Shear bond of composites-to-brick applied with highly deformable, in relation to resin epoxy, interface materials

The paper presents comparison of a work of stiff and flexible bonds fastening composite strengthening to masonry. In the first approach (traditional), barely deformable interface material made of stiff epoxy resin is used as shear bonds of composites-to-brick. In the second one (innovative), highly deformable interface material made of flexible polymer is used as repair shear bonds of composites-to-brick. Behavior of both materials was compared using single-lap shear tests made on four kinds of fiber fabrics (glass, carbon, basalt and steel) applied to clay brick units. The results indicated that highly deformable interface materials allow increasing load capacity, because deformable adhesive layers reduce shear stress concentrations in bond, redistributing stress more evenly along the whole lap joint. Usefulness of the theory which allows calculating the bond shear stress-slip characteristic was also discussed in accordance to the highly deformable interface materials.