| Among soil stabilization methods, calcium-based stabilizers; primarily lime is widely used due to its cost effectiveness and its ability to improve expansive soil properties. However, in certain sulfate-rich soils, lime stabilization results in either increased heaving or mitigating the effectiveness of lime in reducing the overall swelling of control soil. This heave, known as sulfate heave, is influenced by the formation of ettringite mineral in treated soils. Several factors including soil types, lime content, sulfate levels, and alumina present in treated soils are known to influence the formation of ettringite. Hence, the main objective of this research is study the effects of these factors on the formation of ettringite mineral in treated soils. Three soil types, including Kaolinite clay, mixed soil (30% Kaolinite clay and 70% sand) and sand were selected as control soils in the research. Five different sulfate levels were selected. These levels were 0 ppm, 1000 ppm, 2500 ppm, 5000 ppm and 10000 ppm. Sodium sulfate (Na2SO4), a high soluble sulfate salt, was selected as the sulfate source material. Sodium aluminum oxide (Al2O3Na2O) was selected as the source of alumina. Three levels of lime treatment (0%, 4%, and 8% by dry weight of soil) were considered in this research. (Abstract shortened by UMI.)... |
