DYNAMIC PROPERTEIES AND ITS CONSTITUTIVE MODEL OF STEEL FIBER REINFORCED HIGH-STRENGTH MORTAR UNDER TRIAXIAL RAPID COMPRESSIVE LOADS

To assess the application of steel fiber reinforced high-strength concrete with compressive strength of over 100 (N/mm2) in RC structures subjected to impact/impulsive loads, the dynamic mechanical properties of steel fiber reinforced high-strength concrete under high strain-rates and triaxial stress states are essential. Thus, this study is to investigate the behavior of steel fiber reinforced high-strength mortar subjected to high strain-rates and triaxial stresses. The volume fraction of steel fibers, the confining pressure and the loading rate are chosen as test parameters. From test results, the effects of these parameters on the mechanical properties of steel fiber reinforced high-strength mortar are examined. Furthermore, based on the concept of the equivalent uniaxial strain, the orthotropic constitutive model with the strain-rate effects is proposed.