Airport Markings

Paint and Bead Durability

Airport pavement markings are a critical component of airfield visual aids, and it is especially important that they be properly maintained. In order to accomplish this, airports expend considerable resources to maintain the effectiveness of the marking system.

The approach taken during the course of this project was to evaluate potential materials for operational and environmental suitability, select materials, and install them at an airport test site. The Federal Aviation Administration Office of Aviation Research, Airport Technology Research and Development Branch, Airport R&D, has evaluated paint and bead durability in three areas:

1. Water emulsion paint performance
2. Glass bead performance
3. Application thickness of paint

 

It was also the intent to evaluate a cementitious pavement marking material, however due to installation problems this material was not evaluated.

A series of airport pavement markings were placed at the Atlantic City International Airport for evaluation.
The three paints used were from:

 

1. Rohm and Haas
2. Sherwin-Williams
3. TMT

 

The four beads used were:

 

1. 1.5 IOR Visibead A (L-511)
2. 1.5 IOR Visibead B (L-511 Millennium)
3. 1.5 IOR Megalux A (Airport and Highway High Quality and High Performance Drop-On)
4. 1.5 IOR Megalux B (Airport “Beacon” High Quality and High Performance).

 

Conclusions:

 

1. HD-21A Rohm and Haas water emulsion paint held retro-reflective beads better. The coupling agent sprayed on the beads improves bead retention on the paint, initially and over time.
2. Type III (1.9 IOR) airport beads had the best retro-reflectivity, initially and over time. All four new 1.5 IOR beads are acceptable.
3. At the application thickness of 0.33 mm (15 mil) more beads adhere to the paint, allowing better retro-reflective readings.

 

The following research paper is available in Adobe Acrobat Reader format if you click on this link. This document describes the glass bead and waterborne paint research performed at the Technical Center.

Paint and Durability Study

Author: Holly Cyrus
Format: Adobe Acrobat
Size: 25.2MB

Contact Project Lead: Holly Cyrus, Airport R&D

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Development of Methods for Determining Airport Pavement Marking Effectiveness

Airport pavement markings on runways, taxiways, and ramps play an important role in preventing runway incursions.  Airport paint markings, however, deteriorate in terms of their conspicuity and must be replaced over time.  Presently, the conspicuity is determined by visual inspections of segments of these markings, but the validity of these inspections cannot always be confirmed.

This study was undertaken to develop a method for a quick and accurate evaluation of paint markings.  A manual method was required for eliminating subjectivity in the current method, and an automated method was developed for evaluation of larger surface markings over a vast airport area.  In addition, the study also established a threshold pass/fail limit for white and yellow paint.

It was found that for the manual method, three devices are required:

• A retro-reflectometer is required for determining retro-reflectivity of the beads.
• A spectrophotometer is required to determine whether or not the paint marking has faded out of tolerance.
• A transparent grid is used to determine coverage of the paint.

If any one of these three tests fails, the pavement marking fails.

For the automated method, a van-mounted Laserlux or similar mobile unit is required.  The automated method increases the speed and sample size.  It works well for large airports, which have very long runway centerlines and threshold markings.

The retro-reflective threshold limit for yellow paint is 70 mcd/m²/lx.  The coverage threshold pass/fail limit is 50%.

The research paper entitled “Development of Methods for Determining Airport Pavement Marking Effectiveness” can be obtained in adobe format if you click on this link. This document describes the research performed concerning when to repaint airport pavement markings.

Development of Methods for Determining Airport Pavement Marking Effectiveness

Author: Holly Cyrus
Format: Adobe Acrobat
Size: 9.8MB

 

Contact Project Lead: Holly Cyrus, Airport R&D

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Last Update: 05/18/09