Construction and Building Materials最新文献_第3页

Multi-mechanical performance evaluation of a more sustainable ultra-high-ductile fiber-reinforced cementitious composite with recycled ceramic sand and waste ceramic powder 再生陶瓷砂与废陶瓷粉复合材料的多力学性能评价

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145243

Zhiming Ma , Yuanhui Wu , Bo Wang , Youchao Zhang , Changqing Wang

Using recycled ceramic sand (RCS) and waste ceramic powder (WCP) for developing ultra-high-ductile fiber-reinforced cementitious composite (UHDFRCC) provides an effective approach for recycling ceramic waste and enhances the sustainability of UHDFRCC. This study systematically investigated the effects of replacing silica sand and cement/slag with RCS and WCP on the microstructural characteristics and multi-mechanical performances of UHDFRCC. The use of WCP to replace cement/slag reduced the hydration heat and the amount of hydration products, but increased the hydration degree and hydration heat per unit mass of cement in the UHDFRCC. High-content replacement of cement/slag with WCP deteriorated the microstructure and micromechanical properties of the matrix. Incorporating either RCS or WCP at replacement ratios below 30 % had a minor or even beneficial effect on the strength of UHDFRCC, while the addition of 100 % RCS and 50–70 % WCP led to a degradation in strength, though the strength remained at a relatively high level. Under an uniaxial tensile load, the addition of RCS and WCP improved the ductility of UHDFRCC. The tensile strain exhibited an initial increase followed by a decrease with increasing RCS and WCP content, and it remained similar to or even higher than the tensile strain of the control UHDFRCC. The ultimate tensile strains of control UHDFRCC, WCP-70Cement, RCS-100Sand, and 100RCS+ 70WCP were 6.1 %, 6.0 %, 6.7 %, and 5.8 %, respectively. By optimizing the content of RCS and WCP, sustainable UHDFRCC tailored to different strength and ductility requirements can be produced.

利用再生陶瓷砂（RCS）和废陶瓷粉（WCP）制备超高韧性纤维增强胶凝复合材料（UHDFRCC），为陶瓷废弃物的再生利用提供了有效途径，提高了UHDFRCC的可持续性。本研究系统研究了RCS和WCP替代硅砂和水泥/矿渣对UHDFRCC微观结构特征和多力学性能的影响。WCP替代水泥/矿渣降低了UHDFRCC的水化热和水化生成量，但增加了UHDFRCC的水化程度和单位质量水泥的水化热。高掺量水泥/矿渣替代WCP会使基体的微观结构和微观力学性能恶化。当RCS或WCP的替代比低于30 %时，对UHDFRCC的强度有轻微甚至有益的影响，而添加100 %的RCS和50-70 %的WCP会导致强度下降，尽管强度保持在相对较高的水平。在单轴拉伸荷载下，RCS和WCP的加入提高了UHDFRCC的延性。随着RCS和WCP含量的增加，拉伸应变呈现先增大后减小的趋势，与对照UHDFRCC的拉伸应变保持相近甚至更高。对照UHDFRCC、WCP-70Cement、RCS-100Sand和100RCS+ 70WCP的极限拉伸应变分别为6.1 %、6.0 %、6.7 %和5.8 %。通过优化RCS和WCP的含量，可以生产出符合不同强度和延性要求的可持续UHDFRCC。

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引用次数: 0

Axial compressive behavior and modeling of FRP-confined limestone calcined clay cement (LC3) concrete frp约束石灰石煅烧粘土水泥（LC3）混凝土轴压特性与建模

