An Experimental Investigation on Mechanical Behavior of Macro Synthetic Fiber Reinforced Concrete

Abstract Concrete is an indisputable material for the construction of various types of structures in the modern advancement of civil infrastructures. Concrete is strong in compression but weak in tension and shear. To eliminate those problems, the introduction of fiber was brought in as an alternative to developing concrete in view of enhancing its tensile and shears strength as well as improving its ductile property. Hence, the purpose of this study was to investigate the mechanical behavior of concrete reinforced with macro (structural) synthetic fibers. To determine these properties experimental work was carried out. Four batches of concrete were cast: one with no fibers and the remaining three with three different volume fractions fibers of 0.33, 0.42 and 0.51%, respectively. Concrete specimens (cubes, prisms and beams) were cast to determine the mechanical behavior such as compressive, tensile, shear strength and stress-strain relationships. Test results showed that macro synthetic fiber enhanced the compressive strength insignificantly. However, macro synthetic fibers at 0.33, 0.42 and 0.51% volume fractions improved the tensile strength by at least 10, 15 and 14%, respectively, compared to the control specimen. Similarly the ultimate shear strength was increased significantly by at least 15, 45 and 65% for macro synthetic fibers of 0.33, 0.42 and 0.51% volume fractions, respectively, compared to the control beams. The failure of plain concrete specimens was sudden (brittle) for both the tensile and shear strength tests. However, the concrete reinforced with macro synthetic fibers showed more ductile behavior compared to the plain concrete. Macro synthetic fibers improved the ultimate strain value by at least 50, 60 and 60% for macro fibers of 0.33, 0.42 and 0.51% volume fractions, respectively.