Case Studies in Construction Materials最新文献_第10页

Resource recovery for sustainable construction: Strength and microstructure characteristics of municipal solid waste incineration ash as a green alternative to cement in cementitious composites 可持续建筑的资源回收：作为水泥复合材料中绿色替代品的城市生活垃圾焚烧灰的强度和微观结构特征

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-09 DOI: 10.1016/j.cscm.2025.e05675

Siva Avudaiappan , Ramon Francisco Arrue Munoz , G. Murali , Manuel Chávez-Delgado , Ramirez-Madrid Andres , Paulraj Manidurai , Erick Saavedra Flores , Nelson Maureira-Carsalade

The building sector is confronted with significant issues related to sustainability due to high carbon emissions and resource consumption from conventional cement production. Additionally, the disposal of municipal solid waste incineration bottom ash (MSWI-BA) poses environmental risks. This study examines the potential of MSWI-BA as partial substitution of cement in cementitious composite formulations, with particular emphasis on its influence on strength and microstructure. The research aims to promote resource recovery, reduce landfill usage, lower carbon emissions, and foster eco-friendly building solutions and efficient waste utilization. Cement was partially replaced with MSWI-BA at substitution levels of 0 %, 10 %, 20 %, and 30 %, and the effects on density, porosity, water absorption, compressive strength, flexural strength, and microstructural characteristics were systematically investigated. Results show a consistent reduction in density and compressive strength with elevating the proportion of MSWI-BA. The compressive strength declined at all ages with higher MSWI-BA levels, showing a 28.49 % loss at 30 % replacement after 28 days. At early age (3 days), the mortar incorporating 10 % MSWI-BA exhibited a modest reduction in flexural performance (13.83 %). However, by 28 days, this mixture surpassed the control matrix with an 8.15 % improvement, reflecting the delayed benefits associated with BA incorporation. In contrast, higher replacement levels (20–30 %) resulted in flexural strength reductions of up to 37 %. Overall, up to 10 % MSWI-BA replacement is optimal for balancing performance and sustainability. Incorporating up to 10 % MSWI-BA as a partial cement replacement supports sustainable construction and circular economy practices without significantly affecting material performance.

由于传统水泥生产的高碳排放和资源消耗，建筑行业面临着与可持续性相关的重大问题。此外，城市生活垃圾焚烧底灰的处理存在环境风险。本研究考察了MSWI-BA在胶凝复合配方中部分替代水泥的潜力，特别强调了其对强度和微观结构的影响。该研究旨在促进资源回收，减少垃圾填埋场的使用，降低碳排放，促进生态友好的建筑解决方案和有效的废物利用。在0 %、10 %、20 %和30 %的取代水平上，用MSWI-BA部分替代水泥，系统地研究了对密度、孔隙率、吸水率、抗压强度、抗弯强度和微观结构特征的影响。结果表明，随着MSWI-BA比例的增加，密度和抗压强度呈一致的下降趋势。随着MSWI-BA水平的升高，抗压强度在所有年龄段都有所下降，在28天后更换30 %时，抗压强度下降28.49 %。在早期（3天），含有10 % MSWI-BA的砂浆显示出适度的弯曲性能降低（13.83 %）。然而，到了28天，这种混合物超过了对照基质，改善了8.15 %，反映了与BA掺入相关的延迟效益。相比之下，较高的置换水平（20-30 %）导致弯曲强度降低高达37 %。总体而言，高达10 %的MSWI-BA更换是平衡性能和可持续性的最佳选择。将高达10% %的MSWI-BA作为部分水泥替代品，支持可持续建筑和循环经济实践，而不会显著影响材料性能。

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引用次数: 0

Study on mechanical properties and microscopic mechanism of expansive soil improved by eggshell ash-silica fume composite 蛋壳灰-硅灰复合材料改良膨胀土力学性能及细观机理研究

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-09 DOI: 10.1016/j.cscm.2025.e05666