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145236

JinJing Liao , Can Sun , Yu Zheng , Jiahao Li , Zhenyu Huang , Hong Guan

Despite the promising outlook of limestone calcined clay cement (LC3) concrete, steel reinforcements are still required for LC3 concrete in engineering applications. Alternatively, fiber-reinforced polymer (FRP) confinement is a well-established reinforcement method and a reliable substitute for traditional reinforcing steel. Using carbon fiber-reinforced polymer (CFRP), this study presents the first investigation into the axial compressive behavior of CFRP-confined LC3 concrete cylinders by testing 24 specimens with different concrete grades, confinement levels, and calcined clay replacement rates. The results showed two types of axial stress-strain responses: FRP-confined LC3 normal strength concrete (NSC) exhibited a typical “bi-linear” response, while FRP-confined LC3 high performance concrete (HPC) showed a “stress reduction-recovery” behavior. However, increasing the number of FRP layers could alleviate the stress reduction severity. The LC3 HPC had a smaller initial ascending slope and a lower concrete strength than the HPC without LC3 replacement. Furthermore, the initial ascending slope may decrease further with increasing calcined clay replacement rates. The adequate confinement thresholds for FRP-confined LC3 HPC required either an actual confinement ratio of at least 0.05 or a confinement stiffness ratio of at least 0.025. Moreover, two existing design-oriented models were revised to predict the axial compressive stress-strain behavior of FRP-confined LC3 concrete, and demonstrated strong agreements.

尽管石灰石煅烧粘土水泥（LC3）混凝土具有良好的应用前景，但在工程应用中仍然需要对LC3混凝土进行钢筋加固。另外，纤维增强聚合物（FRP）约束是一种成熟的加固方法，也是传统钢筋的可靠替代品。本研究采用碳纤维增强聚合物（CFRP），通过测试24个不同混凝土等级、约束水平和煅烧粘土替换率的试件，首次对CFRP约束的LC3混凝土圆柱体的轴压特性进行了研究。结果表明：frp约束LC3正强混凝土（NSC）表现为典型的“双线性”响应，而frp约束LC3高性能混凝土（HPC）表现为“应力减小-恢复”行为。但增加FRP层数可以减轻其应力减小程度。与未更换LC3的HPC相比，LC3 HPC的初始上升斜率更小，混凝土强度更低。随着煅烧粘土替代率的增加，初始上升斜率进一步减小。对于frp约束的LC3高性能混凝土，足够的约束阈值要求约束比至少为0.05，约束刚度比至少为0.025。此外，修正了现有的两个面向设计的模型，以预测frp约束LC3混凝土的轴压应力-应变行为，并证明了很强的一致性。

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引用次数: 0

Investigation on a new all-solid-waste cementitious material: Mix design, mechanical performance, and negative-carbon sustainability 一种新型全固废胶凝材料的研究：配合比设计、机械性能和负碳可持续性

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145248

Qi Sun , Yuhuan Zhu , Fei Wang , Yuxin Zhu , Yue Qiu , Rongxi Tian

In the context of the cement industry’s transition toward low-carbon and sustainable development, the advancement of all-solid-waste cementitious materials has emerged as a pivotal direction. This study proposes a novel all-solid-waste cementitious system and establishes a multi-variable design framework to simultaneously evaluate macroscopic mechanical performance, microstructural evolution, and environmental carbon footprint, while investigating the effects of composition ratio and water-binder ratio (W/B) on both performance and mechanism. By organically linking mechanical testing with SEM-based microstructural characterization and life-cycle assessment, this study clarifies the mechanisms governing the development of material properties and their corresponding environmental benefits. The optimal performance was achieved by the composite containing 40 % calcium carbide slag (CCS), 30 % ground-granulated blast-furnace slag (GGBS), 20 % fly ash (FA), and 10 % wood-based biochar (WBC), with a W/B of 0.36, exhibiting flexural and compressive strengths of 11 MPa and 23 MPa at 28d, respectively. The compressive strength displayed an approximately linear relationship with the CCS-to-GGBS ratio and was jointly regulated by W/B and CCS content. The incorporation of WBC not only densified the microstructure but also enabled a negative-carbon effect (-93.98 kg CO₂/m³) within the study-defined system boundary and under locally sourced material conditions, highlighting its dual contribution to performance enhancement and carbon mitigation. Overall, this study establishes a complete closed-loop pathway from mix design and performance verification to mechanism interpretation and environmental optimization, thereby providing a practical methodology for developing all-solid-waste cementitious materials with both high performance and negative-carbon potential.

