This work looked at the ways in which waste plastic can be effectively recycled as an alternative material in concrete production. The granulated plastic waste was used to partially replace fine aggregate (quarry dust) at 0, 5, 10, 15, and 20% and the concrete formed from the replacement was termed P0, P5, P10, P15 and P20, respectively. Slump tests were used to determine the workability of the wet concrete, while compressive strength, tensile strength, bending moment and deflection tests were carried out on the hardened concrete. The slump test results obtained showed that P20 concrete has shear failure, while the test on hardened concrete showed gradual reduction in concrete strength as more granulated plastic was added to the concrete mix. The work concluded that granulated plastic can partially substitute fine aggregate in concrete up to 20%, and recommended the concrete for lightweight concrete based on defined standards.

The need for proper disposal of plastic waste has prompted researchers to consider the best way of recycling this non-biodegradable material. This research has looked into the production of sandcrete blocks, using shredded waste plastic in replacing fine aggregate at 0%, 5%, 10%, 15%, 20% and 100%. The laboratory experiments conducted were: compressive strength, flexural strength, density and water absorption tests. Both the compressive and flexural tests revealed that sandcrete blocks that contains 5% partial replacement of fine aggregate with shredded plastic have the highest strength when compared with other mixes, the density and water absorption test showed that the control sample has the best result. The study concluded that plastic waste can be used to partially replace fine aggregate in sandcrete block at not more than 5%.

This study evaluates the effect of rubber crumb on the microstructural properties of concrete which was used to partially replace fine aggregate by 0, 4, 8, 12, and 16% proportion and designated as M₀, M₄, M₈, M₁₂, and M₁₆ respectively. The wet and hardened properties of concrete were investigated by conducting a slump test and a compressive strength test, and by measuring the concrete bulk density. The crack formed as a result of compressive strength was investigated using a digital microscope, while the micro-cracks formed in the concrete structure were investigated using a scanning electron microscope (SEM). The results showed that concrete slump for all the samples range between 25 and 10 mm, with M₀ and M₄ having the highest slump. The compressive strength and density of the concrete decreased as the amount of rubber crumb increased in the mixture, with M₀ having a compressive strength of 51.88 N/mm² and M₁₆ having the lowest compressive strength of 19.40 N/mm². The SEM analysis showed that there was a weak bond between the concrete paste and the rubber crumb, which resulted in to a weak adhesive force, and the development of micro-cracks which contributed to the week compressive strength in concrete with higher rubber crumb.