Asphalt on Tires

Occasionally, the tires on the spreader and the haul trucks should be checked for asphalt (and aggregate) sticking to them. This should be corrected immediately.
The following conditions may cause tires to pick up asphalt:
  • Aggregate is rolling over causing asphalt to be exposed to the tires. This can be caused by not using enough asphalt to hold the aggregate or by applying too much aggregate. Refer to
    Section 14
    for more information on the proper time to begin spreading the aggregate.
  • Too much asphalt has been applied.
  • A puddle of asphalt may have leaked or spilled onto the pavement without cleanup prior to aggregate application.
  • One of the discharge gates on the spreader may have clogged momentarily, preventing the aggregate from covering the asphalt.
  • Failure to use deflector nozzles and overlapping the shot in the second lane causes an excess of asphalt.
  • Detouring traffic onto the fresh seal may cause aggregate pickup.
  • Construction and other traffic accelerating, turning, and braking abruptly on the fresh seal can dislodge aggregate. Accelerating quickly may cause a tire to spin because of the soft asphalt and unrolled aggregate. Turning quickly may cause the aggregate to roll over, exposing some of the asphalt. Braking suddenly may cause the wheels to lock and shove aggregate. These situations can occur with any asphalt but are most likely to occur when using asphalt emulsions.
  • Improper tire inflation pressures on construction vehicles.
If any of the above situations occur, the seal patching crew should repair the spot before rolling. Tires should be cleaned immediately and the condition remedied before the situation gets worse.