Experimental Investigation on Dynamic Compressive Properties of Phosphogypsum-Based Concretes

In this study, hemihydric phosphogypsum (HPG) was used to partially replace cement to prepare phosphogypsum-based concrete (PGBC). A split-Hopkinson pressure bar (SHPB) system was used to perform dynamic compression tests on PGBC in the strain rate range from 136 s−1 to 432 s−1. The effects of the strain rate on the dynamic compressive performances, impact toughness, and failure modes of the PGBC with different HPG replacement rates (30%, 35%, 40%, 45%, and 50%) were quantitatively discussed. The results showed that, like plain concrete, PGBC exhibited a significant strain rate effect and its dynamic compressive mechanical properties increased with the increase in the strain rate. The dynamic compressive mechanical properties of concrete were weakened by HPG replacement, but the strain rate sensitivity of concrete was improved when HPG was replaced. The dynamic compressive strength and dynamic modulus of elasticity of the PGBC approximately followed a trend of first increasing and then decreasing with the increase in the HPG replacement rate.