University of Kassel, Department of Structural Engineering, Kassel
André Rotzetter & Partner AG, Consulting Engineers, Baar/Zug


Post-strengthening of masonry structures with fiber-reinforced polymers (FRP) is important. To ensure load transfer between masonry surface and FRP the ultimate load and the failure mode of the interlock has to be predicted properly.
To consider the widespread variety of bricks and blocks overall 91 bonding tests were carried out with seven types of bricks and blocks. Two different types of adhesive were used in combination with four types of glass and carbon fibers. The main results of the tests will be presented.
Furthermore a mechanical model based on fracture energy was adopted. This model can be used to predict failure for bonding on single bricks as well as bonding geometries with more than one brick where bonding length is separated by bed joints or head joints.

Key words
post-strengthening, frp, debonding, fracture mechanics