Swelling Potential of a Stabilized Expansive Soil: A Comparative Experimental Study

The efficiency of typical chemical and mechanical soil stabilization techniques in mitigating the swelling problemof an expansive soil is investigated through a comprehensive experimental study. Chemical stabilization was generated by traditional agents consisting of lime and cement, and by a commercially branded polymer (CBR PLUS). Mechanical stabilization was applied by means of fiber-reinforcement and swell-shrink cycles. Chemically-treated and fiber-reinforced soil samples were tested for swelling potential in a conventional oedometer apparatus; while swellshrink cycles were applied using a modified temperature- controlled oedometer. Swell-shrink cycles were applied under room temperature for wetting cycles while the drying processwas conducted under a constant temperature of 40 +/- 5 degrees C, and swelling and shrinkage potential were recorded during successive cycles to a point in which swell-shrink equilibrium was attained. Typical strength tests were also conducted for each stabilization scenario which led to maximum reduction in swelling potential. In addition to the experimental program, the swell-time relationship for various stabilization scenarios was simulated using a two-parameter rectangular hyperbola function (2P-RH). Results indicated that all of the proposed stabilization scenarios can guarantee a significant reduction in swelling potential. In the case of lime and cement, reduction in swelling potential was observed to be a function of agent percentage and curing time; whereas for polymertreated samples the effect of curing was found to be insignificant. Regarding fiber-reinforced samples, reduction in swelling potential was a function of fiber percentage, aspect ratio and fiber tensile strength. Overall, traditional agents proved to be more effective compared to non-traditional techniques. The proposed non-traditional methods, however, displayed promising results posing as great alternatives to lime and cement.