An Experimental Study on the Effect of Plastic Waste Powder on the Strength Parameters of Tuff and Bentonite Soils Treated with Cement

This experimental study investigated the effect of plastic waste powder on the strength and swelling behavior of tuff and bentonite soils treated by cement since the plastic powder is highly compressible and does not absorb much water. This study aimed to improve the tuff and bentonite soils used in construction by adding plastic waste powder in various ratios (5, 10, 20, and 25%) and a low cement content (2.5%). Atterberg limit, swelling consolidation, and loading-unloading tests were performed to determine the optimal composition of the mixture. The results demonstrated that as the plastic powder content increases, the liquid limits, swelling pressure, swelling potentials, and duration to swelling peak decrease. This reduction is particularly notable for the soil with the highest swelling potential. Compression and recompression indices increase significantly with the content of plastic powder due to its high compressibility. The findings suggest that plastic powder with low cement can be utilized as a soil modification reinforcement material, but with a content that shouldn't significantly alter the compressibility of the mixture.