Physical and Mechanical Properties of Steel-Polypropylene Composites Reinforced OPC Concrete

Abstract. Fiber reinforced concrete (FRC) consists of a cement matrix with randomly dispersed fibers, enhancing its overall durability compared to conventional concrete. Ordinary Portland Cement (OPC) concrete faces significant challenges, and incorporating varying percentages of steel and polypropylene fibers may influence its physical and mechanical properties. This study aims to produce OPC-based reinforced concrete with composite fibers specifically, steel and polypropylene to determine the optimal fiber ratio for enhanced performance. The advantages of this research lie in identifying the ideal hybrid fiber ratio for producing high-performance concrete, along with determining the most suitable materials for specific conditions. Concrete samples with different fiber ratios will be tested to evaluate their physical and mechanical characteristics ranging from 0 % - to 2 %. Slump, density, and water absorption tests were conducted for physical analysis. Meanwhile, compressive strength is conducted for mechanical analysis. The slump test shows a reduction of workability when fibers are added compared to unreinforced concrete and shows a significant effect on the addition of steel compared to PP fibers. Density and water absorption show an effect of the addition of steel and PP fibers. The density of samples with additions of various fibers ranges from 2216 kg/m3 to 2451 kg/m3 which is within the ranges of normal concrete. Besides, the addition of hybrid fibers shows a range of water absorption 6.37 % (S1.5PP0.5) to 8.61 % (unreinforced concrete). Meanwhile, the compression test shows an improvement in the sample by adding hybrid steel-PP fibers. The findings indicate that a mixture containing 1.5% steel and 0.5% polypropylene fibers offers the highest performance.