Stabilization of Clay Soils with Nontraditional Additives

Abstract

A laboratory experiment was conducted to evaluate the stabilization of low- and high-plasticity clay soils with nontraditional chemical or liquid stabilizers. Clay soil specimens were mixed with various stabilization products and compacted using a gyratory compaction machine to approximate ASTM D1557 moisture–density compaction. Each specimen was subjected to wet and dry testing following a 28-day cure. Twelve nontraditional stabilizers were evaluated, including an acid, enzymes, a lignosulfonate, a petroleum emulsion, polymers, and a tree resin. Additional specimens were stabilized with Type I portland cement and hydrated lime for comparison with traditional stabilizers under the same mixing, compaction, and curing conditions. Analysis of the test data consisted of determining the average strength, in terms of unconfined compressive strength, of three replicate specimens of each mixture. The average strength of the three replicates of each additive was compared with the average strength results of the remaining nontraditional additives, the traditional stabilization results, and a series of control specimens that were not stabilized. The experiment results indicate an increased strength of some nontraditionally stabilized specimens when compared with that of both the control series and the traditional stabilization alternatives. Other nontraditional stabilizers did not demonstrate significant increased strength compared with that of the control series for the conditions of this experiment. Many of the stabilized specimens were highly susceptible to moisture, indicating the potential for poor performance when exposed to adverse environmental conditions, whereas a few specimens demonstrated excellent performance when exposed to moisture. Specific product categories are recommended for stabilizing low- and high-plasticity clay soils.