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How to magnetize a concrete wall?

  1. Feb 8, 2012 #1
    As we know that concrete is an insulator, but if I apply extremely high voltage through this concrete at a certain level, the concrete's property may become semi-conductor. In this way, will it be possible to magnetize a concrete wall using an extremely high voltage in this way?
    Does anyone have any suggestions?
    Thanks in advance for any suggestions
     
  2. jcsd
  3. Feb 8, 2012 #2
    There is no such thing as a "true" insulator because at a high enough voltage everything becomes a conductor. You would need a ridiculously high voltage for the concrete to conduct even a miniscule current. Even then the concrete won't become magnetized because the magnetic field is being generated by the electric current flowing through the concrete. As soon as the current stops the magnetic field goes away. Go read up on electricity and magnetism before you ask any more bizarre questions.
     
  4. Feb 9, 2012 #3
    Magnetic field can magnetize any ordinary metal as shown on below video, if magnetic field is being generated by electric current flowing through the concrete, and concrete may contains any metal substance within its components, it should also be magnetized in this way, isn't it?

    Does anyone have any suggestions on any mis-concept within my statement?
    Thanks everyone very much for any suggestions

    http://www.youtube.com/watch?v=oA3yCjjbG-0&feature=related
     
    Last edited: Feb 9, 2012
  5. Feb 9, 2012 #4
    Is this a theoretical or practical question? In other words, what are you trying to do? Are you considering making a magnetic concrete wall, perhaps?
    Concrete is a mixture containing what's called an aggregate. You could use pieces of steel for the aggregate, or you could pre-position magnets in yet-to-cure concrete. Using one of these methods, you could make a magnetic concrete wall.
     
  6. Feb 9, 2012 #5
    Concrete contains sand too, which depends on where you live. Sand can contain quartz, magnetite, olivine, feldspar, obsidian, pieces of coral, shells, or dead sea organisms.

    So in general, can I conclude that concrete wall can be magnetized if there is high enough electric current flowing through the concrete?

    Does anyone have any suggestions on any mis-concept within my statement?
    Thanks everyone very much for any suggestions
     
  7. Feb 9, 2012 #6
    You can't magnetize regular concrete.
     
  8. Feb 9, 2012 #7
    And here you are again, arguing for the sake of arguing. Will you ever start listening to the answers given.
     
  9. Feb 9, 2012 #8
    Can you explain little more please?

    if magnetic field is being generated by electric current flowing through the concrete, and concrete may contains any metal substance within its components, it should also be magnetized in this way, isn't it? It is possible, isn't it?

    Does anyone have any suggestions on any mis-concept within my statement?
    Thanks everyone very much for any suggestions
     
  10. Feb 9, 2012 #9
    Of course.

    There is no way to get electric current to flow trough concrete.

    Even if you could, the magnetic field generated by the current would disappear once you stopped. The concrete is never magnetized.
     
  11. Feb 9, 2012 #10

    Bobbywhy

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    oem7110, Yes, I do have "Does anyone have any suggestions on any mis-concept within my statement?"

    Ordinary concrete is an insulator...that means you CANNOT pass an electric current through it. If you increase the voltage the concrete does NOT become a semiconductor as you wrote in the OP. So, accept (and obey) the laws of physics: you CANNOT magnetize a concrete wall.

    Now, if you make concrete with metallic materials, magnets, etc. you change the above statements because it would not be "Ordinary concrete".
     
  12. Feb 9, 2012 #11
    If lighting from Thunder hits the concrete wall, how can it be grounded if you assume that ordinary concrete is an insulator? it does not seem making any sense, isn't it? so how can I accept or obey the laws of physics from your interpretation?

    Does anyone have any suggestions on any mis-concept within my statement?
    Thanks everyone very much for any suggestions
     
  13. Feb 9, 2012 #12
    Lighting very rarely strikes concrete since it's such a good insulator and it would rather go somewhere else.

    When it does it causes the concrete to explode from the heat generated (the entrapped moisture expands). In theory, you can get current to pass through concrete, but it takes so much voltage that it will explode, making it completely impossible in practice.

    You really like concrete!

    (also, lighting doesn't come from thunder, it's the other way around)

    EDIT: I would also like to point out that the concrete really isn't 'grounded', it's just busting through the concrete to get to something that is / the ground itself.
     
  14. Feb 9, 2012 #13
    Thanks you for your interpretation, you are talking about physics now from your interpretation, so if there is no chance to get current passing through concrete before it explodes, there is no way to magnetize a concrete, right?

    Thanks everyone very much for suggestions
     
  15. Feb 9, 2012 #14
  16. Feb 9, 2012 #15

    sophiecentaur

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    Gold Member

    No seems to have mentioned that many concrete structures are reinforced with Steel. That could change things a bit, in practice. It could explain how a particular concrete wall has been magnetised.
     
  17. Feb 9, 2012 #16
    What about radiation from space? Would radiation change the property of reinforced concrete with Steel? Radiation can get through concrete without breaking it and reach the steel. Can steel be magnetized this way? furthermore, Can concrete be magnetized by radiation?

    Does anyone have any suggestions?
    Thanks everyone very much for any suggestions
     
  18. Feb 9, 2012 #17
    Thank you very much for your suggestions
     
  19. Feb 9, 2012 #18

    sophiecentaur

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    Gold Member

    We're too much into the realms of Science Fiction here. IFFFF there is steel reinforcing in concrete, it could possibly have become magnetised during electric welding. There are some heavy currents involved and that could generate a small magnetic field which could magnetise the steel.

    There is no point in repeating the question about concrete becoming magnetised. The answer won't change.
    What mechanism did you have in mind whereby this 'radiation' from space could magnetise ANYTHING? Are we talking Radio Frequency Radiation, Infra Red, Light, UV ????? Magic rays (straight from the 1930s)?

    If you want a Science discussion then you need to be Scientific!
     
  20. Feb 9, 2012 #19
    OK, let focus on heavy currents only, during the thunderstorm, there are many positive charges on the ground, please see following images, could this charges magnetize the steel within concrete? the positive charges can easily get through concrete with no problem.

    Do you have any suggestions?
    Thanks everyone very much for any suggestions

    cloud_charge.jpg
     
  21. Feb 9, 2012 #20
    No.
    Incorrect.

    A lighting strike could in theory magnetize steel however.

    EDIT: Make sure you read and understood that link I gave you, it will help you tremendously.
     
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