial potential of vaterite and CaCO3 polymorphs in low-carbon cement: A review 低碳水泥中水晶石和碳酸钙多晶的科学依据和工业潜力

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2026-01-02 DOI: 10.1016/j.cemconcomp.2026.106464

Zhonglin Tian , Kiyofumi Kurumisawa

Vaterite, a metastable polymorph of CaCO₃, is emerging as a promising multifunctional additive for low-carbon-cement design. Its distinct reactivity arises from a thermodynamically unstable and structurally disordered crystal lattice, which results in solubility and surface energy higher than that of the stable calcite form. Through its high reactivity and strong interfacial interactions with hydration products, vaterite accelerates early-age reactions and contributes to long-term improvements in the microstructure and mechanical properties. In contrast, calcite acts primarily as a filler and nucleation aid, while aragonite's effects are predominantly morphological. Scalable and carbon-negative synthesis routes for vaterite have been developed based on CO₂ mineralization and industrial-waste utilization. This review synthesizes the knowledge across vaterite's lifecycle—from crystallographic origins and synthesis strategies to its hydration mechanisms and performance impacts—identifying it as a programmable material for the next-generation eco-efficient concretes.

Vaterite是CaCO3的亚稳多晶，是一种很有前途的多功能低碳水泥添加剂。其独特的反应性源于其热力学不稳定和结构无序的晶格，这导致其溶解度和表面能高于稳定的方解石形式。通过其高反应活性和与水化产物的强界面相互作用，钒矾加速了早期反应，有助于长期改善微观结构和力学性能。相反，方解石的作用主要是作为填料和辅助成核，而文石的作用主要是形态上的。基于二氧化碳矿化和工业废物利用，开发了可扩展和负碳的水晶石合成路线。这篇综述综合了跨水化石生命周期的知识——从晶体起源和合成策略到水化机制和性能影响——将其确定为下一代生态高效混凝土的可编程材料。

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引用次数: 0

Three-stage synergistic hydration in CFBFA–GGBFS–steel slag–desulfurization gypsum binders: a coupled calorimetry–ion release quantification cfbfa - ggbfs -钢渣-脱硫石膏粘结剂的三级协同水化：耦合量热-离子释放定量

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2026-01-02 DOI: 10.1016/j.cemconcomp.2026.106461

Xinyi Liu , Wenhuan Liu , Lu Zhang , Yongfeng Wan , Hui Li , Meili Bai

Sustainable low-carbon cementitious materials offer a dual solution to global warming and resource depletion by enabling large scale use of industrial solid waste and reducing the high carbon footprint of cement production. However, quantitative understanding of the dynamic hydration processes in multi-source solid waste binders remains limited. To address this gap, this study combined the coupled calorimetry-ion release analysis to quantitatively investigate the hydration of CFBFA-based binders. This approach led to the establishment of a novel three-stage synergistic hydration model (“rapid dissolution–dynamic equilibrium–sustained-release diffusion”). The research findings are as follows: (1) CFBFA inhibits Ca(OH)₂ formation and gypsum consumption; (2) The porous structure and particle packing of CFBFA govern the long-term release of active Si and Al, thereby controlling the kinetics of later-stage hydration and ultimately determining the development of long-term strength; (3) The synergy of DG and SS provides the chemical environment for dissolution, while the synergistic hydration of SS-GGBFS and the sustained-release mechanism of CFBFA contribute to the early and later strength, respectively. The optimal mix (45 % CFBFA+27 % GGBFS+20 % SS+8 % DG) achieved the compressive strength of 56.2 MPa at 28 d. This study conducted a quantitative analysis of the hydration process in multi-source solid waste systems by combining calorimetric and ion release analytical methods, providing a new perspective for the design and mechanistic exploration of low-carbon cementitious materials.

