Strength Characteristics of Soil Fly Ash Mixtures Reinforced with Randomly Oriented Polypropylene Fibers

Fly ash is a waste produced from thermal power stations, which contributes to environmental pollution. A number of studies have been conducted to investigate the influence of randomly oriented fibers on the strength behavior of coarse grained and fine grained soils. The effect of fiber inclusion on the strength characteristics of soil fly ash mixtures has not been reported so as much detail as in the case of the soils. In present study, polypropylene fibers were mixed with various proportions of soil fly ash mixtures to investigate the relative strength gain in the terms of unconfined compression strength (UCS). Samples of soil fly ash mixtures were tested in unconfined compression with 0, 0.5, 1.0 and 1.5 per cent polypropylene fibers. The results presented show that the UCS increases with the increase in the per cent of fibers for all the proportions of soil fly ash mixtures under consideration. Samples of soil and soil fly ash showed significant higher increase in UCS and residual strength compared to the samples of the fly ash. Results are, also, presented to show that the addition of polypropylene fibers increase the residual strength of soil fly ash mixture significantly more than the increase in the UCS.