EFFECT OF PONDING ON ENGINEERING PROPERTIES OF COMPACTED COAL ASH

Abstract

A common method of disposal of ash generated from coal-fired thermal power plants is to mix the ash with water and place the ash-slurry in ponds or lagoons. Such a disposal system allows for the ash-water interaction, which results in leaching of ash. The effect of leaching (ponding) on the engineering properties of compacted coal ash has been investigated in the present work. A mixture of fly ash and bottom ash of equal proportion is missed with water and slurry placed in a tank simulating the condition of a pond ash allowing the ash to get leached. Tests such as compaction and shear tests were carried on such leached ash and on unleached mixture of fly ash and bottom ash. Direct shear tests were carried on ash compacted at OMC and at saturation moisture contents. Further, to study the effect of leaching in a stabilized ash fill, ash with 2% lime was conducted in a tank and allowed to leach and shear tests carried out on specimens extracted from the tank.