重点研究了混凝土材料静动强度的差异和动强度提高机理,认为混凝土类非均匀脆性材料的动强度与材料的非均匀程度和惯性力有关,且混凝土材料的动强度并非一个定值,而是随着加载应变率而变化的。三点抗折物理试验表明,混凝土材料动强度的提高主要受破坏骨料的面积大小和惯性力控制,骨料的破坏面积与加载应变率之间存在一定的函数关系,应变率较大时,惯性力的影响更为显著。
The paper focuses on the differences of the static and dynamic strength of concrete material,and the mechanism for enhancement of dynamic strength. This paper points out that the dynamic strength of heterogeneous brittle material like concrete is related to the inhomogeneous degree and inertia force. The dynamic strength is not a fixed value,but varies with the loading strain rate. Physical test shows that increasing of the dynamic strength of concrete materials mainly caused by the crack in the aggregate and the inertia force. A certain function relation is existed between the damage area of aggregate and the loading strain rate. The influence of inertia force is more significant when the strain rate is larger.