基于地聚物骨料的高延性纤维增强水泥基复合材料力学性能与拉伸本构模型  

Mechanical properties and tensile constitutive model of engineered cementitious composites based on geopolymer aggregates

作　　者：苏骏 钟子龙[1] 蔡雅琼 郑文君 蔡新华 SU Jun;ZHONG Zilong;CAI Yaqiong;ZHENG Wenjun;CAI Xinhua(School of Civil Engineering Architecture and the Environment,Hubei University of Technology,Wuhan 430068,China;Intelligent Health Perception and Ecological Restoration of Rivers and Lakes,Ministry of Education,Hubei University of Technology,Wuhan 430068,China;State Key Laboratory of Water Resources&Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,武汉430068 [2]湖北工业大学河湖健康智慧感知与生态修复教育部重点实验室,武汉430068 [3]武汉大学水资源与水电工程科学国家重点实验室,武汉430072

出　　处：《复合材料学报》2024年第11期6122-6137,共16页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金面上项目(52178247)。

摘　　要：为探究地聚物骨料(GPA)对高强度高延性纤维增强水泥基复合材料力学性能的影响,对不同GPA取代率下的地聚物骨料高延性纤维增强水泥基复合材料(GPA/ECC)进行抗压强度与单轴拉伸试验,通过分析GPA/ECC抗压强度与拉伸应力-应变关系曲线,研究GPA/ECC抗压性能、拉伸性能及拉伸应力-应变关系,同时结合SEM-EDS对其微观结构与元素含量进行分析以揭示GPA对GPA/ECC宏观力学性能的影响机制。结果表明:相比于精细石英砂基体,随着GPA取代率的增加,GPA/ECC整体强度与弹性模量略有下降,但其应变硬化能力、裂缝控制能力及基体韧性明显提升,相应拉伸峰值应变分别提高约19.3%、50.3%、64.6%和130.7%,硬化阶段强度提升率分别提高约5.6%、34.3%、42.4%和91.4%,应变能密度最高提升约20.0%;GPA与水泥水化产物Ca(OH)_(2)发生反应,在骨料-基体界面过渡区处生成了水化硅酸钙(C-S-H)与水化铝酸钙(C-A-H)等附加反应产物,提高了GPA/ECC微观结构的致密性。根据试验结果,通过最小二乘法对GPA/ECC拉伸应力-应变曲线进行回归分析,建立了GPA/ECC拉伸本构模型,可为GPA/ECC的性能设计与工程应用提供参考。To investigate the influence of geopolymer aggregates(GPA)on the mechanical properties of highstrength engineered cementitious composites,compressive strength tests and uniaxial tensile tests were conducted on geopolymer aggregates engineered cementitious composites(GPA/ECC)with different replacement rates of GPA.The compressive performance,tensile performance,and stress-strain relationship of GPA/ECC were studied by analyzing the compressive strength and tensile stress-strain relationship curves of GPA/ECC.At the same time,SEM-EDS analysis was used to reveal the influence mechanism of GPA on the macroscopic mechanical properties of GPA/ECC by analyzing its microstructure and element content.The results indicate that compared to the fine quartz sand matrix,as the GPA replacement rate increases,the overall strength and elastic modulus of GPA/ECC slightly decrease.However,its strain hardening capacity,crack control ability,and matrix toughness significantly improve.The corresponding ultimate tensile strain increases by about 19.3%,50.3%,64.6%,and 130.7%.The strength improvement rate in the hardening stage increases by about 5.6%,34.3%,42.4%,and 91.4%.The strain energy density shows the highest increase of 20.0%.GPA reacts with the hydration product Ca(OH)_(2)of cement and generates additional reaction products such as hydrated calcium silicate(C-S-H)and hydrated calcium aluminate(C-A-H)at the interface transition zone between the aggregates and matrix,which improves the compactness of GPA/ECC microstructure.Based on the experimental results,regression analysis of the tensile stress-strain curve of GPA/ECC was performed using the least squares method.A constitutive model for GPA/ECC under tension was established,providing a reference for the performance design and engineering application of GPA/ECC.

关 键 词：地聚物骨料 高延性纤维增强水泥基复合材料 单轴拉伸试验 本构模型 微观机制 

分 类 号：TU528[建筑科学—建筑技术科学] TB332[一般工业技术—材料科学与工程]