What is an Asphalt Rejuvenator?
An asphalt rejuvenator is a liquid that crews spray on an asphalt surface to restore the aged binder in its top 9 mm.
What the FAA specifies
FAA item P-632 covers the application of a rejuvenation product. The item says the product is commonly called a fog seal. It rejuvenates the upper 3/8 inch (9 mm) of aged binder. It must not cause an unacceptable reduction in friction, and it must not cause distresses such as raveling or rutting.
The item gives these limits for use:
- A note to the engineer says the item suits pavements on which aircraft do not operate, such as shoulders, overruns, roads and parking areas.
- The same note allows airport pavements, except runways and acute-angled exit taxiways. This applies at airports that serve airplanes under 60,000 lb (27,216 kg).
- The surface must be low to moderately weathered, as ASTM D5340 defines it.
- A pavement is a candidate if it has no structural, load-associated distresses and has low to moderate environmental distresses. P-632 recommends a corrected PCI of 70 or more.
The pavement condition survey is therefore an input to the decision. It gives the type, amount and severity of the distresses, and the PCI.
Control on site
Before full production, the contractor places control strips to find the application rate. The owner’s resident project representative (RPR) checks them after 24 hours. A rate that has not fully penetrated the surface in that time cannot be used. On runway and taxiway surfaces, aircraft cannot use a control strip until its friction meets the levels in AC 150/5320-12, Table 3-2.
The surface must be dry. Do not apply the product if rain or freezing temperatures are likely within 24 hours before or after the work. The contractor must cover runway and taxiway edge lights, signs and retro-reflective markings against overspray. If product reaches a light or marker, the contractor cleans it, and replaces it if the cleaning is not satisfactory. The application rate may vary by 5 percent from the approved rate.
Acceptance test
The contractor takes three cores from the untreated pavement and three from the treated pavement at each sampling location. The contractor takes the treated cores 30 to 45 days after the application. The laboratory recovers the binder from the top 3/8 inch (9 mm). It then measures the decrease in complex modulus (G*) at 60 °C against the untreated cores.
| Pavement age | Required decrease in G* |
|---|---|
| 3 years or less | 25 percent or more |
| More than 3 years | 40 percent or more |
This page covers only the surface treatment in P-632.
Frequently Asked Questions
- What is a rejuvenator in FAA item P-632?
- It is a product that crews apply to a placed asphalt surface. It rejuvenates the upper 3/8 inch (9 mm) of oxidized or aged binder. The product must not cause an unacceptable loss of friction. P-632 says it is commonly called a fog seal.
- Can an airport use a rejuvenator on a runway?
- The P-632 guidance note allows airport pavements, except runways and acute-angled exit taxiways. This applies at airports that serve airplanes under 60,000 lb (27,216 kg). The same item also describes friction control strips for runway and taxiway surfaces. The project specification decides.
- Which pavements are candidates for rejuvenation?
- A pavement with no structural, load-associated distresses and with low to moderate environmental distresses. P-632 recommends a corrected pavement condition index (PCI) of 70 or more, from a survey to ASTM D5340.
- How does an owner check that a rejuvenator worked?
- The contractor takes cores from the treated and untreated pavement. A laboratory tests the binder that it recovers from the top 3/8 inch (9 mm). The binder viscosity must decrease by the percentage that P-632 sets for the pavement age.
References
This is a reference entry. TarmacView provides drone inspection services and doesn't sell the equipment or materials described in this glossary.
