基于多场耦合模型的混凝土冻融三维细观研究  

Three-dimensional mesoscopic study on freeze-thaw of concrete based on multi-field coupled model

作　　者：黄康桥 赵程 周伟[1] 刘杏红[1] 马刚[1] HUANG Kang-qiao;ZHAO Cheng;ZHOU Wei;LIU Xing-hong;MA Gang(State Key Laboratory of Water Resources and Hydropower Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《浙江大学学报（工学版）》2021年第1期62-70,共9页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(51879206).

摘　　要：基于蒙特-卡洛理论和工程粗骨料粒径分布情况,将骨料形状简化为球形,应用Matlab与Comsol Multiphysics接口进行二次开发,以生成区分骨料、界面过渡区(ITZ)和砂浆的混凝土三相三维细观模型.采用改进的热-水-力耦合模型,将耦合模型与物理试验进行验证分析,结果吻合较好.将该耦合模型应用于研究冻融作用下混凝土三维细观尺度的性能演化规律.研究结果表明,当渗透率较高时,试件整体第一主应力急剧减小,且出现骨料受压而砂浆受拉的情况;当骨料体积分数增大时,试件应力整体呈现下降趋势.砂浆渗透率和骨料体积分数对混凝土抗冻融性能的影响较大.不同的ITZ线膨胀系数下混凝土应力变化不大,说明ITZ线膨胀系数对混凝土抗冻融性能的影响相对较小.The shape of aggregate was simplified into sphere based on Monte-Carlo theory and the distribution of coarse aggregate particle size.Matlab and Comsol Multiphysics interface were applied for secondary development to generate a three-phase three-dimensional mesoscopic model of concrete that can distinguish aggregate,ITZ and mortar.The improved thermo-hydro-mechanical model was used,and the results accorded well with the experimental results.The coupled model was applied to analyze the behavior evolution law of concrete three-dimensional mesoscale under freeze-thaw conditions.Results show that the first principal stress of the whole sample decreases sharply and the aggregate is in compression while the mortar is in tension when the permeability is high.The overall stress of the sample shows a downward trend when the aggregate volume fraction increases.Motar permeability and aggregate volume fraction have great influence on the freeze-thaw resistance of concrete.The stress of concrete does not change much under different ITZ coefficients of linear thermal expansion,indicating that ITZ coefficient has relatively little influence on the freeze-thaw resistance of concrete.

关 键 词：混凝土 冻融循环 三维细观尺度 随机骨料模型 多场耦合分析 Comsol Multiphysics 

分 类 号：TV331[水利工程—水工结构工程]