What is ASTM D5340?

Definition

ASTM D5340 is a test method that rates the surface condition of airport pavement with the Pavement Condition Index (PCI). Its full title is Standard Test Method for Airport Pavement Condition Index Surveys. An inspector looks at the pavement, records each distress, and the method turns the records into a PCI from 0 to 100. A PCI of 0 is a failed pavement and 100 is a new pavement.

What it covers

The method covers asphalt-surfaced pavement, including porous friction courses, and jointed concrete pavement, plain or reinforced. The US Army Corps of Engineers developed the PCI for airport pavement with funding from the US Air Force. The FAA and the US Naval Facilities Engineering Command adopted it.

ASTM sells the standard. ASTM lists D5340-24 as the active edition. A survey must follow the edition that the contract names. ASTM D6433 is the matching method for roads and parking lots.

How a survey works

The inspector separates the pavement by use into runways, taxiways and aprons. The inspector divides each area into sections with the same design, construction history, traffic and condition. The inspector then divides each section into sample units:

• Asphalt: 5,000 square feet, plus or minus 2,000 square feet (450 plus or minus 180 square metres).
• Concrete: 20 slabs, plus or minus 8 slabs. If the joint spacing is more than 25 ft (8 m), the inspector divides each slab into imaginary slabs of 25 ft or less.

The 1998 edition gives a formula for the minimum number of sample units for a 95 percent confidence level. It also allows a lower sampling rate.

The calculation has these steps:

1. Divide the quantity of each distress and severity by the area of the sample unit. The result is the density.
2. Read a deduct value for each distress and severity from the standard’s curves.
3. Combine the deduct values into a maximum corrected deduct value.
4. Subtract the maximum corrected deduct value from 100. The result is the PCI of the sample unit.

The PCI of the section is the average of the sample unit PCIs. It is a weighted average if the inspector added extra sample units.

Distress types

The FAA PAVER manuals list 17 asphalt distress types (codes 41 to 57) and 16 concrete distress types (codes 61 to 76). They implement STANAG 7181. The 1998 edition of the standard lists 16 and 15. The count depends on the edition.

• Asphalt, codes 41 to 49: alligator cracking, bleeding, block cracking, corrugation, depression, jet blast erosion, joint reflection cracking, longitudinal and transverse cracking, oil spillage.
• Asphalt, codes 50 to 57: patching and utility cut patch, polished aggregate, raveling, rutting, shoving, slippage cracking, swell, weathering.
• Concrete, codes 61 to 68: blowup, corner break, cracks, durability cracking, joint seal damage, small patching, large patching, popouts.
• Concrete, codes 69 to 76: pumping, scaling, settlement or faulting, shattered slab, shrinkage cracks, joint spalling, corner spalling, alkali-silica reaction (ASR).

Many severity levels depend on foreign object debris (FOD) potential. A joint reflection crack is low severity with little or no FOD potential. It is high severity when it is severely spalled, with definite FOD potential. If an inspector records high severity ASR on a slab, the inspector records no other distress on that slab.

What the PCI does not measure

The PCI cannot measure structural capacity. It gives no direct measurement of skid resistance or roughness. It does not replace direct measurement of roughness, structural capacity, texture or friction. AC 150/5320-6G names AC 150/5380-9 for roughness and AC 150/5320-12 for friction.

Use by the FAA

FAA AC 150/5380-7B describes the airport pavement management program. A federally obligated airport must make a detailed pavement inspection at least once a year. A PCI survey to ASTM D5340 allows the interval to be three years. The FAA PAVEAIR web program is one pavement management tool. The AC is mandatory for projects that AIP or PFC funds pay for.

Drone surveys

The 1998 edition assumes that inspectors walk on the pavement. Its apparatus list includes a hand odometer wheel, a straightedge or string line and a ruler. It names traffic and aircraft noise as hazards.

TarmacView is building a drone survey of airfield pavement. It records distresses to the D5340 definitions and computes a PCI for each sample unit. TarmacView offers the service as early access.