Improvement of tensile properties of carbon fibre-reinforced cementitious matrix composites with coated textile and enhanced mortars

Abstract

Fibre Reinforced Cementitious Matrix (FRCM) systems are composite materials used for retrofitting structures thanks to their high strength-to-weight ratio and their compatibility with different substrates. The mechanical properties of FRCM depend on textile and mortar characteristics and on the interfacial bond behaviour between grid and matrix. In this research, FRCM systems made of two different carbon grids (one impregnated and one unimpregnated) and employing five different mortars were compared to assess the influence of both grid and mortar on the mechanical properties of the reinforcement. Tensile tests were carried out with a displacement and strain monitorization using Digital Image Correlation (DIC). The results reveal a remarkably better performance of the systems with impregnated grid, especially when combined with high strength mortars. The enhancement was particularly observed in terms of ultimate tensile strength, crack spacing, existence of a trilinear stress–strain curve, and efficiency factor (exploitation of the fibres in the composite).