It used to be that when concrete structures needed to be demolished, the concrete was sent to landfills. Concrete recycling, however, is becoming more common because it provides several benefits, such as reducing the need for gravel mining, and reducing the pollution caused by trucking materials from gravel mines to new construction projects.
The process of recycling concrete begins with a piece of concrete recycling equipment called a crushing machine. Concrete aggregate is placed between two solid surfaces, and pressure is applied to reduce the size of the concrete pieces. Larger pieces may be put through the process several times, until all the concrete pieces are of the desired size. Metals in the concrete aggregate are then removed with magnets and melted down for other recycling uses.
Concrete crushing can be done at the site, rather than at a facility, by using portable concrete recycling equipment. This would either consist of a road-portable plant, or a portable self-contained mini-crusher. Road-portable plants can process up to 600 tons of concrete an hour, while self-contained mini crushers can process up to 150 tons of concrete an hour. The mini crushers can, however, fit into much tighter areas than the plants.
A road-portable plant consists of the following concrete recycling equipment: a rubble crusher, a side discharge conveyor, a screening plant, and a return conveyor to return objects from the screening plant to the crusher’s intake point for reprocessing large pieces.
Thanks to the use of concrete recycling equipment, old concrete can be reused as sub-base gravel for the lowest layer of new roads. It can be used as gravel for other construction pro0jects. It can also, if uncontaminated, be used as aggregate for new concrete. It can be used in landscaping, or packed together in wire cages called gabions to use as economical retaining walls. Further, the use of concrete recycling equipment can help hold down your project’s costs, since transporting concrete to a landfill can cost $.25/ton/mile, and disposal of concrete can cost as much as $100/ton.
In fact, some construction companies are purchasing their own concrete recycling equipment. Ron Blessing, of Blessing Construction notes that before purchasing their own concrete recycling equipment, they were paying contractors between $5.50 -$6.50 per ton to crush concrete, for a total of over $150,000 (in 2006) for crushing services, and not getting enough product back to meet demand. They determined that purchasing their own equipment would cut their costs (after all the expenses) to approximately ¼ of what they were paying the contractor, with better quality and quantity control.
As anyone can see, the use of concrete recycling equipment is clearly one of the best ways to recycle and reuse concrete, so that our landfills can be used for other, truly non-recyclable materials.