Strength behaviour of surface coal mine overburden-fly ash mixes stabilised with quick lime

Surface coal mine overburden, typically treated as waste material, consists of a mixture of coarse-grained particles, rock fragments and fine-grained particles. It often causes geotechnical and environmental problems at the disposal site. Fly ash, a coal combustion by-product, has the potential to change the behaviour of other similar products when mixed at optimum conditions. Both fly ash and overburden are still being treated as waste products. An investigation has been carried out to evaluate the utilisation prospects of both combined. This article describes the results of an investigation on the compressive strength and bearing ratio behaviour of surface coal mine overburden material and fly ash mixes stabilised with quick lime at varying percentages. The same has also been compared with results obtained from fly ash-mine spoil and mine parting mixes and fly ash-soil.