Improvement of debonding strength with consideration of adhesive layer property and its FEM analysis

Abstract

Adhesive resin is the important material to bond the strengthening material with concrete substrate and transfers the force between two materials. Adhesive layer plays a major role for debonding strength. This study attempts to find a way to enhance debonding strength through investigating the influence of adhesive layer property, such as thickness and inclusion of FRP sheet on the bond behavior between UFC and ordinary concrete (for concrete cohesion failure), and the bond between steel and steel (for adhesive layer failure) under direct shear test by using nonlinear finite element analysis. The results indicate that adhesive thickness strongly affect the debonding strength. However, FRP sheet inserted to adhesive layer shows small effect on the debonding strength.