Can you "refresh" cement?

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Hi. I bought cement to make concrete to be used to effect a border around my garden. So, great strength of concrete is not required. Now, I've had this cement 2 years. Say I have six bags, can I "refresh" the cement by adding a bag a new cement to three bags of the old? Would not attempt this if the concrete was to be used in a structural way. Thanks for replies. Rich
 
Normally what happens to cement is that it takes on water, goes lumpy, them turns I to a sort of pre-wrapped solid block. Your shed must be drier than mine! Why not mix up a small bit of it to see if it's still effective?
 
If the cement is still free flowing powder or easily crumbled in the hand to a fine powder, it will work fine but it will have reduced strength - so not suitable for structural use.

I guess if you make up concrete it will be stronger if you have a percentage of new.

I would say fine for concrete, not suitable for mortar for bricklaying.
 
As mentioned, making up a test mix with a portion of new cement seems to be the thing to do, to see what gives. I'm hoping that adding one third new to old might give the mix a fair propotion of the original strength that comes with fresh cement. Thanks for comments made Rich
 
the cement industry advice (used to be) that cement is OK to use unless it contains lumps that cannot easily be broken with the fingers. When you have handled a few bags I think you will be able to recognise the difference.

it's probably on https://www.thenbs.com/PublicationIndex/documents?Pub=BCA here but it seems you have to be a member now to read it.
 
In November, I asked a mate of mine who is a plasterer if he had a small amount of bonding plaster I could have. I only needed about 3kg.

He gave me some out of date hard wall and warned me that it would go off really quickly. He omitted to tell me that once it dried it would be super crumbly.
 
In November, I asked a mate of mine who is a plasterer if he had a small amount of bonding plaster I could have. I only needed about 3kg.

He gave me some out of date hard wall and warned me that it would go off really quickly. He omitted to tell me that once it dried it would be super crumbly.

Yep. I get that kind of thing with old cement. Hoping it can be refreshed with a portion of new cement added.
 
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