Experimental investigation on dynamic properties of ultra-high-performance rubberized concrete (UHPRuC)

This study developed ultra-high-performance rubberized concrete (UHPRuC) incorporating different volume fractions of rubber powder and 2% by volume of steel fibres. The quasi-static and dynamic compression characteristics of the UHPRuC were examined by using a universal testing machine and a Split-Hopkinson Pressure Bar (SHPB) equipment, respectively. The quasi-static results indicated that the compressive strength of the UHPRuC reduced from 136.1 MPa to 67.8 MPa when increasing rubber contents from 0% to 40%, due to the weak interfacial transition zone of rubber and cement. It was also found that the percentage of strength reduction of the UHPRuC was less than that of the high strength rubberized concrete (HSRuC) and normal strength rubberized concrete (NSRuC) for the same rubber content, demonstrating the combination of UHPC and rubber powder could provide acceptable compressive strength than other rubberized concrete. The SHPB test results indicated that the dynamic compressive strength and energy absorption of the UHPRuC were sensitive to strain rate, and the sensitivity increased with the rubber content. Finally, the empirical formulae were proposed based on the testing results to predict the dynamic increase factor (DIF) of the compressive strength of the UHPRuC with different rubber contents.