Constructed in 1968, 40 Westminster Street is a 24-story office complex located in the heart of the Providence, Rhode Island's financial district. Situated beneath the building is a sublevel parking garage used by staff and personnel in the business community.

With time, the heated garage became contaminated with salts that were brought in on the undersides of cars during winter months. Even with exemplary supervision, maintenance, and regular attention to patching repair, spalling occurred. Concrete deterioration accelerated in the late 1980s, after several particularly harsh winters.

The owner and its architect, asked Carl Walker Engineers to inspect the facility and recommend repair options. The building owners imposed three criteria: the preferred solution must be cost-effective, provide a long service life, and require minimal maintenance.

Using life cycle cost analysis, the engineering consultants evaluated six options, each for an evaluation period of 45 years. Based on the results, Carl Walker Engineers recommended conventional repair with cathodic protection (CP). The owner's management concurred, and the ELGARD™ titanium anode mesh system embedded in a concrete overlay was selected. Installation was completed in late 1989. A recent field survey conducted at the parking garage has indicated a high level of corrosion protection to the reinforcing steel and no concrete delamination.

CP arrests corrosion in parking decks by eliminating the corroding areas on the rebar and making the steel more passive. Corrpro, the world wide licensee of the ELGARD™ system for cathodic protection of reinforced concrete structures, provides CP system design, materials, installation, testing and supervision.

Project Data:

Structure:	Sublevel Parking Garage
Location:	40 Westminster St., Providence, RI
Owner Contact:	Mr. Ray Mendes; telephone: (401) 457-2259
Engineer:	Carl Walker Engineers
Engineer Contact:	Mr. Mike Ortlieb telephone: (616) 381-2222
Contractor:	Structural Preservation Systems
Anode Type:	ELGARD™ 150 Anode Mesh
Installation Date:	1989
Size:	2,500 sq. ft

Leading governmental and independent trade organizations have monitored, tested, and reported on corrosion control strategies over the past three decades. These groups include the American Concrete Institute, National Association of Corrosion Engineers, and Federal Highway Administration. They advocate CP as the only rehabilitation technique that effectively stops corrosion in salt-contaminated structures, regardless of the chloride content of the concrete.

ELGARD™ is a trademark of Eltech Systems Corporation.