Tensile behaviour of glass FRCM systems with fabrics' overlap: Experimental results and numerical modeling

The use of Fabric Reinforced Cementitious Matrix (FRCM) systems to reinforce existing masonry and concrete structures is nowadays a well-established practice. The mechanical characterization of FRCM systems is of fundamental importance to define the correct parameters needed to design a strengthening intervention. However, some aspects regarding FRCM tensile behaviour need to be further investigated. The aim of this paper is to provide a detailed overview on the mechanical behaviour of FRCM specimens subjected to tensile tests. In this context, the effect of fabrics' overlapping on the global behaviour of the system is extensively analyzed. Different sample's configurations have been studied: one reinforced with a single layer of bidirectional glass fabric and three others with different fabrics' overlap lengths, varying between 100 and 200 mm. Digital Image Correlation (DIC) has been also used to measure displacements in experimental testing. A phase-field model, that accounts for brittle fracture of cementitious matrix and fabric reinforcement and possible slippage at the fabric-to-matrix interface, has been developed. The variational formulation has been implemented in a finite element code to simulate the tensile behaviour of FRCM systems and the effects of using different fabrics' overlap lengths.