大骨料混凝土应变局部化中不同粒级粗骨料的作用效应  

Effects of coarse aggregate of different size grades on the strain localization of mass concrete

作　　者：姜磊 徐磊[1] 张菁倪 徐兰玉[2] 任青文[1] JIANG Lei;XU Lei;ZHANG Jingni;XU Lanyu;REN Qingwen(College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210098,China;Nanjing Research Institute of Hydrology and Water Conservation Automation,Ministry of Water Resources,Nanjing 210012,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]水利部南京水利水文自动化研究所,江苏南京210012

出　　处：《水资源与水工程学报》2022年第3期169-175,共7页Journal of Water Resources and Water Engineering

基　　金：国家自然科学基金项目(51979092、51739006、U1765204);江苏省水利科技项目(2020024)。

摘　　要：为探究不同粒级粗骨料在大骨料混凝土损伤开裂应变局部化过程中的作用效应,在建立大骨料混凝土细观有限元模型的基础上,通过开展不同细观结构下的损伤开裂模拟,分析了大骨料混凝土应变局部化区域的演化过程和分布特征;通过在原细观结构中单独改变某一粒级粗骨料分布,分别探究了不同粒级粗骨料在应变局部化中的作用效应。研究表明:应变局部化主要发生在大粒径粗骨料与砂浆间的界面过渡区处,特大石粒级粗骨料在很大程度上控制着应变局部化区域的主要分布特征,大石和中石粒级粗骨料均可直接或间接在应变局部化区域形成过程中发挥明显作用,而小石粒级粗骨料在应变局部化中的作用效应微弱。研究成果可为在大骨料混凝土细观损伤断裂分析中通过简化细观结构来降低模拟难度和减小计算规模提供参考。In order to reveal the effects of coarse aggregate of different size grades on the strain localization of mass concrete, we established a mesoscopic finite element model to simulate the damage and fracture of fully-graded aggregate mass concrete under the conditions of different mesoscopic material structures, so as to analyze the evolution process and distribution characteristics of the region of strain localization. In the simulation, the effects of coarse aggregate of different size grades on the strain localization were respectively brought to light by changing the coarse aggregate distribution of one individual size grade while keeping that of the other size grades unchanged. Numerical results show that most of the strain localization appear in the interfacial transition zone between the large coarse aggregates and the mortar, and the main distribution characteristics of the strain localization region is mainly controlled by the extra-large coarse aggregate. Moreover, the large and medium aggregates play important roles in the evolution process of the strain localization region directly or indirectly, whereas the small coarse aggregate has little effect. The research findings can provide a preliminary basis for reducing the simulation difficulties and computational demand by simplifying the mesostructure of mass concrete.

关 键 词：大骨料混凝土 应变局部化 混凝土损伤 细观结构 粗骨料 作用效应 有限元 

分 类 号：TV431[水利工程—水工结构工程]