Experimental and modeling study of dynamic mechanical properties of cement paste, mortar and concrete

摘要

Understanding the strain rate effects on cement-based materials are important for accurately modeling concrete structure damage to high-velocity impact and blast loads. This paper reports experimental results of the strain rate effect on paste, mortar and concrete. A pulse-shaped split Hopkinson pressure bar (SHPB) was employed to determine the dynamic compressive mechanical responses and failure behavior of paste, mortar and concrete under valid dynamic testing conditions. Quasi-static experiments were conducted to study material strain rate sensitivity. Strain rate sensitivity of the materials is measured in terms of the stress-strain curve, elastic modulus, compressive strength and critical strain at peak stress. Empirical relations of dynamic increase factor (DIF) for the material properties are derived and presented. A compressive constitutive model with strain rate and damage effects was modified to accurately describe the dynamic compressive stress-strain curves of the materials.