中文摘要：

混凝土结构在使用过程中均会受到动态荷载作用,混凝土的动态力学特性与静态情况下有很大的不同。应用MTS试验机,对C45混凝土在应变速率为10-5~10-2 s-1范围内进行单轴动态拉伸试验,全面系统的介绍了混凝土动态受拉试验设备和试验方法。系统研究了不同应变速率下混凝土的抗拉强度、弹性模量、峰值应变等抗拉力学特性,并给出了不同应变速率下混凝土抗拉强度、弹性模量的计算公式。试验结果表明：混凝土抗拉强度、峰值应变随着应变速率的增加而增加,泊松比离散性比较大,增加趋势不明显。这些成果可以为混凝土结构的动态设计提供一定的理论基础和技术参数。

英文摘要：

Concrete structures unevitably are subjected to dynamic loads.The mechanical properties of concrete under dynamic loads differ from that under static loads greatly.Dynamic direct tensile tests of concrete specimens（C45） are carried out on MTS,with the uniaxial strain rate ranging from 10-5 s-1 to 10-2 s-1.Test equipment and test method under dynamic loads are introduced.The tensile properties of concrete under different stain rates,which include tensile strength,elastic modulus and peak strain,are studied systematically.The formulas which can describe the change law of the tensile strength and elastic modulus of concrete under different the strain rates are proposed.The test results show that the tensile strength,elastic modulus and peak strain of concrete would increase with the strain rate increasing.The discreteness of Poisson＇s ratio is larger.And it has not obviously increasing trend with the strain rate increasing.The stress-strain curves under dynamic tensile loads is similar as that under static loads.These research achievements can provide us with some technical parameters and theoretical basis for the dynamic design of concrete structure.