Concrete recycling

Concrete recycling is an increasingly common method of disposing of the rubble. Concrete debris used to be routinely shipped to landfills for disposal, but recycling has a number of benefits to make it a more attractive, in this age of greater environmental awareness, more environmental laws, and the desire to keep construction costs down.

Concrete aggregate collected from demolition sites is put through a crushing machine, often with asphalt, bricks, dirt, and rocks. Crushing facilities accept only uncontaminated concrete, which must be free of trash, wood, paper and other materials. Metals such as rebar are accepted, since they can be removed with magnets and sorting devices and melted down for recycling elsewhere. The remaining aggregate chunks are sorted by size. Larger chunks can go through a crusher again. Smaller pieces of concrete are used as gravel for new construction projects. Sub base gravel is laid down as the lowest layer in a road, with fresh concrete or asphalt poured over it. Crushed recycled concrete can also be used as the dry aggregate for new concrete if free of contaminants.

There are a variety of benefits in recycling concrete rather than dumping it or burying it in a landfill. Keeping concrete debris out of landfills saves space. Using recycled material as gravel reduces the need for gravel mining. There are also economic benefits. Recycled concrete is a construction material a community does not need to pay for; those who generated the concrete waste pay a fee to have it recycled. It can save on the national resouces.

Decorative concrete involves concrete structures being used in roles that are not strictly related to concretes functional elements.

http://www.cdrecycling.org/ Construction Materials Recycling Association (CMRA)

http://www.concretecentre.com