Underwater Cement

[rScotty]

I need to repair some cement structures in my pond. It's going to involve attaching some clean cement blocks to some clean cement culvert - and then the whole thing will be put in the pond to stay. There won't be much stress on it, at least there won't be as long as the cement holds it all together. Does anyone have a recommendation on what type of cement to use for this kind of work?
thanks,
rScotty

 

[BukitCase]

Any mix with portland cement can be poured under water, and cures harder than air cured - one of the tricks is keeping it from moving til it sets. In a pond the water should be still enough for that NOT to matter... Steve

 

[Fuddy1952]

I had to use Sodium bentonite clay around the drain pipe.

 

[MAX-24-Dean]

Hydraulic cement. Edited hydraulic cement is Portland Cement. As stated above by BukitCase.
Age got the best of me on this one. Forgetful sometimes.

 

[Smokeydog]

Moving/placing a cement structure is more concerning than the hydraulic aspect. Cement has low tension strength unless reinforced.

Used a product called surewall, a high strength, fiber reinforced surface bonding cement successfully on several repair projects. Great adhesive strength, waterproof and tensile strength to prevent cracking. Downside it’s more expensive than cement.
You could coat over a cement project to make stronger.

Be sure to clean your mixing/handling tools before letting it set. Like I said high adhesion.