Compressibility of materials and backfilling mixtures with addition of solid wastes from flue-gas treatment and fly ashes

The article presents laboratory tests of pressure compressibility characteristics of materials and backfilling. The tests were carried out for three different types of backfilling: rock fill (dry), hydraulic and paste in oedometers for three different volume configurations with the addition of waste from flue-gas treatment or in the form of fly ash. For the rock fill, compressibility was determined for the backfilling made only from dolomite, while in subsequent tests 50% and 25% by volume of the waste from the flue-gas treatment were added to the backfilling material, respectively. In the case of hydraulic backfilling, the mixture was sand mixed with water and fly ash in a fixed ratio: a mixture of sand and water in a 1:1 ratio, a mixture of sand with water and fly ash in a volume ratio of 50% sand with water and 50% fly ash and 75% sand with water and 25% fly ash. The last type of research was paste backfilling, for which compressibility was determined for a mixture of waste (fly ash), binder and water in a volume ratio of: 50% fly ash, 40%, 45% and 48% water and 10%, 5% and 2% binder.