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Why is concrete taking 12 hours harden?

Why is concrete taking 12 hours harden?

Why is concrete taking 12 hours harden?

In Spain the crete is taking at least 12 hours to harden enough to put a steel trowel finish on it.  The crete is cold to the touch, the sand feels like beach sand.  We complete placing at 12 noon and at midnight the stuff is still cold and pasty.  Does anyone know what they might be using in their cement?
Thank you.

RE: Why is concrete taking 12 hours harden?

Have you checked the mix for high levels of cement replacement materials ie ggbs?

The other possibilities are:
You have inadvertently put a retarder in the mix.
The delivery driver for pfa has accidentally loaded the pfa into the cement silo at the batching plant.
You have a duff supply of cement

Andy Machon


RE: Why is concrete taking 12 hours harden?

I have used sakrite mortar mix in 31-36 degree F weather
to repair my front steps.  Fourteen hours later i put my index finger thru the top eigth inch of soft material but was afraid to push harder in case there is some small chance that this is not really the nightmare i now believe to be.  My question is: is there any hope?

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