Description
Fibre Reinforced Cementitious Matrix composite systems display outstanding capabilities for the reinforcement of existing structures. Their modeling is challenging for the numerous damage scenarios, and test methods for mechanical characterization are still debated. An open issue concerns the improvement of textile-matrix bonding due to the low capacity of matrix particles to imbue all textile filaments. In this study, the influence of epoxy coating of glass-fiber textile on bond and tensile behavior of FRCM system are addressed through an experimental and an analytical investigation. Six different FRCM systems were considered by combining the same glass-fiber textile, dry or epoxy-coated, and three different matrices based on cement, lime, and gypsum binders. The experimental campaign comprises Direct Tensile Tests (DTT) textile pull-out (TPT), and Direct Shear Tests (DST). The results highlighted the beneficial effect of the epoxy resin coating that modifies the fiber-matrix adhesion mechanism. An analytical investigation was then conducted to verify the results obtained experimentally. In particular, the analysis concerned the analytical modeling of tensile behavior of FRCM systems through integration of the nonlinear differential problem and assuming an exponential Cohesive Material Law (CML). Assumptions also include linear elastic behavior of the textile with limited tensile strength, elastic-brittle matrix, and random distribution of mortar strength. Cracks can open in any position free from the grips, and the global load-slip diagram is built as a composition of partial global-load slip diagrams of the crack-separated sub-portions. For the calibration of the CLMs of the six FRCM systems, the experimental results of TPT and DST were used.
