Stabilization of Silty Sand with Nontraditional Additives

A laboratory experiment was conducted to evaluate the stabilization of a silty- sand (SM) material with nontraditional chemical or liquid stabilizers. SM 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 the designated cure period. Twelve nontraditional stabilizers were evaluated in this experiment, including acids, enzymes, lignosulfonates, petroleum emulsions, polymers, and tree resins. Additional specimens were stabilized with an asphalt emulsion, cement, and lime to provide a comparison with traditional stabilizers under the same mixing, compaction, and curing conditions. The analysis of the test data consisted of determining the average strength, in terms of sustained load, 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 results of the experiment indicate increased strength of some nontraditionally stabilized specimens compared with that of both the control series and the traditional stabilization alternatives. Other nontraditional stabilizers did not demonstrate significantly increased strength compared with the control series for the conditions of the experiment. Many of the stabilized specimens were highly moisture susceptible, indicating the potential for poor performance when they are exposed to adverse environmental conditions, whereas a few specimens demonstrated excellent performance when exposed to moisture. Specific product categories are recommended for stabilizing SM soils.