EVALUATION OF LIME-FLY ASH AND ALTERNATIVE CKD STABILIZED BASE MATERIALS FOR HIGHWAY CONSTRUCTION IN MISSISSIPPI

Cement stabilized base has been traditionally used in Mississippi because of the scarcity of rock and stone materials there. Lime-fly ash stabilized base has been used in road construction for the last 2 decades in Mississippi. This material stabilized with in-place soils is a less expensive alternative. However, several highway pavement projects constructed with lime-fly ash have failed in recent years, prompting a study to investigate the reasons for unexpected failures and try alternative stabilizing materials. This paper presents results of lab testing and field evaluation of road bases stabilized with lime-fly ash and a new alternative cement-kiln-dust material used for US Highway 45 Alt asphalt pavement project in Monroe County, Northern Mississippi. Results of in situ nondestructive falling weight deflectometer testing, lab testing of cores, and mechanistic analysis indicate that lime-fly ash base sections will outperform other sections made with alternative cement-kiln-dust stabilized base sections.