The concrete mixer is a key part of any construction site. They transport large quantities of concrete and allow workers ample time to use it without the concrete drying out. They may be slow on our roads however, the evolution of the concrete mixer trucks has been a continuous effort over the years and demonstrates the long journey from their original design.
Early Horse-Drawn Concrete Mixers
R. Bodlaender’ Mortar Mixer
The first recorded version of the portable concrete mixer was horse-drawn. It was patented in 1904, by a German inventor called Richard Bodlaender who gave it the title ‘Mortar Mixer’. The front wheels were replaced by a large drum that contained paddles for churning the concrete and as the horses pulled the vehicle, the wheel would turn, creating the mixing action. This machine was extremely heavy and would take horses a long time to transport the mixer from place to place.
First motorized concrete mixer
Stepanian’s Concrete Mixing and Transporting Vehicle
Stephen Stepanian, an Armenian-American inventor, is credited with being the inventor of the self-discharging motorized transit mixer, which is the predecessor to the concrete mixer. He is also the inventor of the wrench and adopted the name the ‘Farther of the ready-mix concrete industry’. In 1916, he applied for a patent for his design, however, in 1917 it was rejected. There is some dispute as to whether it was rejected due to there being no previous patents around what he was designing, resulting in a lack of proof that the integration of the mixer and truck would work, or whether the patent was rejected because he was not a US citizen.
Stepanian reapplied for the patent in 1928, which then received approval in 1933. He also received universal recognition for his contributions to the industry. At the 1954 Chicago NRMCA convention, several thousand people celebrated him as he was made an honorary life member of the ‘National Ready Mixed Concrete Association Board of Directors’.
Bickel’s Apparatus for Concrete Work
Due to Stephen Stepanian not being able to claim his original patent, the history books credit Ackert Bickel with being the inventor of the first concrete mixer truck. The Kansas inventor patented his concrete truck in 1920 naming it “Apparatus for Concrete Work”.
This new concrete truck required no horses and no steam boiler. It had a steering wheel and an internal combustion engine, although it did still require a hand crank to start it. The truck also had a large amount of dead space between the driver’s compartment and the drum containing the concrete. Nobody noticed the wasted space; workers were probably just happy that the workload had been reduced. Bickel’s truck remained the leader for a decade.
Next Generation of Concrete Mixers
Ball’s 1932 Mixing and Agitating Machine
In 1930, Charles Ball from Milwaukee, Wisconsin had his patent approved for his new machine titled the ‘Mixing and Agitating Machine’. His machine was able to hold a substantially larger amount of concrete. Ball radically changed the design of the mixing drum over the next two years. The 1930s led to an increase in demand for concrete trucks because more highways were being built to connect major cities.
Lee’s Transit Concrete Mixer
On Christmas day in 1934, Roscoe Lee was granted his patent for his transit concrete mixer design. Lee’s version of the mixer required a crane to put a drum on the back of a standard truck. His design allowed for the new trucks to be turned into a flatbed or even dump trucks, once the concrete drum had been used. His design was less expensive than a normal concrete truck.
The Modern-Day Concrete Mixer
Modern-day Concrete Mixer Truck
Today’s design of the concrete truck hasn’t changed much since Stephen Stepanians’ ideas. As technology has changed, the concrete mixer has improved, which allowed workers more time for transport and use on the concrete when it arrives. The modern concrete transit mixer has a separate water tank in the truck. The spinning drum contains the dry ingredients and when the driver is close to the construction site, the water is released into the spinning barrel to make fresh concrete. The trucks have also had to become more powerful due to the 13,000kg’s of weight they carry.
The concrete mixer market continued to grow from 1930, with the reconstruction of many buildings and roads after WWII being a key demand for them. The market for the trucks hasn’t changed today as many more housing development sites are being formed, requiring large amounts of concrete.