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.