可持续低碳胶凝材料通过大规模利用工业固体废物和减少水泥生产的高碳足迹，为全球变暖和资源枯竭提供了双重解决方案。然而，对多源固体废物粘合剂中动态水化过程的定量理解仍然有限。为了解决这一空白，本研究结合了耦合量热-离子释放分析来定量研究cfbfa基粘合剂的水化作用。这种方法建立了一种新的三阶段协同水化模型（“快速溶解-动态平衡-缓释扩散”）。研究结果表明：(1)CFBFA抑制Ca(OH)2的生成和石膏的消耗；(2) CFBFA的多孔结构和颗粒堆积控制了活性Si和Al的长期释放，从而控制了后期水化动力学，最终决定了长期强度的发展；(3) DG和SS的协同作用为溶解提供了化学环境，而SS- ggbfs的协同水化作用和CFBFA的缓释机制分别对早期和后期强度起作用。最佳配比（45% CFBFA+ 27% GGBFS+ 20% SS+ 8% DG） 28 d抗压强度达到56.2 MPa。本研究结合量热法和离子释放分析方法，对多源固废体系水化过程进行了定量分析，为低碳胶凝材料的设计和机理探索提供了新的视角。

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引用次数: 0

Microfibre-reinforced cementitious materials for preventive concrete pavement crack repair: Balancing extrusion-based crack-filling with mechanical performance 预防性混凝土路面裂缝修补用微纤维增强胶凝材料：用力学性能平衡挤压填充裂缝

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-12-29 DOI: 10.1016/j.cemconcomp.2025.106460

Damian Palin , Jie Xu , Christos Vlachakis , Michael Ambrose , Fumiya Iida , Abir Al-Tabbaa

Preventive repair of cracked concrete pavements requires materials that balance effective extrusion and crack-filling with high mechanical performance. Here, we present a polyvinyl alcohol microfibre (PVAF)-reinforced commercial belitic calcium sulphoaluminate mortar, engineered with this balance. A fresh mix of the mortar plus 1 % (w/w) of a water reducer and up to 0.6 % (v/v) of short (∼1–2 mm) PVAF could be extruded and fill cracks 6 mm wide. Cracked concrete specimens repaired with this material under flexural loading exhibited a 30 % increase in ultimate strength and twice the modulus, strain at failure, toughness and residual strength compared to plain RS. Under slant shear loading, repaired specimens demonstrated a modest increase in slant shear strength. These enhancements are attributed to fibre-induced crack bridging within the repair materials and reduced stress concentration at the repair interfaces. To accelerate material development, we implemented a rapid real-to-simulation workflow that reduced the crack-filling screening time for a material from several hours to less than 1 h.

混凝土裂缝路面的预防性修复，需要兼顾有效挤压和高力学性能的裂缝填充材料。在这里，我们提出了聚乙烯醇微纤维（PVAF）增强的商业贝氏岩硫铝酸钙砂浆，设计了这种平衡。砂浆加上1% （w/w）的减水剂和高达0.6% （v/v）的短（~ 1 - 2毫米）PVAF的新混合物可以挤出并填充6毫米宽的裂缝。在弯曲荷载下，用这种材料修复的开裂混凝土试件的极限强度比普通RS提高了30%，模量、破坏应变、韧性和残余强度是普通RS的两倍。在斜剪荷载下，修复后的试件的斜剪强度有适度的提高。这些增强是由于修复材料中纤维引起的裂缝桥接和修复界面应力集中的减少。为了加速材料的开发，我们实施了一个快速的实时模拟工作流程，将材料的裂缝填充筛选时间从几个小时减少到不到1小时。

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引用次数: 0

Performance evaluation of ultra-high-performance fiber-reinforced concrete incorporating waste OLED glass powder as a cement replacement 废OLED玻璃粉替代水泥的超高性能纤维增强混凝土性能评价

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-12-27 DOI: 10.1016/j.cemconcomp.2025.106459

