Response of high-strength reinforced concrete beams under shock-tube induced blast loading

This paper presents the results of study examining the blast performance of reinforced concrete beams constructed with high-strength concrete (HSC). As part of the experimental program, a series of five beams are tested under simulated blast loading using a high-capacity shock-tube at the University of Ottawa. Parameters investigated include the effect of concrete strength, shear reinforcement and longitudinal reinforcement ratio. The effect of loading rate is investigated by testing a companion set of five beams with identical properties under slowly applied (quasi-static) loading. The results show that increasing the reinforcement ratio improves the blast performance of HSC beams by increasing overall blast capacity and reducing maximum and residual displacements at equivalent blast loads. The effect of concrete strength on blast performance is found to be more limited, with companion normal-strength and high-strength concrete beams showing similar performance. The results also confirm the importance of providing transverse reinforcement to prevent blast-induced shear failures in HSC beams. As part of the analytical study, the blast response of the HSC beams is predicted using dynamic inelastic single-degree-of-freedom (SDOF) analysis.