Graded Hot Mix Asphalt Pavement Density. Abstract approved:

The Oregon Department of Transportation (ODOT) standard specifications require a minimum density for the construction of dense-graded hot mix asphalt (HMA) pavements. Currently, the standard specifications call for density measurements for quality control (QC) and quality assurance (QA) testing to be made using nuclear density gauges that are calibrated using reference blocks and correlated (adjusted) to densities from pavement cores. QC measurements (performed by the contractor) are verified by QA measurements (performed by ODOT); then ODOT utilizes the contractor’s QC results for determining acceptance of the pavement (in conjunction with other specification criteria). Hence, appropriately accepting an HMA pavement, based on the in-place density criterion, relies on the accuracy of the density measurements. However, density measurement results using nuclear gauges have been observed by ODOT to be questionable on a number of projects, and repeatability and reproducibility with the same gauge and between gauges has been unattainable. The overall objective of the project described herein was to develop a system that accurately quantifies density of dense-graded HMA pavements. More specifically, th