Effect of impact loading on residual flexural capacity of high-strength reinforced concrete beams

In this study, an experimental investigation is carried out on the dynamic response of high-strength full-scale reinforced concrete beams subjected to different impact energies. The rectangular cross-sectional dimensions of the tested high-strength RC beams were 250 mm × 400 mm. The impact tests were performed by dropping masses of 240, 360, and 480 kg from a height of 3 m. After the performances of the beams were assessed under impact, the residual capacities of the specimens in terms of strength and ductility were evaluated through static tests. These tests showed that the strengths of the specimens subjected to different magnitudes of impact were not affected considerably. This is because the specimens were designed to fail in flexure based on capacity design principles. However, the ductility capacities of the beams subjected to impact were significantly lower than that of the reference specimen, which was not subjected to impact before. In addition, it was also clearly assessed that the flexural stiffness of the specimens were remarkably reduced as a function of the magnitude of the impact experienced.