Stray current in reinforced concrete
Stray current in reinforced concrete
(OP)
Hello,
we are currently involved in a project where a big statue is to be constructed in concrete. (The foundation of the statue is a big plate (3m*40m*0.6m). The statue itself is in fact two semi-arcs in concrete (0.5*1.2m), total height 12m.) Now there is a tram passing next to this statue (approx. 5m). I heard that there is a danger that stray current could affect the steel in the reinforced concrete.
Is this wright? If there are problems concerning the stray current, is this only for the steel in the ground, or also above it?
I heard about a solution in which one should connect a diode to the tram rails to "catch" the stray current. Is this the only solution?
Many thanks,
Karel
we are currently involved in a project where a big statue is to be constructed in concrete. (The foundation of the statue is a big plate (3m*40m*0.6m). The statue itself is in fact two semi-arcs in concrete (0.5*1.2m), total height 12m.) Now there is a tram passing next to this statue (approx. 5m). I heard that there is a danger that stray current could affect the steel in the reinforced concrete.
Is this wright? If there are problems concerning the stray current, is this only for the steel in the ground, or also above it?
I heard about a solution in which one should connect a diode to the tram rails to "catch" the stray current. Is this the only solution?
Many thanks,
Karel






RE: Stray current in reinforced concrete
A "power" electrical engineer should be able to work out the details with you.
RE: Stray current in reinforced concrete
The first part of the problem stays however: is it really necessary to provide such a system (not really cheap...)?
For instance, when I design a building along a tram railway, should I take precautions for my foundations, or for every beam and plate, or is this neglictible? What is the radius of influence of the stray current (maybe depending on the type of soil?)?
Many thanks.
RE: Stray current in reinforced concrete
It is usually not necessary to connect each steel member to a grounding grid. Most steel frame buildings (say typical pre-engineered buildings) are connected to a grounding loop on 10% to 20% of their columns. You do want a minimum two grounding connections to the loop for redundancy; this is also the reason that the underground loop is closed - if it gets cut a one location the structure is still grounded.
RE: Stray current in reinforced concrete