Boat ramps under water

[Raesen]

Easiest question for all you Guru's.

How do they pour the concrete slab of a boat ramp out past the low water mark????

Fast setting concrete, bunding to keep the water at bay (that is not a play on words) or what.

Thanks and cheers
Pete

Oh and by the way - Go The BLUES

[HIGH and DRY]

could be wrong, but i think there was a thread on this recently. i just can't remember where. try a search and see what you find. they pretty much barricade off the area with corrogated type stuff and pump the water out!!!

[BilgeBoy]

There have been a few posts on this one. The pictures I have seen use a retaining wall system, pump it out, poor and dry.

BilgeBoy

[Raesen]

Thanks guys I'll do a search. Sounds about right to place sheet piling and pump out area.
Regards
Pete

[Noelm]

easy, there is concrete that sets under water, people think that it sets when the water dries out WRONG!! it is a chemical reaction that takes place, and can indeed be slowed down (as done by delivery drivers who get caught in traffic) they can pour in a chemical and it will delay setting.

[Noelm]

OH, and if possible, of course you can "dam" the area and use pumps to do the job "dry" that is also done, but not a possiblity in deeper places where conctrete is needed, the biggest drawback is finnishing, you cannot "float" it off under water (well pretty difficult at least)

[Sea-Dog]

http://www.waterstructures.com/Applications/page3.html

This was from a previous thread where all the photos have disappeared in the migration to the new system.

http://www.ausfish.com.au/vforum/showthread.php?t=78630

[roz]

In a lot of cases they pre fabricate the slabs.

[Tinn]

Like Roz said some places they just drop in a slab of concrete that is all ready to go just like they build tilt slab sheds

[oztrav]

high performance concreting as for the finish well look at boat ramps the rougher the finish the better steel troweling an area like a boat ramp is just ridiculous if i was to do one it would be prefab barracading and pumping is just silly and a waste of time and money