Yoon Kyung Na , Hong-Joon Choi , Ilhwan You , Doo-Yeol Yoo

In this study, the potential of waste organic light-emitting diode (OLED) display glass powder as a sustainable pozzolanic material for partial cement replacement in ultra-high-performance fiber-reinforced concrete (UHPFRC) was investigated. While conventional UHPFRC has excellent strength and durability, its high cement content raises environmental concerns. OLED glass, which is rich in amorphous silica and free from backlight or plastic layers, offers a recyclable alternative to conventional binders. By replacing ordinary Portland cement with OLED powder at varying dosages (0–75 %), the effects on hydration behavior, microstructure, and mechanical performance were investigated. At a 25 % replacement level, the formation of additional C-(A-)S-H gels and lower porosity enhanced both compressive strength and fiber–matrix interfacial bonding. Single-fiber pull-out tests and microstructural imaging (atomic force microscopy, scanning electron microscopy, and energy dispersive X-ray) confirmed stronger bond strength and denser matrix morphology. Under tensile loading, digital image correlation showed effective crack dispersion and finer crack widths, indicating improved ductility and crack control. Life-cycle analysis showed that the 25 % OLED mix reduced CO₂ emissions and embodied energy by 15.7 % and 11.3 %, respectively, with minimal cost increase. These results highlight the suitability of OLED waste as a high-performance, eco-efficient binder that promotes both mechanical improvement and environmental sustainability of the next generation of UHPFRC.

在这项研究中，研究了废弃有机发光二极管（OLED）显示玻璃粉作为一种可持续的火山灰材料，在超高性能纤维增强混凝土（UHPFRC）中部分替代水泥的潜力。虽然传统的UHPFRC具有优异的强度和耐久性，但其高水泥含量引起了环境问题。OLED玻璃富含无定形二氧化硅，没有背光或塑料层，是传统粘合剂的可回收替代品。以不同掺量（0 ~ 75%）的有机发光二极管（OLED）粉替代普通硅酸盐水泥，考察其水化行为、微观结构和力学性能的影响。在25%的替代水平下，额外的C-(a -)S-H凝胶的形成和较低的孔隙率提高了抗压强度和纤维-基质界面结合。单纤维拉伸试验和显微结构成像（原子力显微镜、扫描电子显微镜和能量色散x射线）证实了更强的键合强度和更致密的基体形态。在拉伸载荷下，数字图像相关显示有效的裂纹分散和更细的裂纹宽度，表明塑性和裂纹控制得到改善。生命周期分析表明，25%的OLED混合材料分别减少了15.7%和11.3%的二氧化碳排放量和隐含能量，而成本增加最少。这些结果突出了OLED废料作为高性能、生态高效粘合剂的适用性，可以促进下一代UHPFRC的机械改进和环境可持续性。

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引用次数: 0

Performance study of alkali-activated waste concrete powder mortar: experimental study evaluation and molecular simulation 碱活化废混凝土粉末砂浆性能研究：实验研究、评价及分子模拟

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-12-26 DOI: 10.1016/j.cemconcomp.2025.106454

Zhiyu Zhang , Dingyi Yang , Xin Liu , Wan Shi , Junbao Yu

The enhancement of waste concrete powder (WCP) which occurs within alkali-activated systems is aimed to improve its utilization. Therefore, a multiscale framework integrating molecular dynamics (MD) simulations and experimental study was developed in the article. The study aims to elucidate the interaction of alkali content and silicate modulus on activation kinetics, gel formation, and pore structure evolution. MD simulations revealed that an 8 % alkali content led to synchronized jumps in the Mean Square Displacement (MSD) of Na⁺ ions and OH⁻ ions at approximately 1.8 × 10⁶ timesteps, indicating rapid depolymerization and channel connectivity, followed by accelerated polycondensation. Although 10 % alkali content promoted faster initial dissolution, excessive ion strength caused reaction passivation in later stages. Combined Radial Distribution Function (RDF) and Qⁿ analysis confirmed that enhanced Na–O inner-sphere coordination and increased Q⁰ species signify more favorable activation at 8 % alkali content. Replacing 25 % of metakaolin (MK) with WCP led to a 19.54 % improvement in 28-day compressive strength and 14 % improvement in 28-day flexural strength. Notably, thermal curing resulted in a substantial increase in compressive strength ranging from 45.36 % to 152.96 %, accompanied by a marked decrease in water absorption and porosity. However, higher WCP content or over-alkalization increased drying shrinkage and dehydration risks. The optimum mixture was identified as 75 % WCP activated with 8 % alkali and 1.5 silicate modulus under thermal curing. This study offers mechanistic insights and practical guidance for the performance optimization and sustainable use of WCP in alkali-activated binder systems.

