effect of fly ash and different lengths of polypropylene fibers content on the soft soils

the total coal and lignite consumption of the thermic power plants in turkey is approximately 55 million tons and nearly 15 million tons of fly ash is produced. the remarkable increase in the production of fly ash and its disposal in an environmentally friendly manner is increasingly becoming a matter of global concern. studies for the utilization of fly ash in turkey are necessary to reduce environmental problems and avoid economical loss caused by the disposal of fly ash. efforts are underway to improve the use of fly ash in several ways, with the geotechnical utilization also forming an important aspect of these efforts. an experimental program was undertaken to investigate the effects of multifilament (mf19average) and fibrillated (f19average) polypropylene fiber on the compaction and strength behavior of ch class soil with fly ash in different proportions. the soil samples were prepared at three different percentages of fiber content (i.e. 0.5%, 1% and 1.5% by weight of soil) and two different percentages of fly ash (i.e. 10% and 15% by weight of soil). a series of tests were prepared in optimum moisture content and laboratory unconfined compression strength tests, compaction tests and atterberg limits test were carried out. the fiber inclusions increased the strength of the fly ash specimens and changed their brittle behavior into ductile behavior.