The Kentucky Transportation Center, the Asphalt Institute, and the Kentucky Transportation Cabinet worked together in order to identify factors that affect asphalt pavement density, and to then evaluate their effect on long term pavement performance.

By determining which variables are most influential to pavement performance (i.e. roller pattern, temperature when rolled, etc.), and then monitoring the attention given to those variables, Kentucky would be able to increase the service life of asphalt roadways by at least 25%, therefore saving as much as $30 million annually on a resurfacing budget of $129.2 million (2007), while still maintaining the current roadway level of service.

Ensuring that the pavement roller is able to roll the surface at the appropriate temperature can result in increases in density of up to 4%. An asphalt mix having 11% voids failed at approximately 400,000 cycles @ 350 microstrains, compared to that same mix at 7% air voids failing at 600,000 cycles @ 350 microstrains, resulting in a lab fatigue life increase of 50%.

Two primary results were found from this study. First, by ensuring the compaction roller reaches the pavement before the temperature is allowed to drop substantially, up to a 4% increase in density can be achieved. Second, by increasing density 4%, lab fatigue life can be increased by as much as 50%. From these results, by practicing proper construction techniques one could conservatively expect to see increases in the service life of an asphalt surface of up to 25% in the field.

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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 University of Kentucky, the Transportation Cabinet, nor the Asphalt Institute. This report does not constitute a standard, specification, or regulation. The inclusion of manufacturer names and trade names are for identification purposes and are not to be considered as endorsements.