Rebar and DC current
Rebar and DC current
(OP)
New site to be designed.
Measured 10 to 20 amps dc ground current at site.(Source of DC current will never go away and is generated by some other group).
What is the best way to protect the rebar in the concrete from electrolysis?
Epoxy coatings?
Galvanizing?
Sacrificial anodes?
Thanks
Measured 10 to 20 amps dc ground current at site.(Source of DC current will never go away and is generated by some other group).
What is the best way to protect the rebar in the concrete from electrolysis?
Epoxy coatings?
Galvanizing?
Sacrificial anodes?
Thanks






RE: Rebar and DC current
Where does the interfering source come from - your own facility or external? If external then you would have reasonable grounds to request them to modify their installation.
I think you'll have a rapid turnover using sacrificial anodes. I don't know much about coatings for steel in this application. Have you considered an impressed current CP system of your own, or including your structure within the protected zone if an ICCP system is the origin of your problem?
RE: Rebar and DC current
RE: Rebar and DC current
Answers etc.
The DC current is stray current from a city transportation system.They freely admit they are generating stray current and it is up to any new building designs to "accomodate" this stray current situation.
Rebar inside this concrete slab will corrode faster with this DC current flow ,will build up additional internal concrete stress and eventually weaken this concrete slab.
That is the real concern and is a very odd design requirement with very little technical information available.
Thanks for your help.
RE: Rebar and DC current
RE: Rebar and DC current
In the case of your project, it might be useful to consider a drainage cable from the rebar system to the rail track. It seems that the corrosion occurs at the point where the current leaves the underground structure and flows into the Earth near the substation, a drainage cable bypasses this route.
The above partly from the Electric Railway Handbook, published before 1917.
Just a historical note...
rasevskii
RE: Rebar and DC current
SceneryDriver
RE: Rebar and DC current