Monday, March 10, 2008

Cement Mixer Truck

Cement Mixer TruckConcrete mixer From Wikipedia, the free encyclopedia

Concrete transport truck: Special concrete transport trucks (in–transit mixers) are made to transport and mix concrete from a factory/plant to the construction yard.
They are charged with dry materials and water, with the mixing occurring during transport. (Although, more modern plants load the truck with 'Ready Mixed' concrete. With this process, the material has already been mixed, and then is loaded into the truck. The ready mix truck maintains the material's liquid state, through agitation, or turning of the drum, until delivery.) The interior of the drum on a concrete truck is fitted with a spiral blade. 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-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 connected to a flexible hose, or onto with a conveyor belt which can be extended some distance (typically ten meters). A pump provides the means to move the material to precise locations, multi-floor buildings, and other distance prohibitive locations.

"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 was designed and built by Royal W. Sims of Holiday, Utah.

Concrete mixers generally do not travel far from their plant, as 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 need to enter the barrel with jackhammers; dynamite is still occasionally used to break up hardened concrete in the barrel under certain circumstances.

Stephen Stepanian filed a patent application for the first truck mixer in 1916. Trucks weigh 20–30,000 pounds (9–13.5 tonnes), and can carry roughly 40,000 pounds (18 tonnes) of concrete although many varying sizes of Mixer Truck are currently in use. The most common truck capacity is six cubic metre.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article, Hummer SEE FULL License, Credit and Disclaimer

I, (sookietex) the creator of this work, hereby release it into the public domain. This applies worldwide. In case this is not legally possible, I grant any entity the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

If This image is subject to copyright in your jurisdiction, i (sookietex) the copyright holder have irrevocably released all rights to it, allowing it to be freely reproduced, distributed, transmitted, used, modified, built upon, or otherwise exploited in any way by anyone for any purpose, commercial or non-commercial, with or without attribution of the author, as if in the public domain.

No comments:

Post a Comment