Engineering Behavior Of Lime Treated High Sulfate Soils

Abstract

Regardless of increased knowledge and awareness of sulfate heave, the Texas Department of Transportation (TxDOT) continues to experience pavement failures during and immediately after construction on transportation infrastructures intended to last at least 20 years. Failures are predominantly observed in sites where high sulfate soils of 8,000 ppm or higher levels. Many of these failures are attributed to sulfate-induced heave where an expansive mineral called Ettringite is formed from calcium-based stabilizers (lime or cement) reacting with water, clay, and sulfates. The reactions responsible for Ettringite formation are extremely complex which make generalizations concerning the rate and magnitude of heaving in different treated soils impossible. The main objective of this research is to advance the state of knowledge of the engineering behaviors of lime treated high sulfate soils. In this research several tests have been identified to understand the change in volume behavior (swell and shrinkage strains) of lime treated high sulfate soils under two different moisture conditions and different mellowing periods to see the effects on swell strains reduction.