Despite what those in the public might think, we know that concrete does not “dry out” and can set just as well—even better—under water as in dry air. But placing under water does require some special techniques and mixes to prevent segregation, washout, and poor bonding between placements (cold joints). The following articles describe methods, materials, and equipment that have been used successfully in the past to place concrete under water.

December 1968: Placing Concrete Under Water
When circumstances demand that concrete be placed under water, every effort should be concentrated on assuring continuity of placement between the construction joints.

February 1986: Tremie Concrete
Methods for placing high quality concrete under water.

November 1986: Concrete Placed Under Water
A major concern in underwater concreting is that the water in which concrete is placed will wash away cement and sand or mix with the concrete and increase the water-cement ratio.

January 1988: Were the Romans First to Place Concrete Underwater?
Remnants of a breakwater built 2,000 years ago suggest that the Romans knew how to make massive concrete placements underwater.

February 2013: Third Straw
Continuous 12-day concrete pour challenges barge-mounted concrete placing system to place special mix 390 feet underwater.