在碱活化体系中对废混凝土粉（WCP）进行强化处理是为了提高其利用率。为此，本文建立了分子动力学模拟与实验研究相结合的多尺度框架。本研究旨在阐明碱含量和硅酸盐模量对活化动力学、凝胶形成和孔隙结构演化的相互作用。MD模拟表明，8%的碱含量导致Na+离子和OH-离子的均方位移（MSD）以大约1.8×106的时间步长同步跳跃，表明快速解聚和通道连接，随后加速缩聚。虽然10%的碱含量促进了初始溶解，但过量的离子强度导致后期反应钝化。结合径向分布函数（RDF）和Qn分析证实，在8%的碱含量下，Na-O球内配位的增强和Q0种的增加预示着更有利的活化。用WCP替代25%的偏高岭土（MK）可使28天抗压强度提高19.54%，28天抗弯强度提高14%。热养护显著提高了材料的抗压强度（45.36% ~ 152.96%），同时吸水率和孔隙率显著降低。然而，较高的WCP含量或过度碱化会增加干燥收缩和脱水风险。在热固化条件下，最佳配比为75% WCP、8%碱、1.5硅酸盐模量。该研究为WCP在碱活化粘合剂体系中的性能优化和可持续使用提供了机理见解和实践指导。

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引用次数: 0

Graphene enriched concrete using ultrasonication assisted exfoliation 超声辅助剥离石墨烯增强混凝土

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-12-26 DOI: 10.1016/j.cemconcomp.2025.106457

Moboluwaduro Akande , Jiří Němeček , Panagiotis Danoglidis , Maria Konsta-Gdoutos

This study unveils a definitive energy threshold governing graphene nanoplatelet (GNP) exfoliation, revealing a direct relationship between ultrasonication energy, graphene nanoplatelet morphology, and the enhanced microstructural and electromechanical performance of cementitious nanocomposites. Comprehensive material analyses using Ultraviolet–Visible (UV–Vis) spectroscopy, Dynamic Light Scattering (DLS), Zeta Potential, Raman spectroscopy, Scanning Electron Microscopy (SEM) verified the high-quality dispersion and robust colloidal stability of the exfoliated graphene nanoplatelets (GNPs). Sub-optimal sonication results in insufficient exfoliation and poor dispersion, while excessive energy induces structural damage and colloidal destabilization. At the optimum energy level, GNP suspensions exhibit maximized exfoliation, colloidal stability, and a continuous conductive network, as confirmed by Electrochemical Impedance Spectroscopy (EIS) through reduced charge transfer resistance. By comparing the functional and structural performance of mortars reinforced with multi- and few-layer GNPs, this work delivers a methodical approach from exfoliation state to application performance, and establishes a protocol that maximizes reinforcement efficiency, as demonstrated by the substantial enhancement in load bearing capacity, up to 69 % increase in modulus of elasticity, 43 % in flexural strength, 20 % in compressive strength, and 130 % in fracture energy.

该研究揭示了控制石墨烯纳米血小板（GNP）剥离的明确能量阈值，揭示了超声能量、石墨烯纳米血小板形态与增强的胶凝纳米复合材料的微观结构和机电性能之间的直接关系。利用紫外可见光谱（UV-Vis）、动态光散射（DLS）、Zeta电位（Zeta Potential）、拉曼光谱（Raman spectroscopy）和扫描电子显微镜（SEM）对材料进行综合分析，验证了剥离后的石墨烯纳米薄片（GNPs）的高质量分散性和强大的胶体稳定性。次优超声会导致剥离不足和分散性差，而过多的能量会导致结构破坏和胶体不稳定。在最佳能级下，GNP悬浮液表现出最大的剥离性、胶体稳定性和连续的导电网络，电化学阻抗谱（EIS）通过降低电荷转移电阻证实了这一点。通过比较多层和少层GNPs加固砂浆的功能和结构性能，本研究提供了从剥离状态到应用性能的系统方法，并建立了一个最大限度提高加固效率的方案，其承载能力大幅提高，弹性模量提高69%，抗弯强度提高43%，抗压强度提高20%，断裂能提高130%。

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引用次数: 0

Can concrete pumping pressure be predicted from mixture composition? Insights from machine learning on full-scale pumping experiments 混凝土泵送压力能否由混合料组成预测？从机器学习到全尺寸泵实验的见解

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-12-24 DOI: 10.1016/j.cemconcomp.2025.106458

