Experimental study of biaxial compressive damage behaviour of concrete at different strain rates

摘要

Reported herein are the results of biaxial dynamic compressive tests on plain concrete specimensnthat were carried out on a static–dynamic triaxial test system, with strain rates ranging from 10–5nton10–2ns–1n. The effects of strain rate on dynamic strain–strain curves, dynamic compressivenstrengths, initial elastic moduli and critical strains of concrete are studied. Test resultsndemonstrate that the biaxial compressive strength and the initial tangent modulus of concretenincrease with increasing strain rate, but the critical strain of concrete decreases with increasingnstrain rate. Also, the effects of strain rate on the damage threshold stress and strain of concretenare studied. On the stress space, the damage threshold stress of concrete increases with thenincrease in strain rate, while its ratio to the ultimate strength is independent of the strain rate. Onnthe strain space, the damage threshold strain of concrete and its ratio to the critical strain arenindependent of the strain rate.