Fly Ash in Construction Industry. Strength Tests of Soil Stabilized with Mixture of Ash and Cement

The part of the waste from coal combustion process, in which the mineral grains smaller than 0.075 mm are in advantage, i.e. more than 50% is called fly ash [BN/79/6732.09]. Fly ash is a unique and universal material, which is still waiting for full use in many industries. The paper presents the methodology and results of stabilization of organic soil mixture with cement-water-ash, using fly ash from the Belchatow Power Station, working on brown coal. At first classification of fly ash due to its chemical composition is given. Possibility of the use of ash in construction is discussed. The paper presents methods of using such material for strengthening the soils. Main part of the paper describes the laboratory tests aimed at determining changes of uniaxial compressive strength of soil samples reinforced with ash. The paper presents methodology and results of investigations of organic soils reinforcement from Koszalin, Szczecinek area. Peat, bog lime and clayey mud have been tested regarding their usefulness for reinforcement using cement-fly ash admixture. Physical soil properties have been examined as well as compression strength. The admixture contained 0/100, 75/25, 50/50, 25/75, 100/0 of cement/fly ash and it has been added in amounts of 150, 250 and 300 kg/m(3). Stabilized soil samples maturated for 28 days. The compression strength is presented in Figs. 3, 4 and 5.