The work at BLI began on April 27, and the project was substantially complete on October 14, 2010. Pavement grooving required a 30-day cure period for the new paved surface. Therefore, grooving was complete on October 28.
Complying with FAA specs
One tool ICON Materials used on the BLI project was its Paveset Grade Control System.
PaveSet is an electronic screed control computer from PaveSet America that has desired pavement elevations input into its memory in a grid determined by the contractor from the design drawings.
"ICON used an 18.75-foot by 25-foot grid pattern," says Babick. "Entering the existing elevations versus desired elevations can be done with a simple spreadsheet or can be input manually in the field."
The PaveSet control allows for the screed to place the pavement to the desired elevations including providing an allowance for uncompacted versus compacted hot mix. A PaveSet consultant can be employed for training and initial system set-up.
PaveSet is a "plug-and-play" system with robust components, says Babick. The system can be installed in minutes and can be adapted to any brand of screed control. It is plugged into the grade/ slope control valve of the paver with the computer "brain box" mounted at the back near the screed operator station.
During paving, the PaveSet system checks the screed elevation every 2.5 feet and makes adjustments accordingly. When used with a 20 foot ski, the result is a smooth "automatic" pavement surface, says Babick.
"PaveSet was used on all the critical paving passes to ensure compliance with FAA surface elevation specifications," he says. "The final surface elevations were 99+% within the FAA specification of not more than a 0.04 feet of variance from design elevations. 90+% of the survey certified elevations were with 0.02 feet of variance. One survey shot out of over 600 was out by 0.05 feet.
"This has been ICON's typical experience since replacing stingline systems with PaveSet in 2006," Babick continues. "This is the fifth runway/ taxiway paved by ICON using this system. PaveSet allows ICON to pave at full speed with assurance that we are paving the surface to exacting tolerances."
If the acceptance criteria for the pavement is the FAA "grade" specification, it is imperative PaveSet be used, explains Babick.
"Stringlines and slope control will not meet the FAA pavement grade spec," he says. "ICON prefers to input the elevations from points surveyed on the pavement for the last few lifts so that the paver operators can cross-check the screed controls constantly. This requires additional surveying, but is not strictly necessary for the use of PaveSet. "
As ICON chooses to input final elevations in the field, the survey crew must work in tandem with the paving crews.
"Everything we learned from the first runway we paved with PaveSet in 2006 has been used and refined in the five airport projects pavements we have constructed since 2006," says Babick. "We learned that the PaveSet system is stable, reliable and robust. If we set it up correctly, we can trust it and produce excellent results."