Leachate studies on lime and portland cement treated expansive clays

Chemical stabilization of clays is widely accepted in many countries and was proved to be effective in mitigating the expansive behavior. Several cases are reported that described premature failures in clay subgrades after stabilization. The reasons for these failures could be the ineffectiveness of stabilizer dosage or due to loss of stabilizer from soil over a period of time due to rainfall infiltration. The main objective of the present research project was to study the cause of premature failures in stabilized clays. Four soils showing expansive behavior were selected for this study and were studied with different stabilizer dosages of Lime and Portland cement. Accelerated curing was adopted in the current research as it saves time and provides better results. Leachate apparatus, an experimental set up used to study the soil specimens for stabilizer loss and how it replicates the moisture inflow was used in this research. Calcium concentration, pH and Unconfined Compressive Strength (UCS) of the soil specimens were monitored thorough out the experiment. It was found out that stabilizer loss has not much impact on the stabilizer ineffectiveness of a treated soil.