Strain Rate Effect on Impact Tensile Strength of Concretes by Method of Reflected Tensile Stress Waves

摘要

This paper is concerned with the tensile strength and strain rate of concrete materials by means of the experimental method of reflected tensile stress waves. The experiment is conducted by the Hopkinson bar technique and it is based on the superposition and concentration of tensile stress waves reflected both from the free ends of a striking bar and a specimen bar. The impact tensile experiment for concrete materials was carried out and the tensile strength of concrete under impact loadings was discussed as well as the effect of strain rates. This study focuses on the measurement of strain rates using both strain gages and crack gages. It is found that the impact tensile strength of concrete is remarkably influenced by strain rates ranging from 10{sup}0 to 10{sup}2 sec{sup}(-1).