Thermal-mechanical properties of stabilized clayey sand subgrade soils

Abstract

Stabilization of the problematic subgrade soils is extensively studied over the years to enhance their engineering properties, most commonly strength and deformation characteristics. Recent studies demonstrated that the recycled waste materials are viable sustainable alternatives to chemical stabilizers resulting in low costs and environmentally friendly solutions. In this research, investigative studies were performed to evaluate the durability, mechanical, and thermal properties of clayey sands when treated with recycled high-density polyethylene (HDPE) plastic pellets and flakes with cement as a binder. A series of experimental laboratories studies were performed to evaluate the unconfined compressive strength, strength retention, swell pressure, soil loss, and volumetric strain of the stabilized soils with different wetting-drying durability cycles. In addition, this study addressed the influence of recycled plastic form and dosage content on the thermal conductivity of the candidate soil. Threshold dosage contents of recycled plastics are established based on the multiscale scale criteria that suffices all the thermal, mechanical, and durability requirements of treated soils. This research indicated that the addition of recycled HDPE plastics led to enhancement in strength, swell characteristics, durability, and thermal conductivity when compared to the untreated soils and demonstrated the feasibility of using recycled plastic wastes in sustainable stabilization practices.