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RE: H2O at bot of forms

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First have the contractor use sump pumps and compressed air to dewater the interior of the forms.

OK now for whatever reason the water can't be removed.  

Use a tremie pipe.  Place the pipe discharge at the bottom of the forms.  Place the concrete so that the opening of the tremie is always below the top of the plastic concrete.  Continue placing the concrete and displace the water.  Allow the water to flow over the top of the forms.

The one thing that will happen is an irregular bond to the hardened concrete.  You can't completely avoid the water lenses and unbonded sections between the hardened concrete and the newly placed concrete, but it can be minimized by proper vibration.  Don't vibrate until the full wall height has been place.

Concrete placement underwater is done fairly commonly.

Harold Sprague
Krawinkler, Luth & Assoc. 

-----Original Message-----
From:	Mike Brown [SMTP:mike.brown(--nospam--at)]
Sent:	Thursday, May 14, 1998 1:32 PM
To:	seaoc
Subject:	Re:  H2O at  bot of forms

Al and Charley:
The forms are steel forms that go from the top of footing to the 15 foot height.  Therefore, removing a portion of the form is to remove several form panels to adequately access the 2x4 continuous key way.  The key way is not accessible to use a pump to remove the water due to the reinforcing steel (2 curtains), without removing the form work.  By the time a portion of the form work is removed and replaced, there is a good chance that water will collect in the key again (forecast for rain everyday for the next week).
As you might be aware, the project is on a fast track.  The owner does not want to postpone construction due to rain, unless absolutely necessary.  I need to be able to justify stopping construction or proceeding.
In other words, what are the risks and worst case scenario?  I need a comfort level.
Thank you.