Use of Self-Cementing Fly Ashes as a Soil Stabilization Agent

Abstract

Fly ash produced in the combustion of sub-bituminous coals exhibits self-cementing characteristics that can be adapted to a wide range of stabilization applications. Ash treatment can effectively reduce the swell potential of fat clay soils and increase subgrade support capacity of pavement subgrades. Ash hydration occurs rapidly and must be addressed by the construction procedures to obtain maximum potential benefit from the ash treatment. This can be accomplished by limiting the delay between incorporation of the ash and final compaction to less than 2 hours. Hydration chemistry can differ significantly between specific sources and design mixes must be based on the specific ash to be used. Compressive strengths of ash treated materials are dependent upon moisture content at time of compaction and strict moisture control is required during construction. For the covering abstract see IRRD 863991.