Qingrui LU , Rong Hu , Zihan Wu , Jinhe Gao

To reduce the high carbon emissions of traditional modifiers (cement/lime) and address gaps in ESA–SF studies—unclear dosage-age-performance relations and insufficient micro-mechanism and durability analysis. Weak expansive soil from Huainan City, China, was stabilized using ESA and SF—both obtained from solid wastes. Macroscopic tests (free swelling ratio, unconfined compressive strength, direct shear strength) and microscopic analyses (XRD, SEM, dry–wet cycling) were conducted to evaluate the effects of ESA content (0 %, 3 %, 6 %, 9 %), SF content (0 %, 4 %, 8 %, 12 %), and curing age (1 d, 7 d, 14 d, 28 d). The results demonstrated that the composite of 9 % ESA + 8 % SF effectively reduced the free swelling ratio to below 20 % after 28 days, converting the soil to non-expansive. An unconfined compressive strength of 1.90 MPa was achieved at 28 days, with the stress–strain curve showing an excellent fit. Under 300 kPa vertical pressure, the shear strength increased to 279.49 kPa, accompanied by a 292.15 % rise in cohesion and a 43.6 % increase in the internal friction angle compared to plain soil. Microstructural analysis indicated that Ca2⁺ from ESA compressed the double layer, while SF reacted with Ca(OH)₂ to form C-S-H gels. After seven dry-wet cycles, the stabilized soil retained 40 % of its strength, whereas plain soil collapsed after only three cycles. Overall, the optimal 9 % ESA + 8 % SF formulation effectively mitigates expansion-contraction hazards, enhances long-term soil stability, and exemplifies waste-to-resource utilization consistent with carbon neutrality objectives, offering an economically viable, environmentally sustainable, and technically robust solution for expansive soil engineering applications.

减少传统改性剂（水泥/石灰）的高碳排放，解决ESA-SF研究中的空白——剂量-龄期-性能关系不明确以及微观机制和耐久性分析不足。对淮南市软弱膨胀土进行了固体废弃物中ESA和sfs稳定化处理。通过宏观试验（自由膨胀比、无侧限抗压强度、直剪强度）和微观分析（XRD、SEM、干湿循环），评价了ESA含量（0 %、3 %、6 %、9 %）、SF含量（0 %、4 %、8 %、12 %）和养护龄期（1 d、7 d、14 d、28 d）的影响。结果表明：9 % ESA + 8 % SF复合处理28 d后，有效地将自由膨胀率降低至20 %以下，使土体转为非膨胀状态。28 d无侧限抗压强度为1.90 MPa，应力-应变曲线拟合良好。竖向压力为300 kPa时，抗剪强度达到279.49 kPa，黏聚力比平原土提高292.15 %，内摩擦角比平原土提高43.6 %。微观结构分析表明，来自ESA的Ca2+压缩了双层膜，而SF与Ca(OH)2反应形成C-S-H凝胶。经过7次干湿循环，稳定土的强度保持了40% %，而平原土只经过3次循环就发生了崩塌。总体而言，最佳的9 % ESA + 8 % SF配方有效地减轻了膨胀-收缩危害，增强了土壤的长期稳定性，并体现了与碳中和目标一致的废物转化为资源的利用，为膨胀土工程应用提供了经济上可行、环境上可持续、技术上稳健的解决方案。

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引用次数: 0

Structural optimization and anchorage performance analysis of Basalt Fiber-Reinforced Polymer (BFRP) anchor bolt system 玄武岩纤维增强聚合物（BFRP）锚杆体系结构优化及锚固性能分析

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-09 DOI: 10.1016/j.cscm.2025.e05678

