Silt subgrade modification and stabilization with ground granulated blast furnace slag and carbide lime in areas with a recurring high groundwater

摘要

Deformation of wet silt subgrade is often problematic during pavements construction as well as under regular vehicular traffic loads. In order to create a sturdy and stable platform for pavement, soil modification and stabilization with combined ground granulated blast furnace slag (GGBS), carbide lime (CL) and ordinary Portland cement (OPC) was employed in this study. Mix proportion parameters of stabilized soils are analyzed by using the Taguchi's experiment design methodology for optimal design. Results show that OPC and GGBFS content play significant roles for the early strength and long-term strength of stabilized soil, respectively; whereas CL has an optimum content of 9% at the initial stages. Maximum unconfined compressive strength (UCS) of 1.61 and 2.32 MPa were achieved, respectively, at the optimum conditions of 4%GGBFS/6%CL//3.2%OPC at the curing age of 7 and 28 days. Splitting tensile strength (STS) increases rapidly with curing ages and reaches 0.45–0.48 MPa at the age of 56d. More dosage of carbide lime can help to the long-term strength.