Maximum Time Ready Mix Concrete Can Be Used

Hi Rinus, in European and British standards it's defined as 2 hours from when the cement and water come together in the mixing process. However, there are many factors that can allow ready mix to be workable and placeable for considerable time after initial mixing, eg: use of cement additives, plasticisers etc. You are in the Middle East so I assume the mix design incoporates allowances for concreting in hot weather, which will extend the working life of the concrete before final placement?

Hello paul, usually here in the Middle East 60% of ground granulated blast furnace slag(GGBS) and 8% microsilica is added in the concrete design mix. Is microsilica is the plasteciser or cement additives?

Thanks,

Rinus

Hello from Panama, Central America.

I suppose that they tell you that because they are treatment the mix with retarders endurement additives. In the market you will find mix concrete accelerators and retarders additives formuled for each case.

plasticizers make concrete flow essayer.retarder slows the initial set of the concrete. after the retarder time is up the concrete sets up very very fast.hot loads and watered down concrete is no good,it looses its strength.why don't they have a batch plant on site. try going to the ACI web site (AMERICAN INSTITUTE OF CONCRETE)they set the standard in the USA. concrete is only guarantied to do 2 things,get hard and crack.