so im in a little bit of a pickle. I poured my concrete on Sunday the 26th. Got home from work this morning to check on it and it seemed, fine? Went out a little later to start working on scrapping the areas of the drains that got messy and noticed the concrete was just flaking out. So I tested an area right in front of the build plate and I can dig a hole in this stuff an inch deep with very little effort. not sure what to do. I mixed the Quikcrete 80lb bags EXACTLY to the directions. I was going to start epoxy this Sunday which would be 7 full days of cure but I dont think im going to be able to.
Did temps get below 40 degrees during cure? If your concrete is this soft after 4 days, something went wrong. Possible very old bags of quickcrete? They do have a shelf life. You may have to dig it out and go again…But give it another day or three and see what happens.
The temp in my shop is definitely in the lower range for Quikcrete (per their PDF sheet). They suggest 5 days cure for temps above 70 and 7 days for temps between 50 and 70 and im in that range. 60 to be exact. Im gonna give it until Sunday when I get back home from my shift and make the decision then. Im in no rush so waiting till Sunday anyway was my plan for epoxy. I may just be breaking it out instead of mixing epoxy.
As far as shelf life I did grab bags from the pallet so they were the oldest ones. And I have had a buddy get screwed by our local HD on bagged concrete. Hopefully it’s just taking longer. Im going to stop messing with it and let it go.
If it seemed a little moist, it just hasn’t dried enough. Give it time and maybe a dehumidifier.
Cement does not dry it cures.
It’s part of the chemical reaction.
Properly cured cement should retain most of its water, which does not evaporate.
So do you think it has a chance to cure?
It’s hard to say without me being there. But a lot of the cement I see is rock hard on the surface in 24 hours.
Certainly by 4 days
Yea this isn’t by any chance my first round doing concrete projects and every other time ive ever done any bagged concrete job, its always been rock hard within a day no matter what. I have a feeling this is getting broken out and redone.
Well that just sucks. I really empathize with you and as someone facing this step in the near future wish you luck.
Quikrete has a shelf life? Never heard that before. Is there an expiration date on the bag then?
Well took a total of 1 hr and all the concrete is broken out and all the parts are piled back up. It was the right call. I only had about a bag or two actually cure, the rest was powder and rubble. Stuff broke apart like nothing. All the machine parts seem ok. Going to have to clean them up a little and do it all over. This time im going to get some bagged concrete from another source. uughh
Its Concrete, Cement is a ingredient of Concrete. I just had to do that!!!
I have spoken with a specialist on the cement world and after telling him all my issues he asked me what water I used and I told him my tap water. Well… MY tap water is some of the absolute worst well water known to man. We dont drink it (buy bottled water) and I treat the ever loving shit out of it. Salt based softener and I inject 35% food grade hydrogen peroxide into my water. He replied. “well, thats your problem”.
Never dawned on me, that my well water could have assisted in screwing up the concrete set. The remaining salt from my backwash softener coupled with the high test peroxide probably wreeked havoc with the cure. He said get regular city water next time so I’ll be bringing in about 10 gallons of potable municipal water for my next go around.
That (water issue) makes a lot more sense for the poor results than the mix having a expiration date.
I have used cement mix that was 10 years old and it set up fine. Mind you, it was like a solid bag appearing as a lump of concrete but easily purverized by striking with a hammer. Once it was broken up, added water and mixed as usual.
Thanks for the update, glad you’re back on track.
I would have to agree here. I’ve used 4-5 year old quikcrete that sat in my barn and got clumped up in the corners of the bag. I bust it up with a sledge and pour it wet, and it works just fine. Not something I’d do regularly but it was for an erosion problem in a ditch. Point is, until properly activated I’m not sure there is a shelf life on cement (the binding ingredient in concrete).
Glad you got to the bottom of it! I similarly used well water but my outside hydrants are pre-softener. I wouldn’t have thought either concentration, salt or peroxide, would’ve made a huge difference.
Salt is most likely the problem. It is why cities don’t like to salt (sodium chloride) the streets for ice and snow removal. It eats the concrete, and requires earlier repairs.
You don’t have a water spigot before your treatment? I’ve used well water on several concrete jobs around the property. I have high calcium and silt but haven’t experienced the problem you’re having. Hope it works out for you. BTW I use a 1 micron filter and a water softener.