Hao Wang , Geng-ming Yan , Wen-hao Jiang , Zeng-kui Sun , Qiang Tong

Basalt Fiber-Reinforced Polymer (BFRP) anchor bolts offer high strength, corrosion resistance, and electrical insulation. To promote the reliable use of GFRP anchor bolts, this study investigates three typical locking structures (glass fiber reinforced plastic nut, steel wedge, and adhesive-type steel sleeves) to analyze their mechanical behavior and failure modes. The interfacial performance of the anchor bolt-grouting material system under multiple influencing factors is examined, and the effects of alkaline service environments on bolt performance are evaluated through corrosion tests. The results indicate that when epoxy resin is used as the adhesive and the clearance distance between the steel sleeve and the bolt is controlled at 1 mm, the adhesive-type steel sleeve locking structure can effectively utilize the tensile strength of the bolt, with a maximum tensile strength of 388.19 kN for a 28 mm-diameter bolt. The geopolymer shows the best interfacial bonding performance with the bolt. Bolt diameter and anchorage length have significant effects on tensile performance. In an alkaline environment with a pH value of 12.5, the mechanical properties of the bolt deteriorate noticeably, with a strength retention rate of 92.97 % after 112 days. This paper systematically investigates the selection, strength, and deformation characteristics of the locking structure-GFRP anchor bolt-grouting material system, and quantitatively analyzes the corrosion resistance of the bolts under alkaline environments. On this basis, optimization design recommendations for BFRP anchor bolts anchorage system under different working conditions are proposed, providing technical support for their practical engineering applications.

BFRP（玄武岩纤维增强聚合物）地脚螺栓具有高强度、耐腐蚀和电绝缘的特点。为了促进GFRP地脚螺栓的可靠使用，本研究研究了三种典型的锁定结构（玻璃钢螺母、钢楔和胶粘剂型钢套），分析了它们的力学行为和破坏模式。考察了多种影响因素下锚杆-注浆材料体系的界面性能，并通过腐蚀试验评价了碱性服役环境对锚杆性能的影响。结果表明：当采用环氧树脂作为粘结剂，钢套与螺栓间隙控制在1 mm时，粘结型钢套锁紧结构能有效利用螺栓的抗拉强度，对于直径为28 mm的螺栓，其最大抗拉强度为388.19 kN；地聚合物与锚杆的界面结合性能最好。锚杆直径和锚固长度对锚杆抗拉性能影响较大。在pH值为12.5的碱性环境下，锚杆的力学性能明显恶化，112天后强度保持率为92.97 %。系统研究了锁紧结构- gfrp锚杆-注浆材料体系的选择、强度及变形特性，定量分析了锚杆在碱性环境下的耐腐蚀性能。在此基础上，提出了不同工况下BFRP锚杆锚固体系的优化设计建议，为其实际工程应用提供技术支持。

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引用次数: 0

Utilization of industrial by-products as binders and fine aggregates for one-part lightweight controlled low-strength materials: Turning waste to value approach 工业副产物作为粘结剂和细集料用于单件轻质可控低强度材料：变废为利方法

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-09 DOI: 10.1016/j.cscm.2025.e05676

Warayut Dokduea, Potchara Praneedpolkrang, Weerachart Tangchirapat, Chai Jaturapitakkul

This study investigated the fresh and hardened properties of controlled low-strength material (CLSM) using ground coal bottom ash (GBA) mixed with ground calcium carbide residue (GCR) as the primary binder. Sieved coal bottom ash (SBA) fully replaced the river sand by volume. The effects of sodium metasilicate pentahydrate (SM) at 2 %, 4 %, 6 %, and 8 % by weight of binder as a solid activator for one-part CLSM were also examined. Fresh and hardened properties, including flowability, hardening time, bleeding, ball drop, unconfined compressive strength (UCS), and elastic modulus, were evaluated. The microstructures of the CLSM pastes were analyzed using X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). All CLSM mixtures exhibited high flowability (>200 mm). The proportions of GBA and GCR significantly influenced the fresh and hardened properties. Replacing river sand with SBA resulted in lightweight CLSM; however, complete replacement increased hardening time, bleeding, and ball drop value and reduced UCS. An optimal SM dosage of approximately 4 % resulted in a 28-day UCS of 2.54 MPa, bleeding of 0.6 %, hardening time of 33 h, and a ball drop value of 68.5 mm, meeting typical CLSM requirements. XRD and SEM-EDS results revealed that the GCR acted as a crucial source of calcium oxide. Their effective reaction to strength development in C-S-H and N-A-S-H gels, particularly when activated by 4 % SM, positively contributed to the observed compressive strength and denser matrix of the CLSM. Incorporating GBA, GCR, and SBA offers a sustainable, low-carbon approach for CLSM production, promoting waste valorization and conserving natural resources.

