LIME AND FLY ASH PROPORTIONS IN SOIL, LIME AND FLY ASH MIXTURES, AND SOME ASPECTS OF SOIL LIME STABILIZATION

THE MAIN OBJECTS OF THE INVESTIGATIONS WERE TO FIND A POSSIBLE BEST RATIO OF LIME TO FLY ASH AND THE OPTIMUM AMOUNT OF THE LIME AND FLY ASH ADMIXTURE FOR STABILIZING VARIOUS TEXTURED SOILS, TO DETERMINE THE EFFECTS OF LIME CONTENT AND CURING PERIOD ON THE STRENGTH OF SOIL AND LIME MIXTURES, AND TO COMPARE THE STRENGTHS OF SOILS TREATED WITH LIME, LIME AND FLY ASH, OR CEMENT. FOUR SOILS WERE USED: DUNE SAND, FRIABLE LOESS, ALLUVIAL CLAY, AND GUMBOTIL. FOUR LIMES (A CALCITIC HYDRATED AND THREE DOLOMITIC MONOHYDRATED) AND EIGHT FLY ASHES WERE TRIED. SEVEN-DAY AND 28-DAY CURING PERIODS WERE USED WITH SOIL, LIME, AND FLY ASH MIXTURES, AND AND STRENGTH CONTOUR LINES FOR 28-DAY RESULTS ARE PRESENTED. NINETY-DAY CURING WAS ALSO USED WITH SOIL-LIME MIXTURES. MOISTURE-DENSITY AND MOISTURE-STRENGTH RELATIONSHIPS OF SOIL -LIME MIXTURES ARE COMPARED. THE BEST RATIO OF LIME TO FLY ASH AND THE OPTIMUM AMOUNT OF LIME AND FLY ASH WERE FOUND TO DEPEND ON THE KIND OF LIME, FLY ASH, AND SOIL USED. RECOMMENDED AMOUNTS OF LIME AND FLY ASH FOR STABILIZING THE DIFFERENT SOILS ARE GIVEN. DATA ARE PRESENTED TO SHOW THE INFLUENCE OF TYPE OF LIME AND KIND OF FLY ASH ON THE UNCONFINED COMPRESSIVE STRENGTH OF STABILIZED SOILS. A DURABILITY EVALUATION OF SELECTED SOIL-LIME-FLY ASH AND SOIL CEMENT MIXTURES BY THE IOWA FREEZE-THAW TEST IS PRESENTED. THE OPTIMUM AMOUNT OF LIME FOR STRENGTH IMPROVEMENT INCREASES WITH LENGTH OF CURING MIXTURES OF SOIL AND LIME. DOLOMITIC MONOHYDRATE LIME PROVED TO BE BETTER THAN CALCITIC HYDRATED LIME, ALTHOUGH THE CALCITIC LIME MAY BE MORE BENEFICIAL IN THE ADDITIONS OF SMALL AMOUNTS. ADDITIONS OF LIME TO SUCH CLAYEY SOILS AS GUMBOTIL AND ALLUVIAL CLAY MODIFY THE LUBRICATION EFFECT OF WATER WHEN THE MIXTURES OF SOIL AND LIME ARE COMPACTED, AND THE MIXTURES MAY NOT HAVE A WELL-DEFINED OPTIMUM MOISTURE CONTENT. /AUTHOR/