![GH-SA](https://upload.wikimedia.org/wikipedia/commons/5/5c/GH-SA.jpg)
A concrete mixer (often colloquially called a cement mixer) is a device that homogeneously combines
cement
A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mi ...
,
aggregate such as sand or gravel, and
water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
to form
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wid ...
. A typical concrete mixer uses a revolving drum to mix the components. For smaller volume works, portable concrete mixers are often used so that the concrete can be made at the construction site, giving the workers ample time to use the concrete before it hardens. An alternative to a machine is mixing concrete by hand. This is usually done in a wheelbarrow; however, several companies have recently begun to sell modified
tarps
The Tactical Airborne Reconnaissance Pod System (TARPS) was a large and sophisticated camera pod carried by the Grumman F-14 Tomcat. It contains three camera bays with different type cameras which are pointed down at passing terrain. It was ori ...
for this purpose.
The concrete mixer was invented by
Columbus, Ohio industrialist Gebhardt Jaeger.
History
One of the first concrete mixers ever was developed in 1900 by T.L. Smith in
Milwaukee
Milwaukee ( ), officially the City of Milwaukee, is both the most populous and most densely populated city in the U.S. state of Wisconsin and the county seat of Milwaukee County. With a population of 577,222 at the 2020 census, Milwaukee ...
. The mixer already exhibited the still common basic construction with a tiltable conical drum (as double cone at that time) with blades. 1925, at least two mixers, built 25 years ago, were still in use (serial numbers 37 and 82). The ''Smith Mascot'' in essence has the same construction of the small mixers used today. In the 1920s, the ''T.L. Smith Company'' in Milwaukee built the world's largest concrete mixers. Mixers of this company were used e. g. for the construction of the
Wilson Dam
Wilson Dam is a dam spanning the Tennessee River between Lauderdale County and Colbert County in the U.S. state of Alabama. Completed in 1924 by the United States Army Corps of Engineers, it impounds Wilson Lake, and is one of nine Tennessee Va ...
(six 2-yard and two 4-yard mixers, at the time the largest single installation of the largest concrete mixers in the world), the
first stadium of the
Ohio State University
The Ohio State University, commonly called Ohio State or OSU, is a public land-grant research university in Columbus, Ohio. A member of the University System of Ohio, it has been ranked by major institutional rankings among the best publ ...
and the
Exchequer Dam.
Industrial mixers
Today's market increasingly requires consistent
homogeneity
Homogeneity and heterogeneity are concepts often used in the sciences and statistics relating to the Uniformity (chemistry), uniformity of a Chemical substance, substance or organism. A material or image that is homogeneous is uniform in compos ...
and short mixing times for the industrial production of
ready-mix concrete
Ready-mix concrete (RMC) is concrete that is manufactured in a batch plant, according to each specific job requirement, then delivered to the job site "ready to use".
There are two types with the first being the barrel truck or in–trans ...
, and more so for precast/prestressed concrete. This has resulted in refinement of mixing technologies for concrete production. Different styles of stationary mixers have been developed, each with its own inherent strengths targeting different parts of the concrete production market. The most common mixers used today fall into three categories:
![Twin shaft concrete mixer](https://upload.wikimedia.org/wikipedia/commons/9/9a/Twin_shaft_concrete_mixer.JPG)
*Twin-shaft mixers, known for their high intensity mixing, and short mixing times. These mixers are typically used for high strength concrete, RCC and SCC, typically in batches of .
*Vertical axis mixers, most commonly used for precast and prestressed concrete. This style of mixer cleans well between batches, and is favoured for coloured concrete, smaller batches (typically ), and multiple discharge points. Within this category, the pan mixers are losing popularity to the more efficient planetary (or counter-current) mixers, as the additional mixing action helps in production of more critical concrete mixes (colour consistency, SCC, etc.).
*Drum mixers (
reversing drum mixer and tilting drum mixers), used where large volumes (batch sizes of ) are being produced. This type of mixer is capable of high production outputs.
All the mixer styles have their own inherent strengths and weaknesses, and all are used throughout the world to varying degrees of popularity.