Wenkai Shen , Chunxiang Jiang , Zuquan Jin , Qiang Yuan , Youhong Ji , Rong Zeng , Youwu Wu , Lilin Lao , Caijun Shi

Pumping pressure loss is a key technical indicator in concrete pumping. In this study, a machine learning-based model was developed to predict pumping pressure from concrete mixture composition and operational parameters. A total of 410 full-scale coiled pipeline pumping tests were conducted, covering a wide range of flow rates (1.8–18.9 L/s), pumping distances (325–1044 m), and concrete strength grades (C30–C100). A hybrid modeling strategy combining unsupervised clustering and supervised learning was adopted. Specifically, density-based clustering was first employed to group the data by feature similarity, and the resulting cluster labels were incorporated into the supervised learning model as additional input features. Subsequently, Euclidean distance analysis, grid search, and five-fold cross-validation were used to optimize the hyperparameters of both the clustering and the Extremely Randomized Trees regression model. The developed model exhibited good prediction accuracy (R² > 0.9). SHAP (SHapley Additive exPlanations) analysis was further applied to reveal the influence of individual mixture parameters on the predicted pumping pressure. Publicly available full-scale pumping data from the literature were used to evaluate the applicability of the model, and key factors influencing cross-project prediction accuracy were analyzed. Finally, a strategy for cross-project application of the pressure prediction model was proposed. This study highlights the potential of using mixture composition to predict concrete pumping pressure and provides insights for the optimized design of pumpable concrete and pumping operations.

泵送压力损失是混凝土泵送的关键技术指标。在这项研究中，开发了一个基于机器学习的模型来预测混凝土混合物组成和操作参数的泵送压力。共进行了410次全尺寸连续管道泵送试验，涵盖了大范围的流量（1.8-18.9 L/s）、泵送距离（325-1044 m）和混凝土强度等级（C30-C100）。采用了无监督聚类和监督学习相结合的混合建模策略。具体来说，首先采用基于密度的聚类，根据特征相似性对数据进行分组，并将得到的聚类标签作为额外的输入特征纳入监督学习模型。随后，利用欧几里得距离分析、网格搜索和五重交叉验证对聚类和极端随机树回归模型的超参数进行优化。所建立的模型具有较好的预测精度（R2 > 0.9）。进一步应用SHapley加性解释（SHapley Additive exPlanations）分析揭示了各混合参数对预测泵送压力的影响。利用文献中公开的全尺寸抽水数据来评估模型的适用性，并分析了影响跨项目预测精度的关键因素。最后，提出了压力预测模型的跨项目应用策略。该研究强调了使用混合成分预测混凝土泵送压力的潜力，并为可泵送混凝土和泵送作业的优化设计提供了见解。

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引用次数: 0

Self-sensing concrete with enhanced linearity and conductivity prepared by alkali-activated materials and polyacrylamide-modified carbon fibers 用碱活化材料和聚丙烯酰胺改性碳纤维制备线性和导电性增强的自感混凝土

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-12-22 DOI: 10.1016/j.cemconcomp.2025.106453

Tao Yang , Yuwei Ma , Zongjin Li , Haoliang Huang , Bokai Liao , Hao Wang

Self-sensing concrete is crucial for the development of smart infrastructure due to its ability to monitor structural health by measuring changes in electrical resistivity. This study developed a novel alkali-activated material (AAM)-based self-sensing concrete by incorporating polyacrylamide (PAM)-modified carbon fibers (CFs), achieving enhanced conductivity and highly linear piezoresistive performance. The mechanisms underlying the PAM modification were systematically investigated. The results showed that PAM treatment significantly improved CF dispersion within the AAM matrix and promoted the formation of a stable CF–polymer interfacial structure through carboxylate–calcium/aluminum coordination. Single fiber pull-out tests confirmed that these interfacial crosslinking products increased the fiber–matrix bonding strength, which in turn stabilized the conductive pathways and facilitated more efficient electron transfer. With only 0.1 vol% PAM-modified CFs, the composite exhibited an ultralow bulk resistivity of 51.4 Ω cm and a highly linear strain–resistance response up to 1800 με, outperforming traditional cement-based self-sensing concretes at comparable or higher CF contents. These findings demonstrate that optimizing fiber–matrix interactions is critical for improving the electromechanical performance of self-sensing concretes. The PAM surface modification approach provides a cost-effective and operationally simple strategy for developing high-performance self-sensing concrete.

