Bonding characteristics of multifilament polymer yarns and cement matrices

This work characterizes the bonding mechanisms, by pullout tests and microstructure analysis, of PVA and PP bundles to cement matrices of various water/cement ratios. The PVA bundle obtained better bonding with cement matrix compared to PP bundle, due to differences in their compatibility, which could be improved for PP by surface treatment. The effect of the cementitious matrix was exhibited in different penetration modes: at the external filaments by presence of calcium silicate, at the inner filaments by the inclusion of calcium hydroxide and absence of hydration products in the bundle core. Good fiber–matrix compatibility is essential for good cement penetrability which in turn results in improved bonding.