Design of the shear strengthening of masonry walls with fabric reinforced cementitious matrix

Fabric reinforced cementitious matrix (FRCM) composites are widely used for retrofitting existing structures, especially in earthquake prone areas. After nearly two decades of scientific studies, experimental evidence proves their effectiveness for enhancing the ultimate strength and displacement capacity of masonry walls. There remains a need to develop design guidelines for use in rehabilitation practice. This paper proposes a method for the design of the shear strengthening of masonry walls with FRCM, and provides the calibration of the partial coefficients for the calculation of the ultimate limit state. The design relationships are validated on the basis of an experimental database that includes 72 tests and are suitable for engineering purposes. The possibility of applying the same design format to the walls strengthened with composite reinforced mortar (CRM) is investigated, by considering 54 additional tests and comparing to FRCM retrofitted ones. Finally, the enhancement of displacement capacity achieved with FRCM and CRM, which is particularly useful for seismic retrofitting, is estimated, and a design value for the ultimate drift capacity is provided.