单轴压缩条件下混凝土细观损伤演化机理的CT试验研究  

Experimental Study of Concrete Meso-Damage Evolution Mechanism Based on Uniaxial Compression CT Method

作　　者：田威[1] 党发宁[2] 陈厚群[2,3] 

机构地区：[1]长安大学建筑工程学院,西安710061 [2]西安理工大学岩土工程研究所,西安710048 [3]中国水利水电科学研究院工程抗震中心,北京100044

出　　处：《实验力学》2011年第1期54-60,共7页Journal of Experimental Mechanics

基　　金：国家自然科学基金资助项目(51009010);中央高校基本科研业务费专项基金(CHD2010JC114);长安大学基础研究支持计划专项基金资助项目;建设部给水排水重点实验室开放基金资助

摘　　要：混凝土是一种非均质的材料,在细观层次上将混凝土看作由骨料、砂浆和两者之间的界面组成的三相复合材料。本文在对混凝土进行单轴压缩试验的基础上,根据CT扫描图像反映的细观破损过程,分析了基于CT数平均值变化规律的特点;将混凝土材料的损伤过程进行了分段,提出了损伤变量的提取方法。随后结合试验得到的宏观应力应变曲线,经过拟合得到损伤变量与宏观应变的关系公式,建立了新的分段损伤演化方程及损伤本构模型。通过对比分析,验证了损伤变量的计算结果和试验结果整体吻合较好。以此深入研究了混凝土材料细观破损机理。Concrete is a heterogeneous material and may be considered as a three-phase composite consisting of aggregate,mortar and interface between aggregate and mortar from a mesoscopic view.The variation characteristics of CT average number were analyzed by CT scan images of meso-damage process,based on CT testing of concrete meso-damage evolution under unaxial compression.Concrete damage process may be divided into several stages,and the method of extracting the damage variable was proposed.Considering the experimentally obtained macro stress-strain curve,the relation between the damage variable and macro strain was obtained by data fitting.A new equation of damage evolution damage and a damage constitutive model were established.Through comparing and analyzing,the obtained theory results coincide well with the experimental results.So the concrete meso damage-fracture mechanism was deeply investigated.

关 键 词：混凝土 细观损伤 CT 损伤变量 本构模型 

分 类 号：TU22[建筑科学—建筑设计及理论]