在水泥行业向低碳可持续发展转型的背景下，全固废胶凝材料的推进成为一个关键方向。本研究提出了一种新型的全固体废物胶凝体系，并建立了一个多变量设计框架，同时评估宏观力学性能、微观结构演变和环境碳足迹，同时研究了成分配比和水胶比（W/B）对性能和机理的影响。通过将力学测试与基于sem的微观结构表征和生命周期评估有机地联系起来，本研究阐明了控制材料性能发展及其相应的环境效益的机制。结果表明，含40 %电石渣（CCS）、30 %磨粒高炉渣（GGBS）、20 %粉煤灰（FA）和10 %木基生物炭（WBC）的复合材料性能最佳，W/B为0.36,28d的抗折强度分别为11 MPa和23 MPa。抗压强度与CCS- ggbs比呈近似线性关系，并受W/B和CCS含量的共同调节。WBC的加入不仅使微观结构致密化，而且在研究定义的系统边界和当地材料条件下实现了负碳效应（-93.98 kg CO₂/m³），突出了其对性能增强和碳减排的双重贡献。总体而言，本研究建立了从配合比设计和性能验证到机理解释和环境优化的完整闭环路径，从而为开发高性能和负碳潜力的全固体废物胶凝材料提供了一种实用的方法。

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引用次数: 0

Experimental investigation of nonlinear stress-strain behaviour of various elastomeric materials under cyclic loading 循环荷载作用下各种弹性体材料非线性应力-应变特性的试验研究

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145234

Hailong Cao , Karl Minta , Hossein A. Beigi , Evangelia Georgantzia , Mohammad M. Kashani

This study investigates the nonlinear mechanical responses of elastomeric materials under complex loading paths. The experimental programme involved a series of uniaxial tensile and compressive tests under various loading protocols, systematically comparing the mechanical responses of different materials. The results show that amorphous polymers, including Thermoplastic Polyurethane, Neoprene rubber, and Neoprene/NBR rubber, exhibit more linear (elastic) load–unload behaviour, with improved shape recovery, resistance to stress relaxation, and reduced residual strain, although their energy dissipation capacity remains limited. In contrast, semi-crystalline polymers, including Polypropylene, Ultra-High-Molecular-Weight Polyethylene, and High-Density Polyethylene, demonstrate pronounced strain-dependent behaviour. As the strain increases, stress softening and cyclic relaxation effects are reduced. These materials exhibit significant energy dissipation but considerable residual strain. A key outcome of this research is that Thermoplastic Polyurethane presents the most favourable combination of high stress retention, low residual strain, and creep resistance, making it a strong candidate for use in the segmental construction of prefabricated bridges as a seismic damage-avoidance element. Ultra-High-Molecular-Weight Polyethylene, when combined with post-tension systems, also shows potential due to its strain hardening and enhanced energy dissipation, thereby improving seismic resilience under major events. These findings provide valuable insights into the deformation mechanisms of elastomeric materials and offer practical guidance for their effective implementation in energy-dissipating structural systems.

研究了弹性体材料在复杂加载路径下的非线性力学响应。实验方案包括一系列在不同加载协议下的单轴拉伸和压缩测试，系统地比较不同材料的机械响应。结果表明，包括热塑性聚氨酯、氯丁橡胶和氯丁橡胶/丁腈橡胶在内的非晶态聚合物表现出更多的线性（弹性）加载-卸载行为，具有更好的形状恢复、抗应力松弛和减少残余应变，尽管它们的能量耗散能力仍然有限。相比之下，半结晶聚合物，包括聚丙烯、超高分子量聚乙烯和高密度聚乙烯，表现出明显的应变依赖行为。随着应变的增加，应力软化和循环松弛效应减小。这些材料具有显著的能量耗散和相当大的残余应变。这项研究的一个关键成果是，热塑性聚氨酯呈现出高应力保持、低残余应变和抗蠕变的最有利组合，使其成为预制桥梁分段结构中作为地震损伤避免元件的强有力候选者。超高分子量聚乙烯（ultra - high - molecular weight Polyethylene）与后张力系统结合使用时，由于其应变硬化和增强的能量耗散，从而提高了重大事件下的抗震弹性，也显示出了潜力。这些发现为弹性体材料的变形机制提供了有价值的见解，并为弹性体材料在耗能结构系统中的有效应用提供了实用指导。

