2007-2008 Airfield Concrete Rehabilitation CPR - Denver International Airport

Project Focus
This $16.7 million Concrete Pavement Restoration (CPR) project at Denver International Airport removed and replaced 83,000 SY (approximately 2000 panels) of heavy-duty, 17" thick airfield pavement on taxiways and runways in four different areas, including more than 450 in-pavement lights. In addition to the traditional construction processes involved with panel replacement, the project also included 500 cubic feet of spall repair, replacement of heavy duty expantion joints, 34 panels stabilized with mud-jacking, joint & crack sealing, and 4000 SY of surface grinding to eliminate ponding of water.

Project Details
Schedule & Complexity
Bid in August 2007, the original plan to complete milestone #1 that fall was abandoned because of an unexpected delay in the Notice to Proceed to October, too late to ensure completion of the important intersection prior to winter. The project was delayed until 2008, requiring that all four milestones be completed in the 2008 construction season. The Contractor, DIA Operations and the FAA combined efforts to plan and prepare over the winter months to implement a workable schedule, considering the logistics of traffic flow before, during and after peak hours, to best accommodate airfield operations while constructing milestones in four different airfield areas.

With taxiing aircraft only a few feet from the work zone, management for safety was critical. The haul routes for materials in and out of the airfield required the crossing of active taxiways with as many as 25 construction trucks on the airfield at peak production. All Contractor personnel were initially trained, attended weekly safety meetings and were monitored on a daily basis to ensure that the haul route procedures were strictly followed. Foreign-object-debris (FOD) “watchers” were placed at impact areas to monitor traffic and cleanup FOD immediately.

All milestones were completed ahead of the required time and overall runway closure was 17 days less than the 65 days originally planned. Significant change orders were constructed concurrently with the original scope, without adversely impacting the scheduled milestones. This extra work included replacing 2000 square yards of PCCP around gate areas; correction of profile for “heaving” concrete at a high speed taxiway; an additional 54 light can replacements; a manhole vault reconstruction and an emergency sewer repair.

Construction & Innovation
The panel replacements varied in thickness including 17”, 19” and 21”. 8025sy of replacement panels were reinforced. The contractor optimized the time required for the removal of the existing PCCP using three CAT 325 series backhoes with breaker attachments, a 460 backhoe with thumb and a 980 loader. As the removal of concrete took place, the cement-treated base was inspected, and if deemed unsuitable, removed and replaced with lean concrete. This helped maintain the schedule and minimize the impact for these conditions.

Concurrently with the start of a milestone, the Contractor began breaking and crushing concrete at the waste area to make Class 6 road base and Rip-Rap for the project, optimizing the turnaround time of the trucks removing waste material to this area.

Quality
The Quality Control plan was a cooperative effort between the Contractor’s Quality Control (CQC) Program and the Owner’s Quality Assurance (QA) program. Split samples were used for all PCCP strength determinations. For Lean Concrete the Contractor’s certified lab ran the QC tests for acceptance, verified by the Owner QA program on a one in ten basis. All QC testing was logged in a database and compiled in weekly QC reports that were transmitted to the Owner’s QA department for review. This Project required a 100% QC Inspection by the contractor and a QA monitored random inspection.

Public Relations
All FAA, Airline, and City and County of Denver personnel were informed of construction areas and activities before work began on this project. NOTAMS (Notices to Airmen) were required 48 hours prior to any closure. Also, weekly meetings were held and updated schedules were distributed. In addition to the standard project progress meetings, the Contractor also met weekly with personnel from United Airlines to coordinate work in and around their ramp area. These meetings were held to ensure the work had minimal impact on United Airlines Operations at Denver InNternational Airport. Meetings were also held with all other airlines on an as needed basis. The FAA tower was notified 3-4 weeks prior to major closures and advised all airlines.