Debonding Detection in Reinforced Concrete Beams with the Use of Guided Wave Propagation

One of the most frequent damage of the reinforced concrete structures is debonding between steel bar and concrete cover. In the case of debonding occurrence not only the strength of the structure decreases, but also it is more vulnerable to corrosion damages. For this reason fast and effective methods of debonding detection in an early stage of its development need a significant boost. The paper presents analytical and experimental investigation of debonding detection in reinforced concrete beams using non-destructive method based on guided waves propagation. Concrete beams of rectangular cross-section consisting of four steel rebars with pre-existing debonding are investigated. Lack of adhesive connection between one rod and concrete cover is provided by introducing cellophane film of a small thickness (90 μm). The research is focused on detection of debonding with variable length on the basis of time-domain signals captured by piezoelectric sensors. Presented method of damage detection takes advantage of the time of flight of the reflections registered at the ends of the specimens.