混凝土单轴压缩下细观损伤特性的CT研究  

CT Real-Time Observation of Meso-Damage Process for Concrete Material under Uniaxial Compression

作　　者：田威[1] 党发宁[1] 梁昕宇[1] 陈厚群[1,2] 

机构地区：[1]西安理工大学岩土工程研究所,西安710048 [2]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》2009年第3期184-190,共7页Journal of Experimental Mechanics

基　　金：国家自然科学基金重点项目(90510017);国家自然科学基金资助项目(50679073)资助;西安理工大学优秀博士基金项目(602-210806)

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。本文利用CT技术对混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件实时静力压缩CT图像,提取出图像上各点的CT数并根据分区理论定义了一个基于CT数的统计损伤变量。通过对图像和CT数以及损伤变量的分析表明混凝土试件在静力压缩条件下经历了压密阶段、扩容阶段,损伤急剧增大到破坏的细观损伤演化全过程,以此反映了混凝土细观损伤演化的特性。进而通过细观损伤对混凝土材料裂纹的扩展、贯通以及最后失稳破坏的破坏实质进行了有益的探索。Concrete is a heterogeneous material and may be considered as three-phase composites consisting of aggregate, mortar and interface between aggregate and mortar. Real time scanning observation on the evolution of meso-damage in concrete was carried out by means of CT technology, and the real time scanning CT image of static compression was obtained. The CT image data were collected and a statistical damage variable based on CT number was defined according to the divisional zones theory. Analysis of concrete CT image, CT data and damage variable under static compression shows that concrete specimen has experienced different stages of condense, expansion of volume, crack rapid propagation and failure, therefore the characteristics of concrete meso-damage evolution is reflected. Through the meso-damage evolution, the process of crack propagation, coalescence and failure in concrete material is explored instructively.

关 键 词：混凝土 细观损伤 CT(计算机处理X线断层摄影术) CT数 损伤变量 

分 类 号：TU22[建筑科学—建筑设计及理论]