Modelling of in-plane strengthening of unreinforced masonry buildings: a numerical comparison between traditional and FRCM jacketing

The in-plane seismic strengthening of masonry walls often resorts to the jacketing technique; over time steel rebar and shotcrete systems (SRC) have been replaced by fibre reinforced material and cementitious mortars (FRCMs). Equivalent frame models (EFMs) are a viable option for the assessment of existing masonry buildings and estimating the effects of the strengthening. The paper proposes a numerical evaluation of the effect on seismic capacity of SRC and FRCM jacketing as a function of the modelling strategy (equivalent coefficient or modification of the nonlinear behaviour) and the scale of the problem, from a single wall to a simple masonry building. The analytical strength domains of the wall are compared to the results of pushover analyses in a FME model showing a different seismic behaviour at low and high vertical loads. At the building scale, pushover curves show strength and ductility increments which are comparable to the changes in the nonlinear behaviour of the walls induced by the strengthening, as observed in the analytical domains; the results are compared to the available literature.