Unconfined Compressive Strength and Water Stability Behavior of a Soil Treated with a Non-traditional Stabilizer

The main objective of this study was to analyze the compressive strength behavior of fine soil stabilized with a mixture of sodium silicate, sodium hydroxide, and cement. The soil was classified as high-plasticity silt–MH (USCS classification) or Group A 7-5 (AASHTO classification). Proctor standard tests were performed to determine the maximum dry density and optimum moisture content of the natural soil. A series of test specimens was prepared to estimate the ranges for each stabilizer by assessing the sample integrity after 4 h of water immersion. Compression tests were conducted on samples with selected dosages at curing ages of 7 and 28 d. For this purpose, the specimens were molded with only 3 % and 15 % cement, which served as the comparison samples. Based on the previous results, the specimens were treated with various dosages of sodium silicate, sodium hydroxide, and cement: 4 % cement, 3 % sodium hydroxide, and three different concentrations of sodium silicate (6 %, 8 %, and 10 %). Compression tests were conducted under three conditions: without water immersion, with water immersion, and with capillary absorption. The specimens treated with 8 % sodium silicate showed the best performance under all three conditions, achieving compressive strength values of 3.74, 2.06, and 2.07 kg/cm² at 7 days and 5.38, 3.15, and 3.09 kg/cm² at 28 days of curing, respectively.