The Influence Of Cations Exchanges To Atterberg Limit On Soft Clay Soil

Abstract

Clay is composed of sheets of tetrahedral (Si4 + - O2-) and octahedral (Al3 + - O2-). Comparison of the composition of the tetrahedral sheets (Silica, Si4+) - octahedral (Alumina, Al3+) causes clay soil has a stable bond (ratio 1: 1) and unstable bond (ratio 2:1) between the layers. To stabilize the bond, the clay that surrounds the form of cation binding of free ions and dissolved in water. Strong - weak bonding condition between the cations contained in the layer depends on the type of metal bound. This causes the character of clay is easy to swell and shrink. Early identification of swell of clay type can be seen in the value Atterberg limit of the soil. This research was conducted to determine the effect of cations exchanges on clay soil compared with the value of Atterberg limits (liquid limit (LL), plastic limit, (PL) and shrinkage limit (SL)). Exchange of cations in clay soil using electrokinetic processes with direct current (DC). Analysis of soil cation composition of the original and final test conducted by the chemical process by AAS method (Atomic Absorption Spectrum). From the results of chemical testing and compared with Atterberg limits under the same conditions, showed the result that the characteristics of the cations Ca2+ and Mg2+ show a similar trend, but vice versa. As for the other cations, has no permanent behavioral changes in Atterberg limits. The results of this research can be used as the basis and consideration in the implementation of the stabilization of expansive clay.