A firm hired to do inspection services on a botched $44.8-million concrete paving job in North Carolina is denying any role in the problems that led to potholes and crumbling on Interstate 40 in 2005. The newly paved 10.6-mile stretch between Raleigh and Durham needs at least $18.6 million in repairs. Contractor Granite Construction, Watsonville, Calif., accepted no blame but agreed to contribute $3 million to the fix. Inspection services provider HNTB Corp. does not plan to contribute.
In 1999, the North Carolina Dept. of Transportation opted to bond a 3-in. layer of concrete to the existing surface. Full-depth transverse joints must be cut into the overlay to prevent compression-related failure. But the design failed to specify cut depths for the joints, according to a report issued late last year by state Secretary of Transportation Lyndo Tippett. Subcontractors cut the overlay at depths from 1.5 to 3 in.