Effects of crumb rubber particles on the dynamic response of reinforced concrete beams subjected to blast loads

Abstract

Crumb rubber particles (RPs) can improve the impact resistance of concrete structures owing to their high toughness. In the current paper, the dynamic behaviours of RPs reinforced concrete beams under blast loads were investigated. The near-field explosion tests were first performed on the rubber-modified reinforced concrete (RRC) beams with different content of RPs (0%, 10%, 20%, 30%, and 50%). Numerical simulations based on the ConWep, Karagozian and Case concrete (KCC) models were then used to analysis the deformation/failure mechanisms of RRC beams. Finally, an improved single-degree-of-freedom (SDOF) method was proposed to predict the dynamic deflection of RRC beams. The experimental results indicated that the crack patterns of the RRC beams changed from bending cracks to shear–bending cracks as the scaled distance decreased. When the blast load had a small scaled distance (0.234 m/kg1/3), the number of cracks decreased with increased rubber content, particularly shear cracks. The numerical simulation revealed that due to the low damping ratio of RRC beams, the vibration amplitude of the RRC beams was lower than that of the beams without RPs. It is believed that the current study can provide valuable insights into the key factors for designing the blast resistance of RPs reinforced concrete structures.