IN-PLANE STRENGTH OF MASONRY PANELS REINFORCED WITH INORGANIC-BASED SISTEMS: NOVEL DESIGN-ORIENTED FORMULAS

In case of masonry walls, effectively connected each other and/or to the horizontal diaphragm, a common failure is the in-plane diagonal cracking due to the seismic action. The plastering by means of new material is commonly adopted in order to improve the shear strength of the masonry, which is generally poor because of the negligible tensile strength in the mortar joints. Among the other, the use of composite systems was largely considered in the last decades. Firstly, the Fiber Reinforced Polymers (namely FRPs) were experienced and, later, the Inorganic Mortar Composites (namely IMCs) were growingly well-thought-out as a valid alternative. In fact, IMC demonstrates an improved compatibility with the historical masonry with respect to the FRP, mainly from the breathability point of view. The larger knowledge of the FRP-behavior produced many analytical models able to accurately predict the shear strength gain provided by the reinforcement. On the other side, the current stateof-knowledge regarding the IMC is more limited. In fact, Fabric Reinforced Cementitious Mortar (i.e. FRCM) and Composite Reinforced Mortar (i.e. CRM) are both in the IMC-family. The former involves a dry- while the latter a pre-impregnated fabric within an inorganic matrix. The available analytical models, forecasting the IMC shear capacity, are essentially based on the FRP’s theory. For this reason, the present research aims to propose new design-oriented empirical formulas calibrated with an available dataset of IMC-shear-wall experimental results. The novelty consists in the definition of the contribution of the strengthening mortar with respect to the masonry shear strength gain.