Evaluation of Chemical Modifiers and Stabilizers for Chemically Active Soils—Clays

Abstract

Of the types of soils that occur in nature, clay soils are the most physicochemically active. Their natural tendencies to change volume with moisture level changes cause billions of dollars of damage annually to transportation facilities. Methodologies to modify and stabilize their damaging behavior have been widely sought. In fact, there is evidence of clay soil stabilization in antiquity. Because these problematic soils are chemically active and their behavior can be improved through the application of chemical agents, a multitude of these agents have been applied. Some of these agents are naturally occurring, some are derived by manufacture, and some are the waste products of manufacturing processes. Why these clays are chemically active, how agents can be applied to improve the behavior of clays, and why the agents proposed should be evaluated are reviewed. Minimum requirements for adequate testing and evaluation are provided.