Award of Excellence: Historic Category
Restoration of Historic Concrete at Ronald Reagan Washington National Airport
Submitted by Vector Corrosion Technologies
Metropolitan Washington Airport Authority
John Milner Associates, Inc.
Vector Corrosion Technologies
Wesley Chapel, Florida
Shalom Baranes Associates
Parsons Management Consultants
When first built, National Airport Terminal A was to be the “last word” in building design and technology. Over the years, this remarkable 1941 historic concrete building has suffered great loss. Evaluation and testing concluded the concrete was carbonated and its reinforcement was corroding causing severe cracking and spalling.
In order to save as much historic material as possible, traditional repairs were coupled with modern techniques to insure a long-lasting repair.
Selection of materials and procedures was based on providing a long service life with minimum impact on the historic façade. Traditional repairs were first made to the concrete. then electrochemical realkalization and electrochemical chloride extraction (ECE) were used to provide long-term corrosion mitigation while respecting the historic nature of the facility. Realkalization was used in areas with carbonated concrete. ECE was utilized in the limited areas where chloride contamination was determined during the condition evaluation, in order to break the cycle of corrosion.
In total over 34,000 ft2 (3159 m2) of carbonated concrete façade was successfully re-alkalized as verified by the independent quality inspector. ECE was performed on 1895 ft2 (176 m2). The result of this restoration program is a beautiful building that has reclaimed its status as being the “last word” in concrete restoration as it embraces technology once again.