REACTION OF HYDRATED LIME WITH PURE CLAY MINERALS IN SOIL STABILIZATION

Abstract

THE USE OF HYDRATED LIME HAS BEEN GROWING IN THE FIELD OF SOIL STABILIZATION. ALTHOUGH IT HAS BEEN USED FROM COAST TO COAST IN THE UNITED STATES AND BY SOME NATIONS ABROAD, THE REACTION OF HYDRATED LIME WITH THE SOIL IS STILL A MYSTERY, PARTICULARLY WITH RESPECT TO ITS RELATIVE EFFECTIVENESS AND RATES OF REACTION WITH VARIOUS SOILS. A RESEARCH PROJECT TO DETERMINE THE REACTION OF HYDRATED LIME AND SOIL IS UNDER WAY AT THE UNIVERSITY OF ILLINOIS. BECAUSE OF THE COMPLEXITY OF SOILS AND BECAUSE LIME IS OF GREATER BENEFIT TO A HEAVY CLAY SOIL, THE FIRST PART OF THE INVESTIGATION HAS BEEN DEVOTED TO A STUDY OF THE EFFECTS OF HYDRATED LIME ON PURE CLAY MINERALS. BY THE AID OF X-RAY DIFFRACTION AND DIFFERENTIAL THERMAL ANALYSIS, IT HAS BEEN POSSIBLE TO WATCH AND IDENTIFY THE REACTIONS WHICH TAKE PLACE. THE FIRST REACTION, WHICH IS BROUGHT ABOUT IMMEDIATELY WHEN LIME IS ADDED, IS REPLACEMENT OF ABSORBED IONS BY CALCIUM IONS, THE SECOND, FORMATION OF A SERIES OF NEW MINERALS, THE THIRD, CARBONATION OF THE HYDRATED LIME. THESE REACTIONS, ILLUSTRATED BY TYPICAL X-RAY EXAMPLES, OFFER DEFINITE PROOF AS TO WHY DIFFERENT RATES OF REACTION OCCUR WITH DIFFERENT SOILS. /AUTHOR/