Asphalt Plug Joint for Airport Runways and Taxiways

Asphalt plug joints on airport runways and taxiways must meet more stringent requirements than highway bridge joints due to the critical nature of airport operations and the risk of foreign object damage (FOD) to aircraft engines. FOD prevention is the primary concern for airport pavement joints. Any loose material at the joint that could be ingested by aircraft engines must be prevented. The asphalt plug material must have high aggregate retention to prevent aggregate loss under the repeated loading from aircraft tires and jet blast. Aircraft loading on airport pavement joints is different from highway loading in several ways. Aircraft have multiple wheels arranged in complex gear configurations, creating different loading patterns than highway vehicles. The tire pressure for aircraft is much higher than for highway vehicles, typically 1.0-1.5 MPa compared to 0.8 MPa for trucks. The joint must be designed for these higher tire pressures. Jet blast resistance is required for joints on taxiways and aprons where aircraft engines operate at high thrust. The jet blast creates high-velocity hot air that can soften and displace asphalt plug material. The joint material must have a high softening point to resist jet blast temperatures, which can exceed 200 degrees C at close range. Movement range for airport pavement joints is typically small (5-15 mm) because the pavement slabs are shorter than bridge spans. The joint must accommodate this small movement while maintaining a flush surface for aircraft operations. Any step at the joint can cause tire damage and must be prevented. Maintenance of airport pavement joints must be performed during periods when the runway or taxiway is closed to aircraft operations. The maintenance window is typically limited to a few hours overnight. The joint must be restored to the required surface condition before the runway is reopened.