Impact Performance of RC Beams Reinforced by Engineered Cementitious Composite

Abstract

To mitigate potential damage to RC structures subjected to impact load—especially spalling damage—engineered cementitious composite (ECC) is applied, with the aim of reinforcing the RC members, so as to improve their impact performance. In the present study, the response of beams, with and without ECC reinforcement, to impact loading was investigated. Firstly, the mechanical properties of the ECC were characterized by quasi-static compression and tension tests, as well as by dynamic direct tension tests. Then, the K&C model (Karagozian and Case Concrete Model) was employed to delineate the ECC behavior, whose parameters were calibrated using the test data. Subsequently, models of RC beams with and without ECC reinforcement, validated using the drop weight test, were established to investigate the impact response. The numerical results suggested that the performance of the impact resistance of the ECC-reinforced RC beams was significantly improved. The damage degree of the ECC-reinforced members was effectively reduced, the degree of deformation was effectively controlled, and the energy consumption capacity was significantly increased while the impact load and transferred load increased. In particular, the method of multiple separate layers as reinforcement, proposed in this study, was found to reduce effectively the response and damage extent, improve the energy dissipation, and control the impact load and transferred load within certain levels. In addition, the multiple separate ECC layers effectively prevented the crack propagation caused by the cracking of the member, ensured the residual integrity of the member, and further improved the performance of the impact resistance of the member comprehensively.