Flexural behaviour of FRP strengthened brick cavity walls

Abstract

The seismic vulnerability of unreinforced masonry (URM) walls to out-of-plane loading is widely acknowledged. Much research has been undertaken to develop practical techniques to provide ade-quate flexural strength for these URM walls which are often an integral part of the gravity load resisting struc-ture. In solid URM walls, the surface treatments that provide tensile capacity to the wall have been shown to be very effective flexural retrofit techniques. Cavity wall construction, on the other hand, has received little attention and surface treatments are not possible to the inner faces of the two leaves of construction. This pa-per presents the results of preliminary tests of two techniques with the aim of enabling near surface mounted FRP reinforcement on the external faces of unreinforced clay brick cavity walls to work under full reverse cy-clic loading. In these experiments, one system used expanding foam in the cavity to maintain the cavity di-mension and prevent the cavity ties from buckling under compression forces and the second system investi-gated the use of heavier duty metal connecters that could withstand the compression forces without buckling.