Improving the interfacial properties of PVA fiber and cementitious composite: Design and characterization

Poly vinyl alcohol (PVA) fiber has been widely applied to improve the ductility of cementitious materials, and the overall performance of fiber reinforced cementitious materials largely depends on the interfacial properties of the fiber and cementitious matrix. In this work, a novel design of graphene oxide (GO) modified PVA fiber is proposed to improve the interfacial properties of PVA fiber and cementitious matrix. It is found that the interaction between GO and PVA fiber forms the hydrogen bond and enables the GO to form a tight three-dimensional bonding on the surface of the PVA fiber. Meanwhile, the oxygen-containing functional groups of GO could form chemical bond with the hydration products and promote the formation of denser microstructure at the interface. Therefore, the introduction of GO prominently improves the interfacial properties of PVA fiber and cementitious matrix, which is verified by the characterizations on the microstructures and morphologies. Furthermore, it is found that GO remarkedly improves the interfacial mechanical properties and results that a zone with the enhanced mechanical properties appears near the interface, verified by the characterizations on the micro-mechanical properties including fracture toughness near the interface.