Experimental study and numerical simulation on damage assessment of reinforced concrete beams

Abstract

In order to study the dynamic response characteristics and damage effect of reinforced concrete beams in an adjacent physical field of explosion, in this study, three groups of nine 1:6 scale models of reinforced concrete beams are subjected to blast loads. All factors, such as the weight of explosive charge, distance from the model to the explosion center (including the contact explosion), and position of explosive charge are all considered. Thereafter, the pressures, displacements, accelerations, and strains are introduced at certain typically measured points to investigate the dynamic response characteristics as well as the local state of these models that have been subjected to the blast. And then, a monotonic loading test is conducted to assess the damage of these models. Finally, a series of numerical simulation analyses are conducted on the reinforced concrete beams that have been subjected to blast load. Results show that the damage index increases as the scaled distance decreases, and moreover, the models that have been subjected to the blasts from larger amount of explosive charges suffer extensive destruction; the models that have been exposed to the blasts from smaller amounts of explosive charges experience severe local damage. As the explosive charge is moved away from the mid-span to the beam column joints, the damage index in the reinforced concrete beam gradually decreases. The influence of different parameters (compressive strength of concrete, section size, longitudinal reinforcement ratio, and transverse reinforcement ratio) on the damage change law of reinforced concrete beams is different, and the failure mode of reinforced concrete beam is severely effected by the section sizes, particularly in the height of the beam. The results prove that the blast resistance of reinforced concrete beam is greatly affected by the column. Accordingly, the results of this study can be used as technological support and theoretical basis for engineering applications.