Durability of glass FRCM systems: Effects of different environments on mechanical properties

Composite systems consisting of fibers in the form of open fabrics embedded within inorganic matrices (Fabric Reinforced Cementitious Matrix, FRCM) have become a well-established technique for strengthening interventions on masonry and concrete structures. In particular, the use of fabrics made of glass fibers coupled with inorganic matrices showed to be very promising, thanks to the high mechanical properties of the fibers, low cost of the raw materials and good compatibility with the substrate, especially in the case of masonry structures. However, the durability of FRCM systems, such as the resistance to salt attack, alkaline environments or moisture, is an issue that hasn't be thoroughly investigated yet. In this study, the effect of saline and 100% Relative Humidity (RH) environments on the mechanical behavior of FRCM systems reinforced with glass fabrics has been investigated. The glass FRCM systems have been studied and characterized considering both the constituent materials (hydraulic mortar and glass fabric) and the substrate (fired clay brick) on which they were applied. Mechanical characterization tests on mortars and fabrics have been performed before and after exposure to different aging conditioning protocols. The same protocols have been adopted for specimens constituted by FRCM strips applied on clay brick substrates, to study the effect of different environments on the shear bond behavior of the composite system.