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引用次数: 0

Aggregate particle size distribution impact on the microstructure characteristics in the interface transition zone of recycled concrete 骨料粒度分布对再生混凝土界面过渡区微观结构特征的影响

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145294

Yuan Gao , Siyuan Zhang , Siyao Wang , Hui Jiang , Hao Sui , Lilin Zhao

The application of recycled aggregate concrete (RAC) is an effective way to recycle construction waste, which can significantly reduce the consumption of natural sand and gravel aggregates and help promote the low-carbon development of the building materials industry. However, the surface of recycled aggregates usually adheres to old mortar, resulting in the formation of the interface transition zone (ITZ) and influencing the micropore structure in RAC matrixes, thus limiting the RAC’s engineering application. In present study, the pore structure optimization of the ITZ in RAC matrix is achieved through the regulation of the particle gradation of recycled aggregates. The proposed method not only effectively improves the mechanical properties of RAC, but also does not require any other costs, highly conforming to the low-carbon and low-energy consumption concept of recycled concrete utilization. The results indicate that through the optimized regulation of recycled aggregate gradation, the porosity and maximum pore size distribution in the RAC matrix can be reduced by 25.5% and 28.5% respectively, thereby increasing the compressive strength of RAC by approximately 8.7–17.5%. Furthermore, with the aid of convolutional neural network and the deep Taylor decomposition algorithm, the visual heat maps of the feature shapes of the pore structure in the RAC matrix under different gradations are extracted. By means of fractal theory, a linear fitting relationship is directly established between the extracted pore structure characteristics and the mechanical properties of RAC, with an ultra-high fitting goodness equaling to 96%. The findings of this study broaden the understanding of the influence mechanism and strengthening effect of the microstructure of graded recycled concrete, providing certain theoretical support for the efficient utilization of recycled concrete.

再生骨料混凝土（RAC）的应用是回收建筑垃圾的有效途径，可以显著减少天然砂石骨料的消耗，有助于促进建材行业的低碳发展。然而，再生骨料的表面通常会粘附在旧砂浆上，导致界面过渡区（ITZ）的形成，影响RAC基体的微孔结构，从而限制了RAC的工程应用。在本研究中，通过调节再生骨料的颗粒级配来实现RAC基质中ITZ的孔隙结构优化。所提出的方法不仅有效提高了RAC的力学性能，而且不需要任何其他成本，高度符合再生混凝土利用的低碳、低能耗理念。结果表明：通过优化再生骨料级配，可使RAC基体孔隙率和最大孔径分布分别降低25.5%和28.5%，从而使RAC的抗压强度提高约8.7-17.5%；在此基础上，借助卷积神经网络和深度泰勒分解算法，提取了不同层次下RAC矩阵中孔隙结构特征形状的视觉热图。利用分形理论，将提取的孔隙结构特征与RAC力学性能直接建立线性拟合关系，拟合优度高达96%。本研究结果拓宽了对级配再生混凝土微结构影响机理和强化效果的认识，为再生混凝土的高效利用提供了一定的理论支持。

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引用次数: 0

Bamboo springs with high dimensional stability and cyclic durability by heat treatment 竹制弹簧经热处理，尺寸稳定性高，循环耐久性好

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145259

Zujie Chen , Xiaohan Xing , Xinyu Zhang , Xi Zhao , Lei Li , Zhuokai Qin , Xin Wei , Ge Wang

