Moving Concrete 'Up Hill' ...
An inside view of a concrete truck mixer drum showing the fins that help mix the ingredients during transport and when adding water or coloring agent. These same fins also create the moveable "ramp" that allows the concrete to be poured out of the chute without actually lifting the drum. When turned in the opposite direction, the concrete moves "up" the ramp into the top of the delivery chute at the back of the concrete truck.