研究了以煤底灰（GBA）和电石渣（GCR）为主要粘结剂的可控低强度材料（CLSM）的新鲜和硬化性能。筛分煤底灰（SBA）在体积上完全取代了河砂。考察了五水偏硅酸钠（SM）在黏合剂质量分数为2 %、4 %、6 %和8 %时作为固体活化剂对单组CLSM的影响。评估了新鲜和硬化性能，包括流动性、硬化时间、出血、落球、无侧限抗压强度（UCS）和弹性模量。采用x射线衍射仪（XRD）和扫描电镜-能谱仪（SEM-EDS）分析了CLSM膏体的微观结构。所有CLSM混合物均表现出高流动性（>200 mm）。GBA和GCR的比例对其新鲜和硬化性能有显著影响。用SBA代替河砂，获得了轻质CLSM；然而，完全置换增加了硬化时间、出血和球降值，并降低了UCS。当SM的最佳剂量为4 %时，28天的UCS为2.54 MPa，出血率为0.6 %，硬化时间为33 h，球滴值为68.5 mm，满足典型的CLSM要求。XRD和SEM-EDS结果表明，GCR是氧化钙的重要来源。它们对C-S-H和N-A-S-H凝胶强度发展的有效反应，特别是当4 % SM激活时，对观察到的CLSM抗压强度和更致密的基质有积极的贡献。结合大湾区、GCR和SBA为CLSM生产提供了可持续的低碳方法，促进了废物增值和保护自然资源。

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引用次数: 0

Monitoring of reinforced concrete beam damages using EMD-based acoustic emission and digital imaging correlation technologies 基于emd声发射和数字成像相关技术的钢筋混凝土梁损伤监测

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-09 DOI: 10.1016/j.cscm.2025.e05674

Ziping Wang , Dongwei Shang , Napoleon Kuebutornye , Jiazhen Zhang , Nataša R. Trišović

A comprehensive experimental method for monitoring and characterizing the damage evolution of Reinforced Concrete (RC) beams was conducted under three-point bending load, using a combination of Hilbert-Huang Transform (HHT) based Acoustic Emission (AE) technology and Digital Image Correlation (DIC). AE sensors capture the passive elastic waves emitted during damage progression, and their signals are analyzed using Empirical Mode Decomposition (EMD) to extract key features such as frequency and amplitude. Simultaneously, DIC and strain gauges monitor the deformation and stress distribution on the beam surface and reinforcement. The experimental results demonstrate a clear correlation between AE signal characteristics and the various stages of crack initiation, propagation, and structural failure. AE signals exhibit stage-specific spectral changes, evolving from low-frequency, low-amplitude patterns during micro crack formation to high-frequency, high-amplitude signals during major crack propagation. The DIC strain fields visually capture deformation concentration zones that align well with AE signal trends. This integrated monitoring approach enables the quantitative evaluation of structural damage and offers a reliable method for health monitoring of concrete structures. Subsequently, a database of characteristic parameters for different damage stages is established, providing theoretical support for the application of HHT in analyzing non-stationary signals in Structural Health Monitoring (SHM).

采用基于Hilbert-Huang变换（HHT）的声发射（AE）技术和数字图像相关（DIC）技术，对钢筋混凝土（RC）梁在三点弯曲荷载作用下的损伤演变过程进行了综合监测和表征。声发射传感器捕获损伤过程中发射的被动弹性波，并使用经验模态分解（EMD）对其信号进行分析，提取频率和幅度等关键特征。同时，DIC和应变仪监测梁表面和钢筋的变形和应力分布。实验结果表明，声发射信号特征与裂纹萌生、扩展和结构破坏的各个阶段有明显的相关性。声发射信号表现出阶段性的频谱变化，从微裂纹形成过程中的低频、低振幅模式演变为大裂纹扩展过程中的高频、高振幅模式。DIC应变场可以直观地捕捉到与声发射信号趋势一致的变形集中区。这种综合监测方法能够定量评价结构损伤，为混凝土结构健康监测提供了可靠的方法。随后，建立了不同损伤阶段的特征参数数据库，为HHT在结构健康监测中非平稳信号分析中的应用提供了理论支持。