Bamboo springs have numerous advantages over lightweight composite springs, such as low cost, environmentally friendly manufacturing processes, and short growth cycles of raw material. However, it is naturally hygroscopic, making bamboo springs dimensionally unstable. Here, we performed a clean, convenient heat treatment (160 °C, 190 °C, 220 °C) on bamboo springs to degrade its internal hemicellulose and amorphous cellulose, which can inhibit its hygroscopic rebound. The results showed that the hygroscopic rebound of HBS (Heat-treated bamboo spring) was obviously reduced by more than 13 % (160 °C), which was due to the partial degradation of hemicellulose and cellulose and the increase of cellulose crystallinity caused by different temperatures, as shown by FTIR, XRD, and XPS. And through mechanical property tests, it can be seen that the mild heat treatment (160 °C, 190 °C) of HBS basically retained the mechanical properties of bamboo springs and the basic morphological structure of the cells. Higher temperatures (220 °C) resulted in a 36.5 % reduction in spring stiffness. This decrease was attributed to increased porosity within bamboo cells due to the degradation of cellulose and hemicellulose, coupled with damage to the LCC (lignin-carbohydrate complex) matrix structure. At 190 °C, HBS retained 85 % of its residual spring stiffness after 10,000 compression cycles, demonstrating its excellent cyclic durability and showing the potential of HBS for building and home applications.

竹制弹簧与轻质复合弹簧相比有许多优点，如成本低、制造过程环保、原材料生长周期短。然而，它具有天然的吸湿性，使得竹制弹簧在尺寸上不稳定。在此，我们对竹弹簧进行了清洁，方便的热处理（160°C, 190°C, 220°C），以降解其内部的半纤维素和无定形纤维素，从而抑制其吸湿反弹。FTIR、XRD、XPS分析结果表明，在160℃时，热处理竹弹簧的吸湿回弹明显降低了13 %以上，这是由于不同温度下半纤维素和纤维素的部分降解以及纤维素结晶度的增加所致。并且通过力学性能测试可以看出，HBS的轻度热处理（160℃、190℃）基本保留了竹弹簧的力学性能和细胞的基本形态结构。较高的温度（220°C）导致弹簧刚度降低36.5% %。这种减少是由于纤维素和半纤维素的降解增加了竹细胞内的孔隙度，加上LCC（木质素-碳水化合物复合物）基质结构的破坏。在190°C下，HBS在10,000次压缩循环后保留了85% %的残余弹簧刚度，证明了其出色的循环耐久性，并显示了HBS在建筑和家庭应用中的潜力。

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引用次数: 0

Half-lap cross laminated timber panel-to-panel connections using hardwood dowels 使用硬木销钉的半搭交叉层压木板与木板连接

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145273

Parker Kraenzlein , Daniel P. Hindman , Adam R. Phillips

The use of cross-laminated timber (CLT) in buildings has become more common due to advantages in quick erection and reduction of carbon footprint. Connections for CLT panels tend to rely on metal fasteners combined with either butt, half-lap, or spline panel-to-panel connections. This study explored the substitution of hardwood dowel connections as replacements for metal panel-to-panel connections. Testing used small-scale, half-lap specimens and applied both monotonic and cyclic loading to compare hardwood and softwood CLT panels and different hardwood dowel diameters. From both monotonic and cyclic loading, Mode II failures were more prevalent in the lower specific gravity softwood CLT, and Mode V failures were more prevalent in the greater specific gravity hardwood CLT. For the cyclic yield load, both the CLT species and diameter were significantly different, and for the cyclic stiffness, only the CLT species was significantly different. Ductility ratios of these connections were classified as brittle for monotonic loading, and low to medium ductility for cyclic loading. The 25.4 mm and 31.8 mm diameter dowels were similar in ultimate load and stiffness to partially-threaded self-tapping screws 8 and 10 mm in diameter, respectively. Due to the brittle failure modes, SDPWS guidelines exclude these connections for use in CLT diaphragms, but could be used in CLT shearwall elements combined with other connections to produce needed ductility. Advantages of hardwood dowel connections may exist in achieving sustainability goals and aesthetic detailing. The use of small-scale specimens for CLT connection evaluation requires further validation, but appears promising.

