Behaviour of cement-stabilized fiber-reinforced fly ash-soil mixtures

An experimental program was undertaken to study the individual and combined effects of randomly oriented fiber inclusions and cement stabilization on the geotechnical characteristics of fly ash-soil mixtures. An Indian fly ash was mixed with silt and sand in different proportions. The geotechnical characteristics of the raw fly ash-soil specimens and fly ash-soil specimens containing 1% randomly oriented polyester fiber inclusions were investigated. Unconfined compression tests were carried out an Ay ash-sail specimens prepared with 3% cement content alone and also with 3% cement and 1% fiber contents, after different periods of curing. The study shows that cement stabilization increases the strength of the raw fly ash-soil specimens. The fiber inclusions increase the strength of the raw fly ash-soil specimens as well as that of the cement-stabilized specimens and change their brittle behavior to ductile behavior. Depending on the type of fly ash-soil mixture and curing period, the increase in strength caused by the combined action of cement and fibers is either more than or nearly equal to the sum of the increase caused by them individually.