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引用次数: 0

Effects of specimen longitudinal dimensions on the compressive mechanical properties of timber: Experimental investigation and quantitative analysis 试件纵向尺寸对木材压缩力学性能的影响：试验研究与定量分析

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-08 DOI: 10.1016/j.cscm.2025.e05665

Jifei Liao, Zhenlin Chen, Xiao Hu, Yang Song, Huaxin Lu

Wood is recognized as a sustainable, low-carbon construction material, yet a comprehensive theoretical model explaining length-dependent size effects on its longitudinal compressive properties is lacking. Although previous studies have highlighted the importance of longitudinal compressive performance, the impact of wood species variation on this property has not been fully explored. Critically, quantitative relationships between longitudinal compressive behavior and specimen length across various species remain undefined, hindering the application of laboratory results to engineering practice. This study addresses existing knowledge gaps by examining three wood species: Pinus sylvestris var. mongolica (conifer), Elm (broadleaved) and Paulownia (broadleaved). Specimens with varying lengths were subjected to systematic longitudinal compression tests. The analysis focused on compression characteristics across different sizes and a thorough investigation of failure mechanisms. Load-displacement and stress-strain curves were used to elucidate the relationship between mechanical properties and specimen size. Longitudinal compressive strength size effect coefficients were determined using Weibull's weakest-link theory, while finite element simulations modeled axial compression behavior based on experimental data. Key findings include: (1) A significant negative correlation between longitudinal compressive strength and specimen length, with size effect coefficients of 0.08 for Pinus sylvestris var. mongolica, 0.16 for elm, and 0.18 for paulownia. (2) The elastic modulus decreased with increasing specimen length, whereas Poisson's ratio remained unaffected by size variations. (3) Finite element models accurately replicated axial compression failure patterns but required strength reduction factors to account for length-dependent size effects. The proposed model for length-dependent size effect coefficients offers a new framework for characterizing the multiscale mechanical behavior of wood.

木材被认为是一种可持续的低碳建筑材料，但缺乏一个全面的理论模型来解释长度依赖的尺寸对其纵向压缩性能的影响。虽然以前的研究强调了纵向压缩性能的重要性，但木材种类变化对这一特性的影响尚未得到充分探讨。重要的是，纵向压缩行为和不同物种的试样长度之间的定量关系仍然不确定，这阻碍了实验室结果在工程实践中的应用。本研究通过考察三种树种：蒙古松（针叶树）、榆树（阔叶）和泡桐（阔叶）来填补现有的知识空白。不同长度的试样进行了系统的纵向压缩试验。分析的重点是不同尺寸的压缩特性和对破坏机制的深入研究。采用载荷-位移曲线和应力-应变曲线分析了试样尺寸与力学性能的关系。纵向抗压强度尺寸效应系数采用Weibull最弱链接理论确定，而有限元模拟基于实验数据模拟轴向压缩行为。主要发现包括：(1)纵向抗压强度与标本长度呈显著负相关，蒙古松、榆树和泡桐的尺寸效应系数分别为0.08、0.16和0.18。(2)弹性模量随试样长度的增加而减小，泊松比不受尺寸变化的影响。(3)有限元模型准确地模拟了轴压破坏模式，但需要强度折减因子来考虑长度相关的尺寸效应。提出的长度相关尺寸效应系数模型为表征木材的多尺度力学行为提供了一个新的框架。

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引用次数: 0

Combined influence of treated eggshell powder and polypropylene fiber on the mechanical, durability and microstructural properties of sustainable concrete: Experimental and machine learning-based analysis 处理过的蛋壳粉和聚丙烯纤维对可持续混凝土力学、耐久性和微观结构性能的综合影响：实验和基于机器学习的分析

