Is cement good to use?

looksee

I mixed some cement from a slightly old bag to make footings for some posts. I used a 4:1 mix and it looked fine, but doesn't seem to be setting as it should. It seems sandy/soft.

The cement was pretty smooth and powdery, and any small (maybe pea sized) lumps just turned to powder easily, is there any way of knowing if the cement was still good?

Its a long time since I made cement and I may have got the proportions wrong - 4:1 does depend a bit on how much is on the shovel!

Calahonda52

how long is it poured?

looksee

When I checked it, 24 hours, that was yesterday.

looksee

Just checked again (which I should have done before posting :P) and it seems as though it is improving, maybe no problem. Thanks.

Dtp1979

You say 4/1. Are you heaping the cement onto the shovel like you are with the sand? It can be tricky to get a full heaped shovel of cement as the bags are small. So realistically you may have mixed it at 5:1 which is weak and would explain the delayed setting time maybe

Calahonda52

Dtp1979 wrote: »

You say 4/1. Are you heaping the cement onto the shovel like you are with the sand? It can be tricky to get a full heaped shovel of cement as the bags are small. So realistically you mace have mixed it at 5:1 which is weak and would explain the delayed setting time maybe

5:1 is not weak, it will take a bit longer to set initially but over the 7 and 28 day tests it will be strong.
After the war, when money and cement were scare/expensive respectively, I mixed with my later father as child, 18 or 24:1 was not uncommon for pedestrian paths around the house, they are still there.
\
For posts 8:1 will be fine, just wont set as fast as post set:)

looksee

I agree I may have mixed it a bit weak, but anyway it has set sufficiently for the job (which is not anything majorly structural, just small posts) so I think I was just too quick to decide it was not working