Page 81 - Highway Engineering Handbook Building and Rehabilitating the Infrastructure

64 CHAPTER ONE

TABLE 1.18 Highway Uses of Scrap Tires

Common uses Innovative uses
Fills and embankments Railroad grade crossing
Erosion control Valve box coverings
Shoulder stabilization Drainable materials
Channel slope protection Planks and posts
Windbreak Culverts
Side slope fill Interlocking blocks
Slope reinforcement
Retaining wall
Membranes
Safety hardware
Tire-sand inertial barrier

Source: Based on National Cooperative Highway Research
Program (NCHRP), Transportation Research Board, Uses of
Recycled Rubber Tires in Highways, Washington, D.C., 1994.

formulation processes for the conventional concrete asphalt that is being used for a stan-
dard vary tremendously also. Common and innovative uses of scrap tires are summarized
in Table 1.18.

1.6.8 End Uses in Highways

It is apparent that there are many uses of recycled materials in highway construction and
related applications. Table 1.19 provides a summary of these uses for reference.

1.6.9 Recycling Hazardous Wastes
Under Subtitle C of RCRA, EPA has the authority to regulate recyclable hazardous waste
material. It is critical to determine the type of waste and the proposed method of recycling
in determining whether it is regulated under Subtitle C. The definition of solid waste under
Section 261.2 identifies four types of recycling activities for which recycled wastes may be
subject to Subtitle C regulation: use constituting disposal, burning waste-derived fuels for
energy recovery, reclamation, and speculative reclamation.

Use Constituting Disposal. Use constituting disposal is defined as placing or applying a
solid waste or a material contained in a product that was a solid waste on the land in a man-
ner constituting disposal. In this case, land disposal regulations under RCRA Parts 264 and
265 apply. Use constituting disposal may include the following uses involved in the con-
struction of highways or maintenance of highway landscaping: fill material, cover mater-
ial, fertilizer, soil conditioner, dust suppressor, asphalt additive, and foundation material.

Burning and Blending of Waste Fuels. Burning and blending would be the applicable
method for recycling used oil for fuel in asphalt plants. Used oil is not currently considered
a hazardous waste unless it has a characteristic of ignitability, corrosivity, reactivity, or
extraction procedure toxicity (ICRE characteristic). If the used oil is mixed with a haz-
ardous waste, it is regulated as a hazardous waste fuel under RCRA, Part 266, Subpart D.
Specifications for nonhazardous used oil fuel are described in Table 1.20. Used oils that do