Use of a Double Chip Seal to Correct a Flushing Hot Mix Asphalt Pavement in Washington State - Final Report

A double chip seal was applied to an existing HMA pavement to mitigate severe flushing that existed throughout the project. Special care was taken to adjust the amount of binder used to account for the degree of flushing in the existing pavement. The double chip seal was effective for approximately two years before flushing began to appear through the seal. After five years the flushing extended throughout the project in the wheel paths of both lanes. The origin of the flushing in the double seal was judged to be from the underlying HMA and not the
double seal. For this particular HMA pavement a double chip seal was not the long term solution. The double seal and underlying HMA pavement will be removed by grinding and replaced with a new HMA pavement.
Publication Date: 
Wednesday, September 7, 2016
Publication Number: 
WA-RD 760.2
Last modified: 
10/12/2016 - 15:41
Keith Anderson, Kevin Littleton, Jim Weston, Jeff S. Uhlmeyer, Brett Johnson, Scott Dunham, Stephen A. Van De Bogert.
Washington (State). Department of Transportation. Materials Laboratory.
Number of Pages: 
Hot mix asphalt, Flushing, Bleeding (Pavements), Chip seals, Binders, Seal coats, Durability tests, Pavement performance, Pavement components, Pavement maintenance, Evaluation and assessment.