An experimental study on debonding of steel plates bonded to concrete in the presence of embedded shear connectors

Abstract

In the present paper the problem of brittle debonding between steel plates and concrete was experimentally investigated by means of single lap shear tests. New embedded adhesive and steel connectors were proposed to mitigate or delay debonding and to enhance bond strength at the concrete- steel interface. Strain gauges along 20 mm wide steel plates to measure longitudinal strains were used and the progressive debonding along the bonded length was followed. The experimental results showed that the interfacial bond strength between steel plates and concrete was increased remarkably when using these connectors. The investigation clarified that the steel connectors are more effective in increasing the shear bond strength, it also showed that increase the diameter of those connectors increase the interfacial shear stress and delay the debonding failure. Finally, a new simple and rational model was proposed based on the existing fracture mechanics analysis and experimental observations to predict the bond strength. The new model is believed to be suitable for practical application in design solutions of steelto-concrete bonded joints.