John Wayne Airport (JWA), a prominent Los Angeles regional facility that is tightly surrounded by high density commercial and residential areas, recently completed reconstruction of its primary runway. Kimley Horn & Associates Inc. provided project administration and engineering while Butier Engineering, Inc. provided construction management. All American Asphalt Inc. provided construction supervision, materials, labor and equipment to build the project
Primary work included coring the top three inches of aged pavement on the 5,700-foot main runway then repaving the area with a PG 76-10 overlay. Included in the specification was the requirement for protecting 68,000 square yards of runway shoulder and aprons with a protective coating which was:
- Environmentally clean (no VOCs, no HAPs, no toxins or carcinogens, and no Polycyclic Aromatic Hydrocarbons)
- Fuel resistant
- "Skid neutral" or better
- Insoluble to rain within one hour of curing
- Able to cure at night, at 50 degrees F, in less than six hours.
Those requirements set standards that only new innovation could solve.
Due to its neighborhood proximity, the airport is regularly closed between the hours of 11 p.m. and 6 a.m. This presented the challenge of developing and installing a coating that could be placed and would achieve full cure within this time window so heavy jet traffic could resume operations.
Since the contract penalty for interrupting normal JWA activities was $10,000 per minute, the decision process for selecting a coating which met all the requirements, especially those of the curing window was, to say the least, characterized by heightened drama.
Ramsey Oil Inc., a division of All American Asphalt, would install the coating. Paul Snow, Ramsey's crew manager, was tasked with coordinating nighttime field test applications of coating alternatives; which were then evaluated by JWA representatives.
After considering many options provided through the All American management team, the head of procurement, John Todorovich, concurred with the JWA representatives that the product supplied by Ecostar Science & Technology Inc. was the best choice.
That product was Carbon Plex H-25 - manufactured under an Ecostar license by Delta Trading, Inc. of Bakersfield, CA.
The installation of the coating was scheduled for late December 2008 but 40 degree F nighttime temperatures left little margin for error. The Carbon Plex emulsion, which has exhibited the quality of fully curing down to that temperature, had only been tested at John Wayne at nighttime with 50 degree F temperatures. The job was pushed back to January 8-9.
Everyone was antsy to wrap up this project after the months of coating study, even if it meant going in the middle of the winter, at night. The weather report for those dates was for rising temperatures and clear skies, with possible 'Santa Anna' winds which would provide excellent drying conditions. Everyone felt comfortable with pulling off this last critical phase of the project.
Seven thousand gallons of the "cold cure" version of the Carbon Plex H-25 was prepared, then diluted 25 percent and shipped to the jobsite ready to use. A light tower-rigged 2,000 gallon Bearcat distributor truck was readied, together with three mobile light tower platforms.
Against the backdrop of jet engine roar, the Ramsey Oil crew put on their 'game face' and huddled in the staging area at the pre-installation tailgate meeting with four JWA engineers and two inspectors. Air and pavement temperatures were in the low 50s F. The table was set for finishing the project except for one fly in the ointment - fog.
Snow, who had the most experience with the Carbon Plex, felt a cautious start was possible, paying close attention to the 'break' time. The plan was to install a short run of the H-25, time the cure and then decide whether to continue or scrub the effort for the night. The JWA engineers and inspectors then present concurred with Snow's cautious start proposal.
At 10:45 p.m. the gates were opened and the convoy of trucks was escorted out through the fog hovering over the main runway. As the Carbon Plex H-25 does not need to be heated to cure under nighttime conditions, minimal heat (110 degrees F) was used to encourage drying. At 11:07 p.m. the first 12-foot swath was placed at a spread rate of .10-.12 gallons per square yard.
When the Bearcat operator 'dropped the hammer' and disappeared into the fog on his first mile-plus run, every eye at the start line leaned forward under the glare of the light tower to glean information from the flow pattern and color change of the freshly placed coating.
The entire span of runway pavement surface had been saw cut with 3/8-inch deep grooves at one inch on center. A special characteristic of the Carbon Plex H-25 is its rapid 10:1 (static/shear thin) viscosity rise after being pumped and sprayed. In less than one second from hitting the pavement the static viscosity is nearly restored, assuring a significant resistance to puddling in the grooves. On this foggy night it was performing as designed, with virtually no uneven film thickness between the pavement surface and the groove bottoms.
At this point other good things began to happen. Before the Bearcat returned painting its second 12-foot swath, a black hue began to show in the over-spray zone. The Carbon Plex emulsion was breaking! Even with the atmospheric vapor content above the surface being at or near saturation the exothermic reaction designed into the "cold cure" version of H-25 was kicking in and forcing the micronized emulsion water component to volatize.
The JWA engineers granted that the installation could proceed. By 1:45 a.m., the 640,000-square-foot project was coated and curing at a predictable pace. At about 3:30 a.m. the entire job was drivable, even though the fog had actually worsened at times.
The first critical stage of the job had been accomplished.
The coating was installed and cured in the allotted time and under the conditions prescribed. Curing had progressed to a film sufficiently tough to resist tire displacement as well as becoming water fast with no chance of re-emulsification.
Stage Two came the next morning when heavy jet traffic began moving over the fresh, shiny black coating. Jets rolled over the 3-foot-wide, white thermoplastic stripe defining the runway, without one hint of any tracking.
Stage Three will occur over the coming months and years, to see how well the product performs under the insult of hot jet exhaust, unspent J5 vapor, salty fog and a hot Southern California solar bake.
Information provided by William Coe, President, Ecostar Science and Technology Inc.