PREDICTING THE UNIAXIAL COMPRESSIVE CAPACITY OF NON-STRENGTHENED AND FRP-STRENGTHENED MASONRY COLUMNS USING A FAST NUMERICAL APPROACH

The work addresses the retrofitting of masonry columns through jacketing with polymeric-based composites. The presented numerical procedure assumes a strain-based incremental formulation relying on equilibrium, compatibility, and kinematic equations and precluding a strenuous integration required by a Finite Element approach. The strength domain of brick units and mortar joints is bounded by a multi-surface yield criteria: Mohr-Coulomb criteria in shear, a compression cap and a Rankine tension cut-off. Failure of the FRP is governed by limited tensile strength. A brittle response is considered for the system constituents, with exception for mortar joints in which an elasto-plastic response with limited ductility is assumed. The numerical strategy is validated with data from several experimental campaigns, but also compared with existing approaches from literature and code-based formulas. A good agreement has been found and the main purpose achieved, i.e. to develop a strategy that is accurate and fast.