Experimental Investigation of Impact Behaviour of RC Slab with Different Reinforcement Ratios

Abstract

Reinforced concrete (RC) slabs may be exposed to the low-velocity impact load during their service periods. In low-velocity impact scenarios, the effect of strain rates has been remarkably higher than quasi-static loading because the loading duration is very short. Thus, structural responses and failure modes will be different. The present study aims to investigate dynamic response and failure modes of simply supported two-way RC slabs exposed to low-velocity impact load. In the experimental part of this study, nine RC slabs with the dimension of 1,000 × 1,000 × 80 mm were tested. The reinforcement ratio of RC slabs and the input impact energy applied to RC slabs were experimental variables investigated. A drop-weight test setup was utilized to apply impact load to RC slabs. By varying drop-height as 1,000, 1,250 and 1,500 mm, three different impact energies have been applied to RC slabs via a hammer of which weight is 84 kg. The time histories of the accelerations, displacements and impact loads were recorded. The dynamic responses obtained by tests and the failure modes observed has been interpreted in detail. Besides, a finite element model where explicit dynamic analysis is performed has been established for verification of the experimental results. There was observed good accordance between numerical and experimental results. Consequently, it is considered that the present finite element treatment can be used for the evaluation of the dynamic responses and failure modes of RC slabs exposed to low-velocity impact load. © 2019, Korean Society of Civil Engineers.