Abstract
Soil stabilized with fly ash is the most frequently used method in improvement of the geotechnical properties of soil in South Africa and it is increasingly gaining interest internationally. However, South Africa has several standards and regulations for the use of fly ash and other by products in the soil stabilization process as well as in concrete production. Activated fly ash has not been explored for stabilization of soils in South Africa. Therefore, the present study is an attempt to empirically evaluate the use of chemically activated class „F‟ fly ash obtained from Lethabo power plant in South Africa. The use of the activated fly ash could improve the geotechnical properties [including consistency limits, compaction properties, unconfined compressive strength (UCS), elasticity modulus, durability, california bearing ratio (CBR) and hydraulic conductivity]of the two different fine-grained soils tested in this study. A Red soil sample collected from Parktown, Johannesburg, South Africa was studied in two combinations; a proportion of 50% Kaolinite + 50% Red soil = Kaolinite soil and 30% Bentonite + 20% Kaolinite + 50% Red soil = Bentonite soil. Soils used in the study were built up from the red soil with different proportions to Bentonite and Kaolinite clays. One of the significant objectives of this study was to use mechanically and chemically activated class „F‟ fly ash to improve the geotechnical properties of the heavy clay content soils and to compare these properties with those of the same soils when untreated...
M.Ing. (Civil Engineering)