Page 642 - Materials Chemistry, Second Edition

CAT3525_C21.qxd 1/27/2005 12:56 PM Page 613
Construction and Demolition Debris 613
debris generated in a region also depends on the overall economic status of the region, the occurrence
of natural disasters, and special projects underway. In rapidly growing areas, the C&D waste stream
consists primarily of construction debris, with only small volumes of demolition debris. In contrast,
in older urban areas demolition debris makes up the majority of the C&D waste stream.

21.3 MANAGEMENT OF C&D DEBRIS
C&D debris is characterized as a nonhazardous waste subject to regulation under RCRA Subtitle D
(Figure 21.4). As discussed in Chapter 1, other Subtitle D wastes include municipal solid waste
(MSW), solids from water and wastewater treatment plants, nonhazardous wastes from industrial
processes, agricultural wastes, oil and gas wastes, mining wastes, spent automobiles, and trees and
brush.
C&D debris is most commonly managed via landfilling. Final disposal sites include dedicated
C&D landfills, MSW landfills, and unpermitted sites. Between 35 and 45% of C&D debris was dis-
posed in C&D landfills in 1996, and another 30 to 40% was managed on-site, at MSW landfills, or
at unpermitted landfills. A survey conducted for the U.S. EPA identified about 1900 active C&D
landfills in the United States (Franklin Associates, 1998). Approximately 20 to 30% of building-
related C&D debris is recovered for recycling. There is a trend toward increasing recovery of C&D
debris in the United States. Approximately 3500 facilities process C&D materials in the United
States (Franklin Associates, 1998).
The C&D materials most frequently recovered for recycling are concrete, asphalt, metals, and
wood. Metals have the highest recycling rates among the materials recovered. The recycling rate for
C&D steel is about 85% (18.2 out of 21.4 million tons generated) (Franklin Associates, 1998). These
numbers include scrap steel from buildings, rebar from roads, and structural steel from bridges.
There are about 500 wood processing facilities in the United States that obtain wood from C&D
debris. The leading states for wood processing plants are North Carolina, Oregon, and California.

21.4 MANAGEMENT OF SELECTED C&D WASTE COMPONENTS

21.4.1 AGGREGATE
Portland cement concrete and asphalt concrete are the two predominant materials used in road con-
struction. Both consist primarily of aggregate and cement. Aggregate is composed of inert mineral

Nonhazardous Wastes Subject to
Regulation under Subtitle D of RCRA
Construction and demolition debris
Municipal solid waste
Municipal sludge
Construction and demolition debris
Industrial nonhazardous wastes
(1) Building-related waste
Agricultural waste
Construction
Oil and gas waste Demolition
Renovation
Mining waste (2) Roadway-related waste
(3) Bridge-related waste
Auto bodies (4) Landclearing and inert
debris waste
Trees and brush

FIGURE 21.4 C & D debris as a component of Subtitle D wastes (Franklin Associates, EPA530-R-98-010,
1998. Reproduced with kind permission of Franklin Associates, Prairie Village, KS.)