Modeling environmental ageing in masonry strengthened with composites

The effects of environmental ageing due to rising damp and salt crystallization on composite strengthening systems, e.g. fiber reinforced polymer (FRP) and fiber reinforced cementitious matrix (FRCM), bonded to masonry substrates are still scarcely known. Although few laboratory tests have been recently conducted to this aim, very limited information is available. In this paper, the simulation of accelerated weathering/ageing cycles of masonry strengthened with composites is proposed by means of a multiphase model which accounts for salt transport and crystallization. This multiphase model is implemented together with ad hoc boundary conditions and a restart analysis procedure which attempt to reproduce the repetition of weathering cycles (composed of a wetting phase in a saline solution and a drying phase in the oven). Laboratory accelerated weathering tests on masonry specimens strengthened with lime mortar-based FRCM are numerically reproduced. Additional information on the salt crystallization process within the specimen is obtained along with the weathering procedure. Further numerical insights are shown and compared for different strengthening systems, i.e. cement mortar-based FRCM and FRP. Different salt crystallization patterns in the specimens with different strengthening systems are observed and discussed.