Dynamic Mechanics and Damage Evolution Characteristics of Rubber Cement Mortar under Different Curing Humidity Levels

Abstract

The dynamic compressive test of rubber cement mortar (RCM) under two different curing humidity levels (the relative humidity was 95% and 50%, respectively) was carried out by using a split Hopkinson pressure bar (SHPB) device, and the dynamic mechanics and damage evolution characteristics of RCM were studied. The results show that the impact resistance of cement mortar is obviously improved by adding rubber particles and is decreased by reducing the curing humidity. The stress-strain curve of the RCM has a transverse fluctuation in the top region, which reflects the excellent ductility and toughness of the RCM. Both dynamic peak stress and dynamic increase factor (DIF) have a linear positive correlation with strain rates, and the DIF is reduced due to the decrease in curing humidity. A damage analysis was carried out, and the reduction of curing humidity and the incorporation of rubber particles increased the damage variable D and significantly changed the dynamic damage evolution process of the cement mortar. Finally, the blasting disturbance and the surrounding rock stability were analyzed along with the material properties and underground engineering issues. Therefore, this engineering application analysis demonstrated that the rubber cement-based materials have a prospective application.