Presenting a CBR Estimation Model and Compaction Characteristics of Base Layer of Pavement Using a Dynamic Cone Penetrometer (DCP) Test

ABSTRACT In general, the basis of any type of management decision-making system is a correct evaluation of the current situation, future prediction, and finally optimal decision-making. There are various field methods for road pavement evaluation, among which are destructive and nondestructive methods. One of the nondestructive testing methods is dynamic cone penetrometer (DCP) testing. The main objective of this study is to investigate the feasibility of using DCP to control the quality of pavement layers and estimate parameters such as California bearing ratio (CBR) and compaction ratio. For this purpose, DCP, CBR tests, and determination of density percentage have been used as parameters used to control the quality of pavement layers. The dynamic resistance meter or DCP is a device that is used to quickly measure the resistance of different pavement layers. This device causes a small destruction on the surface. Hence, it is also called nondestructive testing. However, to use DCP, it is necessary to measure its results with the results of prevalent and widely used tests such as CBR and to examine their relationships. In this research, the DCP, CBR, density, sieve analysis, moisture content, and Atterberg limit tests were performed on two locations (a highway under construction and a landscaping project). Then, the results of the DCP test with CBR and soil compaction ratio (R) in two different locations were investigated and the relationships between these parameters were determined. The results showed that there is a good relationship statistically between DCP and CBR parameters in both locations. Also, for the first time, a very good correlation between the R parameter and the results of the dynamic penetrometer cone test was obtained. The observations represented that the correlation coefficients are higher than 0.9 in the highway location, which had well-graded soil in comparison with the landscaping project.