What do you think of these recently poured foundation footings? I don’t have much experience looking at these and was hoping to get the opinion of someone who’s more knowledgeable. I’ve included a link to 2 pics that looked suspicious to me. These were poured 5 days ago. The last 3 days have been bitterly cold with high temps in the single digits. Thanks.
They should have been protected from the cold until cured
Visually, I don’t see anything wrong.
Concrete should not be poured on frozen ground.
Concrete should be protected when poured during freezing weather.
Concrete footings should be protected from frost damage exposure from ground below.
Pictures do not tell the whole story of events.
Thanks for all the replies. As far as I know, The footings were poured when the temp was about 50F, but the temp has stayed below 0F since about 36 hours after the initial pour. The footings have not been protected from the cold. Should I recommend a structural engineer to evaluate the strength of the concrete? I probably won’t have much luck convincing the builder to dig out the footings without evidence of structural compromise. Thanks!
spall, honeycomb & cracks are potential signs of inferior cold weather pour/finishing safeguards being implemented…imo
these can also occur during moderate & hot temperatures
cold weather standards
less technical read
Good links Barry.
And as I well know, when you pour footings in cold weather, you have to be prepared for the worst and protect it.
Here are a few pictures of cold weather concreting.
Pictures are not in order, but you get the idea.
The links provided by Barry Adair are the “Go To Source” ACI wrote the bible on concrete. Are these commercial or residential footings? The residential market typically doesn’t require 3rd party inspection/testing, unfortunately they get away with cutting corners.
Why would it matter if they are Commercial Footings, wouldn’t the protection of a cementious product be the same?
Would not the protection of frozen ground action on freshly poured concrete be the same?
Would not a frozen concrete less than 500 psi pose a defect to the final product?
Cant see enough of them to tell. But it looks like multiple pours (as opposed to one continuous pour) where one aspect was poured and had time to set up and then another pour happened behind it a little while later.
What I see in the pictures is approx. a 16" footing and based on a 1500 square foot home would only be 5.5 cubic yds. of concrete, so multiple pours would not be an issue.
Not consolidated would be more in order. :)
A few things to watch out for when pouring concrete in cold weather. Don’t pour on frozen ground, alike Marcel said. The concrete curing process (heat of hydration) slows down to zero as the concrete temperature approached 32°F or 0°C for you northern folks. Large massive pours generate more heat and can withstand the cold for longer periods of time, but small pours and thin slabs cool down very quickly and by the third day the heat generated by the curing process is about gone. So the most critical time for concrete damage on most residential pours is on or near day three.
In the residential market I have noticed lack of diligence in weather protection, much higher quality control in the commercial market.
If it were my building, I’d want to see a few core samples tested for compressive strength. Since it’s an inspection, I’d pass the decision on whether to test to an engineer.
If you are only interested in compressive strength Kenton, it would be cheaper to just use the Schidt Hammer.
The key to cold weather concreting is to protect the product from freezing.
Cold weather after concrete has attained at least 500 PSI just stops hydration and does not gain any more strength.
Hydration will resume once the temperature is above 45 degrees.
The critical factor is protecting the subsurface under the concrete from freezing and causing damage to the concrete footings just poured.
That would provide an unsuitable footing for a foundation wall to be cast upon.
Settlement of the footing and foundation would later be eminent.
That’s not the pronunciation you were looking for.
That conjures an image of a German with his buttock’s against a concrete wall.
I’d forgotten about those things! I checked them out about a year ago. The cheapest one was about $700 with the calibration device, and they went up sharply in price from there. I don’t even know anyone who’s ever used one. Have you Marcel?
Oh FIE Cameron.! Bad inspector! You must go to bed without any beer. Terrible mental image to inflict on board readers just before bedtime.
Last time I had one used was about 15 years ago.
The testing labs had them. Used in lieu of coring when field test cylinders failed 3 consecquetive test at 28 days.
Can’t say if they still being used.
Did I just sense someone with his mind in the gutter again?:)
A couple of years ago I wrote something on inspecting floating homes, many of which were floating on concrete barges. I was thinking about ways to test those barges for soundness, because right now all you do is look for rust stains indicating that the salt water has reached the reinforcement steel and corrosion is bleeding to the surface. Someone suggested that Schmidt hammers might be helpful, but I’m not sure they’d show deterioration, maybe just inadequate concrete design/strength at the time of original construction.