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+-- Thread: concrete dry time (/showthread.php?tid=7255973)
concrete dry time - JKimel - 03-31-2016
Well, I was doing some patchwork with an old bag of vinyl concrete patch in some areas, and 2 old bags of concrete mix in another. All bags about 5 years old. Basement floor probably about 50 degrees F when I put it down. 6 days later, still soft for the mix and patch didn't bind together. It worked the first time I used it?
Any thoughts. No big deal to redo the repair areas if I have to because they weren't that big.
Re: concrete dry time - Robert Adams - 03-31-2016
Well looked it up and the shelf life is 12 months so it should still be good for another 12 in many cases but 5 years old maybe not...
Re: concrete dry time - cndamm - 03-31-2016
Concrete doesn't dry, it cures. Usually 24 hours you can walk on it ....Carefully better to wait a week. 95% cure in 28 days 28 years to reach 100%. I would get some fresh mix and try again. Be careful because too much water will cause a lot of problems.
Re: concrete dry time - JKimel - 03-31-2016
Robert Adams said:
Well looked it up and the shelf life is 12 months so it should still be good for another 12 in many cases but 5 years old maybe not...
didn't see a shelf life on packages unless I missed it. oh well. I wait a bit and try again.
Re: concrete dry time - JKimel - 03-31-2016
must be the binder that degrades because I don't see how sand, gravel, flyash, or other intert materials would cause a shelf life.
Re: concrete dry time - R Clark - 03-31-2016
Concrete sets as the result of a chemical reaction; so it makes sense to me that it can degrade if not used within a certain period of time after manufacture.
If it's been six days and the patches are still soft, I'd plan on redoing them.
Re: concrete dry time - Robert Adams - 03-31-2016
JKimel said:
must be the binder that degrades because I don't see how sand, gravel, flyash, or other intert materials would cause a shelf life.
This stuff has vinyl additives and binders which make it a different animal. But yeah sand gravel and Portland cement dont go bad.
Re: concrete dry time - theeviltwinn - 03-31-2016
Moisture in the air is enough to make Portland cement set (go bad).
Re: concrete dry time - Curlycherry - 03-31-2016
theeviltwinn said:
Moisture in the air is enough to make Portland cement set (go bad).
My friend did not finish up he stone work on his house last fall. His concrete supplier told him bring back the unused bags because they would use them up and he would not be stuck with bad cement this spring.
Re: concrete dry time - JTTHECLOCKMAN - 03-31-2016
If you are patching I highly recommend using this as well.
www.homedepot.com/p/SikaLatex-1-Gal-Concrete-Bonding-Adhesive-and-Acrylic-Fortifier-187782/202521398