Trucks and trailers
Concrete mixing transport trucks
![Operation of a truck mixer](https://upload.wikimedia.org/wikipedia/commons/1/1c/Operation_of_a_truck_mixer.gif)
Special concrete transport
truck
A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame constructi ...
s (in-transit mixers) are made to mix concrete and transport it to the construction site. They can be charged with dry materials and water, with the mixing occurring during transport. They can also be loaded from a "central mix" plant; with this process the material has already been mixed prior to loading. The concrete mixing transport truck maintains the material's liquid state through agitation, or turning of the drum, until delivery. These trucks have an interior turbine that pushes the mixed concrete up against gravity inside the drum. The interior of the drum on a concrete mixing truck is fitted with a
spiral blade
A blade is the portion of a tool, weapon, or machine with an edge that is designed to puncture, chop, slice or scrape surfaces or materials. Blades are typically made from materials that are harder than those they are to be used on. Histor ...
. In one rotational direction, the concrete is pushed deeper into the drum. This is the direction the drum is rotated while the concrete is being transported to the building site. This is known as "charging" the mixer. When the drum rotates in the other direction, the
Archimedes' screw
The Archimedes screw, also known as the Archimedean screw, hydrodynamic screw, water screw or Egyptian screw, is one of the earliest hydraulic machines. Using Archimedes screws as water pumps (Archimedes screw pump (ASP) or screw pump) dates back ...
-type arrangement "discharges", or forces the concrete out of the drum. From there it may go onto chutes to guide the viscous concrete directly to the job site. If the truck cannot get close enough to the site to use the chutes, the concrete may be discharged into a
concrete pump
A concrete pump is a machine used for transferring liquid concrete by pumping. There are different types of concrete pumps.
A common type of concrete pump for large scale construction projects is known as a boom concrete pump, because it uses ...
, connected to a flexible hose, or onto a conveyor belt which can be extended some distance (typically ten or more metres). A pump provides the means to move the material to precise locations, multi-floor buildings, and other distance-prohibitive locations. Buckets suspended from cranes are also used to place the concrete.
The drum is traditionally made of steel but on some newer trucks, fibreglass has been used as a weight reduction measure.
![CementMixerM2439](https://upload.wikimedia.org/wikipedia/commons/2/20/CementMixerM2439.jpg)
"Rear discharge" trucks require both a driver and a "chuteman" to guide the truck and chute back and forth to place concrete in the manner suitable to the contractor. Newer "front discharge" trucks have controls inside the cab of the truck to allow the driver to move the chute in all directions. The first front discharge mixer, patented in 1974, was designed and built by Royal W. Sims of Holladay, Utah, United States.
Concrete mixers are equipped with two or more axles. Four-, five- and six-axle trucks are the most common, with the number being determined by the load and local legislation governing allowable loads on the road.
The axles are necessary to distribute the load evenly, allow operation on weight restricted roads, and reduce wear and tear on normal roads. A two- or three-axle truck during the winter when road weight limits are reduced has no usable payload in many jurisdictions. Other areas may require expensive permits to operate.
Additional axles other than those used for steering ("steers") or drivetrain ("drives") may be installed between the steers and drives, or behind the drives. Mixers commonly have multiple steering axles as well, which generally result in very large turning radii. To facilitate maneuvering, the additional axles may be "
lift axles", which allows them to be raised off the ground so that they do not scrub (get dragged sideways across the ground) on tight turns, or increase the vehicle's turning radius. Axles installed behind the drives are known as "
tag axles" or "booster axles", and are often equipped to turn opposite to the steering axle to reduce scrubbing and automatically lift when the truck is put into a reverse gear.
Tractor trailer combination mixers where the mixer is installed on a trailer instead of a truck chassis are used in some jurisdictions, such as the province of Quebec where even six-axle trucks would have trouble carrying a useful load.
Concrete mixers generally do not travel far from their plant, as the concrete begins to set as soon as it is in the truck. Many contractors require that the concrete be in place within 90 minutes after loading. If the truck breaks down or for some other reason the concrete hardens in the truck, workers may need to enter the barrel with jackhammers.
Stephen Stepanian filed a patent application for the first truck mixer in 1916.
Trucks weigh , and can carry roughly of concrete although many varying sizes of mixer truck are currently in use. The most common truck capacity is .
Most concrete mixers in the UK are limited to a speed of .
Concrete mixer trailers
![CartAwayMixingTrailer](https://upload.wikimedia.org/wikipedia/commons/c/c5/CartAwayMixingTrailer.JPG)
A variant of standard concrete transportation is the concrete or cement mixing trailer. These small versions of transit-mix trucks are used to supply short loads of concrete. They have a concrete mixing drum with a capacity of between . Cart-aways are usually pulled behind a pick-up truck and batched from smaller batching systems. The mixing trailer system is popular with rental yards and building material locations, which use them to supply ready-mix to their regular customer base.
