Establish Policies and Procedures for Use of Subgrade Stabilization in Michigan

Project Details









Nishantha Bandara


Michigan Department of Transportation


Cost effectiveness, Drainage, Pavement performance, Soil stabilization, Subgrade (Pavements)

Project description

MDOT has, on occasion, stabilized the subgrade as part of a pavement reconstruction project. These have generally been in situations where it was more cost-effective than undercutting the subgrade, or when building a longer life pavement. MDOT would like to explore the use of subgrade stabilization more often. Projects where subgrade stabilization has been used appear to be performing very well. However, MDOT does not have any criteria for when/where subgrade stabilization would be a cost-effective choice to improve the performance of the constructed pavement. Where it has been used, special provisions outline the mix design process and testing protocol, but is this the optimum methodology? Multiple versions of these specifications with different allowable stabilization agents, acceptance methods and testing requirements have been used. These need to be unified. Traditionally, fine-grained soils have been viewed as candidates for stabilization due to their lower support characteristics and high loss of modulus in moist conditions. There has been some interest in exploring stabilization of coarse-grained soils to see if pavement performance can be increased. However, does the potential loss of drainage through the subgrade outweigh the potential increase in support? The work completed and documented in research report RC-1635, “Performance Evaluation of Subgrade Stabilization with Recycled Materials” started some of this analysis. This project will use the information from this previous project to create policies for when stabilization of the subgrade can be used, what the construction procedures should be, and finalize inputs used in the pavement design process.