Cement in sealed plastic bags - Question!

[Granitechops]

over 12 months ago I bought 2 bags of cement, the blue circle, in the tough plastic blue & yellow bag.
I did not need to use the second one, so it sat unopened till about a month ago,
normally if I use up old cement, I increase the amount of cement in the mix and ONLY use it for cosmetic & NOT STUCTURAL use
usually the damp has got to it & lumps have formed, but the cement in this bag, seemed as dry & fine as if I had only just bought it, & it performed just as well while mixing & using
QUESTION
Does the exclusion of moisture extend the life of cement
OR
is it compromised just by age alone
Any experts out there??

 

[trammayo]

It is the moisture that kills it. I wouldn't like to say how long it lasts when moisture is totally excluded but I would say it will last a few years. DIY stuff which include ordinary portland cement has a long shelf life before opening.

 

[Rhinochugger]

Curing of cement is a chemical reaction bewteen the cement and the water.

Keeping it in sealed polythene bags obviously is successful, limited only by the ability of the manufacturer to exclude all moisture before sealing the bag.

I'm certainly impressed that it's lasted so long, but then, I only have experience of the stuff that comes in paper bags (or already stirred up with stones and water in big orange mixer lorries )

 

[Granitechops]

Curing of cement is a chemical reaction bewteen the cement and the water.

Keeping it in sealed polythene bags obviously is successful, limited only by the ability of the manufacturer to exclude all moisture before sealing the bag.

I'm certainly impressed that it's lasted so long, but then, I only have experience of the stuff that comes in paper bags (or already stirred up with stones and water in big orange mixer lorries )

Well I was impressed & a bit surprised too, I normally only buy any split bags that are on the shelf at a big discount, normally the paper bagged ones
on getting them home I immediately put them individually into heavy duty plastic bags ( sometimes the DIY barn does that for me to contain the spill)
but find that I have to use them within 4-5 weeks depending on ambient humidity, a foggy day obviously admits more moisture into the bag than a hot dry day.
I was expecting to have to dump this one, but am glad I decided to try it first
Thanks Ian