Effect of Shredded Plastic Waste on Unconfined Compressive Strength of Cement-Stabilised Lateritic Soil

Abstract

A study to evaluate the effect of shredded plastic waste material on cement-stabilized lateritic soil was undertaken. The air dried soil was treated with shredded plastic waste (SPW) at 0, 2, 4, 6, 8% and cement at 0, 1, 2, 3, 4% by dry weight of the soil. The index properties of the natural soil showed it to belong to A-7-6(12) based on AASHTO classification system and ML in accordance with the unified soil classification system (USCS). However, soils under this group are poor materials for road pavement construction. Compaction characteristics of the natural and treated soil samples were determined using British Standard Light, (BSL) compaction energy. The Maximum Dry Density (MDD) result for the untreated lateritic soil was 1.68 Mg/m³ while the Optimum Moisture Content (OMC) value was 20.2%. There was a decrease in MDD as the result of introducing the shredded plastic waste and the minimum MDD value was recorded as 1.44 Mg/m³ at 4% cement and 8% SPW and the OMC value of the natural state increased from 19.5% to a value of 21% at 3% cement 4% SPW. The unconfirmed compressive strength (UCS) value for the natural soil at 7days curing period was 323.91kN/m² which increased to a value of 950.76 kN/m² at 2% cement and 8% SPW and this value fell short of the requirement of 1710 kN/m2 for base course of pavement. However, it met the requirement of 687 kN/m² for subbase of pavement.