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 high-strength 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 E-HSC 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.
Read full abstract