Comparing the Influence of Kinds of Lime on Time and Swelling Pressure of Bentonite

This research compares the influence of different kinds of lime on the amount and time of swelling pressure of bentonite. In the present research, constant volume method was used for measurement of samples of bentonite soil mixed with 3 % of quick and hydrated lime compacted at 2 – 3 % dry of optimum water content and after curing period of 0,1,7,28 and 90 days. The results showed that adding quick lime to bentonite decreased the magnitude of swelling pressure, the time to reach to primary swelling pressure, time rate of secondary swelling pressure and both stress and strain controlled swelling indices more effectively than the use of hydrated lime. It was also determined that the values of these parameters decreased further with increase in curing period. Traditional quick lime had the least slope of secondary swelling pressure with time. The slope of secondary swelling pressure with time for samples stabilized with industrial quick lime were lower than those which were stabilized with industrial hydrated lime.