循环孔隙水压力作用对混凝土动态抗压特性的影响

为研究混凝土在经历循环孔隙水压力后的力学性能,利用10 MN大型多功能液压伺服静动力三轴仪,进行了常规三轴混凝土动静力加载试验,采用Weibull-Lognormal模型和规范推荐的模型对应力-应变全曲线进行拟合对比分析。试验结果表明:经历循环孔隙水压作用后,在准静态和低应变速率下,混凝土强度明显减少,在高应变速率下,混凝土强度增加;较高加载速率对混凝土峰值应变影响较小,随着加载速率的增加,混凝土的峰值应变有增大的趋势;与未经历循环孔隙水压力相比,经历循环孔隙水压力的混凝土弹性模量有所提高,且弹性模量随着循环孔隙水压力的增加总体呈现增大趋势;采用的Weibull-Lognormal模型和规范推荐的模型对混凝土应力-应变全曲线拟合效果较好,在下降段,Weibull-Lognormal模型拟合效果比规范推荐的模型好

Dynamic Compressive Behavior of Concrete under Cyclic Pore Water Pressure

The mechanical properties of concrete subjected to cyclic pore water pressure are studied via dynamic and static triaxial loading tests using 10 MN large multifunctional hydraulic servo instrument. Weibull-Lognormal model and standard-recommended model were used to fit and analyze the stress-strain curves. Test results revealed that in the presence of cyclic pore water pressure, concrete strength decreased apparently under quasi-static and low strain rate loading, while augmented under high strain rate. However, higher loading rate had little effect on the peak strain of concrete. With the increase of loading rate, the peak strain of concrete increased. The elastic modulus of concrete undergone cyclic pore water pressure was higher than that in the absence of cyclic pore water pressure. In the meantime, with the climbing of strain rate, elastic modulus increased also. The full stress-strain curve of concrete can be well fitted by using Weibull-Lognormal model and standard-recommended model, of which the former has better fitting effect in descending segment than the latter does