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-08 DOI: 10.1016/j.cscm.2025.e05656

Samiha Islam , Md. Ikramul Hoque , Md. Habibur Rahman Sobuz , Md. Kawsarul Islam Kabbo , Abdullah Alzlfawi , Sani Aliyu Abubakar

In recent years, there has been a rise in the application of waste materials as a result of the carbon emissions associated with concrete production. This study investigates the fresh, mechanical, durability, and microstructural properties of concrete incorporating a combination of treated waste eggshell powder (ESP) at replacement levels of 5 %, 10 %, and 15 %, and polypropylene fiber (PPF) at dosages of 0.05 % and 0.10 %. Mechanical performance was evaluated through compressive, tensile, and flexural strength tests, while durability was assessed by water permeability, sorptivity, and rapid chloride permeability tests. Furthermore, the microstructures of the concrete matrix were examined using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) tests. In addition, supervised machine learning (ML) models were developed to predict compressive strength. Results showed that the optimum mix of 5 % ESP and 0.10 % PPF enhanced compressive, tensile, and flexural strength by 13.47 %, 22.37 %, and 12.47 %, respectively, compared to the control. The significant durability performance was noted in the 5 % ESP and 0.10 % PPF mix, with reduced chloride permeability and water penetration. Among the ML models, XGBoost showed superior predictive accuracy, achieving an R² of 0.954 and the lowest MAE of 3.776 MPa. These study outcomes suggest that the incorporation of ESP and PPF into concrete results in elevated mechanical and durability performance, thereby committing to more sustainable and eco-friendly concrete production.

近年来，由于与混凝土生产相关的碳排放，废料的应用有所增加。本研究考察了将处理后的废蛋壳粉（ESP）替换为5 %、10 %和15 %，聚丙烯纤维（PPF）替换为0.05 %和0.10 %，结合在一起的混凝土的新鲜度、机械性能、耐久性和微观结构性能。机械性能通过压缩、拉伸和弯曲强度测试来评估，而耐久性通过透水性、吸附性和快速氯化物渗透性测试来评估。此外，采用扫描电子显微镜（SEM）和能量色散x射线光谱（EDX）测试对混凝土基体的微观结构进行了检测。此外，还开发了监督机器学习（ML）模型来预测抗压强度。结果表明，与对照相比，5 % ESP和0.10 % PPF的最佳掺量分别提高了13.47 %、22.37 %和12.47 %的抗压、抗拉和抗弯强度。在5% % ESP和0.10 % PPF的混合物中，发现了显著的耐久性能，降低了氯化物渗透率和水渗透性。在ML模型中，XGBoost的预测准确率最高，R2为0.954，MAE最低，为3.776 MPa。这些研究结果表明，在混凝土中加入ESP和PPF可以提高混凝土的机械性能和耐久性，从而实现更可持续、更环保的混凝土生产。

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引用次数: 0

Design and evaluation of restoration strategies for a fractured ancient stone stele (618–907 CE): Experimental characterization, numerical simulation and theoretical analysis 古石碑（618-907 CE）断裂修复策略设计与评价：实验表征、数值模拟与理论分析

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-08 DOI: 10.1016/j.cscm.2025.e05657

Zhuofeng Chen , Chen Wu , Wanqian Feng , Pengcheng Zhou , Jing Cao , Wenqiang Dong , Mara Camaiti , Yijian Cao

