Even at the end of the
lifespan of a concrete building, bridge or highway, the concrete used to
construct it still has a use. Since concrete
is the most widely used man-made material in the world, it is important that
concrete is recycled rather than taking up space in landfills as was done in
the past. Also by using recycled
material as gravel, it reduces the need for gravel mining as well as reduces
the amount of pollution created in making new concrete.
Today concrete is
routinely recycled and the aggregate produced is used to create new concrete or
for a number of other purposes. Recycling
concrete from a building starts right at the site of the demolition. Crews work to prepare the concrete by
removing as many contaminates as possible by separating the concrete from
material such as roofing, trash, and wood.
Now the concrete is
put through several steps such as crushing, pre-sizing, sorting, screening and the
further elimination of any contaminants.
Typically it is cleaned by a water method in order to eliminate dirt and
any other remaining materials. It is
critical that materials such as asphalt, sealant, chlorides and gypsum are
removed.
Also it is at the
recycling facility where the reinforced steel (rebar) is removed. This involves the use of huge magnets that
attract and identify the steel for removal.
Once the rebar is removed, it is transported to plants that specialize
in processing steel materials.
If the recycled concrete
is free of contaminants, it will be used as a dry aggregate in brand new
concrete. Another easy method to reuse concrete
pavement is to break it in place and use it as a base layer for an asphalt
pavement through a process called “rubblization.” Furthermore, there is a
market for used concrete that has not been processed and screened as carefully.
This is used as an aggregate for fill,
drainage, or as sub-base gravel before asphalt or new concrete is poured.
The Conco Companies' mission is to be
the best supplier of concrete services in the Western U.S. and to bring
experience, expertise and quality to each project. We continue to upgrade and
expand facilities to better serve the growing market for a wide range of
construction development. We
have four regional offices serving California, Oregon, Nevada, Colorado and
Washington.
Source: en.wikipedia.org/wiki/Concrete_recycling
No comments:
Post a Comment