Final Report FHWA/IN/JTRP-2005/20 Stiffness of Hot Mix Asphalt By Terhi K. Pellinen Principal Investigator Professor of Civil Engineering and Shangzhi Xiao Graduate Research Assistant School of Civil Engineering Purdue University Joint Transportation Research Program Project No. C-36-31M File No. 2-11-13 SPR -2644 Conducted in Cooperation with the Indiana Department of Transportation and The Federal Highway Administration The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of the Indiana Department of Transportation and Federal Highway Administration. This report does not constitute a standard, specification, or regulation. Purdue University West Lafayette, Indiana March 2006