Stabilization of Oklahoma Source Soils using Fly Ash, Lime, and Fly Ash in Conjunction with Lime with Respect to Rural Road Building Applications

Rural roads are typically constructed using local soils or bringing in costly material from another area. Oklahoma is dominated by fine-grained soils that do not provide a reliable road base, and thus soil stabilizers are often used to remediate the deficient soil properties. This study tested the relative effectiveness of two commonly used soil stabilizers, fly ash and lime, on four Oklahoma source soils. Uniaxial unconfined compressive strength was tested after adding 10% fly ash, 20% fly ash, 30% fly ash, and 20% fly ash with 10% lime to the soils. The experiments yielded a linear increase of strength with increasing additive content. Peak strength increased by 78.5 and 85.2 PSI over baseline values for 30% fly ash and 20% fly ash plus 10% lime respectively. Due to its economic and environmental benefits along with similar strength increases compared to lime, this study indicates that fly ash is a viable option for road stabilization of fine-grained soils in Oklahoma.