A new model for adhesive shear stress in damaged RC cantilever beam strengthened by composite plate taking into account the effect of creep and shrinkage

Abstract

In this paper, a closed-form solution for interfacial stresses in reinforced concrete damaged cantilever beam strengthened by bonded composite plate including the effect of the adherent shear deformations, the creep and shrinkage effect is presented. In such plated beams, tensile forces develop in the bonded plate, and these have to be transferred to the original beam via interfacial shear stresses. Consequently, debonding failure may occur at the plate ends due to a combination of high shear interfacial stress. The analysis is based on the deformation compatibility approach where the shear stress is assumed to be invariant across the adhesive layer thickness. In this study, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both the concrete beam and the bonded plate. The influence of creep and shrinkage effect relative to the time of the casting, and the time of the loading of the RC damaged cantilever beams is taken into account. Numerical results from the present analysis are presented both to demonstrate the advantages of the present solution over existing ones and to illustrate the main characteristics of interfacial stress distributions.