Selected Answers

From Jim Johnson of CHLOR*RID International Inc. on May 18, 2015:
The best way to prevent corrosion of rebar is to s ...read more The best way to prevent corrosion of rebar is to start the process at the time the concrete is mixed. Specify that the water to be used for the mix does not exceed a specific level in parts per million of chloride. Specify that the aggregate also not exceed a certain level of chloride. The resulting mix can also be tested for the overall level of chloride before it is poured. Making every effort to control the contamination level in the concrete itself can make a major difference in controlling corrosion of the rebar. After the concrete is poured, every effort can be made to deter the penetration of contaminants in the future. Coating of the rebar helps, but to attain the best corrosion protection, the process should be addressed before the concrete is even mixed.

From Mark Bowen of City Of Ravenna on May 15, 2015:
Use epoxy-coated or stainless steel rebar. ...read more Use epoxy-coated or stainless steel rebar.

From Anthony Asmar of gulf silicone on May 15, 2015:
A zinc-rich primer with DFT of 75 micron is good e ...read more A zinc-rich primer with DFT of 75 micron is good enough for protecting rebar against corrosion. It is fast curing, easy to apply, and has an  acceptable cost. Concrete can be overcoated with any water-based paint system in a normal environment. Use an epoxy or polyurethane in a harsh environment.

From Joe Miller of NextGen Green Building Products, Inc. dba Direct2Contractors.com on May 11, 2015:
Coating the rebars will work to slow the corrosion ...read more Coating the rebars will work to slow the corrosion process but will not stop it. The only method I am familiar with to completely stop the corrosion process is impressed current cathodic protection. This is where a current is passed through the rebar to protect them from corrosion. There are also sacrificial anodes that have now been used for many years. These anodes give themselves up to protect the steel rebar. Similar sacrificial anodes are used on boar propellers to protect them. Given the massive costs of most steel reinforced structures (such as office towers, residential towers, bridges, airport runways, tunnels, etc.), it seems prudent to protect steel rebars against corrosion. Even using liquid crystalline penetrating sealers can help  to keep water and water- soluble chlorides and other ions away from the steel.

From Kiran Pawar of Asiab Paints Berger Bahrain on May 11, 2015:
Maintain the high alkalinity of the concrete. Use ...read more Maintain the high alkalinity of the concrete. Use an anti-carbonation coating  Coat the rebar with an anti-corrosive epoxy coating.

From Warren Brand of Chicago Corrosion Group on May 7, 2015:
Coat the rebar by hot dip galvanizing.
...read more Coat the rebar by hot dip galvanizing.

From Trinidad Diaz of Keppel Prince Engineering on May 5, 2015:
Galvanize your rebar. ...read more Galvanize your rebar.

From Rick Simpson of Zinga UK on November 22, 2012:
 We have coated over 200,000 tons of rebars w ...read more  We have coated over 200,000 tons of rebars with a one-component zinc coating, and have used these rebars in both concrete road bridge supports and  in concrete support towers on the world's longest road bridge in Hangzhou Bay, China. The system works so well that the blasting and coating operation is now fully automated. A 20-ton truck-load can be done in an hour. Concrete can be poured within an hour of coating the reinforcing bars, even where the cement is a high-alumina type (pH14), and for this reason, the zinc is applied at a nominal thickness of DFT. Due to zinc being amphoteric (attacked by acids and very strong alkalines), the immediate zinc-loss is around 5- 7 microns. I hope this helps.

From Carl Thompson of Hill Brothers on November 19, 2012:
     Densify the surface with ...read more      Densify the surface with lithium silicate.

From Arun Gopinathan of BASF Construction Chemical on November 22, 2012:
     Use a good anti-carbonati ...read more      Use a good anti-carbonation coating! Simple Option 2: use rebars coated with a with fusion bond epoxy coating.