Abstract
The influence of maleic anhydride-grafted polypropylene (mPP) on the bond characteristics of macro propylene (PP) fibre and styrene butadiene (SB) latex-modified, cement-based composites was investigated. The mPP content ranged from 0 to 40% of the cement weight. Bonding strength and interfacial toughness were measured in accordance with standard method JCI SF-8. Both bonding strength and interfacial toughness increased with increasing amounts of mPP up to 15% but decreased with mPP levels above 20%. mPP strengthens the interfacial bonding between fibre and cement by forming hydrogen bonds. Because mPP is hydrophilic, it also fills pores created at the interface between macro PP, a non-hydrophilic material, and the cement composite. As a result, the overall bonding performance of the composite was enhanced by increasing the frictional force and inhibiting crack generation and growth under fibre pullout loads. These mechanisms were confirmed by fine structure analyses of the micro-PP fibre surface after pullout tests. The amount of mPP used in the composite had a strong influence on the frictional force generated at the interface between the fibre and the cement matrix.