Fine grained soil stabilization using class F fly ash with and without cement

This paper presents the results of laboratory research of high plasticity clay stabilization using non self-cementing class F fly ash (also known as pulverised fuel ash or PFA) with and without activator - cement. Fly ash was collected from Serbian electric power plant "Kostolac". Soil-fly ash mixtures were prepared at different fly ash contents (10-25%). Tests were conducted on specimens compacted at the optimum water content from Standard Proctor compaction test. Effects of fly ash on physical and mechanical properties of soil such as plasticity, unconfined compressive strength, effective shear strength parameters, CBR, deformation parameters and swell potential were evaluated. Results of the research indicate that used fly ash without activator can effectively improve some engineering properties of the soil. After addition of cement the stabilization effects substantially were improved