GEOTECHNICAL CHARACTERISTICS OF FLY ASH-SOIL MIXTURES

Abstract

This paper presents the results of laboratory experimental studies carried out on fly ash-soil mixtures. Two fly ashes, one from Rajghat thermal power station, New Delhi, India, and the other from a chemical manufacturing industry Baumineral near Bochum, Germany, were collected and their physical and chemical characteristics were studied. The fly ashes were mixed with the soils available near their respective areas in different proportions and their geotechnical characteristics were investigated. The laboratory test program included compaction tests, unconfined compression tests, direct shear tests, unconsolidated undrained triaxial shear tests, consolidaiton tests, permeability tests and CBR tests. The results obtained were of similar magnitude and showed comparable characteristics as those reported in the literature on fly ashes from other parts of the world. It might be possible to make a reasonable estimate of the maximum dry unit weight and the optimum moisture content of fly ash-soil mixtures from their specific gravity. (A)