Properties of soil-ash mixtures and their use in environmental engineering

摘要

The paper presents the results of studies on physico-mechanical, mineralogical and structural properties of mixtures composed of cohesive dump soils originating from the "Turow" lignite open pit mine and fly ash derived from the "Turow" power plant, which burns lignite from this mine. The dump soils, which include mostly Miocene clays with minor sands and gravels were mixed with variable proportions of raw fly ash, desulphurized fly ash from pulverized fuel furnaces and desulphurized fly ash from fluidized fuel furnaces. Fly ash and soil mixtures have been subjected to setting for 28 days under the optimum moisture content. Then physical and chemical properties, phase composition, mineralogical composition and microstructures were determined Similar properties were measured for soils and for three types of fly ash. The results demonstrated the increasing shear strength parameters - mainly cohesion, particularly for mixtures of fluidized fly ash and soil. The changes and pecularities of mineral and phase compositions, and mixrostructures were described, which control the properties of mixtures. The possible applications of fly ash and soil mixtures in environment engineering were proposed.