Oklahoma Air National Guard, Tulsa

Facts and Figures

Tigerbrain developed the reconstruction of the F-16 apron. The original concrete was severely cracked due to freeze-thaw damage and generating high FOD amounts. Built in 1959, the 12 inch concrete apron included about 68,000 square yards and an additiona1l 17,000 square yards for hangar access aprons. The project as designed was sized to 51,000 square yards to meet DD1391 allowances; the excess 14,000 square yards were converted to non-airfield equipment staging. The hangar access area remained at 17,000 square yards. This accommodates 18 F-16 aircraft parking positions, plus an additional four positions for the combined mission area serving arm/disarm, hung munitions, and fire-control radar check facility functions.

Historical/Significant Fact

The design utilized rubblization instead of removal of the existing concrete, saving about $4 million and reducing construction time by 8 months. Rubblization is a concrete fracturing process that converts deteriorated concrete into high-stability crushed concrete base, in-place. This saves the time and expense of demolition, excavation, and replacement with new materials. The new pavement is then built on top of the rubblized layer. To accommodate matching surrounding grades to hangar throats and taxiways, full-depth concrete transition pavements were built. Clay soils in excavated areas were recycled by providing a work platform using hydrated lime. Lime stabilization saved another $1 million and about 1.5 months of construction time. Rubblization and lime stabilization are LEED techniques.

Challenges

The project had several major challenges to overcome. First was balancing the need to provide apron space for C-5 transient aircraft for weekend missions. This was accomplished by utilizing the combined mission area of the apron. Second, the apron only had one taxiway to access the runway. Maintaining mission flight tempo was accomplished by initially building the asphalt shoulder to support routine fighter movements.

Rubblized Concrete with Multi-Head Breaker

Rubblized Concrete with Multi-Head Breaker

Third, fire/rescue access from the on-apron fire station was maintained at all times by balanced construction phasing. Fourth was reclassifying the excess old apron as non-airfield equipment staging. Finally, a revetment was built to protect down-range dwellings and personnel from the arm-dearm apron. Located on a steep embankment, the available space was governed by apron set back requirements and property lines. Tigerbrain stabilized and leveled the embankment to support a sand-filled corrugated metal revetment structure.

Asphalt

The apron includes 46,495 square yards of 4 inch airfield asphalt surface mix to cap the rubblized concrete base and provide a stabilized platform for the drainage layer and concrete surface. There are 4,470 square yards of 6 inch airfield asphalt used as a taxiway during construction and then remarked as a shoulder. The remaining shoulders are 7,368 square yards of 4 inch airfield asphalt.

Title I and Title II

As a subconsultant to Cyntergy, Tigerbrain led the design effort from conception through finalization, including apron layout charrettes, grading, geometry, paving and markings. Drainage, permitting and airfield electrical were provided by Cyntergy.

Tigerbrain’s Title II effort included inspecting the work, periodic site visits, submittal review and resolving RFI’s. For the concrete, Tigerbrain ensured the mixture was optimized to reduce spalling potential. Optimization was achieved by enforcing Air Force aggregate standards and evaluating the mixture for constructability. Tigerbrain proactively engaged the contractor by defining process adjustments during paving.

Relevance

This apron demonstrates Tigerbrain’s ability to assess existing conditions, optimize use of local materials, and provide a sustainable pavement. The project had a construction value of $12 million sealed by Tigerbrain

Concrete Paving

Concrete Paving

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