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TR News September–October 2013: Environmental Sustainability in Transportation (2013)

Chapter: Environmental Sustainability in Transportation: Recycling Materials and Techniques to Improve Sustainability: Delaware Department of Transportation s Model

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Suggested Citation:"Environmental Sustainability in Transportation: Recycling Materials and Techniques to Improve Sustainability: Delaware Department of Transportation s Model." National Academies of Sciences, Engineering, and Medicine. 2013. TR News September–October 2013: Environmental Sustainability in Transportation. Washington, DC: The National Academies Press. doi: 10.17226/22466.
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Page 30
Page 31
Suggested Citation:"Environmental Sustainability in Transportation: Recycling Materials and Techniques to Improve Sustainability: Delaware Department of Transportation s Model." National Academies of Sciences, Engineering, and Medicine. 2013. TR News September–October 2013: Environmental Sustainability in Transportation. Washington, DC: The National Academies Press. doi: 10.17226/22466.
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Page 31

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TR N EW S 28 8 SE PT EM BE R– O CT O BE R 20 13 30 The author is Assistant Director, Design, Delaware Department of Transportation, Dover. Recycling Materials and Techniques to Improve Sustainability Delaware Department of Transportation’s Model J I M P A P P A S From project development through delivery,the Delaware Department of Transportation(DOT) works to maintain and develop an infrastructure that is a sustainable asset for current and future use. One of the goals advanced in Delaware DOT’s Mission Statement of Excellence in Transportation is to “minimize the environmental impact of the state’s transportation system.” The agency is committed to protecting the environment and to planning, constructing, and maintaining a transportation network with increased sustainability. For Delaware DOT, sustainability is defined as economic development that meets the needs of the present generation without compromising the abil- ity of future generations to meet their own needs (1). Most people may not associate highway con- struction with sustainable practices. Sustainability typically conjures up images of recycling house- hold items such as newspapers, plastic and glass bottles, cardboard, batteries, and the like. Yet the road and bridge building industry is a beneficiary of recycled materials and industrial byproducts. Incor- porating these materials into construction projects provides economic, environmental, and engineer- ing benefits for the projects and ultimately for the users of the infrastructure by providing long-lasting roadways. Materials and Technology For example, for the past 20 years, Delaware DOT projects have made use of recycled asphalt pavement and more recently have incorporated other recycled materials, including asphalt shingles, concrete aggre- gate, tire-derived aggregate, crumb rubber, cellulose fibers, and plastic from bottles. The agency also has used industrial byproducts, such as ground, granu- lated blast furnace slag, silica fume, and fly ash in the portland cement concrete placed on projects. In addition, in the past decade, Delaware DOT has specified in-place roadway reclamation and recycling operations for maintaining roadways. The process keeps pavements in place for pulverizing, stabilizing, and reshaping. The reclaimed and recycled pave- ment provides a base course as a stable construction platform for the overlay of pavement materials designed for the roadway. The overlay could be a surface treatment for a low-volume road or a major structural overlay for a higher-volume facility. Delaware DOT has used two in-place reclama- tion and recycling techniques: full-depth reclama- tion and cold in-place recycling. Both techniques pulverize the pavement section to a specified depth and add a stabilizer—such as portland cement or emulsified asphalt—to produce a stabilized base for overlays appropriate to the traffic needs. Environmental Sustainability in Transportation P H O TO : B LO G.U D O T.U TA H.G O V Emulsion being added to crushed asphalt in full- depth, in-place asphalt reclamation. Delaware DOT has used this and other materials recycling techniques to “minimize the environmental impacts of the state’s transportation system.”

