This $21.5 million rehabilitation project for Denver International Airport (DIA) provided 59,827 square yards of airfield pavement for Runway 8/26 and adjacent taxiways. In addition, the project included 56,430 square yards of Cement Treated Soil installation, over 465 in-pavement lights, installation of 2,670 feet of various sized drainage pipe and 26,790 tons of asphaltic bituminous pavements. The panel replacements varied in thickness including 17"and 21" at thickened edges. 51,309 square yards of panels replaced were low production (4 panels or less), 8,518 square yards of panel replacement was considered high production, and over 17,750 square yards of PCCP were reinforced.
Schedule and Complexity
The 165 calendar day schedule included a 45-day runway closure, ensured with a $50,000 per day liquidated damage specification. A 20 day administrative NTP allowed pre-construction verification that all materials met "Buy American" requirements, avoiding any delays for runway closure. The bid consisted of 15 sections, based on Federal and City funding. DIA awarded 7 sections, but just days prior to the start of construction, added widening of taxiway shoulder areas, thus doubling the electrical scope and adding 80,000 cubic yards of embankment. The overall project consisted of removing concrete panels in small groups throughout the entire runway complex, making the scheduling and coordination of the flow of work crucial to the project's completion. The runway was closed on August 25 and re-opened on time by October 8.
Construction and Innovation
To ensure concrete removals stayed on schedule, three sawing companies were utilized to deep saw the removal areas. Extra large off-road articulated trucks hauled rubble from the work site. In order to utilize the off-road trucks with their larger loads, special haul roads were constructed with Roller Compacted Concrete placed at needed locations to ensure a stable roadway.
Throughout removal operations, large areas of subgrade material required evaluation and remediation prior to replacing the PCCP. With removal operations ahead of schedule, sufficient time was available to allow re-scheduling of paving operations to accelerate the schedule. In conjunction with the panel removals, the electrical subcontractor had to remove all fixtures within a panels-width of any areas affected during the construction process. To ensure the paving operations stayed on schedule, three separate pavers were used to pave multiple lane widths.
The Quality Control plan was a cooperative effort between the Contractor's Quality Control Program and the Owner's Quality Assurance Program. Split samples were used for all PCCP strength determinations.
For Lean Concrete, an independent certified lab ran tests for acceptance, which were verified by the Owner's program on a one in ten basis. The project required a 100% Quality Control Inspection with random Quality Assurance monitored inspection.