In-plane and out-of-plane structural performance of fully grouted reinforced masonry walls with varying reinforcement ratio – A numerical study

Most international masonry design standards include the contribution of reinforcements to enhance the capacity of reinforced masonry walls subject to seismic loading. As masonry is brittle, it can potentially fail before the reinforcing bars yield, especially in closely spaced reinforced masonry walls. The assumption that these bars yield at the ultimate load could, therefore, result in an unrealistic over-prediction of the flexural and shear capacities of the walls. This paper presents a detailed investigation of several fully grouted reinforced masonry (FGRM) walls subject to in-plane and out-of-plane loading that is independent of each other. The analyses include the level of pre-compression and a wide range of reinforcement ratios. The assessment has been carried out through an explicit finite element (FE) model. Validation of the FE model is briefly presented and the structural performance, i.e., load capacity, lateral drift index, displacement ductility and stiffness of the FGRM walls are discussed in detail. The influence of reinforcement ratio on the yielding of reinforcing bars in the FGRM walls under in-plane and out-of-plane loading is also shown. It is found that the increase in reinforcement ratio beyond a critical limit degraded the structural performance of the FGRM walls and a suitable reinforcement ratio range is proposed.