Experimental quasi-static out-of-plane test of a U-shaped brick masonry wall

Past earthquakes demonstrated the vulnerability of brick masonry facade walls even against moderate earth-quakes. The present work aims at providing an insight into the out-of-plane response of clay brick masonry walls, especially focusing on a traditional Portuguese building typology, namely the 'placa', towards a correct inter-pretation and assessment of their seismic behaviour. A thorough experimental campaign in laboratory envi-ronment was conducted, including material characterisation through destructive and non-destructive techniques and the quasi-static test with airbag on a U-shaped clay brick masonry specimen. Main experimental results are discussed with specific attention to the analysis of the masonry wall cyclic response, the damage pattern, the seismic performance, and the evolution of the modal parameters at distinct stages of the test. The material characterisation demonstrates the low mechanical properties of the masonry associated with such buildings. The specimen presents a stiff and almost linear behaviour until the peak, followed by an initial softening until about 60% of the peak. The damage pattern evidences a failure governed by an out-of-plane rotation combined with shear sliding.