Assessment of Durability of Chemically Stabilized Soils Using Different Moisture-Susceptible Methods

Abstract

The durability of chemically treated subgrade soils is important for pavement design life, and it is a major concern for transportation and defense agencies. Stabilized soil layers should retain strength and stiffness properties under wetting–drying-related durability cycles and moisture exposure. Many durability test methods, including wetting and drying, tube suction, and Engineer Research and Development Center’s wet-test methods, have been developed and used in several stabilization studies in the past. It is important to study and determine how these methods address the long-term performance of chemically stabilized soils with a focus on stabilizer permanency. Therefore, this research study conducted a comprehensive laboratory investigation using all three methods to assess the durability of stabilized soils as per the US Department of Defense protocols. Three types of soils, silty sand, clayey sand, and high-plasticity clay, and three types of stabilizers, vinyl acetate-ethylene (VAE) copolymer, Portland cement type I, and hydrated lime, were considered in this study. Silty sand, clayey sand, and high-plasticity clay soils were treated with VAE copolymer, cement, and lime, respectively. Results of cement-stabilized soil showed that it is unsusceptible to moisture fluctuations, whereas VAE-stabilized soil indicated its higher susceptibility to moisture variations. Both the ASTM wet–dry (W-D) test and tube suction test methods revealed that lime-treated clayey soil is moisture-susceptible. All three methods showed similar findings, with good agreement existing between tube suction and ASTM W-D tests for all combinations of soils and stabilizers considered in this study.