The use of composite materials in rehabilitation of existing constructions is getting more and more common in Europe. Several experimental campaigns have been carried out for investigating the behaviour of masonry members strengthened by fibre-reinforced polymers (FRP) under static loads; a few investigations have been carried out in case of FRP strengthened masonry walls under in-plane cyclic loads. No widely accepted design rule is yet available for estimating the contributions of composite materials to the shear strength of the FRP strengthened walls and strong research effort in this area is needed.

The paper presents the experimental campaign conducted at the laboratory of the University of Salerno to investigate the cyclic response of clay brick masonry walls externally strengthened by FRP laminates. Eleven walls have been tested under in-plane cyclic shear-compression loads: three unreinforced walls and eight walls externally strengthened by Carbon-FRP strips.

In order to evaluate the contribution of the composite to the shear strength, various geometrical configurations of FRP strips have been applied according to horizontal, vertical, diagonal and grid patterns.

The aim of the experimental campaigns has been the evaluation of strength, ductility and energy dissipation connected to the examined geometrical configurations of FRP strengthening.