Stress-Strain Behavior and Statistical Continuous Damage Model of Cement Mortar under High Strain Rates

The effects of strain rate on the dynamic stress-strain behavior of cement mortar were investigated in split Hopkinson pressure bar (SHPB) tests; the resulting strain rates ranged from 20 to 280 s−1. A total of 39 specimens were subjected to static and dynamic axial compressive loadings. The results showed that cement mortar is a typical strain-rate dependent material. Both dynamic compressive strength and critical strain increased with strain-rate increases. However, there seemed to be no strain-rate effects on the initial elastic modulus of cement mortar. Based on the stress-strain curves of different strain rates, as well as the random statistical distribution hypothesis for strength, a dynamic damage constitutive model of cement model under compression was used. The relationships of the primary parameters for strain rate are also presented in this paper. The simulated stress-strain curves matched the experimental results well. The results showed that the strength of cement mortar obeyed a Weibull distribution.