基于细观层次的再生混凝土抗压强度数值分析  

Numerical analysis of compressive strength of recycled concrete based on meso level

作　　者：金立兵[1] 焦鹏飞 樊太 段杰 董天云 张为博 JIN Libing;JIAO Pengfei;FAN Tai;DUAN Jie;DONG Tianyun;ZHANG Weibo(Institute of Long-term Performance on Concrete Structures,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学混凝土结构长期性能研究所,河南郑州450001

出　　处：《混凝土》2024年第9期113-117,共5页Concrete

基　　金：国家自然科学基金(51509084);河南省重点研发与推广专项(212102110191)。

摘　　要：针对再生混凝土细观结构组成复杂、具有高度的非均匀性的特性,利用Monte-Carlo原理建立了包含新、旧砂浆,新、旧界面过渡区及天然骨料等五相随机凸多边形骨料模型,结合混凝土塑性损伤模型进行单轴压缩模拟。在验证了所建模型合理性的基础上,研究了再生混凝土单轴受压的破坏机理,分析了再生混凝土的破坏与应力分布的关系,并调整相关参数,讨论了新、旧界面过渡区和新、旧砂浆性能对再生混凝土抗压强度的影响。结果表明:大粒径骨料及其形状对再生混凝土的破坏起关键作用;拉应力与切应力集中是其破坏的主要原因;细观上累积损伤形成了再生混凝土的宏观破坏;分析得到提升RAC抗压强度的优先级依次为新砂浆、旧砂浆、新界面过渡区、旧界面过渡区。According to the characteristics of complex meso-structure composition and high heterogeneity of recycled concrete,a five-phase random convex polygon aggregate model including new and old mortar,new and old interfacial transition zone and natural aggregate was established by using Monte-Carlo principle,and the uniaxial compression simulation was carried out by combining with the plastic damage model of concrete.On the basis of verifying the rationality of the model,the failure mechanism of recycled concrete under uniaxial compression is studied,and the relationship between the failure of recycled concrete and the stress distribution is analyzed.The effects of the interface transition zone and mortar properties on the compressive strength of recycled concrete are discussed by adjusting the relevant parameters.The results show that the large-size aggregate and its shape play a key role in the failure of RAC.The concentration of tensile stress and shear stress is the main reason for the failure of RAC.The cumulative damage on the meso-level forms the macro-damage of RAC.The analysis shows that the priority of improving the compressive strength of RAC is new mortar,old mortar,new interfacial transition zone and old interfacial transition zone.

关 键 词：再生混凝土 随机凸多边形骨料 单轴压缩模拟 破坏机理 影响因素 

分 类 号：TU528.01[建筑科学—建筑技术科学]