Masonry Magazine December 1999 Page. 24
Construction Waste and Demolition Debris Recycling
Environmental concerns surround mining, forest cutting activities and landfill space. The recycling of construction waste and demolition debris (C&D) is a rapidly growing industry in North America that reduces the demand on natural resources, while saving on landfill space. The current high rate of residential and office recycling also is prompting many solid waste professionals to look at other sectors of the waste stream for reduction. That is because the C&D waste stream is huge, more than 50 percent larger than municipal solid waste, which is what offices and homes throw away. And the recycling of C&D involves many millions of tons more material than the better known tin can, plastic, and newspaper recycling programs.
History
Recycling construction waste & demolition debris (C&D) dates from the time of the Romans who, when rebuilding their vaunted set of roads, would reuse the stones from the previous road. The industry has been well-established in Europe since the end of WWII when crude aggregate crushers were used to recycle the rubble left over from bombed-out buildings and roads.
It remains a growing industry on that continent as landfill space is at a premium. Indeed, some countries, such as the Netherlands, will require all C&D materials to be recycled by the year 2000. Currently about 75 percent is recycled in that country. In many countries, especially Germany and Belgium, the rate is more than 50 percent.
North American Situation
In North America today C&D makes up approximately 25 percent to 45 percent of the waste stream, depending on the region being studied. Obviously, if an area is having significant construction activity, especially when coupled with demolition work being performed to make way for new construction, then that percentage goes up.
Construction Materials Recycling Association (CMRA) estimates that 35 percent, if that, of the North American C&D waste stream is recycled.
Some parts of the United States and Canada are expressing concern about possible landfill space shortages and increased fees for dumping waste (known as tipping fees) around many urban areas, notably California, New England, Toronto, New York/New Jersey, British Columbia and Florida. This has fueled efforts to recycle consumer goods such as paper, aluminum and steel cans, and old corrugated cardboard (OCC).
But in recent years as state and local governments have required higher percentages of the waste stream to be recycled, solid waste planners have increasingly looked at C&D as a place to meet those goals. Sometimes local governments have set up their own C&D debris recycling plants, but usually private industry is encouraged to step into the breech and begin processing the waste. This trend likely will continue, with growth projected in this now small industry to average at least 10 percent during the next decade.
Materials
Materials that make up this waste stream include, in roughly descending order of tonnage:
Asphalt Obtained almost exclusively from road work. Finished product almost exclusively is placed right back in the hot mix to be placed on the road again. Recycling asphalt and concrete are well-established industries throughout North America, and many operations can and do handle both materials. A very large and established industry exists