Abstrakt

STRENGTH CHARACTERISTICS OF RED SOILS BLENDED WITH FLY ASH AND LIME

Tarh Reema, Ajanta Kalita

An experimental testing program was undertaken for evaluating the effect of a class F fly ash and lime on the strength properties of locally available red soils. Compaction tests and unconfined compression tests were carried out. Fly ash and lime were mixed in different proportions ranging from 20- 80% and 2-4% by dry weight of soil, respectively. The unconfined compression test results on the soil-fly ashlime mixtures indicate that addition of lime to soil-fly ash mixtures leads to increase of both peak stress and stiffness as well as change of behaviour to a brittle one. Brittle behaviour is more marked in soil-fly ash-lime specimens after 7 days of curing in case of red soil. The soil-35%fly ash-lime mixes have higher unconfined strength than the soil-50%fly ash-lime specimens. The study indicates that the soil-fly ash mixes are suitable for good subgrade layer of road embankments, and when blended with lime is appropriate as road subbase or base materials.