INVESTIGATIONS ON FIBRE-REINFORCED EARTH IN PAVEMENT SUBGRADE

Abstract

The role of subgrade in efficient performance of pavements is of paramount importance. Stabilization of soil has been the age old practice of improving subgrade soil. The conventional soil improvement techniques are generally expensive, involving large quantity of costly materials and construction operations. So, there is a need to explore the possibility of using low cost material which can improve the properties of the soil in a better way. Fibre reinforced soil termed as "Ply soil" is a composite material obtained by mixing randomly distributed discrete fibres to soil. Lime is added to the fibre reinforced soil to see its effects. It is observed that the properties of the fibre reinforced soil is further enhanced when lime is added. Moreover it is essential to add lime to weak soil if it is to be reinforced with randomly discrete fibres. This dissertation presents the effects of addition of lime and fibres to the sandy soil. It also deals with the theory behind the mechanism of fibre reinforced soil, its properties and classification. This reports deals with interpretation of proctor's test, CBR test, triaxial tests and plate load test to investigate the effects of lime and fibre inclusion on the strength and behaviour of the soil. An attempt has also been made to recommend a suitable lime-fibre soil combination for practical applications which would create a confidence amongst the construction agencies to adopt the new technique.