Concrete placing booms are the final part of a system that pumps concrete. They unfold from a resting position to move around and cover large areas that can be otherwise difficult to reach.
At the start of the system is a pump. The pump could be in the form of lorry, or it could be a static pump, like the one shown below.
Concrete gets poured into the pump, then gets pushed through pipes (lines), to the placing boom, which disperses the concrete where needed.
