Dynamic compressive and splitting tensile response of unsaturated polyester polymer concrete material at different curing ages

The present study performed quasi-static and dynamic compressive and splitting tensile tests on unsaturated polyester polymer concrete (UPPC) at four different curing ages (6 h, 3 days, 7 days, and 28 days). We examined a total of 136 specimens, specifically 24 cubic specimens and 12 cylindrical specimens for quasi-static tests and 45 cylinders and 55 FBD specimens for dynamic compressive and tensile tests, respectively. The experimental results indicated that UPPC exhibited rapid strength enhancement in the early stages of curing, and the natural curing condition-treated cubic specimens exhibited 6-h compressive and splitting tensile strengths of 40 MPa and 6.5 MPa, respectively, which was almost the 50-60% of the 28-day strengths. The UPPC is also sensitive to the strain rate, such that both the compressive and splitting tensile strengths exhibited significant increases following an increase in the strain rate. Conversely, the strain rate sensitivity decreased with the curing age. We deemed the CEB-FIP equation for normal cement concrete to be inadequate for estimating the strain rate sensitivity of UPPC.