Analytical and Experimental Study of FRCM Composites with Lap-Spliced Textiles

Fiber-reinforced cementitious matrix (FRCM) composites, comprising high-strength textiles embedded in inorganic matrices, represent an effective solution for strengthening reinforced concrete and masonry structures. Compared to traditional fiber-reinforced polymer (FRP) composites, FRCM have some advantages in mechanical and physical properties, such as higher durability and compatibility with inorganic substrates. However, these properties vary significantly depending on the combination of textile and matrix used, which makes a thorough assessment of their mechanical behavior essential to establish reliable design parameters for FRCM-strengthened members. One of the main challenges in applying FRCM over large areas is ensuring continuous stress transfer across the entire composite surface. To achieve this goal, reinforcing textile lap splices are needed. The performance of these splices is fundamental to achieve the composite load-carrying capacity over the entire strengthened surface. This study investigates the tensile performance of polyparaphenylene benzobisoxazole (PBO) FRCM composites with textile lap splice. Specifically designed lap-tensile tests are conducted to investigate how textile lap splices affect the composite tensile response. The experimental results are used to calibrate and validate a new analytical model that considers a cohesive matrix-fiber interface. Results confirm that the analytical model effectively predicts the applied load-slip response of the composite and support the use of a cohesive material law previously obtained for the PBO-FRCM considered.