Reinforced concrete members under drop-weight impacts

Abstract

This paper describes a series of experimental studies to investigate the high-mass, low-velocity impact behaviour of reinforced concrete members including beams and slabs, and to provide high-quality input data and results to validate numerical modelling. Fourteen 2·7 m and four 1·5 m span beams, four 0·8 m square 76 mm thick and two 2·3 m square 150 mm thick slabs were tested under impact loads using a drop-weight facility. Measurements included transient impact loads, accelerations and strains in the steel reinforcement. Additionally the impact events were recorded using a high-speed video camera operated at up to 4500 frames per second. For the beam tests, the local failure pattern of a beam under the impact zone was examined by correlating the images of development of cracks, spalling and scabbing with the impact load history. For the slab tests, the imposed energy on a slab was compared with the minimum energy causing the slab to scab, which was predicted using empirical formulae. The investigations enabled a better understanding of the behaviour of reinforced concrete members subject to impact loads.