Influence of high strain rates on stress-strain relationship, strength and elastic modulus of concrete

摘要

Earlier papers showed a method for strength evaluation at high strain rate from the results of static tests, and a method for evaluating modulus of elasticity at static loading from tests based on stress-wave propagation. This paper presents new results on the influence of high strain rates on the stress-strain relationship, strength and modulus of elasticity using the thermofluctuation theory, principle of accumulation and development damages as well as nonlinear behavior of concrete under loading. Obtained equations explain and unify the influence of high rates on the mechanical properties of concrete for different kinds of uniaxial stress. Comparative study showed again substantial agreement with existing experimental results and general equations by the Comite Euro-International du Beton (CEB) Model Code. The developed approach diminishes the labor expenses for tests of concrete under high rates of loading.