FACTORS AFFECTING UNCONFINED COMPRESSIVE STRENGTH OF SALT-LIME-TREATED CLAY

Statistical procedures were used to analyze the effects of salt content, lime content, curing time, curing temperature, molding-water content, and soil type on the unconfined compressive strength of compacted specimens. A modified central-composite, second-order, rotatable experiment design and analysis of variance techniques were used to determine the significant main effects, curvilinear effects, and linear interactions at an alpha level of 1 percent. The following effects and interactions were significant at an alpha level of 1 percent: (a) main effects--salt content, lime content, curing temperature, curing time, molding-water content, and soil type and (b) interactions--lime content and salt content lime content and curing temperature lime content and molding-water content, salt content and curing temperature, curing temperature and molding-water content, curing temperature and soil type, curing time and soil type, and lime content and salt content and curing temperature. An engineering interpretation of each is given. A coded multiple regression model was developed to the estimate unconfined compressive strength in terms of the statistically significant main effects and interactions.