自感知混凝土对于智能基础设施的发展至关重要，因为它能够通过测量电阻率的变化来监测结构健康状况。本研究开发了一种新型碱活化材料（AAM）基自感混凝土，通过加入聚丙烯酰胺（PAM）改性碳纤维（CFs），实现了增强的导电性和高线性压阻性能。系统地研究了PAM改性的机理。结果表明，PAM处理显著改善了CF在AAM基体中的分散，促进了羧酸-钙/铝配位形成稳定的CF -聚合物界面结构。单纤维拉出测试证实，这些界面交联产物增加了纤维-基质的结合强度，从而稳定了导电途径，促进了更有效的电子转移。该复合材料的体积电阻率为51.4 Ω cm，线性应变抗力响应高达1800 με，优于同等或更高CF含量下的传统水泥基自敏感混凝土。这些发现表明，优化纤维-基质相互作用对于改善自感知混凝土的机电性能至关重要。PAM表面改性方法为开发高性能自感知混凝土提供了一种经济有效且操作简单的策略。

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引用次数: 0

In-situ monitoring bacteria-based crack sealing process in mortar 基于细菌的砂浆缝止裂过程的现场监测

IF 13.1 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Cement & concrete composites

Pub Date : 2025-12-21 DOI: 10.1016/j.cemconcomp.2025.106455

Fuxing Hou, Di Shen, Hanyu Guo, Tian Yao, Aowei Ma, Jianyun Wang

The current challenge for bacteria-based self-healing is that biogenic-precipitates are mainly concentrated on the superficial part, while limited precipitates are in the deep part of the crack. This results in limited strength regain after crack sealing. To figure out the specific reasons, in-situ crack sealing process in the mortar specimens, with spores embedded at superficial layer (5 mm) and deep layer (25 mm), was investigated to disclose the key factors affecting the bio-precipitates distribution. Results showed the sealing depth of specimen with the spores embedded at 25 mm deep was significantly deeper (7.93 mm) than that embedded at 5 mm deep (4.67 mm). Spores in surface layer (pH 9–11.5) germinated first (in about 1 day) and consumed oxygen, resulting in a fast oxygen deficiency in the nearby region; thus the crack mouth was closed fast (42 days) but with a limited sealing depth. Differently, spores at deeper part (pH 12–12.5) germinated slower (in about 3 days) but precipitation could reach more deeper part, since the crack stay incompletely closed until 56-days, which facilitates oxygen diffusion. The results showed that pH distribution served as triggering factors, oxygen deficiency acted as an amplifying mechanism, and the uneven distribution of bio-deposition was the final result. This study clarified the mechanism of the physicochemical environment within the cracks, revealed the causal relationship between the pH-induced stratified spore germination, urease activity recovery and uneven deposition. The “spatial competition effect” between crack sealing width and crack sealing depth was revealed for the first time.

目前基于细菌的自愈面临的挑战是生物沉积物主要集中在裂缝的表面部分，而有限的沉积物在裂缝的深层部分。这导致裂纹密封后强度恢复有限。为了找出具体原因，研究了砂浆试样的原位裂缝密封过程，在表层（5 mm）和深层（25 mm）埋有孢子，揭示了影响生物沉淀分布的关键因素。结果表明，孢子埋置深度为25 mm的样品的封孔深度（7.93 mm）显著高于埋置深度为5mm的样品（4.67 mm）。表层（pH 9-11.5）孢子首先萌发（约1天），并消耗氧气，导致附近区域快速缺氧；因此，裂缝口封闭速度快（42天），但封闭深度有限。不同的是，孢子在较深的部分（pH 12-12.5）萌发较慢（约3天），但降水可以到达较深的部分，因为裂缝直到56天才完全关闭，这有利于氧气的扩散。结果表明，pH分布是触发因子，缺氧是放大机制，生物沉积分布不均匀是最终结果。本研究阐明了裂缝内物理化学环境的作用机制，揭示了ph诱导的分层孢子萌发、脲酶活性恢复与不均匀沉积之间的因果关系。首次揭示了裂缝密封宽度和裂缝密封深度之间的“空间竞争效应”。

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引用次数: 0