A concrete mixer (often colloquially called cement mixer ) is a homogeneous device combining cement, aggregate like sand or gravel, and water to form concrete. A typical concrete mixer uses a rotating drum to mix components. For smaller volumes working portable concrete mixers are often used so that concrete can be made at construction sites, giving the workers plenty of time to use concrete before hardening. The alternative to a machine is to mix the concrete by hand. This is usually done in a wheelbarrow; However, some companies have recently started selling modified tarpaulins for this purpose.
The concrete mixer was created by Columbus, Ohio industrialist, Gebhardt Jaeger.
Video Concrete mixer
Mixer industri
Today's markets are increasingly in need of consistent homogeneity and short mixing times for the production of ready-mix concrete industry, and more for precast/precast concrete. This has resulted in a refinement of mixing technology for the production of concrete. Various styles of stationary mixers have been developed, each with its own inherent strength that targets various parts of the concrete production market. The most commonly used mixer today is divided into three categories:
- Twin-shaft mixers, known for their high mixing intensity, and short mixing times. This mixer is usually used for high quality concrete, RCC and SCC, usually in batches of 2-6 m 3 (2.6-7.8 cu yd).
- The vertical axis mixer, most commonly used for precast and prestressed concrete. This mixer style cleans well between batches, and preferably for colored concrete, smaller batches (typically 0.75-3 m 3 or 0.98-3.92 cuÃ, yd), and some discharge points. In this category, pan mixers lose popularity to more efficient planetary (or counter-current) mixers, because additional blending action helps in the production of more important concrete mixtures (color consistency, SCC, etc.).
- Drum mixers (inverted drum mixers and tilting drum mixers), used where large volumes (batch size 3-9 m 3 or 3,9-11,8 cuÃ, yd) are being produced. This type of mixer dominates the market that is ready to be mixed because it is capable of producing high production speeds and ideal for slump concrete, and is used when the overall cost of production is important. The drum mixer has the lowest maintenance and operating costs of the three types of mixers.
All mixer styles have their own inherent strengths and weaknesses, and they are used all over the world with varying levels of popularity.
Maps Concrete mixer
Trucks and trailers
Concrete mixing transport truck
Special concrete transporter truck (transit carrier) is made to mix the concrete and bring it to the construction site. They can be filled with dry materials and water, with mixing occurring during transportation. They can also be loaded from a "center mix" factory; with this process the material has been mixed before loading. Concrete mixing trucks carry material liquid status through agitation, or change of drum, to delivery. The inside of the drum on a concrete mixer truck is equipped with a spiral knife. In one direction of rotation, the concrete is pushed deeper into the drum. This is the direction the drum is playing while the concrete is being transported to the building site. This is known as a "charging" mixer. When the drum is spinning in the other direction, the Archimedes screw type arrangement "pulls out", or forces out the drum concrete. From there it may go into the launch to guide the viscous concrete directly to the workplace. If the truck is not close enough to the location to use the launch, the concrete may be disposed of into a concrete pump, connected to a flexible hose, or to a conveyor belt that can be extended some distance (usually ten meters or more). A pump provides the means to move the material to the right location, multi-storey building, and other remote locations. Buckets that are hung from a crane are also used to place concrete. Drums are traditionally made of steel but on some new trucks, fiberglass has been used as a weight reduction measure.
The "Rear discharge" truck requires the driver and "chuteman" to guide the truck and pull back and forth to place the concrete in a manner appropriate to the contractor. The newer "discharge" trucks have controls inside the truck's cab to allow the driver to move the channel in all directions. The first front discharge mixer was designed and built by Royal W. Sims of Holladay, Utah, USA.
The concrete mixer comes with two or more axles. Four-, five- and six-axle trucks are the most common, with numbers determined by local loads and legislation governing permissible loads on the road.
Axles are needed to evenly distribute the load, allow operations on weight-restricted roads, and reduce wear on normal roads. Trucks two or three axles during winter when the reduced road weight limit does not have a payload that can be used in many jurisdictions. Other areas may require expensive licenses to operate.
Additional axles other than those used for steering ("direct") or drivetrain ("drive") can be installed between the driver and the drive, or behind the drive. Mixers generally have some steering axles as well, which generally produce a very large turning radius. To facilitate maneuvers, the axle can be a "lifter lift", which allows it to be lifted from the ground to avoid rubbing (dragged sideways across the ground) at narrow bends, or increasing the turning radius of the vehicle. The axle is mounted behind a drive known as the "tag axle" or "reinforcement axle", and is often equipped to turn opposite the steering wheel to reduce the scouring and automatically lift when the truck is inserted into the reverse gear.
Tractor mixer is a combination of tractor in which the mixer is mounted on a trailer instead of the truck chassis used in some jurisdictions, such as the province of Quebec where even a six-wheeled truck will have difficulty carrying a useful load.
Concrete mixers generally do not travel far from their factory, because the concrete starts to be installed immediately after being in the truck. Many contractors require concrete to be installed within 90 minutes of loading. If the truck is damaged or for other reasons the concrete hardens inside the truck, the worker may need to enter the barrel with the jackhammers.
