Geotechnical Characterisation of Soft Clay Treated with a Bottom and Fly Ash Mixture

This paper presents the improved strength properties of soft clay treated with fly and bottom ash added in different amounts. A series of laboratory tests were carried out on both the treated and untreated samples to determine the compaction, consolidation and unconfined compression strength (UCS) properties. The optimum dosage of both the bottom and fly ash levels which one exhibiting the maximum UCS has been determined and estimate the quantitative improvement. The UCS of samples has been tested for various curing periods up to 28 days. The coefficient of consolidation is increases and time required to cause 90% consolidation is decreases with the addition of ash additives. The maximum UCS is obtained at an optimum fly ash level of 20% added to the clay soil and further the strength is decreases. Quantitatively, the strength of soil-fly ash mixture was found to 243 kPa which is improved about 385% over the strength of clay soil.