Research

Pedro Romero, Ph.D., University of Utah and Doug Anderson, Utah Department of Transportation

The use of preservation seals on asphalt pavements is a crucial part of any effective pavement management program. It is important to optimize the use of available budgets to extend the life of our pavements as much as possible. The nation’s highway system is one of our most valuable assets.

Analysis of the performance of surface treatments on Utah pavements indicates that Open Graded Surface Courses (OGSC) have an average life, based on skid resistance of almost 9 years and that Chip Seal Courses (CSC) have a significantly longer life.

Out of all the factors analyzed, traffic has the most significant effect on the performance of the treatment. Factors such as aggregate source and asphalt supplier were also investigated but lack of data prevented from reaching any significant conclusion.

Based on the relative cost of both treatments and the performance observed through this study, it is recommended that Utah Department of Transportation expand the use of CSC to certain roads with AADTs up to 20,000 vehicles and continue the existing procedure of using CSC in highway sections with AADTs below 5,000. It is also recommended that UDOT modified the existing policies and limit the use of OGSC where the running speeds are 55 mph or greater and AADTs are in excess of 25,000 vehicles. Medium volume facilities (5,000 to 25,000 AADT) should be sealed with treatments new to UDOT but proven in other states.

An initial cost analysis showed that the implementation of the changes suggested as part of this report will results in savings of over $2 million per year in the maintenance budget. Thus allowing for better use of resources while still serving the traveling public.

University of Utah conducted this research from 2003 to 2004.  They were supported by the Utah Department of Transportation, Research Division.