Abstract
California bearing ratio (CBR) is the reliable and direct measure of the sub grade but it takes a considerable time for its evaluation strength. As a result of the enormous work being carried out in the field of Transportation Engineering, there has been a shift from empirical to mechanistic-empirical pavement design. Consequently, there need arises to evaluate the modulus value of the subgrade, sub-base and base at a speed consistent with modern construction apparatus and the building pace of the construction industry at design and construction stages. The objective of this study was to correlate the results of one of the state of the art Non Destructive Testing Devices (NDT), the Light Falling Weight Deflectometer (LFWD) with the traditional CBR. LFWD tests were conducted on each sample at 9 locations i.e. middle, corners and sides ofthe samples having various densities. The CBR test following the standard procedure were done on the identical sample used for the LFWD tests . Consequently, an extensive experimental work was carried out and as a result statistical correlations have been developed between Dynamic Deformation Modulus (Evd) and CBR for Granular (A-1-b) and common (A-4) soil. The coefficient of determination for both types of materials shows a strong relationship between Evd and CBR.