Influence and correlation of maximum dry density on soaked & unsoaked CBR of soil

Abstract

Preparation of subgrade plays an significant role in construction of roads as it acts as the foundation to the flexible pavement. The soil subgrade can be utilized to its full extent only if it is well compacted, the subgrade strength is related to the CBR of soil. Determination of stiffness modulus and shear strength of the subgrade using California bearing ratio (CBR) test. The CBR values be contingent on the nature & other properties of soil. CBR test is very laborious, time overwhelming & always be performed on moulded soil samples which makes it difficult to get accurate values and also to implement in reality. In the present study the authors have made an attempt to calculate the CBR values and the index properties of the soil and to develop a relationship between them so that one can obtain reliable CBR values in less time. The authors have collected the samples from Chickballapur district, India and correlated unsoaked and soaked CBR value with maximum dry density, optimum moisture content, percentage fines, liquid limit and unconfined compressive strength etc. Experimental outcomes indicates that the soil properties influence the CBR value of soil. Correlations are developed between the California bearing ratio and maximum dry density with satisfactory R2 values with which CBR values can be predicted.