Effect of interfacial thickness and stiffness on the stress distributions in fibre reinforced cementitious composites

The different microstructure of the fibre-cement interface might result in different failure mechanisms. It is expected that improvement of strength and toughness in fibre-reinforced cementitious composites will depend on their interfacial thickness and stiffness. A three-phase model, subject to a transversely uniform tensile stress, was utilized to investigate the effect of interfacial thickness and stiffness on the stress distributions near the fibre cement interface and the corresponding failure mechanism. The results suggest that optimum interfacial microstructure of fibre-reinforced cementitious composites can be tailored to obtain a higher strength and toughness. Optimum interfacial thickness and stiffness was evaluated for various reinforcements, including steel, carbon, glass and polypropylene fibres.