1-795 repairs will cost millions
By Steve Herring
Published in News on January 9, 2009 1:46 PM
It could cost the state $14 million to $22 million to correct the crumbling pavement on Interstate 795, according to a Federal Highway Administration report released earlier this week.
Meanwhile, Ricky Greene, N.C. Department of Transportation division engineer, said changes in the asphalt mix and design should ensure that the U.S. 70 Goldsboro Bypass now under construction will not be plagued by the same problems.
According to the North Carolina I-795/U.S. 117 Bypass (Goldsboro to Fremont) Flexible Pavement Quality Review Report prepared by the Federal Highway Administration, the DOT "followed all appropriate procedures in the design of the pavement and that the failure was most likely due to deficiencies in the Hot Mix Asphalt (HMA)."
Heavy, overweight trucks might have accelerated the crumbling.
A February 2008 DOT study found that while the overall vehicle count on I-795 is about half what was assumed for design, the percentage of truck traffic is "significantly higher" -- 13.7 percent compared to 9 percent assumed in the U.S. 117 design.
According to the report, the majority of the five-axle tractor-trailers were either empty or partially loaded. However, the study found that a "significant portion (10 percent)" were over the gross vehicle limit.
Greene said that I-795's early pavement failure is not typical of the many miles of pavement the state lays each year.
According to the report, DOT placed more than 6.17 million tons of asphalt at a cost of $208.7 million for HMA in 2005 and that none of the other HMA projects has prematurely failed.
The road is safe and most motorists probably have not been aware of the problem other than having seen the recent "winterization" preventative maintenance performed along sections of the road, Greene said.
That $484,000 project targeted sections of the outside lanes in both directions where the crumbling was most severe. DOT officials had been concerned that winter weather would exacerbate the problem, prompting the repair project.
"We have finished that, and it went very well," Greene said.
For the remaining pavement, the report agrees with the DOT's assessment that the HMA surface be milled out and replaced. According to the report, a new HMA overlay of at least 2.5 inches in thickness (3 inches is preferred) should be placed over the surface layers.
Greene said meetings would be held over the next few weeks between DOT, the Federal Highway Admin-istration and S.T. Wooten, the company that was responsible for the initial paving and subsequent repair work.
He said it was premature to say how soon the project could begin or who would do the work. It would have to be approved by the DOT board.
Originally designed as U.S. 117, the 18-mile four-lane divided highway between Goldsboro and Wilson was added to the Interstate System as I-795 in October 2007.
The pavement problems were noticed within the first 16 months of the highway's opening in December 2005.
The report continues, "After opening the highway to traffic, Department personnel noticed the pavement deteriorating at a rate much faster than normal. Closer inspection revealed that the pavement was more porous than normal, and both pockmarks and clay balls were visible."
The DOT has initiated a review of the Quality Assurance Program as recommended by the Federal Highway Administration.
According to the DOT, its current program, developed in conjunction with Federal Highway Administration and industry leaders, has been in use for about 12 years. It is updated annually and conforms to the United States Code of Federal Regulations Quality Assurance Procedures for Construction.