由于在快速安装和减少碳足迹方面的优势，交叉层压木材（CLT）在建筑中的使用变得越来越普遍。CLT面板的连接往往依赖于金属紧固件结合对接，半搭接或花键面板到面板的连接。本研究探索了硬木销钉连接作为金属板对板连接的替代品。测试使用了小尺寸的半搭接试样，并应用了单调和循环加载来比较硬木和软木CLT板以及不同的硬木钉直径。从单调加载和循环加载两方面来看，低比重软木CLT中II型破坏更为普遍，而大比重硬木CLT中V型破坏更为普遍。对于循环屈服荷载，CLT种数和直径均存在显著差异，而对于循环刚度，只有CLT种数存在显著差异。这些连接的延性比在单调加载时被划分为脆性，在循环加载时被划分为低至中等延性。直径为25.4 mm和31.8 mm的销钉与直径为8 mm和10 mm的部分螺纹自攻螺钉的极限载荷和刚度相似。由于脆性破坏模式，SDPWS指南排除了这些连接用于CLT隔板，但可以用于CLT剪力墙元件与其他连接相结合，以产生所需的延性。硬木销钉连接的优势可能存在于实现可持续发展目标和美学细节。使用小型试件进行CLT连接评估需要进一步验证，但似乎很有希望。

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引用次数: 0

Influence of inter-filament voids on the failure mechanism and compressive strength of 3D printed concrete 细丝间空隙对3D打印混凝土破坏机理及抗压强度的影响

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145266

Xingzi Liu , Richard Buswell , Sergio Cavalaro , Jie Xu , James Dobrzanski , John Temitope Kolawole

Material that has been manufactured using extrusion-based 3D Concrete Printing (3DCP) exhibits anisotropy and larger variability in its mechanical properties. These effects are influenced by the agglomeration of extruded filaments, which presents greater opportunity for air entrapment within the printed volume, as well as creating a network of inter-filament material with different properties. Manufacturing ‘defect free’ is challenging and hence understanding the impact of these defects on mechanical performance is critical, however, there is no published work to date. This reports on an empirical investigation of 155 samples with and without inter-filament void defects. It is demonstrated the presence of the inter-filament voids does influence the failure characteristics: defect free samples exhibit shear failure in all three anisotropic loading directions, whereas the samples containing inter-filament voids predominantly exhibited shear failure in the u-direction (parallel to the filament direction), with a greater occurrence of mixed shear–splitting failures in the v (perpendicular to the filament direction in horizontal plane) and w-directions (layer build-up direction), especially in the w-direction. Inter-filament void size had little effect on the compressive strength in the u and w-direction, while a clear reduction trend in the compressive strength was observed in the v-direction. Therefore, these findings reveal that inter-filament voids introduce direction-dependent failure modes and strength penalties that cannot be captured by design values calibrated for cast concrete. By quantifying the mechanical tolerance envelope of void populations, the study demonstrates the need for recalibrating partial safety factors and acceptance criteria in emerging 3D printed concrete design codes.

使用基于挤压的3D混凝土打印（3DCP）制造的材料在其机械性能上表现出各向异性和较大的可变性。这些效果受到挤压长丝团聚的影响，这为印刷体积内的空气夹持提供了更大的机会，并形成了具有不同性能的丝间材料网络。制造“无缺陷”具有挑战性，因此了解这些缺陷对机械性能的影响至关重要，然而，迄今为止还没有发表的工作。本文报道了155个有和没有丝间空隙缺陷的样品的实证研究。结果表明，丝间空隙的存在确实会影响失效特性：无缺陷试样在三个各向异性加载方向均表现出剪切破坏，而含有丝间空隙的试样主要表现为u方向（平行于丝方向）的剪切破坏，在v方向（垂直于丝方向在水平面上）和w方向（堆积层方向）的混合剪切分裂破坏较多，特别是在w方向。在u和w方向上，丝间空隙尺寸对抗压强度影响不大，而在v方向上，丝间空隙尺寸有明显的降低趋势。因此，这些研究结果表明，细丝间空隙引入了方向相关的破坏模式和强度损失，而这些破坏模式和强度损失无法通过对混凝土进行校准的设计值来捕获。通过量化空洞种群的机械公差包络，该研究表明需要重新校准新兴3D打印混凝土设计规范中的部分安全系数和可接受标准。

