水环境下混凝土动态抗压特性试验研究

Experimental Study on Dynamic Compressive Properties of Concrete under Water Environment

为了了解混凝土在水环境下的力学性能,采用300 mm×600 mm的圆柱体试件,在10 MN大型多功能液压伺服静动力三轴仪上进行不同应变速率(10^(-5)/s、10^(-3)/s、10^(-2)/s)下的饱和混凝土单轴压缩试验和循环孔隙水压预处理后的混凝土常三轴压缩试验,对比分析不同加载方式对混凝土基本力学参数与损伤破坏特性的影响,并基于水环境下的作用机理对试验现象作出解释,研究表明:相对于饱和单轴加载,常三轴作用下的混凝土峰值应力更高,峰值应变更大;围压作用下,随着孔隙水循环次数的增加,混凝土的峰值应力增大,循环孔隙水压作用对混凝土的率敏感性具有促进作用;不同加载方式的损伤组合图中,单轴作用下,混凝土损伤路径最短,损伤变量的增加速度最快;常三轴作用下,不同循环孔隙水压作用下混凝土的损伤路径由于应变速率的提高发生了变化。

In order to study the mechanical properties of concrete in water environment, uniaxial compression test and triaxial compression tests of concrete with size φ300 mm × 600 mm in different cycles of pore water pressure was carried out under different strain rates （ 10-5/s, 10-3/s, 10-2/s）. The effects of different loading modes on mechanical parameters and damage characteristics of concrete were analyzed. The experimental phenomena was explained based on the action mechanism of concrete in the water environment. The research shows that： the peak stress and peak strain under triaxial compression test are higher than uniaxial compression test of saturated concrete. Cyclic pore water pressure has a promoting effect on the rate sensitivity of concrete. The damage distance is the shortest, and the increase of damage variable is the fastest under uniaxial compression test. The damage path of concrete has changed due to the increase of strain rate under different cyclic pore water pressure.