Dynamic compressive behavior of environmentally friendly high-strength concrete: Experimental investigation and modelling

In this study, the mechanical properties of rubber powder and recycled steel fiber made from waste tires as fine aggregate and reinforced fiber of environmentally friendly high strength concrete (E-HSC) were investigated, especially the dynamic response of E-HSC under dynamic loading. The failure mode, stress-strain curve and energy dissipation capacity of E-HSC were investigated with different rubber powder replacement rates (0%, 5%, 20%, 35%, 50%) and different RSF volume fractions (1%, 2%, 3%) by using a separated Hopkinson pressure bar with a diameter of 100 mm. Additionally, the environmental benefits of E-HSC were assessed through carbon emission evaluation. Results indicated that rubber powder and RSFs enhanced the compressive ductility of highstrength concrete. With an increase in the ratio of rubber powder replacement, the static compressive strength of E-HSC decreased, the strain rate sensitivity of E-HSC significantly increased, while the dynamic toughness of EHSC was notably improved. The failure modes of E-HSC under impact loading changed with increasing rubber content, showing an increase in crack quantity and severity of fragmentation. The influence of RSF content on the strain rate sensitivity of E-HSC's dynamic failure mode and toughness were not significant. A viscoelastic correction model considering impact damage was proposed, which can effectively describe the stress-strain behavior of E-HSC under impact loading across various strain rates. Furthermore, E-HSC demonstrated lower carbon emission indicators compared to traditional high-strength concrete.