Fracture Formation Evaluation of Reinforced Concrete Beam Subjected to Cycle Loading Using Acoustic Emission Technique

Abstract

Acoustic emission (AE) technique is one of the non-destructive evaluation (NDE) techniques that have been considered as the prime candidate for structural health and damage monitoring in loaded structures. In present study, AE technique with a new approach was employed to investigate the process of fracture formation in reinforced concrete (RC) structure. Thirty RC beam specimens with continuous and non-continuous longitudinal rebar were prepared. The RC beams were tested under loading cycle and were simultaneously monitored using AE. The AE test data was analyzed using Relaxation, Load and Calm ratio. The trend of these methods during loading and unloading was compared with behaviour of each type of specimens. The trend of Relaxation ratio and Calm and Load ratio method during loading and unloading showed that these methods are strongly sensitive with cracks growth in RC beam specimens and were able to indicate the levels of damage. Also, results showed that AE can be considered as a viable method to predict the remaining service life of reinforced concrete. In addition, with respects to the results obtained from Relaxation, Load and Calm ratio indicated, a new chart is proposed.