The integrity of concrete structures is largely based on the durability of the reinforcing steel. Corrosive elements penetrate the permeable concrete subjecting the rebar to corrosion. The corrosion products that form on steel have a greater volume than the metal consumed in the corrosion reaction, which causes internal concrete pressure to build. As corrosion continues, the pressure will eventually exceed the tensile strength of the concrete causing the concrete to crack and spall. The corrosion products of galvanized rebar are less dense and do not build up pressure to cause concrete spalling. The zinc corrosion products migrate away from the galvanized coating and disperse into the concrete matrix.
This comprehensive 4-page handout, revised in 2005, compares hot-dip galvanized rebar with epoxy-coated rebar including a side-by-side comparison of performance, a detailed account of concrete corrosion, galvanized rebar bridge case studies.
Copies of this resource are available for purchase. Architects, engineers, and other specifiers in North America may request a single copy of any publication at no charge, unless otherwise indicated. Multiple copies require a $25.00 (US funds) minimum order, plus shipping and handling. Prepayment is required. (Member galvanizers are not eligible for complimentary printed copies and require a $75.00 minimum order.) Non-member galvanizers must contact the AGA directly at 720-361-4483.
Repairing damage caused by corrosion costs billions of dollars annually. One significant contributor to the corrosion problem is decaying reinforcing steel bar (rebar), which causes staining, cracking, and spalling of concrete structures throughout... View Details »
A suggested specification in CSI format for hot-dip galvanizing after fabrication. This guide aids in developing a better hot-dip galvanizing specification. MS Word Document - 13 pages. 2022
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