Metered concrete trucks
![Metered concrete truck](https://upload.wikimedia.org/wikipedia/commons/f/f4/Metered_concrete_truck.jpg)
Metered concrete trucks or volumetric mobile mixers contain concrete ingredient materials and water to be mixed on the truck at the job site to make and deliver concrete according to the amount needed.
On-site and portable concrete mixers
![Cement mixer2](https://upload.wikimedia.org/wikipedia/commons/e/ea/Cement_mixer2.jpg)
For smaller jobs, such as residential repairs, renovations, or hobbyist-scale projects, many cubic yards of concrete are usually not required. Bagged cement is readily available in small-batch sizes, and aggregate and water are easily obtained in small quantities for the small work site. To service this small-batch concrete market, many types of small portable concrete mixers are available.
A typical portable concrete mixer uses a small revolving drum to mix the components. For smaller jobs the concrete made at the construction site has no time lost in transport, giving the workers ample time to use the concrete before it hardens.
Portable concrete mixers may be powered by gasoline engines, although it is more common that they are powered by electric motors using standard mains current.
These concrete mixers are further divided based on their loading mechanism. Cement, sand and other aggregates are loaded in a hydraulically operated hopper and then poured into the mixing drum for final mixing. They can be unloaded by tilting the drum. In hand-feed concrete mixers, cement, sand and other aggregates are directly added to the mixing drum manually. Both of these types of concrete mixers are popular in construction activities in Africa, some Middle Eastern countries and in the Indian subcontinent.
Self-loading concrete mixers
![Arutua - Laurent Seignobos 3](https://upload.wikimedia.org/wikipedia/commons/7/72/Arutua_-_Laurent_Seignobos_3.jpg)
Self-loading concrete mixers are unique machines designed to batch, mix and transport concrete. They consist of a rotating drum mounted on an operator-driven cab-mounted chassis frame fitted with a loading bucket.
The operator of the self-loading concrete mixers batches and introduces the ingredients required for mixing concrete (cement, stone aggregates etc.) into the drum using the loading bucket. The drum is usually reversible type, tilt type or a combination of both. A predetermined volume of water is discharged to the drum via a water dispensing unit. The mixture is rotated at mixing speeds within the drum until the concrete discharges via a fitted chute.
Self-loading concrete mixers are suited for construction sites where concrete batching plants are unavailable, underfoot conditions are not suited for concrete transit mixer trucks or labor availability is scarce or constrained. Applications include urban and rural construction, concrete pavement maintenance, bridge and tunnel construction, township-level highways construction, foundation construction, national defense facilities, construction of high-speed railways, etc.
Operating code
Operating concrete mixers correctly is one of the biggest safety issues in construction zones. Workers whose tasks are related to concrete processing currently number more than 250,000. Over 10 percent of those workers, 28,000, experienced a job-related injury or illness, and 42 died in just one year.
In fiction and culture
* In ''
Thomas and Friends
''Thomas & Friends'' (originally known as ''Thomas the Tank Engine & Friends'' and later ''Thomas & Friends: Big World! Big Adventures!'') is a British children's television series that aired across 24 series from 1984 to 2021. Based on ''The ...
'', Patrick is a concrete mixer who is dark brown and cream.
* In ''
Bob the Builder
''Bob the Builder'' is a British animated children's television series created by Keith Chapman for HIT Entertainment and Hot Animation. The series follows the adventures of Bob, a building contractor, specialising in masonry, along with ...
'', Dizzy is an orange on-site and portable concrete mixer and Tumbler is a yellow and green concrete transport truck (commonly called a cement truck). In the
reboot
In computing, rebooting is the process by which a running computer system is restarted, either intentionally or unintentionally. Reboots can be either a cold reboot (alternatively known as a hard reboot) in which the power to the system is physi ...
of the series, Two-Tonne has a concrete mixer trailer.
* In the ''
Transformers
''Transformers'' is a media franchise produced by American toy company Hasbro and Japanese toy company Tomy, Takara Tomy. It primarily follows the Autobots and the Decepticons, two alien robot factions at war that can transform into other forms ...
'' franchise, the
Constructicon Mixmaster is a robot that can turn into a cement truck.
* The ''Cement Truck'' is a gothic sculpture by
Wim Delvoye
Wim Delvoye (born 1965 in Wervik, West Flanders) is a Belgian neo-conceptual artist known for his inventive and often shocking projects. Much of his work is focused on the body. As the critic Robert Enright wrote in the art magazine ''Border ...
.
* Cement Mixer (Put-Ti-Put-Ti) a song by
Slim Gaillard that was inspired by the sound of a concrete mixer.