The rational and non-destructive design of restoration strategies for large and precious stone artworks remains a great challenge worldwide. To study the restoration of a severely fractured ancient stone stele, experimental characterization of the physicochemical and mechanical properties, numerical and theoretical analyses of virtually restored models were conducted. In the study, five different restoration methods were proposed, combining epoxy adhesive with various types of pin materials. Based on the experimental characterization, the basic parameters for model creation were obtained. Through the in-depth analysis of the simulation results (e.g., the first principal stress, displacement and the Rankine safety factor), the most effective method was identified, i.e., a PTFE pin coated with epoxy adhesive applied to the central fracture, with the epoxy adhesive also applied to the fractured surface. Results also reveal that epoxy adhesive applied to the fracture effectively enhances the load-bearing capacity of the stele, achieving the fundamental aim of the restoration practice. The pin can restrict the displacement and reduce the deformation of the entire structure effectively. Under the transversal loads of 4000 N/m² applied to the rear surface (L_y) of the stele and of 16000 N/m² applied to the right surface (L_x) of the stele, the maximum displacement of the models with the pin and adhesive applied was only 16 % of the model without pin application. Whereas the pin also induces localized stress concentration. Furthermore, coating the pin with adhesive materials can both moderately improve the load-bearing capacity and reduce the deformation of the model. This study facilitates the non-destructive design of repair strategies for stone-built heritage, and also broadens the advanced application of material sciences, engineering mechanics in heritage conservation.

大型珍贵石材艺术品修复策略的合理、无损设计仍是世界范围内面临的一大挑战。为了研究严重断裂的古代石碑的修复，对其物理化学和力学性能进行了实验表征，并对虚拟修复模型进行了数值和理论分析。本研究提出了五种不同的修复方法，将环氧胶粘剂与不同类型的销钉材料相结合。在实验表征的基础上，获得了模型创建的基本参数。通过对模拟结果（如第一主应力、位移和朗肯安全系数）的深入分析，确定了最有效的方法，即在裂缝中心处涂覆环氧胶粘剂的PTFE销，在裂缝表面也涂覆环氧胶粘剂。结果还表明，在断口处应用环氧胶粘剂可以有效地提高石柱的承载能力，达到了修复实践的根本目的。销可以有效地限制位移，减小整个结构的变形。在石柱后表面（Ly）施加4000 N/m2的横向荷载和石柱右表面（Lx）施加16000 N/m2的横向荷载作用下，使用销钉和胶粘剂的模型的最大位移仅为未使用销钉的模型的16 %。而销也引起局部应力集中。此外，在引脚上涂覆粘结材料既可以适度提高模型的承载能力，又可以减少模型的变形。本研究为石建筑遗产修复策略的无损设计提供了便利，也拓宽了材料科学、工程力学在遗产保护中的先进应用。

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引用次数: 0

Study on the interfacial bond behavior of steel fibers embedded in cement-based materials under hot-dry environments 热干环境下钢纤维嵌入水泥基材料界面粘结行为研究

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-08 DOI: 10.1016/j.cscm.2025.e05672

Pin Liu , Jie Yang , Chensen Zuo , Junhu Shao , Shengai Cui

In hot-dry environments of high-temperature geothermal tunnels, the severe deterioration of concrete matrix performance significantly weakens the bond between steel fibers and the matrix, thereby compromising the reinforcing efficiency of steel fibers. This study classifies surrounding rock temperatures into four grades and establishes corresponding simulated environments. Through pullout tests, the influence of temperature on the bond-slip behavior of steel fibers is investigated, the degradation mechanism of fiber-matrix interfacial bond properties is analyzed, and numerical simulations are employed to explore the effects of fiber parameters on pullout behavior. The results indicate that: hot-dry conditions reduce the straightening degree of end hooked steel fibers after pullout, accompanied by channel expansion and spalling; above 80°C, excessive initial defects at the fiber-matrix interface inhibit significant plastic deformation of end hooked fibers during pullout, eliminating the second peak in pullout load; the adverse effects of the hot-dry environment on the pullout behavior of steel fibers gradually manifest with increasing curing age, with higher temperatures leading to poorer interfacial bond performance; fiber embedment length, hooked ends, and moderate inclination angles enhance interfacial bond, whereas excessive inclination triggers matrix spalling at the pullout end, diminishing reinforcement effectiveness.

