高应变率下混凝土动态拉伸性能的实验研究

Experimental Investigation on the Dynamic Tensile Behaviour of Concrete Under High Strain Rate

采用分离式Hopkinson压杆,利用圆柱体对径受压原理对直径为74 mm的混凝土试件进行了动态劈裂拉伸实验,得到了不同应变率下的混凝土动态劈裂抗拉强度。证实了混凝土动态拉伸性能的应变率敏感性,抗拉强度随着应变率的增加而增加;并发现了相应的临界应变率,大约是2s-1,当应变率超过它时,混凝土的抗拉强度会有一个较大比例的增加。同时对裂纹发生位置与扩展顺序及裂纹扩展速度进行了初步探讨。

In the present paper, experimental investigation on dynamic splitting tension is carried out by using SHPB to get dynamic tension strengths under different strain state of concrete, and the strain rate sensitivity on dynamic tension behaviour of concrete is proved. A critical strain rate is discovered. The position of crack, sequence and speed of crack propagation in the planar surface of a concrete cylinder are discussed briefly.