Role of Textile Coating in the Tensile Behavior of a Flax Fiber-Reinforced Cementitious Matrix (FRCM) Composite

Fiber-reinforced cementitious matrix (FRCM) composites are frequently preferred over fiber-reinforced polymer (FRP) composites to strengthen existing masonry members due to their physical-chemical compatibility with the substrate, resistance to (relatively) high temperatures, possibility of being removed without damage to the substrate, and ease of application. FRCMs are usually comprised of high-strength open-mesh fiber textiles embedded within an inorganic mortar. In the last decade, the increasing need for sustainable materials has driven research towards the use of natural fiber textiles and lime-based mortars. Although promising results were obtained, natural fiber FRCM provide mechanical properties that are generally lower than those of traditional FRCM and may face durability issues. In this paper, the tensile behavior of an FRCM composed of a flax textile embedded within a lime-based mortar is investigated. FRCM coupons with standard and coated textiles were tested using the clamping-grip test set-up recommended by the European acceptance criteria (AC) for FRCM composites. A textile micro-coating comprising diluted epoxy resin is designed to improve both the fiber-matrix bond and textile durability. Results show that the coating has a limited effect on the FRCM tensile properties, although it influences the matrix-fiber stress-transfer mechanism.