Which term is associated with ensuring the bottom end remains submerged during placement with a tremie?

• A. Bridge Deck Concrete Removal
• B. Neoprene Bearing Pad Texture
• C. Tremie Pipe Placement
• D. Concrete Elapsed Time

Answer: (C)

Keeping the end of the placement conduit submerged during underwater concrete placement is the key idea. The term for this approach is tremie pipe placement. In this method, a long tremie pipe is lowered into the underwater area and remains submerged as concrete is pumped through it. Because the pipe end stays below the water surface, the fresh concrete displaces water rather than mixing with it, forming a continuous, dense concrete column and preventing washout and segregation. This ensures the bottom stays adequately covered and the pour achieves the intended strength and durability. The other options aren’t related to underwater placement techniques: one refers to removing bridge deck concrete, another to the texture of neoprene bearing pads, and another to curing time, which doesn’t govern how the concrete is placed underwater.