考虑围压的混凝土损伤特性试验研究

为了研究水饱和状态混凝土在不同围压下(0、2、5、10 MPa)的损伤特性,对直径150mm、高300mm的圆柱体混凝土试件进行了三轴压缩试验,并定义损伤变量D,选用Weibull-Lognormal损伤本构模型分析了常三轴下不同水围压对混凝土损伤特性的影响。结果表明,0 MPa饱和水环境与干燥无水压下混凝土的损伤变量走势大致相同;应变为4×10-3时,损伤变化差值达到峰值;应变为7×10-3时,损伤达到同一水平为0.81;应变到达4×10-3之前,损伤变量的增长速率逐渐增大;应变在4×10-3~7×10-3之间时,损伤变量增长速率较大并基本恒定不变;应变超过7×10-3时,损伤变量增长速率逐渐减小。

Experimental Study on Damage Properties of Saturated Water Concrete under Hydraulic Pressure

The cylindrical concrete specimen which the diameter is 150 mm and the height is 300 mm is selected to do triaxial compression test so that the damage properties of water saturated concrete is studied under different confining pressures (0 MPa, 2 MPa, 5 MPa, 10 MPa). The damage variable D is defined. And then the impacts of different confining water pressure on the damage properties of concrete are analyzed by adopting Weibull and Lognormal damage constitutive model under constant triaxial compression. The results show that damage variable of concrete with saturated water under confining water pressure of 0 MPa is nearly the same change with dry concrete without confining water pressure; the change rate of damage variable increases with the strain before the strain reaches 4×10-3; when the strain is 7×10-3, it attains the same level and it is 0.81; when the strain is between 4×10-3-7×10-3, it becomes great and keeps stable; however, when the strain exceeds 7×10-3, it decreases gradually.