A concrete pump is a tool for conveying liquid concrete […]
A concrete pump is a tool for conveying liquid concrete.
Concrete pump designers face many challenges because concrete is heavy, viscous, abrasive, contains pieces of hard rock, and solidifies if not kept moving.
Over a period of more than half a century, concrete pumps have slowly taken over from other methods of transferring liquid concrete. A number of different designs of concrete pump were developed in the first half of the 20th century but it was Friedrich Wilhelm Schwing's company Schwing GmbH which invented the twin cylinder hydraulic concrete pump in 1957. The principle of this design was adopted by almost all other manufacturers and is still the worldwide standard design.
The pump works by one piston drawing liquid concrete into a cylinder from a hopper while the other one simultaneously pushes its concrete out into the discharge pipes. A valve which determines which cylinder is open to the concrete hopper and which one is open to the discharge pipes switches over each time the pistons reach the end point and the process continues with the first cylinder now discharging and the second drawing fresh concrete from the hopper.
Concrete skip being lifted by crane up a high rise constructionThe Concrete Pump was particularly important in revolutionising the construction of large high rise buildings. Previously cranes had been employed to lift large buckets (or skips) full of concrete up to where it was needed. A crane could lift one bucket at a time, normally holding around 2 cubic yards of concrete.
There are many advantages in pumping concrete over this bucket and crane system. As well as being able to pump concrete much faster than buckets could lift it, it also means a constant supply of concrete to the top and the placing hoses can be positioned wherever they need to be so the liquid concrete can pour straight out of the hose where it's needed rather than having to distribute a two cubic yard mound of concrete over the desired area.