A Study on the Influence of Coarse and Fine Grained Soils on the Strength Characteristics of Fly Ash

Class F fly ash is the solid residue by product produced by coal-burning electric utilities. They are usually disposed of together as a waste in utility disposal sites with a typical disposal rate of 80 % fly ash and 20 % bottom ash. Direct use of these materials in construction projects consuming large volumes, such as landfills, highway embankment construction etc. , not only provides a promising solution to the disposal problem, but also an economic alternative to the use of traditional materials. Samples of class F fly ash were collected from utility power plant (NTPC) in Vijayawada and tested for their mechanical properties (compaction, direct shear and plate load test). Three mixtures of fly ash with different mixture ratios (i. e. , 50 % and 100 % fly ash content by weight) both fine grained soil (clay) and coarse grained soil (sand) combined with ratios of lime (5 % and 10 %) added as binder were prepared for testing. Tests results indicated that ash mixtures compare favourably with fly ash mixture with fine grained soils and with 10 % addition of lime.