Failure behaviors of reinforced concrete beams subjected to high impact loading

• Impact loads, mid-span deflections, crack profiles and strains were obtained.
• There existed a certain threshold velocity of the maximum load capacity of beams.
• The maximum and residual deflections were almost proportional to the impact energy.
• Based on test data, two empirical formulas were proposed.
• The two equations were in good agreement with the additional experimental results.

To attain a better understanding of the failure behavior of reinforced concrete (RC) beams under impact load, series of high speed impact experiments were performed using an instrumented drop-weight impact machine. The test program was successful in providing a substantial volume of test data including impact loads, mid-span deflections, crack profiles and strains. These data was analyzed, focusing on the impact load characteristics and the impact behaviors of RC beams. Various characteristic values and their relationships were investigated such as the drop height, the static flexural load-carrying capacity, the input impact energy and the beam response values. Two empirical formulas were proposed to estimate the maximum and residual deflection of the beam based on the static flexural load-carrying capacity and the input impact energy. The applicability of the proposed equations was confirmed by comparison with the experimental results obtained by other researchers.