I have a problem with concrete, i made some pillar foundations for fence with old cement and i think its not maturing at all, its been 2 days and is still dark i color and sandy. Is it fucked or is there still a chance for it to get hard ?
takes a month to harden
you are talking about green concrete. its like that.
by sandy do you mean if you step on it you leave a boot print or you can scratch it like kids do to sidewalks?
It shouldn't take longer than a day. If it's taking a month to harden there's not enough cement in your mix. I'd only expect longer than a day or two at most if you were using flux additive or a dry mix with a large sand to cement ratio.
Proper ready mixed post-crete is hard within half an hour of pouring.
Old cement just doesn't seem to work the same. It might harden to the same strength after like several years. I mean you can leave a bag of cement outside and it will eventually form a block.
Usually once the bags open you have a few months, at best, to use it.
For anything that needs structural integrity or has to be demoulded in some way I'd avoid old Cement.
The only uses I've found for old cement are filling hollow objects and making Core Sand.