Accelerated Strength Improvement of Silty Sand with Nontraditional Additives

Abstract

A laboratory experiment was conducted to evaluate the effect of two products used to accelerate strength improvement of a silty sand (SM) material stabilized with nontraditional stabilizers. SM soil samples were mixed with selected products and tested under both “wet” and dry conditions after 1- and 7-day cures. Nine nontraditional stabilizers, including lignosulfonates, polymers, silicates, and tree resins, were evaluated in this experiment. Two accelerator products, an acrylic polymer and Type I portland cement, were evaluated. Samples were also stabilized with either an asphalt emulsion or cement to provide a comparison for traditional stabilizers under the same conditions. The average unconfined compressive strength (UCS) of three replicates of each mixture was compared with the results of the remaining mixtures, the traditional stabilization results, and a series of untreated control samples. The results indicate increased UCS of samples stabilized with Silicate 1 and Polymer 3 compared with both the untreated control series and the traditional stabilization alternatives. Lignosulfonate 1; Polymers 1, 2, 4, 5, and 6; and Tree Resin 1 did not demonstrate significant increased strength over the control series for the conditions of this experiment. The UCS following the 7-day cure provided the maximum UCS of the samples evaluated in both wet and dry conditions. One accelerator, cement, in combination with a nontraditional stabilizer did show significant improvement in early strength gain when compared to the control series.