The methods of using the great variety of forms available are as ingenious as the forms themselves and they involve widely varying techniques. This article gives brief descriptions of some of the most usual methods of constructing with concrete, including: horizontal and vertical slipforming, jump forming and cantilever forming, flying forms, lift slab, tunnel forming, traveling forms, tilt-up, leave-in-place forms, shotcreting, preplaced aggregate concrete, tremie concrete, slurry wall construction, and ferrocement.
Concrete is placed by the tremie method gravity fed through a vertical pipe to seal cofferdams and caissons, build underwater structures, and to hold tunnel sections and other objects in place under water. The end of the tremie pipe is plugged before it is lowered into position in the water; on being filled with concrete, the weight of the material pushes the plug out and the concrete flows into position. Meantime, concrete is added at the top of the tremie pipe as needed while the pipe is slowly lifted. Care must be taken to keep the bottom of the tremie submerged in concrete to preserve the seal that forms around the bottom of the pipe. Fresh concrete passing through the pipe does not contact water except at the surface of the pour.