The National Center for Asphalt Technology (NCAT) has been studying ¾-inch thin-lays since 2012, using both recycled asphalt pavement (RAP) and recycled asphalt shingles (RAS). NCAT has tested these mixes with a smaller aggregate than is typically used on asphalt surfaces (#4 NMAS — or 4.75mm compared to 3/8” or ½”) and found that these mixtures have good cohesiveness.
The Kentucky Transportation Cabinet (KYTC) decided to try a thin-lay mix utilizing the #4 NMAS aggregate on the I-75 section. Having previously achieved excellent results with Surface Tech’s ARCA solutions on other high-traffic roadways, KYTC called for the company’s ACE XP Polymer Fibers™ to be added to the mix design to improve tensile strength, resiliency, and layer adhesion.
“On high volume roads, thin overlays can be risky, and if not designed properly can ravel or delaminate, but adding the ACE XP fibers provides a 3D reinforcement that knits the mix together to form a greatly improved and tough riding surface,” said Phil Blankenship, president of Blankenship Asphalt Tech and Training (BATT).
The Allen Company in Richmond placed the ¾-inch thin-lay surface in May 2022, with assistance from Site Supply providing Surface Tech’s ACE XP Polymer Fibers™ and the precision dosing equipment. With the added aramid reinforcement, the thin-lay surface should exceed the normal service life of this type of maintenance treatment mix, which ranges from five to seven years .
For more information on how Surface Tech’s ARCA solutions can save you time and money and extend the life of your next asphalt pavement, visit surface-tech.com.