Modelling the out-of-plane behaviour of masonry walls retrofitted with engineered cementitious composites

The out-of-plane behaviour of masonry infill walls retrofitted using engineered cementitious composites (ECC) is investigated numerically in this paper. The behaviour of beam-like masonry specimens, considered to provide a simplistic representation of masonry infill walls, subjected to static four-point bending testing is investigated numerically through the use of nonlinear finite element analysis. The specimens are strengthened using a thin layer of ECC which is fully or partially bonded to their lower face (acting in tension). The numerical predictions obtained are validated against relevant test data and are used to provide insight into the mechanics through which the ECC layer enhances the out-of-plane behaviour of the subject specimens in terms of strength, stiffness and deflection. It was found that the specimens retrofitted with a partially bonded ECC layer exhibit more ductile behaviour (deflection) compared to those retrofitted with a fully-bonded ECC layer (the latter exhibiting higher load-carrying capacities). Finally, the validated models are employed to carry out a parametric study to investigate the effect of different design parameters, associated mainly with the properties of the materials used, on the behaviour of the specimens considered.