关键词: 混凝土, 动态劈拉试验, 声发射, 加载速率, 本构模型

Abstract: To research the dynamic mechanical properties of concrete in tension, splitting tensile tests were performed on concrete under different strain rates(10^-5/s, 10^-4/s, 10^-3/s, 10^-2/s) using nondestructive acoustic emission technology. According to the real-time acquired acoustic emission data, the corresponding relation between acoustic emission parameter and stress-time curves under different loading rates were established, and the characteristics and regularities of concrete’s energy release in the whole process of splitting tensile damage were analysed. Results showed that typical characteristics of three phase did not happen in the process of splitting tensile damage, emission signal was weak at the early stage of loading, and energy signal suddenly rose sharply when the concrete material reached peak stress. The acquired acoustic emission data could reflect the real splitting tensile damage of concrete.

Key words: concrete, dynamic splitting tensile test, acoustic emission, loading rate, constitutive model