Warm Mix Asphalt Takes Flight at O’Hare International

The world’s second busiest airport in terms of flight operations behind Atlanta’s Hartsfield-Jackson International is undergoing some major changes. The O’Hare Modernization Program (OMP) as the expansion and upgrading project is named, is currently one of the country’s largest construction projects.

The project is under the management of the Chicago Department of Aviation (CDA) and involves constructing a new runway and taxiways, expanding and/or relocating some existing runways and taxiways, and constructing a new passenger terminal. The work is being done in phases with the new terminal to be built in the future as demand dictates.

The OMP is reconfiguring O’Hare’s airfield into a modern parallel runway configuration from the original system of intersecting runways. This new configuration will reduce flight delays and increase capacity.

Upon completion of the OMP, there will be a total of eight runways, six will be east-west parallel and two will be crosswind. Two relocated runways will have been constructed to accommodate new larger Group VI aircraft. Several miles of new taxiways will have been built as well. Also included in the plan is the eventual construction of a new passenger terminal on the west side of the airport.

Incorporating sustainability

The CDA has continually emphasized the importance of incorporating and utilizing sustainability practices in the design and construction of all projects related to the OMP. Roughly two years ago members of the OMP team evaluated the use of more environmentally friendly warm mix asphalt (WMA) as opposed to hot mix asphalt (HMA).

The CDA had extensive consultations with the Civil Engineering Department of the University of Illinois and with representatives from the Federal Aviation Administration (FAA). Based on research, the CDA concluded that WMA was an appropriate substitute for HMA on O’Hare’s taxiway projects.

O’Hare International as a result of the above research and testing is the first airport in the Great Lakes Region and among the first in the United States to produce and place WMA as part of the construction of new taxiways for the OMP.

The specific names of the projects are OMP Taxiway Zulu Sierra (ZS) and Runway 9C-27C Northeast Projects at O’Hare International Airport. Plote Construction Inc. of Hoffman Estates, IL constructed the Taxiway ZS project. The Walsh/TJ Lambrecht Joint Venture is the contractor for the Runway 9C-27C Northeast project. K-Five Construction Corporation of Lemont, IL, is the asphalt paving subcontractor.

During 2011, OMP contractors placed more than 7,100 tons of WMA to construct the asphalt-treated permeable base (ATPB), binder course and shoulders for Taxiway ZS. This work was done from late July to early August 2011 and the overall Taxiway ZS project was completed in the fall of 2011.

This new taxiway is a component of the OMP Completion Phase 2A and was constructed as a Group V category taxiway. Group V status can accommodate Group VI aircraft (NLAs) with certain operating restrictions. Taxiway ZS is located on O’Hare’s south airfield near the Southwest Cargo area and runs in a north/south orientation between future Runways 10C-28C and 10R-28L.

Concurrently, in the fall of 2011 the OMP deposited approximately 37,000 tons of WMA for the ATPB, binder course, and shoulders of a group of taxiways included in the Runway 9C-27C Northeast project. Approximately 30,000 tons of WMA remain for construction in 2012.

This work is being conducted at the northeastern corner of the airfield and is part of future Runway 9C-27C. The WMA work is slated to be completed in the spring of 2012. The Runway 9C-27C Northeast project consists of new taxiways and the realignment of existing taxiways.

WMA new to aviation

WMA is a relatively new technology in relation to the aviation industry. Therefore, the CDA was required to seek approval from the FAA before using WMA for the OMP. The CDA prepared and submitted a Modification of Standards for FAA review to obtain approval and permission to utilize the more environmentally friendly WMA asphalt production and paving technique.