Concrete Pumps

A concrete pump is a machine that moves fresh concrete through pipes or hoses from a truck mixer or plant to the point where it is placed. Instead of lifting concrete in skips with a crane or moving it in barrows, the pump pushes it continuously, horizontally and vertically, often over long distances and to great heights. The most visible form is the truck-mounted boom pump, a lorry carrying a pump and a folding hydraulic arm that can unfold over a building and place concrete exactly where it is needed. Smaller line pumps, trailer pumps and stationary pumps serve jobs where concrete has to travel through a pipeline.

Concrete pumping has changed how buildings and infrastructure are made. It allows faster pours, reduces labour and crane time, and makes it possible to place concrete in high-rise cores, deep foundations, tunnels and places that other methods cannot reach.

Brief History of Concrete Pumps

The idea of pumping concrete through pipes dates to the 1920s. In Germany, engineers Max Giese and Fritz Hell developed and patented a concrete pump in the late 1920s, and in the Netherlands Jacobus Cornelius Kooijman patented a mechanically driven pump in the early 1930s that built on this work. These early machines were heavy and mechanical, and they were used mainly on large projects.

The modern concrete pump emerged after the Second World War with hydraulics. In 1957 Schwing introduced a hydraulically driven twin-cylinder concrete pump, a layout that became the basis for most later designs, and in 1965 the company launched a truck-mounted pump with a placing boom. Putzmeister, founded in Germany in 1958 by Karl Schlecht, became the other leading name in the industry. Over the following decades booms became longer and lighter, pumping pressures increased, and control moved from levers to radio remote controls. Concrete pumps were used to entomb the damaged reactor at Chernobyl in 1986 and have been used on the tallest buildings in the world. In the 2000s and 2010s Chinese groups entered the market strongly: Zoomlion acquired the Italian company CIFA in 2008, and in 2012 SANY acquired Putzmeister while XCMG became majority shareholder of Schwing.

How a Concrete Pump Works

Most concrete pumps used in construction are hydraulically driven twin-piston pumps.

Hopper. Concrete from the truck mixer is discharged into a hopper with an agitator that keeps it moving and feeds it towards the pumping cylinders.
Delivery cylinders. Two concrete cylinders work alternately. While one piston draws concrete in from the hopper, the other pushes concrete out into the delivery line. Each piston is moved by a hydraulic drive cylinder.
Switching valve. A valve switches between the two cylinders at the end of each stroke so that one is always connected to the delivery line. The most common designs are the S-valve (a swinging tube shaped like an S) and the rock valve, with flat gate valves used on some machines.
Delivery line. Concrete flows through steel pipes, bends and rubber end hoses. On a boom pump the pipe runs along the boom sections to the end hose.
Power. On truck pumps the pump is driven by the truck engine through a power take-off. Stationary and trailer pumps have their own diesel engine or electric motor.
Controls. A radio or cable remote control lets the operator stand where they can see the pour and control the boom and pump output.

Types of Concrete Pumps

Truck-Mounted Boom Pumps

The most common type on building sites. A pump and a folding placing boom are mounted on a truck chassis, with outriggers that stabilise the machine during pumping. Boom folding systems vary, including roll folding, Z folding and combinations of the two, which affect how the boom unfolds under obstacles.

Truck-Mounted Line Pumps

Trucks that carry a pump without a boom, or with a small boom, used to feed a pipeline laid on site or connected to a separate placing boom.

Trailer and Stationary Pumps

Pumps on a towed trailer or a skid, powered by diesel or electric motors. They push concrete through a fixed pipeline, for example to the upper floors of a tall building, into a tunnel or along a long distance. High-pressure stationary pumps are the machines that make pumping to several hundred metres possible.

Truck Mixer Pumps

A truck mixer with a small pump and a short boom. It delivers and places small quantities without the need for a separate pump truck.

Small Pumps and Mortar Pumps

Compact pumps for screed, mortar, grout and fine concrete, used in renovation, residential work and floor screeds.

