EFFECT OF POLYPROPYLENE FIBERS ON MECHANICAL AND PHYSICAL PROPERTIES OF MORTARS CONTAINING NANO-SIO2

It has been demonstrated that the fiber-matrix bond strongly affects the ability of fibers to stabilize crack propagation in the matrix. As the bond between fiber and matrix is mainly mechanical, it seems that incorporating nano-SiO2 (NS) into fiber reinforced cement composites provides better bond with matrix through pore refinement and better distribution of the hydrated products. Hence in this paper an effort was made to study the effect of polypropylene (PP) fibers on mechanical properties and shrinkage of mortar incorporating NS. Three fiber volume fractions, 0.1%, 0.3% and 0.5% were considered. Compressive and flexural strength, water absorption and shrinkage of mortars were reported. Results showed that NS improved mechanical and water absorption characteristics of mortars significantly. It has been observed that the addition of NS fairly enhanced the fibers effectiveness in improving the mechanical strength of mortars.