在高温地热隧道的干热环境中，混凝土基体性能的严重恶化显著削弱了钢纤维与基体的粘结，从而影响了钢纤维的增强效果。本研究将围岩温度分为4个等级，并建立了相应的模拟环境。通过拔拔试验，研究了温度对钢纤维粘结滑移行为的影响，分析了纤维-基体界面粘结性能的退化机理，并采用数值模拟方法探讨了纤维参数对拔拔行为的影响。结果表明：热干条件降低了端钩钢纤维拔除后的矫直程度，并伴有沟道膨胀和剥落；在80℃以上，纤维-基体界面处过多的初始缺陷抑制了端钩形纤维在拔拔过程中的显著塑性变形，消除了拔拔载荷的第二个峰值；随着养护龄期的增加，热干环境对钢纤维拉拔性能的不利影响逐渐显现，温度越高，界面粘结性能越差；纤维嵌入长度、钩端和适度的倾角增强了界面粘合，而过度的倾角会导致拉拔端基体剥落，降低加固效果。

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引用次数: 0

Comparative analysis of the shear response of RC beams strengthened with externally applied and near-surface mounted timber plates 外加力与近表面贴装木板加固RC梁剪力响应对比分析

IF 6.6 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Case Studies in Construction Materials

Pub Date : 2025-12-05 DOI: 10.1016/j.cscm.2025.e05644

Walid Mansour , Mohamed H. El-Naqeeb , Sabry Fayed , Taher A. Tawfik

This research experimentally and numerically investigates the feasibility of using low-cost timber plates to enhance the shear behavior of reinforced concrete (RC) beams. Seven simply supported beams with a shear span-to-depth ratio (a/d) of 1.8 were tested under three-point bending, including one control specimen and six strengthened beams. Two strengthening techniques, externally bonded (EB) and near-surface mounted (NSM), were examined using three attachment methods: epoxy only, 10 mm diameter anchor bolts only, and a combination of both. A 3D finite element model (FEM) was developed in ABAQUS V2017 to evaluate the influence of increasing the a/d ratio from 1.8 to 3.1 on the ultimate load, stiffness, and toughness of the strengthened beams.

Experimental

results showed that timber plates, regardless of the strengthening technique, effectively restricted the propagation of the main shear crack and diverted it into multiple secondary cracks. Externally bonded specimens achieved higher ultimate loads than NSM specimens due to the absence of groove-induced reductions in the concrete section. The use of anchor bolts, either alone or in combination with epoxy, prevented debonding and produced the highest ultimate loads, reaching 91 kN and 92 kN, respectively, representing increases of 21.3 % and 22.7 % over the control beam. Both attachment methods also exhibited stiffness improvements of 10.8 % compared to the control beam. Numerical analysis indicated that increasing the a/d ratio from 1.8 to 3.1 led to reductions in stiffness of 43 %-47 %, ultimate load of 18 %-30 %, and toughness of 7 %-30 %.

本文通过试验和数值研究，探讨了采用低成本木板提高钢筋混凝土梁抗剪性能的可行性。对7根剪跨深比为1.8的简支梁进行三点弯曲试验，包括1根对照梁和6根加固梁。两种强化技术，外粘接（EB）和近表面安装（NSM），使用三种连接方法进行了测试：仅环氧树脂，仅10 mm直径的地脚螺栓，以及两者的组合。在ABAQUS V2017中建立三维有限元模型，评估A /d比值从1.8增加到3.1对加固梁极限荷载、刚度和韧性的影响。试验结果表明，无论采用何种加固技术，木板都能有效地限制主剪切裂缝的扩展，并将其转化为多个次级裂缝。外部粘结试件比NSM试件获得了更高的极限载荷，因为混凝土截面中没有沟槽诱导的减小。使用地脚螺栓，无论是单独使用还是与环氧树脂结合使用，都防止了剥离，并产生了最高的极限载荷，分别达到91 kN和92 kN，比控制梁增加了21.3% %和22.7% %。与控制梁相比，两种连接方法的刚度都提高了10.8 %。数值分析表明，将a/d比值从1.8提高到3.1，刚度降低43 % ~ 47 %，极限载荷降低18 % ~ 30 %，韧性降低7 % ~ 30 %。

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引用次数: 0