Re-bar and mould oil.

Discussion in 'Building' started by Norcon, 26 Jun 2010.

  1. Norcon

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    Thanks for all the advice (its much appreciated) and sorry if I caused any offence.

    Fwiw I agree about taking the structure back to the ground entirely.
    The cost of this would run well up to £10k. Perhaps more.
    Perhaps the SE will lend a hand on the concrete breakers??? Does their insurance cover for mistakes like this?
    Before the threaded bar was used quite a number of phone calls were made by the prinicipal contractor to the SE and roofing engineer who both gave the go ahead for these undersized anchors to be used.
    God knows why. :(
    The ones we have now are 30mm grade 8.8.
    Which I believe has a tensile strength of around 150,000 pounds per square inch.
     
  2. geraint

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  3. geraint

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  4. geraint

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    i have never come across ht holding down bolts... and never seen it specified what would be the point when it is encased...
     
  5. regsmyth

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    I've always used holding down bolts which are grade 8.8, which is a lot stronger than your standard grade 4.6.

    The point is that if you use a high tensile bolt, the holes and hence edge clearances on your baseplate can be smaller than if you use grade 4.6, thus reducing overall steel costs.

    Encasing them in concrete doesn't make them any stronger, but if they are fully encased, you don't need to worry about corrosion protection.
     
  6. alittlerespect

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    Hi

    The issue is to do with the design of the canopy being a cantilevered structure, the tie bars will be acting in tension to resist the overturning moment of the canopy and normal mild steel would not accommodate the embedded stress throughout the design life of the structure.
    The concrete base/extension to the terrace is being used simply for its mass to resist the overturning moment and the only thing holding the roof in place are the tie bars.

    Going by the SEs history he is likely to come back and ask for the 2 concrete pours completed to be demolished and rebuilt.
    I would have anticipated costs for remedial works being nearer £20,000 rather than £2,000 mentioned!

    Just for clarity the tie bars are not supporting the rear of the roof structure, they are there to stop the front of the canopy rotating and crashing into the terraces.

    Regards
     
  7. Norcon

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    Just an update. Jobs nearing completion now. These were a couple of snap shots I took a while back....

    [​IMG]
    [​IMG]
     
  8. geraint

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    surely that cannot be a get out clause on a forum.... :LOL: :LOL: :LOL:
     

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