08-29-2013 Report

Meeting Recap – August 29, 2013

Corrosion Of Steel Within Concrete

Sept_2013bMr. Jorge Costa, P.E., Vice President, Corrosion Solutions of Structural Technologies

Mr. Costa provided an insightful presentation on corrosion of steel within concrete at the August 29, 2013 meeting of the ICRI Georgia Chapter.  Mr. Costa is an expert in all aspects of corrosion of steel; its causes, prevention measures, detection, assessment, and repairs and correction.  He provided a very easy-to-understand explanation of the causes of corrosion.  He explained that steel starts out as iron ore, composed of iron oxide.  This is a naturally occurring, stable material.  When we impart energy into the iron ore to make steel, the material immediately tends to return to its more stable condition as it existed as iron ore.  This is manifest as corrosion of the steel.

Mr. Costa explained that the initial placement of concrete around reinforcing steel results in a very fine film of protective coating around the reinforcing steel.  As long as this thin coating remains in-tact, the steel is protected from corrosion.  However, this film may be breached by chlorine or by carbon dioxide.  As soon as either of these penetrates the concrete and reaches the protective film the film is breached and corrosion immediately ensues.

He also discussed various methods of detecting and accessing corrosion ranging from a chain drag to ground penetrating radar.  He presented proper repair procedures and measures to be taken during repairs to prevent or delay recurrence of the corrosion.  He presented various passive and active methods of preventing corrosion.  This was a highly educational and beneficial presentation and was much appreciated by approximately 45 attendees.