This is a video showing the final process of changing the shape and features of a swimming pool. The wet concrete will have the amount of water adjusted to give it an ideal consistency for this application. Finally, compressed air is released at the end of the nozzle to spray the concrete where it is needed like a big heavy paint gun. The rebar acts as reinforcement for the structures and also has the secondary function of giving the wet concrete something to stick to to hold the shape. As the process goes on the workers will use trowels to cut, level and smooth the new features of the pool.