Acoustic emission characteristics of reinforced concrete beams with varying percentage of tension steel reinforcement under flexural loading

Reinforced concrete (RC) flanged beam specimens were tested under incremental cyclic load till failure in flexure. Simultaneously the acoustic emissions (AE) known as transient elastic stress waves released during fracture process in the same specimens were recorded. These RC flanged beam specimens were cast with different percentage of steel reinforcement (area of steel reinforcement as a percentage of the effective area of beam cross section). Crack widths depend on tensile stress in steel reinforcement present in a RC structural member. Because crack opening is a function of tensile stress in the steel rebars, the percentage of steel in the RC members influence the AE released during fracture process. In this article, a study on damage occurred in RC flanged beam specimens having \ndifferent percentage of steel reinforcement using acoustic emission testing is reported. A relation between the total AE energy released and percentage of steel in RC beams has been proposed. As the percentage of steel present in the test specimen was increased, the loading cycle number entering into the heavy damage zone in NDIS-2421 damage assessment chart also increased.