Cyclic shear behaviour of masonry triplets with rubber joints

This paper presents the outcomes of an extensive experimental campaign and of numerical analyses aimed at characterising the cyclic shear behaviour of masonry triplets with mortar-rubber joints under both monotonic and cyclic loading. These joints consist of rubber strips placed between two mortar layers with the aim of enhancing the flexibility of masonry components while providing some auxiliary energy dissipation. The main application of the rubber joints is for enhancing the performance of masonry-infilled reinforced concrete frames under both in-plane and out-of-plane loading, thanks to a reduced interaction between the infill panels and the frame. Although past tests have investigated the behaviour of multi-layer flexible joints, no in-depth study has been carried out to date on the hysteretic and dissipative properties of mortar-rubber joints. In order to fill this gap, a series of experimental tests were conducted at the University of Strathclyde to characterise the mechanical behaviour of the various components of the rubber-masonry triplets as well as the behaviour of the composite system, with particular focus on the cyclic shear response and the bond strength. The hysteretic responses of the triplets obtained from the experiments are simulated using a micro-modelling strategy developed in Abaqus. The study results are useful for informing modelling strategies for the design and analysis of rubber joints, and for the selection of the most suitable mechanical and geometrical properties of these seismic protection devices.