Reference-free determination of debonding length in reinforced concrete beams using guided wave propagation

This paper presents theoretical and experimental investigations of guided wave propagation in reinforced concrete beams, with pre-existing debonding between steel rebars and concrete blocks, for the purpose of damage detection. The primary aim of these investigations was a detailed analysis of the possible applications of wave propagation in single and multiple debonding detection in reinforced concrete structures and reference-free determination of their total length. Guided waves were excited and measured with the use of piezoelectric sensors in reinforced concrete beams with varying debonding lengths between steel rebars and concrete cover. The influence of damage on wave propagation velocity in both debonded and fully bonded rods was investigated. The effectiveness of the proposed debonding length determination method, which takes advantage of the fastest mode velocity in concrete specimen, was confirmed experimentally. (C) 2019 Elsevier Ltd. All rights reserved.