Effect of water over fresh concrete pier

[Hutten]

Attached photos are of yesterdays 2 pm pour--16-inch >2500psi concrete piers cast in polyethelene form then wrapped with 5-7 inch straw waddle insulation with some suran wrap over.

Last nights temp at 34 degree low, tonight cold front at 18 degree low.

Difficult dewatering leads to water flowing up to poly forms within hour of pour, also resulting in wet(er) straw. No temp readings as of yet of interface between poly form and straw waddle.

QUESTIONS: Is there a detrimental effect of allowing water to pond so soon and then freeze around surface mounted form?

 

[Hutten]

Here is another photo...

 

[Hutten]

Note that the poly form sometimes "floats" up above surface and some concrete spills out from non-continuuously formed column.

Sorry--can't seem to post more than one photo per post

 

[Ron]

Yes. The concrete is at a critical stage and should not be allowed to freeze. Below grade, there is not an issue. Above grade there is an issue, since I doubt that the heat of hydration will keep it from freezing.

A trench should have been dug alongside all the piers and water sitting around the piers directed to drain into the trench, where it could be pumped away.

I would get a couple of portable heaters out there to protect the concrete.

 

[oldestguy]

For your information, I recall some Canadian information indicating that if the concrete has 24 hours not frozen, that later when it thaws and continues to set that it will be OK.

Never had an opportunity to confirm that however.

 

[concretemasonry]

The temperatures posted apparently were the air temperatures (easy to get on TV), but not the concrete, water and contact materials that really affect the concrete properties. The is such a thing as thermal mass and actual material temperatures and not just air temperatures that do not have an immediate effect.

The 2500 psi will have a low cement (low heat of hydration) and the temperature of the placed concrete may not be known or controlled. More information on the details would help and the main areas of concern since 2500 psi is an indication of something like "fill concrete".

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[BigHarvey]

It's a shame to see pictures of such a construction site : you should have a decent working platform from a quality point of view as well as from a safety point of view.