Cationic-electrokinetic improvement of an expansive soil

(Cationic-electrokinetic) soil improvement was shown to be an effective technique for delivering, homogeneously, stabilizing agents into soils. The results of the electrokinetic-stabilization procedure using the K+ and Ca2+ ions as stabilizing agents varied according to the type of the stabilizing ions. The plasticity index of the natural soil (PI = 40) was reduced to 32 for the Ca2+-stabilized soil, and to merely 8 for the K+-stabilized soil. The free swell value was reduced from 14% for the natural soil to 3.1% for the Ca2+-treated soil. and to only 0.4% for the K+-treated soil under identical conditions of dry density and initial moisture content. The friction angle was increased from phi = 24 degrees for the natural soil to 30.9 degrees for the Ca2+-treated soil, and to 36 degrees for the K+-treated soil under identical conditions. (C) 2009 Elsevier B.V. All rights reserved.