* In
Construction Site
Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and co ...
Maxine is a dusty brown and cream cement mixer.
Television
* On an episode of ''
MythBusters'', experiments were done to see if
dynamite can be used to clean out hardened concrete from inside of a mixer truck, with limited practical results. For the finale, an excessive amount of explosive (800 lbs of commercial blasting agent) was used, and was detonated from a long distance away. The explosion left a very clear crater, and only the engine block was recovered.
* On an episode of ''
Wrecked - Life In The Crash Lane'', O'Hare Towing responds to a call on a construction site to recover a mixer truck that had become stuck in mud, continuing to sink and threatening to roll over. After several unsuccessful attempts to hoist the mixer using a
heavy rotator wrecker, the foreman informs the wrecker driver that the mixing drum contains approximately 5 cubic yards of concrete, and asks whether emptying the drum would lighten the truck enough to enable the wrecker to recover it. After emptying the drum, the wrecker operator is able to winch the mixer truck out of the mud onto solid ground.
* In season 5, episode 1 of TV series ''
MacGyver
Angus "Mac" MacGyver is the title character and the protagonist in the TV series ''MacGyver''. He is played by Richard Dean Anderson in the 1985 original series. Lucas Till portrays a younger version of MacGyver in the 2016 reboot.
In both p ...
'', the series' main character uses an engine from a small portable gasoline powered concrete mixer, in order to build an aeroplane.
* Magicians
Penn & Teller
Penn & Teller, Penn Jillette and Teller, are American magicians, entertainers, and scientific skeptics who have performed together since the late 1970s. They are noted for their ongoing act that combines elements of comedy with magic.
The duo h ...
perform a trick called "The Psychic Cement Mixer of Death" in which Teller is strapped blindfolded inside an empty, spinning concrete mixer and picks one half of a signed, broken brick (much like other tricks that tear a card or dollar bill in half) from dozens of other bricks spinning in the mixer.
[Archived a]
Ghostarchive
and th
Wayback Machine
* On the 6th episode of the 13th season of
Taskmaster the contestants were asked to "Use the cement mixer for something other than mixing cement." The task followed "Best use of a cement mixer other than mixing cement wins."
Ardal O'Hanlon
Ardal O'Hanlon (; born 8 October 1965) is an Irish comedian, actor, and author. He played Father Dougal McGuire in ''Father Ted'' (1995–1998), George Sunday/Thermoman in '' My Hero'' (2000–2005), and DI Jack Mooney in '' Death in Paradise'' ...
used the mixer to wash a mannequin's hair. He received one point.
Bridget Christie used it as a musical instrument, to accompany a chant she made about the environment. She received 2 points.
Chris Ramsey used the cement mixer to make a sausage arena, with the aim to eat the sausage on their coloured stick in the cement mixer. He received 5 points.
Judi Love
Judy Veronica Thomas (born 4 June 1980), known professionally as Judi Love, is an English stand-up comedian and presenter. She began her stand-up career in 2011 but came to prominence as a panellist on the ITV talk show ''Loose Women''. As well ...
used the cement mixer to make a cocktail for Alex called "Love Juice". She received 3 points.
Sophie Duker
Sophie Duker (born 1989/1990) is a British stand-up comedian and writer.
Early life
Duker was born in London to first-generation immigrants from West Africa. Her mother is from Cameroon and her father is from Ghana. She studied French and Engli ...
used the cement mixer as a
tombola, containing various ice breakers for her and
Alex Horne
Alexander James Jeffery Horne (born 10 September 1978) is a British comedian and musician. Horne is the creator of BAFTA award-winning TV series '' Taskmaster'', in which he also performs as the Taskmaster's assistant. He is the host and ban ...
. She received 1 point.
See also
*
Mixing paddle
A mixing paddle is a shaped device, typically mounted on a shaft, which can be inserted on the shaft end into a motorised drive, for the purpose of mixing liquids, solids or both.
Paddle mixers may also be used for kneading.
Whilst mounted in fixe ...
*
Types of concrete
Concrete is produced in a variety of compositions, finishes and performance characteristics to meet a wide range of needs.
Mix design
Modern concrete mix designs can be complex. The choice of a concrete mix depends on the need of the project ...
*
Concrete plant
A concrete plant, also known as a batch plant or batching plant or a concrete batching plant, is equipment that combines various ingredients to form concrete. Some of these inputs include water, air, admixtures, sand, aggregate (rocks, gravel ...
References
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Concrete
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