A STUDY OF COLLAPSIBLE BEHAVIOR OF SOIL BLENDED WITH FLY ASH AND KOTA STONE DUST

Abstract

Soil is said to be collapsible in its natural or compacted state if it undergoes abrupt reduction in strength, excessive and sudden settlement upon wetting leading to failure of structure. Before any type of construction, soil should be checked for collapsibility in its natural as well as compacted state because collapsible behavior of soil depends upon various factors such as dry density, water content, applied pressure at wetting and soil type. Collapsibility of soil is measured by determining collapse potential. To determine collapse potential, single oedometer test was performed in laboratory on soil sample. First of all, particle size analysis, consistency limits and compaction test were performed on soil, fly ash and Kota stone dust. Now, compaction test and single oedometer test were performed on soil sample mixed with different proportions (by dry weight of soil) of fly ash and Kota stone dust in order to determine the effect of fly ash and Kota stone dust on compaction behavior and collapsible behavior of soil. Variation of compaction behavior and collapse potential with varying fly ash content was determined at constant content of Kota stone dust mixed. Then, variation of compaction behavior and collapse potential with varying Kota stone dust content was determined at constant fly ash content mixed. Results indicates that mixing fly ash and Kota stone dust to certain content increase maximum dry density of soil and decrease optimum moisture content, collapse potential and settlement of soil. Hence, fly ash and Kota stone dust mixing results in stabilization of soil.