This 'may' be the dumbest question posted here for quite some time but anyhow...

I mixed some concrete for a small job recently (1 cement, 2.5 sand & 4 aggregate) and for some reason it simply didn't take -> after 48 hours the entire pour was a khaki-green colour and simply crumbled if I rubbed it hard.

So I tried again (with cement from the same bag) -> you guessed, same outcome.

All I can conclude is the bag of cement had 'gone-off'

Have I gone off or does bagged cement have a shelf life? The bag was unopened prior to the above and seemed ok to look at...

CJG

 

Probably a little heavy on the sand and ag....that more like what Quikcrete or one of those premix deals does.....and it is fairly crappy.....

A typical mix is 1-2-3 cement/sand/gravel......

The only way I've seen cement go bad is to have the bag open and it "sets" from moisture in the air.

You WERE USING portland cement, right ?

The color I haven't a clue unless your sand or ag was something with green in it.....

 

Thanks for the reply.

I asked around here yesterday and it turns out that portland cement does go off. Apparently bagged cement needs to be used within about a month of purchase. After that it begins to destabilize and is as good as useless after 2-3 months... it'll look fine but when mixed will take on this khaki greenish colour and simply won't set...

Thanks for the advice re ratios - certainly too much ag anyhow ;o). I've reshuttered the pour and will do it again over the weekend with the ratios you suggest

Cheers
CJG