Stephen Stepanian applied for a patent for the first mixer truck in 1916.
The truck weighs 20,000 to 30,000 pounds (9,070 to 13,600 kg), and can carry about 40,000 pounds (18,100 kg) of concrete even though many sizes of Truck Mixer are in use. The most common truck capacity is 8 cubic meters (6.1 m 3 ).
Most concrete mixers in the UK are limited to 56 miles per hour (90 km/h).
Concrete mixer trailer
The standard concrete transport variant is a concrete or cement mixing trailer. Small versions of this mixed truck are used to supply short concrete loads. They have concrete mixing drums with capacities between 1 and 1.75 cubic meters (0.76 and 1.34 m 3 ). Cart-aways are usually pulled behind pickup trucks and collected from smaller batching systems. The mixing trailer system is popular with rental bases and the location of building materials, which use them to supply ready-mix mixtures to their regular customer base.
Concrete meter truck
Metallic concrete or volumetric mobile stirrer trucks contain concrete and water materials to be mixed in the truck at the work site to make and deliver concrete in accordance with the required amount.
Concrete mixer in place and portable
For smaller jobs, such as home improvements, renovations, or hobby-scale projects, many cubic yards of concrete are usually unnecessary. Bagged cement is available in small batch sizes, and aggregate and water are easily obtained in small quantities for small workplaces. To serve this small batch concrete market, there are many types of small portable concrete mixers available.
Portable concrete mixers usually use small rotating drums to mix components. For smaller jobs, concrete made at construction sites do not have time lost in transportation, giving workers enough time to use concrete before hardening.
Portable concrete mixers may be powered by gasoline engines, although it is more common that they are powered by an electric motor using standard electrical current.
This concrete mixer is subdivided by its loading mechanism. Cement, sand and other aggregates are loaded in a hydraulically operated hopper and then poured into a mixing drum for final mixing. They can be lowered by tilting the drum. In a hand-feed concrete mixer, cement, sand and other aggregates are instantly added to the mixing drum manually. Both types of concrete mixers are very popular in construction activities in Africa, some Middle Eastern countries and in Indian subcontinent.
Self-loaded concrete mixer
Self-loading concrete mixers are unique machines designed for batch, mix and transport of concrete. They consist of a rotating drum mounted on a chassis chassis driven by a carrier cabin equipped with a loading bucket.
The operator of the self-loading concrete mixer batch and introduced the materials needed to mix the concrete (cement, aggregate stone etc.) into the drum using a loading bucket. Drums are usually a reversible type, slope type or a combination of both. The predetermined water volume is discharged to the drum through the water dispensing unit. The mixture is rotated at the mixing speed in the drum to the concrete effluent through the installed parachute.
Self-loading concrete mixers are suitable for construction sites where concrete plants are unavailable, soil surface conditions are not suitable for concrete concrete transport trucks or the availability of scarce or limited labor. Applications include urban and rural construction, concrete pavement maintenance, bridge and tunnel construction, municipal highway construction, foundation construction, national defense facilities, high-speed railway construction, etc.
Code of operation
Operating concrete mixers correctly is one of the biggest security issues in the construction zone. Workers whose jobs relate to concrete processing currently number more than 250,000. More than 10 percent of them, 28,000, suffered work-related injuries or illness, and 42 died within just one year.
In fiction and culture
- In Thomas and Friends , Patrick is a dark red concrete mixer and beige.
- In Bob the Builder , Dizzy is an on-site orange mixer and a portable concrete mixer and Tumbler is a yellow and green concrete transport truck (commonly called a cement truck). In the reboot of the series, Two-Tonne has a concrete mixer trailer.
- In the Transformer franchise, Mixmaster is a robot that can turn into a cement truck.
- The Semen Truck is a gothic statue by Wim Delvoye.
Television
- In the episode of MythBusters , an experiment is performed to see if dynamite can be used to clean hardened concrete from inside a mixer truck, with limited practical results. To the end, an excessive explosive amount (800 Â £ commercial blasting agent) was used, and detonated remotely. The explosion left a very clear crater, and only the engine block was found. In an episode of Crash Lane, O'Hare Towing responded to a call at a construction site to restore a mud-stirred truck, continuing to drown and threatening to roll over. After several unsuccessful attempts to dredge the mixer using a heavy rotator destroyer, the foreman told the crane driver that the mixing drum contained about 5 cubic meters of concrete, and asked if draining would simply enlighten the truck to allow its destroyers to recover. After emptying the drum, the winch operator is able to winch the mixer truck out of the mud & amp; to a solid ground.
- In season 5, episode 1 of the TV series MacGyver , the main character of this series uses an engine from a small gasoline-powered concrete mixer, to build an airplane.
- Penn & amp; magician Teller did a trick called "The Psychic Cement Mixer of Death" in which Teller was tied up with his eyes closed in an empty spinning concrete mixer and took half of the signed and broken bricks (like other tricks that tear the card or dollar bill halfway) )) from dozens of other bricks spinning inside the mixer.
See also
- Concrete types
- Concrete factory
References
Source of the article : Wikipedia
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