What is abrasion in airport pavements?
Abrasion is the gradual wearing away of a pavement surface by rubbing, scraping and grinding from traffic and the grit trapped under it.
Where it shows up
On an airfield the wear concentrates where tires roll and brake, such as the touchdown areas of a runway. FAA AC 150/5380-6C names mechanical wear and polishing action from aircraft tires, with rubber deposits, as the main reasons runway skid resistance declines over time. The rate depends on the volume and type of traffic, the weather, the pavement type, the original materials and the maintenance practice.
The visible result is a smoother surface. Aggregate near the top becomes polished, and the texture that gives tires their grip is worn down. The same circular lists “age, i.e., surface wear” as the cause of loss of skid resistance on rigid pavement, and grinding as the remedy.
How a condition survey treats it
The PAVER distress manual for concrete airfields has no distress code for abrasion. The nearest code is scaling (70), which is a different defect. Scaling is the delamination or disintegration of the slab surface. PAVER ties it to construction defects (over-finishing, added water, lack of curing), material defects (too little air entrainment) and environmental factors. PAVER rates scaling by FOD potential. Low severity poses no FOD hazard and medium has some. High severity is a continuing hazard that routine sweeping does not clear.
Testing
Laboratory and field tests compare the abrasion resistance of concrete mixes and finishes. ASTM C779 has three procedures. C944 uses a rotating cutter and suits cores and small specimens. C418 uses sandblasting. These tests rank surfaces against each other. They do not tell you how long a runway surface will last.
Friction needs its own test
AC 150/5380-6C states that visual observation during an inspection is an inadequate predictor of skid resistance. It points to AC 150/5320-12 for friction surveys. An image-based pavement survey records visible wear and does not replace a friction measurement.
Frequently Asked Questions
- How is the abrasion resistance of concrete tested?
- ASTM C779, C944 and C418 each measure it with a different machine. C779 covers three procedures for horizontal concrete surfaces: a revolving disk, a dressing wheel and a ball bearing. C944 uses a rotating cutter, mainly on cores and small specimens. C418 blasts the surface with air-driven silica sand. All three give a relative measure of wear, not a prediction of service life.
- What is the difference between abrasion and scaling?
- Scaling is a surface defect with a construction, material or environmental cause, while abrasion is wear from traffic. The PAVER distress manual lists scaling as a concrete distress (code 70). It names causes such as over-finishing, added water, lack of curing and too little air entrainment. It has no separate distress code for abrasion.
- Does abrasion reduce runway friction?
- Yes. AC 150/5380-6C names mechanical wear and polishing by aircraft tires, together with rubber deposits, as the main reasons runway skid resistance falls. It also says visual observation during an inspection is an inadequate predictor of skid resistance. It points to AC 150/5320-12 for friction surveys.
References
- faa-ac-150-5380-6c
- AC 150/5380-6C, Guidelines and Procedures for Maintenance of Airport Pavements FAA
- faa-paver-concrete
- Concrete Surfaced Airfields, PAVER Distress Identification Manual US Army Engineer Research and Development Center (ERDC-CERL), for the US Air Force, June 2009
- astm-c779
- ASTM C779/C779M, Standard Test Method for Abrasion Resistance of Horizontal Concrete Surfaces ASTM International
- astm-c944
- ASTM C944/C944M, Standard Test Method for Abrasion Resistance of Concrete or Mortar Surfaces by the Rotating-Cutter Method ASTM International
- astm-c418
- ASTM C418, Standard Test Method for Abrasion Resistance of Concrete by Sandblasting ASTM International
This is a reference entry. TarmacView provides drone inspection services and doesn't sell the equipment or materials described in this glossary.
