The Effect of PVA Fibers and Nano-Particles on the Bonding Strength of Fiber Reinforced Concrete

Repairing and Strengthening of concrete structures is of special importance and the mechanical properties of repair mortars and their compatibility with the base concrete are significant aspects in the field of repairing of damaged concrete structures. The bond strength parameter of materials is one of the important properties in the selection of repair mortars. In the current Experimental studies, the bond strength of 7 types of cement base mortars consisting Nano-Silica (NS), Micro-Silica (SF) and Polyvinyl Alcohol (PVA) fibers have been tested on base concrete according to ASTM C882 standard. The base concrete is made of fiber concrete with a target compressive strength of 45 MPa and consisting macrosynthetic fibers. The workability of fiber concrete was 120 mm, and the method of curing the samples was done as the wet method. The obtained results indicate that all 7 types of repair materials of this research were compatible with the base concrete and the sample with the combination of PVA fibers and Nano-Silica in cement-based mortars has increased the bond strength of the samples by 85% compared to the samples without fibers. The highest bond strength among the samples was related to cement based mortar containing PVA fibers and Nano-silica (PVA0.75NS6) with bond strength equal to 21.83 MPa.