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引用次数: 0

Interfacial waterproof performance of shotcrete-sprayed polymer under hygrothermal condition 湿热条件下喷喷聚合物的界面防水性能

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145203

Huan Guan , Chengchao Guo , Lei Qin , Renxiang Dong , Yongning Wu , Fuming Wang , Chaojie Wang

Sprayed polymer (SP) is increasingly adopted as a waterproofing spray material for underground structures in hot, water-rich environments. However, the interfacial properties and waterproofing failure mechanisms of shotcrete-sprayed polymer (SC-SP) composites under such hygrothermal conditions remain poorly understood. Through a novel integration of muti-scale experimental techniques, this study comprehensively investigates these mechanisms under hygrothermal aging (65℃, 95 % Relative Humidity (RH) for 0–56 days). The research combines interfacial bonding performance tests with acoustic emission (AE) monitoring, as well as interfacial waterproof performance tests synergized with AE and infrared thermography. The results indicate that the interfacial failure modes of SC-SP composite structures can be categorized into three types, with Mode II identified as the dominant failure type. The stress-displacement curves exhibited a three-stage characteristic: an initial linear rising stage, a progressive nonlinear rising stage and a final stepwise descending stage. Additionally, the microcrack propagation evaluated using a three-stage model, namely, negligible, stable, and sharply accelerated. The propagation of finer microcracks is a typical feature of microcrack size development, while the growth of tensile microcracks is characteristics of microcrack type evolution. A key finding is the first identification and quantification of a distinct two-stage interfacial flow process (from flow to seepage) by uniquely correlating AE waveforms and infrared thermography with hydraulic pressure. Furthermore, a bilinear displacement response model was developed, and an integrated, microcrack-controlled framework was established to assess the interfacial waterproof potential. This study provides a practical micro-damage-based predictive tool for optimizing the waterproof performance of SC-SP composite in hygrothermal environments, offering significant value for durability design in underground engineering.

在高温、富水环境中，喷塑聚合物（SP）越来越多地被用作地下结构的防水喷雾材料。然而，在这种湿热条件下，喷射聚合物（SC-SP）复合材料的界面特性和防水破坏机制仍然知之甚少。本研究通过多尺度实验技术的新颖整合，全面研究了湿热老化（65℃，95 %相对湿度（RH） 0-56天）下的这些机制。该研究将界面粘结性能测试与声发射（AE）监测相结合，并将界面防水性能测试与声发射和红外热成像相结合。结果表明：SC-SP复合结构的界面破坏模式可划分为3种类型，其中模式II为主导破坏类型；应力-位移曲线呈现出初始线性上升阶段、非线性渐进上升阶段和最终逐步下降阶段三个阶段的特征。此外，采用可忽略、稳定和急剧加速三阶段模型对微裂纹扩展进行了评估。细微裂纹的扩展是微裂纹尺寸发展的典型特征，而拉伸微裂纹的扩展是微裂纹类型演变的特征。一个关键的发现是通过将声发射波形和红外热成像与水压独特地关联起来，首次识别和量化了一个独特的两阶段界面流动过程（从流动到渗流）。此外，建立了双线性位移响应模型，并建立了一个集成的微裂缝控制框架来评估界面防水潜力。该研究为优化SC-SP复合材料在湿热环境下的防水性能提供了一种实用的基于微损伤的预测工具，对地下工程的耐久性设计具有重要价值。

