what do you add before lift pour?

[lejam]

When you have tight column formworks set up and ready for pour. Do you really have to pour a liter of water to wet the old column surface at bottom of column or pour a liter of grout before main pour? What is the purpose of such? What do you usually do?

 

[hokie66]

Nothing. Just cast the concrete. But a litre of water wouldn't hurt.

 

[lejam]

If the bottom is sealed airtight, the liter of water would remain, so no problem with it mixing with the pour and affecting the cement water ratio at the bottom most section?

 

[hokie66]

A litre just isn't that much. By the time it gets to the bottom, much of it will have stuck to the forms and reinforcement, and the rest will just moisten the concrete. I doubt that your forms will be airtight anyway.