Validation of the new mixture design and testing protocol for lime stabilization

Abstract

The Mississippi Department of Transportation (MDOT) has used hydrated lime for over 30 years to stabilize subgrades. In 1998 a project was initiated to assess material properties and performance derived from lime treated subgrades (LTS). This thesis describes some pertinent findings of the study. In situ properties of lime stabilized subgrades are identified based on Falling Weight Deflectometer (FWD) deflection measurements, Ground Penetration Radar (GPR) profiles, and Dynamic Cone Penetrometer (DCP) logs. The in situ properties are compared to laboratory strength and resilient modulus test results for the same materials to establish reliable design resilient and strength properties for these stabilized layers. A laboratory mixture design and testing protocol is presented for lime stabilized subgrades. Comparison of field test data and laboratory test data shows that laboratory design test properties were achieved in the field. These properties are used in a mechanistic analysis to assess the effectiveness of the lime stabilized subgrades in Mississippi. The LTS layers in the four pavements evaluated, are effective structural layers.