Bond of GFRP strips on modern and historic brickwork masonry.

External bonding strengthening (EBS) of masonry walls with fibre reinforced polymers (FRPs) has become a common technique to improve the mechanical capacity of masonry. In particular, glass fibre reinforced polymer (GFRP) strips are usually adopted as EBS to improve shear capacity under in-plane loading of historic masonry walls in monumental buildings located in seismic areas. Reliability of bond between FRPs and the surface of brickwork walls is condition of adequate strengthening; delamination of FRPs on masonry surface is the mechanism that leads to loss of shear capacity of walls. In this paper the results of an investigation on the bond between GFRP strips and masonry surface both with modern and historic brickwork masonry are presented. Pull–push shear tests on bonded GFRP-to-brickwork masonry wallets were carried out considering the effects of mortar bed joints having different thicknesses. The experimental results indicated brittle failure due to delamination of GFRP strips; results were processed to evaluate failure load values, strain vs anchorage length diagrams, shear stress vs slip relationships experimentally and, energy fracture values. Finally, experimental results are compared with theoretical data obtained from theoretical models. [ABSTRACT FROM AUTHOR]