A stringent quality-control program of onsite testing and real-time exchange of performance data among the contractor, engineer, and material producer enabled The Harper Company to place 46,760 square yards of 10-inch-thick jointed reinforced concrete with exceptional flatness. Close tolerance-monitoring of pavement thickness, edge slump, and material consistency, combined with continuous communication between the onsite testing personnel and the concrete producer, resulted in 100% of the new 850x500-foot apron meeting the ¼-inch-per-12-feet smoothness standard. Only one of the more than 1300 truckloads failed to meet material standards; that load was pulled from the delivery rotation and mixed with other material onsite to reduce the bleedwater.
The subbase consisted of 12 inches of lime-treated soil, compacted and cured, built to stabilize a weak, undulating clay soil. Onsite laser and total station survey techniques contributed to the excellent conformance to grade and smoothness. The no-slump concrete was batched offsite, delivered in non-agitating trucks, and then slip formed.
This project was subject to the usual airport constraints—an active taxiway adjacent to the project and concurrent construction of the new AirNet hangar terminal that the apron would serve. Then four underground storage tanks full of jet fuel were discovered on the project site and had to be drained and removed. Because the site was formerly an Air Force Base, that required extensive coordination with the military and the EPA. Even so, the overall project schedule was maintained, thanks to good contingency planning and the close working relationships developed among the project team.
- Contractor: The Harper Company
- Engineer: Crawford, Murphy & Tilly, Inc.
- Owner: Columbus Regional Airport Authority
View all the winners and finalists of the American Concrete Pavement Association's 16th Annual Excellence in Concrete Pavement Awards.