Damage evolution and fracture behavior of under-reinforced concrete beams using acoustic emission technique

In this study, an experimental work was carried to focus on damage evolution and fracture behavior of under-reinforced concrete beams by continuously monitoring using acoustic emission technique.Beams were of three different sizes with geometric similarity having single longitudinal reinforcement without stirrups.The specimens was tested in three point loading under CMOD control in the closed loop servo controlled hydraulic testing machine.The results of load, displacement, CMOD and strain in the steel are acquired in the data acquisition system.The results of acoustic emission such as location, hits, events, amplitude, absolute energy and time were also simultaneously stored in a computer during the testing.The results of acoustic emission such as spread of the events and its distribution within the beams help in understanding the fracture processes.They provide information regarding the sequence of mechanisms taking place such as micro-cracking, coalescing of microcracks to macrocracks, increased width of macro-cracking and final fracture in under-reinforced concrete beams..