Report on Corrosion of Prestressing Steels
|Publication Date:||1 October 2014|
This report covers practices and research relating to corrosion in prestressed concrete systems, including prestressing tendons and other hardware associated with prestressing such as anchorages and ducts that also affect corrosion resistance. In general, ACI 222R covers mechanisms of corrosion of nonprestressed steel in concrete, measures for protecting embedded metal in concrete, techniques for detecting corrosion in structures, and remedial procedures. Many of the mechanisms reported in ACI 222R are valid for and apply to prestressing steels in concrete, and this report supplements ACI 222R. The metallurgy of various common prestressing steels is presented to provide necessary information to understand the mechanisms of deterioration of prestressing steels. Current and proposed techniques for evaluation of prestressed concrete structures with respect to corrosion of strands and tendons are also reviewed. A history of field performance, covering documented cases of corrosion-induced failures in prestressed concrete members, is included in this report. Finally, this document describes methods of protection and remedial techniques applicable to existing structures that exhibit corrosion. Information within this report is applicable to most forms of prestressed concrete construction, including buildings, bridges and parking structures. Prestressed tanks, pipes, and ground anchors are not specifically addressed.