Acoustic emission testing for multi-scale assessment of reinforcement corrosion in concrete structures

Abstract

Degradation of existing structures poses a serious threat to our built environment. The aim of this paper is to investigate the use of acoustic emission monitoring in degradation assessment of existing structures, focusing specifically on corrosion damage detection in reinforced concrete structures. Reinforcement corrosion is seen as one of the most significant and costly degradation mechanisms that impact the durability and structural safety of our built infrastructure and Modern heritage buildings. The paper presents a multi-scale experimental approach, from material to structure, focusing on two challenges: (i) monitoring the evolution of the corrosion process itself and the consequential concrete cracking during accelerated corrosion, and (ii) identifying the different AE sources in this complex process. The application of AE testing for rebar corrosion monitoring is investigated on various sample types and scales under accelerated conditions in a lab environment, and from on-site monitoring of a concrete girder bridge. Results show that the developed test setups, data filtering and processing procedures substantially improve AE-based corrosion damage monitoring, and provide a valuable contribution towards on-site application.