ENGINEERING PROPERTIES OF BLACK COTTON SOIL-DOLIME MIX FOR ITS USE AS SUBBASE MATERIAL IN PAVEMENTS

Abstract

: In this paper, an attempt is made to stabilize problematic expansive Black Cotton (BC) soil by
dolime fines for its use in subbase course of flexible pavements. Atterberg limits, free swell index,
compaction characteristics, unconfined compressive strength (UCS), soaked CBR, shear strength parameters
and resilient modulus are evaluated for different trial mixes cured up to 28 days. BC soil stabilized with a
minimum dolime content of 9% satisfies the criteria recommended by Indian Road Congress for utilization in
subbase layer of flexible pavements. The effects of dolime content and curing period on the above
geotechnical properties of the mixes were investigated. Empirical relationships are developed to estimate
important design parameters such as deviator stress at failure and cohesion of the stabilized mix that can be
used to determine dolime content to achieve a target strength within a given curing period. Different
empirical models are proposed to estimate the resilient modulus of soil-dolime mixes and their performances
for the prediction of resilient modulus are compared.