Performance Evaluation of Stabilized Base and Subbase Material

Abstract

The resilient modulus and permanent deformation are important material properties in the characterization of unbound base materials and subgrade soils and in the design of pavement structures. This study evaluates the effect of stabilizing the base and subbase layers on the performance of a pavement structure. Three test lanes with six sections were constructed at the pavement research facility (PRF) of the Louisiana Transportation Research Center (LTRC). The six sections incorporated six different base course and two sub-base materials. The base materials were crushed limestone, Blended Calcium Sulfate (BCS), BCS stabilized with slag (BCS-Slag), BCS stabilized with flyash (BCS-Flyash), foamed asphalt treated 100% recycled asphalt (RAP) (FA-100RAP), and foamed asphalt treated blend of 50% RAP and 50% soil cement (FA-50RAP-50SC). The subbase materials were lime-treated and cement-treated soils, whereas subgrade was a clay (A-4) soil. The laboratory repeated load triaxial resilient modulus, permanent deformation, and material property tests were performed on these pavement materials. The BCS treated with slag showed the lowest permanent deformation base material followed by BCS treated with flyash, BCS, crushed limestone, and recycled asphalt pavement. Cement-treated soil, among subbase material, showed the lowest permanent deformation followed by lime-treated soil.