Experimental Toughness and Durability Evaluation of FRC Composite Reinforced with Steel–Polyester Fiber Combination

This study investigates the influence of steel and polyester fibers on the mechanical and durability properties of steel–polymer hybrid fiber reinforced concrete (HyFRC) and toughness under indirect tensile loading conditions. Steel and Polyester fibers are used as a single type (FRC) and in combination (HyFRC) in an M45 grade composite with the addition of fly ash and silica fume as a supplementary cementitious material. Steel as a single fiber exhibited a 10% improvement in compressive strength for a 0.75% volume fraction and a maximum of 14% improvement for a 0.5% volume fraction in comparison to plain concrete. The toughness under split tension capacity was enhanced between 26 and 72% for hybrid fibers in comparison with polyester fiber, and it was between 10 and 18% when compared to the steel fiber reinforcement. Water sorpitivity results were improved with the presence of hybrid fiber. Electrical resistivity decreases with the increase in fiber content and the addition of steel fiber in hybrid FRC increases the conductivity value 1.65–2.23 times greater than the control concrete because of the free movement of electrons.