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引用次数: 0

Hydration kinetics, pore refinement, and performance enhancement of cementitious materials modified with NO2-LDHs and NO2-LDHs@MMT NO2-LDHs和NO2-LDHs@MMT改性胶凝材料的水化动力学、孔隙细化和性能增强

IF 8 1区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Construction and Building Materials

Pub Date : 2026-01-15 DOI: 10.1016/j.conbuildmat.2026.145265

Xiaoyi Zhang , Yiheng Huang , Shenglan Ma , Guoliang Lin , Chen Wu , Youqing Su , Wenjin Huang , Guohui Yan

Nitrite-intercalated layered double hydroxides (NO₂-LDHs) and their montmorillonite-supported composites (NO₂-LDHs@MMT) were synthesized by a coprecipitation method and their influences on the hydration kinetics, pore structure, and mechanical performance of cementitious materials were systematically investigated. Hydration calorimetry, X-ray diffraction (XRD), scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) and conventional mechanical tests were employed to elucidate the effects and underlying mechanisms. The results indicate 2 wt% is the optimal dosage for simultaneously accelerating hydration and enhancing mechanical properties. At a dosage of 2 wt%, the initial setting time was reduced by 16.3 % and 18.4 % respectively compared to the blank control group, while the final setting time was shortened by 12.2 % and 13.8 % respectively. Hydration heat release and XRD analyses indicate enhanced formation of Ca(OH)₂, AFt and C-S-H phases in systems containing the additives. SEM and MIP observations reveal pore refinement and a pronounced densification of the interfacial transition zone (ITZ). Mechanically, a 2 wt% incorporation yielded optimum performance: 28 d compressive strength of concrete increased from 39.9 MPa (blank) to 44.9 MPa with NO₂-LDHs and 45.3 MPa with NO₂-LDHs@MMT, while mortar strength reached 54.0 MPa. However, 3 wt% loading leads to particle agglomeration and loss of workability. The synergistic effect of nitrite intercalation and the MMT framework is proposed to enhance ion transport and provide heterogeneous nucleation sites that favor formation of a dense hydration gel network, thereby improving microstructural integrity and durability. These findings demonstrate NO₂-LDHs@MMT act as effective multifunctional cementitious additives for accelerating early hydration, refining pore structure, and enhancing mechanical properties under complex conditions.

采用共沉淀法合成了亚硝酸盐嵌入层状双氢氧化物（NO2-LDHs）及其蒙脱石负载复合材料（NO2-LDHs@MMT），并系统研究了它们对胶凝材料水化动力学、孔隙结构和力学性能的影响。采用水化量热法、x射线衍射仪（XRD）、扫描电镜（SEM）、压汞孔隙度仪（MIP）和常规力学测试等方法分析了其作用机理。结果表明，2 wt%是同时加速水化和提高力学性能的最佳掺量。在添加量为2 wt%时，初始凝固时间比空白对照组分别缩短16.3 %和18.4 %，最终凝固时间分别缩短12.2 %和13.8 %。水化放热分析和XRD分析表明，在添加添加剂的体系中，Ca(OH)2、AFt和C-S-H相的形成增强。SEM和MIP观察显示孔隙细化和界面过渡区（ITZ）明显致密化。机械性能方面，掺入量为2 wt%时，混凝土的28 d抗压强度从NO2-LDHs的39.9 MPa（空白）提高到NO2-LDHs的44.9 MPa和NO2-LDHs@MMT的45.3 MPa，砂浆强度达到54.0 MPa。然而，3 wt%的加载会导致颗粒团聚和工作性的丧失。亚硝酸盐嵌入和MMT框架的协同作用增强了离子传输，并提供了有利于形成致密水化凝胶网络的异质成核位点，从而提高了微观结构的完整性和耐久性。这些发现表明NO2-LDHs@MMT是一种有效的多功能胶凝添加剂，可以加速早期水化，改善孔隙结构，提高复杂条件下的力学性能。

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引用次数: 0