单轴压缩条件下混凝土细观损伤演化机理的CT试验研究

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...

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

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.