The Southern Wake Expressway is part of the Interstate 540 outer loop in Raleigh, N.C. on the southern side of the city, completing the loop from Apex to Knightdale. The first leg connects the towns of Holly Springs and Garner.

Planning for the I-540 project began in the early 1970s. Construction of the first section of the outer loop began in 1992 and was finished in 1997. The newest section, currently under construction, includes several bridges built over wetlands and rivers.

The supports for the bridges are 30 inches in diameter with a ½-inch thick steel wall. The 55-foot-long bridge pipe piles were galvanized by Galvan Industries using a “double dip” or “progressive dip” technique to give the entire pipe a protective, metallurgically-bonded zinc coating, inside and out.

The N.C. Department of Transportation chose to galvanize the pipe piles for longer maintenance-free service life and to protect the steel as it was driven into the ground. Most of the piles were driven to a depth of 45 feet, leaving 10 feet exposed above ground.

Galvan also hot dipped the steel bearing plates supporting the large concrete bridge girders. Galvanizing provides initial cost savings plus greater coating durability, compared to other corrosion-prevention systems, and extends the life and safety of the bridges.



Galvan stored all 64 truckloads of pipe piles at their plant in Harrisburg, N.C. after galvanizing and scheduled shipping to the job sites when equipment was in place for pile driving. This portion of the project lasted around two years requiring long-term storage at the galvanizing facility, one of many value-added services offered by Galvan.

About Galvan Industries, Inc.

Located in Harrisburg, N.C., Galvan Industries has provided the ultimate in corrosion control to steel fabricators and manufacturers since 1958. The first hot-dip galvanizing operation in the Carolinas, the company has grown to become the largest capacity contract galvanizer in the Southeast. For details, or to place an order, call Galvan Industries at (704) 455-5102, Fax (704) 455-5215; e-mail: