Use of Recycled Polypropylene Grains as Partial Replacement of Fine Aggregate in Reinforced Concrete Beams

Waste product from polyethylene materials are non-biodegradable and they form the bulk of the materials been used today. This paper looked into how this waste product was recycled in to polypropylene grains of sizes<4.5 mm and used to partially replace fine aggregate in concrete. Sieve analysis was carried out on the recycled polypropylene waste. Reinforced concrete beams (600 mm x 150 mm x 200 mm) and concrete cubes (150 mm x 150 mm x 150 mm) were made from the mixture of the recycled material at different percentages of 0%, 4%, 8%, 12% and 16%. The beams were subjected to bending moment test, while the cubes were subjected to compressive strength test. Results revealed that 43.71% of polypropylene grains passed through the 4.75 mm sieve. The compressive strength of the 4% mixture was 16.28 N/mm² while the control was 19.07 N/mm². The bending moment test showed that the control mix has the highest value of 14.70 kNm, while the 12% and 16% has the lowest value of 8.40 kNm each. Deflections in the polypropylene mixes were generally higher than the control. The work concluded that recycled polypropylene grains can be used as partially replacement of fine aggregate in concrete at below 4% replacement.