Size Classes

Class	Typical vertical boom reach	Typical use
Small boom pumps	about 20 to 30 m	Housing, small slabs, renovation
Medium boom pumps	about 30 to 45 m	Commercial buildings, general construction
Large boom pumps	about 45 to 60 m	Large buildings, bridges, industrial projects
Very large boom pumps	about 60 m and more	Special projects with long reach

Figures are indicative. Horizontal reach is a few metres less than vertical reach, and pump outputs typically range from about 100 to 200 m³/h theoretical on truck-mounted machines.

Main Manufacturers

Putzmeister, founded in Germany and part of SANY since 2012.
Schwing, the German company whose majority shareholder is XCMG.
CIFA, the Italian manufacturer owned by Zoomlion.
SANY, Zoomlion and XCMG, which also build pumps under their own names.
Everdigm, Junjin and KCP from South Korea.
Liebherr, which offers truck-mounted concrete pumps alongside its mixers.

Main Uses of Concrete Pumps

Placing concrete in floor slabs, walls, columns and foundations of buildings.
Pouring bridge decks, piers and other civil engineering structures.
Pumping concrete to high-rise cores and upper floors through vertical pipelines.
Tunnel linings, underground works and dam construction.
Filling piles, diaphragm walls and other foundation elements.
Pumping screed, mortar and grout in finishing and repair work.

Planning a Concrete Pump Job

Choose the boom length. The boom must reach the furthest point of the pour, taking into account the position of the truck, obstacles and the shape of the building.
Check the set-up area. The pump needs a firm, level area large enough for full outrigger extension. The ground bearing capacity must be checked and outrigger pads used.
Look up and around. Overhead power lines, cranes, trees and neighbouring buildings limit where the boom can move.
Plan the mix. Pumpable concrete needs a suitable aggregate grading, enough fine material and the right consistency. Very stiff or poorly graded mixes can block the line.
Coordinate the trucks. Continuous supply from truck mixers avoids interruptions and blockages. Two trucks should be able to discharge in turn where possible.
Plan cleaning. Washout of the hopper and pipeline must be done in a designated area with suitable containment.

Safety

The main hazards of concrete pumping are loss of stability, boom failure, contact with overhead power lines and uncontrolled movement of the end hose. Outriggers must be fully and correctly deployed on firm ground and pads, and the machine must never be used beyond its approved working range. Line blockages can release energy suddenly when cleared, so pressure must be relieved before opening pipes. No one should stand under the boom or near the end hose at the start of pumping, when air in the line can make the hose whip. Pipe clamps must be secured, and delivery lines and boom wear parts inspected regularly because pipe wall thickness is reduced by abrasion. Operators need training and certification in many countries.

Trends and Technology

Concrete pump manufacturers are working on lighter booms, better control and lower emissions. Boom control systems that damp vibration and let the operator move the tip in a straight line are now available on many machines. Sensors monitor boom stress, outrigger loads and stability, and some pumps limit the working range automatically according to how the outriggers are set up. Electric pumping, powered by a site electricity supply or a battery, reduces noise and emissions in city centres, and fully electric truck-mounted pumps have been introduced. Telematics records pumped volumes, pressures and maintenance data, and pumps are being connected with dispatch systems for truck mixers.

Key Terms

Placing boom: the folding hydraulic arm carrying the delivery pipe to the pour.
S-valve: a swinging S-shaped tube that switches between the pumping cylinders.
Rock valve: an alternative switching valve design, often used with harsher mixes.
Outriggers: extendable legs that stabilise the pump during operation.
End hose: the flexible hose at the boom tip used to direct the concrete.
Priming: lubricating the line with grout or a special mix before pumping concrete.

Frequently Asked Questions

How high can a concrete pump reach? Truck-mounted boom pumps commonly reach from about 20 m to more than 60 m vertically. Stationary pumps with a vertical pipeline can pump concrete several hundred metres up a building.

What is the difference between a boom pump and a line pump? A boom pump places concrete with a hydraulic arm, while a line pump pushes concrete through a pipeline or hose laid by hand to the pour.

Can any concrete be pumped? Most structural concrete can be pumped if the mix is designed for it. Mixes with poorly graded aggregates, very low workability or very large aggregate are harder to pump and can cause blockages.

Why do concrete pumps need outriggers? The extended boom and the moving concrete create a large overturning moment. Outriggers spread the load over a wide base and keep the truck stable.