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.
作者
苏骏
钟子龙
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)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
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)。
作者简介
通信作者:苏骏,博士,教授,博士生导师,研究方向为混凝土结构计算理论、纤维混凝土结构、工程结构抗震与加固技术,E-mail:19981037@hbut.edu.cn。
