INVESTIGATING THE USE OF POLYPROPYLENE FIBRE IN ENHANCING SOME MECHANICAL PROPERTIES OF CONCRETE

Fibre reinforced concrete is a recent innovation in the concrete industry. The aim of this research was to investigate the use of PPF in enhancing the strength performance of concrete. This study examined the effect of polypropylene fiber on concrete workability, compressive strength, flexural strength, and transport quality by water absorption testing. A total of 72 cubes (54 for compressive strength and 18 for water absorption tests) and 18 beams were cast with varying volume fraction amounts of PPF at 0%, 0.5%, and 1.5%. Each specimen underwent testing after curing periods of 7, 14, and 28 days. The findings of the numerous tests conducted suggested that the control concrete exhibited better workability compared to the PPF concrete. The workability test indicated that M30 and M20 concrete exhibited slumps of 80mm and 75mm for the control samples, and 0.5% and 1.5% for PPFC. M20 exhibited slumps of 20mm and 25mm, whereas M30 demonstrated slumps of 20mm and 21mm. The water absorption test indicated that at the PPF percentages utilized in the study, the polypropylene fiber exhibited hydrophobic properties and absorbed more water than the fibreless concrete. Likewise, the compressive strength exhibited an increase at 0.5% PPF for M30. The two mixes had low flexural strengths while the control had a higher flexural. The water absorption test indicated that 0.5% PPFC decreased by 28.67%, whereas 1.5% PPFC resulted in a reduction of 70.97%. At 0.5% PPF, M20 concrete saw a water absorption reduction of 7.89%, whereas at 1.5%, the reduction was 26.70%. Conclusively, the above findings highlight the potential benefits of PPF in enhancing specific concrete properties; however, its influence on flexural strength and workability should be thoroughly assessed when optimizing mix designs for construction applications.