Bonding Characteristics of Macro Polypropylene (Pp) Fibre in Pva/Macro Pp Blended Fibre-Reinforced Styrene Butadiene Latex-Modified Cement-Based Composites

Abstract

The bonding properties of macro polypropylene (PP) fibres in blended fibre-reinforced polymer-modified cement-based composites (BFRPMCCs) containing styrene butadiene (SB) latex were evaluated. A blend of polyvinyl alcohol (PVA) and macro PP fibres was used in the study. The pullout behaviour was investigated using dog-bone test specimens compliant with JCI SF-8. The macro PP fibre was added at 0.45 kg/m3 and the PVA fibre was added at 12.6 kg/m3 to fabricate the BFRPMCCs, and SB latex was added at 0–25 wt% of the cement. The addition of SB latex improved the dispersion of the PVA fibres, increased the pullout resistance of the macro PP fibre embedded in the BFRPMCC, and induced strain hardening in the debonded zone. The maximum bond strength occurred at an SB latex content of 10%, and the maximum interface toughness occurred at an SB latex content of 15%. Microstructural analysis of the macro PP fibre surfaces was carried out following pullout of the fibres embedded in the SB-latex-containing BFRPMCC. The amount of scratches increased with increasing SB latex content until 15%, but then decreased at SB latex contents above 20%, indicating that the bonding of the composite was optimum at a latex content of 15%.