February 15, 2008

Demolition/Environmental Engineering

U.S. Army Corps of Engineers finds no environmental health risk to concrete-recycling workers

Those who follow lead-compliance work protocols deemed safe

DOYLESTOWN, PA

With an estimated 100 million tonnes of concrete generated in demolition projects being recycled each year in the United States — with a relatively small percentage of it containing lead-based paint (LBP) — questions were raised regarding its suitability for reuse. A study conducted under the aegis of the U.S. Army Corps of Engineers has found that there is no environmental or health risk to workers involved in the crushing and recycling of concrete containing LBP as long as they follow certain lead-compliance work protocols. A free copy of this study is now available from the National Demolition Association.

The study, developed by principal investigator Stephen D. Cosper of the Construction Engineering Research Laboratory, deals with the demolition of family housing at Fort Ord, Ca., typical of the older Army building stock, much of which is being demolished.

“The regulatory environment on the issue of concrete reuse is unclear, so a report of this type is extremely important to the demolition industry,” explained Michael R. Taylor, CAE, executive director of the National Demolition Association. “Concrete recycling has become the norm for our industry and has helped tremendously in the preservation of our environment.

What once was routinely shipped to landfills for disposal is now crushed on site and used as aggregate for reuse in projects like highway building. By being able to crush the concrete and either use it again for new construction uses or ship it efficiently off site, we are able to save on transportation cost and the related impact on emissions into the atmosphere.”

The so-called Cosper Report attempts to correlate the concentration of lead on the painted buildings to the concentration of lead in aggregate produced from those buildings’ demolition. The final concentration is the key metric in determining suitable end use. In the case of Fort Ord housing, the final lead concentration was found to be quite low.

The work site was assessed in several ways, including several weeks of worker observation, including monitoring of demolition contractor dust control procedures, worker practices, and analytical evaluation of samples collected during actual demolition and concrete recycling.

The Cosper Report was funded by the Construction Materials Recycling Association and the National Demolition Association. The Construction Engineering Research Laboratory is an element of the U.S. Army Research and Development Center, U.S. Army Corps of Engineers.

To obtain a free copy of the report, contact National Demolition Association through its Web site www.demolitionassociation.com
or call 800-541-2412.

DCN News Services

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