Concrete

Discussion in 'Builders' Talk' started by Crosbie, Feb 20, 2014.

  1. Crosbie

    Crosbie New Member

    Tell me - how long can I reasonably expect a C20 or C25 concrete mix to stay pliable enough to work?

    I hear that adding 0.01% to 0.15% sugar to the mix extends its working life - is this true or is someone just pulling my chain?

    Does the addition of plastisizer help?
  2. BuilderMCR

    BuilderMCR Active Member

    About 2 hours, the only thing sugar will do is make it taste nicer if you get it in your mouth.
  3. BuilderMCR

    BuilderMCR Active Member

    No point putting plasticiser in concrete
  4. Phil the Paver

    Phil the Paver Well-Known Member

    It all depends on ambient temperature, it will not go off as quick in colder temps, the temperature has to be plus 5 and rising to use it without the need of antifreeze mixture, or it has to be covered to stop it freezing.

    Sugar!!!!!! I think someone's pulling your leg and plastersizer is not generally needed in concrete.
  5. Sean_ork

    Sean_ork Screwfix Select

    it's true .....
  6. Phil the Paver

    Phil the Paver Well-Known Member

  7. BuilderMCR

    BuilderMCR Active Member

    It sets by chemical reaction, even IF it does work you shouldn't do it. Slowing the setting time could damage the concrete.
  8. BuilderMCR

    BuilderMCR Active Member

    Got a huge wall to skim tomorrow, might try a bit of salt & pepper in the mix, see if it slows it down :rolleyes:
  9. Sean_ork

    Sean_ork Screwfix Select

  10. Sean_ork

    Sean_ork Screwfix Select

    forget the pepper - but go find out what's in plaster retarders, you might be slightly surprised
  11. BuilderMCR

    BuilderMCR Active Member

    Have you ever ordered readymix and been asked if you want white or brown sugar?

    There's obviously a reason.
  12. BuilderMCR

    BuilderMCR Active Member

    "Hi can I order 3m3 GEN1 S3"

    "Do you want milk and sugar?"
  13. Phil the Paver

    Phil the Paver Well-Known Member

  14. Sean_ork

    Sean_ork Screwfix Select

  15. BuilderMCR

    BuilderMCR Active Member

    "But is more advisable to use a commercial admixture"
  16. Sean_ork

    Sean_ork Screwfix Select

    minor detail
  17. Phil the Paver

    Phil the Paver Well-Known Member

    I said learn something new every day, but would I do it, NO, it would work out about 10 bags of sugar per M3.
  18. BuilderMCR

    BuilderMCR Active Member

    But the first thing mentioned
  19. BuilderMCR

    BuilderMCR Active Member

    But the OP is asking if he can use it.
  20. Phil the Paver

    Phil the Paver Well-Known Member

    I suppose it's not a lot different to using washing up liquid in mortar as a plastersizer.:)

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