水泥砂浆等脆性材料的力学性能与所受围压的大小密切相关。为了研究水泥砂浆在围压下的动态力学性能,研制了适于分立式Hopkinson压杆加载的主动围压装置,最大预加载主动围压大于30MPa。实验得到了水泥砂浆在不同围压、不同应变率下的轴向应力应变曲线,发现材料在围压作用下抗压强度和韧性大大提高并且整体进入了伪塑性,而材料的应变率效应也是显著的。
The behavior of quasi-brittle materials like cement mortar depends on the level of confinement. In order to study the dynamic behavior of cement mortar under active confinement, An device which fits the split Hopkinson bar loading was developed, and it provides the lateral confining pressure upper to 30 MPa. The axial stress-strain curves under various level of confinement and strain rate were derived according to the experiment. It shows that the strength and ductility increase significantly because of confinement, and finally turn into plasticity, also it is strain rate sensitive.