How long will unused concrete mix last?

[3Ts]

Roadworthy has the answer - moisture controls it's shelf life. The humidity level provides moisture also, so the shelf life in the desert is longer than on the humid gulf coast. Here in East Texas, I count on about 1 year before it's no longer usable.

 

[Jstpssng]

I'm glad that I asked here before I tried to use it... unlike afterward which is my normal modus of operating.

 

[LS Tractor Owner]

I just threw away (buried) 4- 80# bags of premix that were just over 1 1/2 years old. They were stored in a dry garage, up on a few 2x6s. We have very low humidity levels in the desert SW, so I thought they would stay usable. NOPE... I was going to use them a few weeks ago, and about 1/2 of each bag was rock solid. Useless.... I wasn't going to take the time to sort out the chunks....

 

[5030]

I just threw away (buried) 4- 80# bags of premix that were just over 1 1/2 years old. They were stored in a dry garage, up on a few 2x6s. We have very low humidity levels in the desert SW, so I thought they would stay usable. NOPE... I was going to use them a few weeks ago, and about 1/2 of each bag was rock solid. Useless.... I wasn't going to take the time to sort out the chunks....

Isn't it amazing how they look perfectly fine sitting there but are hard as a roock? been there, did that.

 

[Jstpssng]

These were actually still supple. I used some of it instead of gravel, to level the ledge that I'm pouring the posts on. The Portland Cement I suspect is harder than a rock, I'll do something with that when I clean the shed next spring.

 

[Tractor Seabee]

Here in Puget Sound you are lucky if it last 6 months. The inner plastic bags are not as moisture proof as you would think and are supposed to keep it longer. I usually wind up throwing away those 1 or 2 left over bags from a project.

Reminds me of my teen years living in Phoenix AZ. My dad was an avid auction guy and we went every week. There was a pallet full of cement, maybe 50-60 bags. Guys were looking and prodding, heard several say "ah that stuff is already set-up and worthless. My dad bid $1 to open, no one else bid. That stuff turned out perfect, the weight of the stack just compressed it to where it felt hardened.

Ron

 

[3Ts]

I was at Lowe's the other day to pick up some concrete bags. There were some outside that were mostly hard, but one employee said they'll be fine, just bust them up with a hammer. He seemed to be serious. Later another said they use the hard ones out back for erosion control.