Correlation Between CBR Values and Index Properties of Soils

Abstract

Presently India’s infrastructure is growing rapidly. Large number of new urban and lightly trafficked roads are being constructed or planned. The California bearing ratio (CBR) is the well known, common and trustful test currently used in road construction. The CBR values are used by the engineers to design the thickness of pavement layer to be laid on the top of the sub-grade. Laboratory tests like consistency tests, standard proctor test and CBR tests were conducted on soil samples. Correlations between index properties and CBR values of the soil samples were investigated and predictive equations estimating CBR from the experimental index values were developed. The findings show that good correlation exists between index properties and CBR values. However, the values of the CBR computed from the regression models are only to be used for preliminary in view of simplicity and economy and not acceptable alternatives to laboratory testing.