Monitoring Corrosion-Induced Cracks in Concrete by Acoustic Emission

Concrete structures suffer from the corrosion of reinforcing steel-bars due to severe environments, in particular, chloride attack. Acoustic Emission (AE) techniques have been extensively applied to concrete and concrete structures. In order to identify the onset of corrosion and the nucleation of concrete cracking due to expansion of corrosion products, continuous AE monitoring is available. These corrosion-induced cracks in concrete are studies in an accelerated corrosion test, where kinematics of micro-cracks is identified by SiGMA (Simplified Green's functions for Moment tensor Analysis). Monitoring the corrosion process of rebar by AE, it is confirmed that the onset of corrosion and the nucleation of corrosion-induced cracks in concrete are successfully identified. Then, generating mechanisms of corrosion-induced cracks are clarified by the SiGMA analysis.