A software glitch has delayed concrete testing on Raleigh's I-540 Outer Loop until Wednesday evening.

The testing will mean temporary lane closures overnight starting on the east bound side of 540 between U.S. 64 Business and Triangle Town Boulevard.

Technicians will check the depth of steel reinforcement bars buried in concrete that connect the traffic lanes.

Iowa-base McCarthy Improvement Company paved the eight-mile stretch which opened to traffic in January of 2007.

McCarthy Southeast Business Development Manager Ben Robuck recalled, "When the tips of these (steel) bars were exposed due to some corrective grinding work, we came in and fixed those right away. It was isolated repair work."

But the state wants to make sure it's isolated to just the two or three spots the paving subcontractor patched.

NC DOT Resident Engineer Cadmus Capehart is overseeing the pavement testing.

"If bars are too close to the surface there could be accelerated corrosion and the possibility for potholes to develop a lot quicker than they should," said Capehart.

The state is withholding final payment on the job until technicians confirm all the steel is properly embedded.

"The department wants assurance before we relieve the contractor of his responsibility on the project that the steel is in the location it should be and that we're getting the quality product that we paid for," said Capehart.

If the tests reveal any trouble spots the contractor will foot the bill for the repairs.

But that wasn't the case two years ago when the State Department of Transportation had to replace crumbling concrete on I-40 at a price of $22 million.

Now the state is spending millions more in repairs to increase the thickness of pavement on I-795 between Wilson and Goldsboro.

Back on 540, the ground penetrating radar test will happen lane by lane.

A pick-up truck will haul a cart with antennas that connect to computers.

Technicians will follow the cart which will travel around 10 miles per hour.

Robuck described it as an X-ray of the pavement that will take up to 10 days along the eight-mile stretch of interstate.

"We want to give the state some piece of mind that an isolated incident was just that," said Robuck.

The radar testing is now scheduled for Wednesday night and will not impact the morning or evening commute.

They'll start in the east bound lanes and at least one lane of traffic will remain open during the testing between 9 p.m. and 5 a.m.