A concrete-steel interface element for damage detection of reinforced concrete structures

The interface between concrete and steel in reinforced concrete governs the interaction between the two types of materials under loading. When the interface is seriously damaged, e.g. when a macro-crack is formed, de-bonding takes place with large slip, and the load-transferring capacity of the interface will drop dramatically. In this study, a damaged reinforced concrete beam finite element based on the constitutive law of the lumped model on the concrete–steel interface is developed. Scalar damage parameters characterizing changes in the interface are incorporated into the formulation of the finite element that is used in the damage identification procedure from static responses. Numerical simulations show that the method is effective to detect failure at the interface between concrete and steel bar in the reinforced concrete beam.