Effects of Lime Stabilization on Engineering Properties of Expansive Ankara Clay

Abstract

With the existing expansive clay in Ankara (Turkey) metropolitan area, some light buildings, road pavements and buried lifelines have suffered some damages due to the heave of the clay. There has been very little work concerning the stabilization of smectite rich Ankara Clay, which is mainly the weathering product of the surrounding volcanic rocks. The main objective of this study is to investigate the performance of quick lime in powder form on laboratory-scaled models to improve physical, swelling and strength characteristics of the clay. The lime-soil mixture design technique was employed in the laboratory , and five different types of lime-clay mixture between 2% and 10% by weight were prepared. Engineering properties of the clay determined from natural and lime-treated samples cured for 3, 7, 14 and 28 days were compared. As a result of reactions uniaxial compressive strength (UCS) increased about 84% after 28 days. However, the results indicated that if the curing period is less than 28 days, the UCS values of the lime-treated samples are higher than those of natural samples. This suggests that the pozzolanic reaction is slower than flocculation in Ankara Clay, which achieves optimum stabilization at 4% lime content and 28 days curing time when swelling is considered.