Laboratory investigations on cracking in reinforced concrete beams using on-line acoustic emission monitoring technique

This article presents an experimental study on variation in acoustic emission (AE) parameters during cracking in reinforced concrete (RC) beams subjected to incremental cyclic loading in laboratory conditions. Nine RC beams with three different span-to-depth ratios ranging from 2.0 to 6.0 with a reinforcement ratio roughly kept the same (1.4-1.5 %) were tested under bending till failure and simultaneously the released AE was recorded. The criteria used to characterize the cracking in RC beams are based on the AE parameters. The AE parameters such as frequency, duration, amplitude, count, rise time, parameters depending on AE signatures such as b-value, and damage parameter D follow the fracture process during the entire loading. The results are useful to distinguish different cracks in RC beams and extend them for field applications. © 2013 Springer-Verlag Berlin Heidelberg.