How long will unused concrete mix last?

[Jstpssng]

With this unseasonably warm weather I may start next year's project, pouring piers for a deck.

I believe that I have about a ton of premix plus a couple bags of Portland Cement which has been stored on a pallet for at least 5 years. It still seems soft but I won't know until I dig it out. My thought is to buy some fresh premix, and use a 50-50 mix. In hindsight I should have mixed a couple of bags last month, just to see how it set up.

 

[Industrial Toys]

It's just gonna be harder to weed out any hardened clumps in the pre-mixed. Also depends on your mixer. I guess a mortar mixer might pulverize clumps better.

 

[Rebeldad1]

Havnt heard of cement or gravel having a freshness date.
I would say that if the contents of the bag are as new (no hardening) You are good to go.

 

[repete]

Likely it will last till the day before you need it. At least that is my experience in Western Washington. Unsure in "Hughett Bend"

 

[dieselscout80]

Interesting today I was talking to two companies about self leveling concrete and the one flat out stated that it has a one year shelf life and that the cement is what goes bad.

I had not heard of that before, but the guy said it is common issue. He went into a local box store within the last year and the product on the shelf was dated from 2017.

 

[Roadworthy]

Moisture is low in southeast Washington so shelf life for me on unmixed concrete is measured in years. If your concrete does not get moisture it lasts "forever". Once moisture hits it the reaction starts and mixed or not it begins to harden. You may break up the clumps but the chemical reaction only happens once.

 

[Jstpssng]

Maybe I would be better off starting fresh, and spreading this someplace less critical next year.

 

[bcp]

Use it for, or sell it for, setting posts.

Bruce

 

[Jstpssng]

I believe that I'll open it into my trailer, get enough fresh Portland cement for a 5 bag mix, and use my old premix for gravel.

 

[s219]

I had mortar go bad from age. Started a thread here about it and that was the consensus.