Experimental study of the dynamic behavior of ordinary concrete under local compression

Abstract

Under different strain rates, in the service life, concrete structures commonly suffer the effect of local compression. In engineering practice, the failure of concrete is always caused by the cracking or insufficient strength induced by local compression area. To this end, this study aims to experimental study the dynamic behavior of ordinary concrete under local compression. The compressive tests on concrete at four different loading areas and five different loading rates were performed to obtain the failure patterns and stress-strain curves. Results showed that regardless of loading area and loading rate, the failure of lower-graded concrete is due to the bonding failure between cement colloid and coarse aggregate. However, the increasing loading rate can improve the peak stress around 1.14∼1.52 times, while has an insignificant effect on peak strain. Besides, the reduction in loading areas can increase the coefficient of peak stress and elastic modulus but linearly decreased the peak strain. Finally, the failure mechanism was further clarified by the local loading model of the constraint of concrete and the shear theory of concrete.