TR N EW S 288 SEPTEM BER–O CTO BER 2013 31 Partners and Benefits The success of these recycled materials, industrial byproducts, and in-place reclamation and recycling technologies was achieved with support from indus- try partners, contractors, and the Federal Highway Administration (FHWA), which not only has pro- vided funding but technical support. FHWA is com- mitted to recycling; in February 2002, FHWA formalized a policy that “recycled materials should get first consideration in overall materials selection” (2). Although not a regulation or requirement, the FHWA policy encourages states to use recycled mate- rials or at least to review and consider the possibil- ity of use on projects. Like many other states, Delaware DOT has determined that the use of recy- cled materials, industrial by-products, and in-place reclamation and recycling techniques is beneficial and has incorporated these materials and methods into projects whenever feasible. These environmentally supportable options, how- ever, also are key as Delaware DOT manages limited funding. The department has a fiscal responsibility to the taxpayers of the state to use funds in the most fis- cally responsible way. Over the years, Delaware DOT, like many other agencies, has realized the economic benefits of an extensive recycling program—for example, significant savings have resulted from using recycled materials and industrial byproducts instead of virgin mixes with no recycled content. Three-E Framework The “triple bottom line” of sustainability balances economic progress, social responsibility, and envi- ronmental protection. Within the transportation industry, the phrase also refers to the three benefits of a recycling program: environment, economics, and engineering—or the three E’s. The success of a recycling program is to integrate the three E’s into the planning, design, construction, operation, and main- tenance of a transportation network to meet the goals of an agency and the needs of the traveling public. Delaware DOT’s recycling program follows the three-E framework: u Environment—By using in-place materials or reusing materials, Delaware DOT reduces aggregate mining and saves precious natural resources, reduces asphalt refining and cement production, and reduces trucking costs and emissions. Reuse saves the costs of extracting, processing, and transporting virgin materials. u Economics—Using materials that have already been paid for reduces the costs of exporting or importing and handling. The time savings translates to additional monetary savings; moreover, the reduced exposure of workers in a construction zone increases safety. u Engineering—Through in-place reclamation and recycling, Delaware DOT can address deterio- rated pavements by stabilizing and strengthening the underlying base pavements; the stable base for over- lays increases long-term pavement performance. Recycled materials and industrial byproducts, more- over, have demonstrated engineering benefits—for example, slag cement reduces the permeability of portland cement concrete. Combining environmental, economic, and engi- neering benefits into the project delivery process can have a significant benefit for the transportation infra- structure. Delaware DOT understands the benefits of reusing materials in highway construction and looks for every opportunity to meet the needs of the trav- eling public and to apply sustainable materials and construction practices. This not only benefits users today but users in the future—a primary goal of a sustainable program. References 1. Epstein, M. J. Making Sustainability Work: Best Practices in Managing and Measuring Corporate Social, Environmental, and Economic Impacts. Berrett-Koehler Publishers, San Francisco, California, 2009. 2. Formal Policy on the Use of Recycled Materials. Federal Highway Administration, 2002. www.fhwa.dot.gov/legsregs/ directives/policy/recmatmemo.htm. Delaware DOT incorporates industrial byproducts such as fly ash (left) and silica fume (right)—both shown under the microscope— into portland cement concrete used in road projects. Recycled materials such as asphalt shingles can be used in asphalt pavement projects. P H O TO S: LEFT, Z EISS M IC R O SC O PY; R IG H T, S ILIC A M A N/W IK IM ED IA C O M M O N S PH O TO : M IS SO U R I D O T

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 TR News September–October 2013: Environmental Sustainability in Transportation
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This issue of the TR News focuses on environmental sustainability in transportation and how it can help improve the quality of life for individuals and communities. Articles highlight practice-ready research and cover such topics as integrating vegetation and green infrastructure into sustainable transportation planning; implementing the Eco-Logical approach in Nevada, Colorado, Utah, Montana, Washington, and Oregon; Virginia's improved construction specifications for stormwater pipe-lining materials; creating a multiagency sustainability framework in Colorado; effective noise barriers in North Carolina; Delaware's use of recycling materials and techniques; sustainability in airspace system planning; and more.

The September-October 2013 issue of TR News includes the following articles:

Environmental Sustainability in Transportation: Improving the Quality of Life

Evaluating Sustainable Development: A Quality-of-Life Focus for Transportation Decision Making

Integrating Vegetation and Green Infrastructure into Sustainable Transportation Planning

Eco-Logical in Practice: Implementing an Ecosystem-Based Approach, Streamlining Environmental Processes for Transportation Projects

Soundscapes: A Sustainability Approach to Transportation Noise Management

Sustainability in Airspace System Planning

Research Pays Off: Reclaimed Asphalt Pavement with Steel Slag Aggregate: Successful Use in Illinois Pavements

The TR News is TRB's bimonthly magazine featuring timely articles on innovative and state-of-the-art research and practice in all modes of transportation. It also includes brief news items of interest to the transportation community, research pays off articles profiles of transportation professionals, workshop and conference announcements, new book notices, and news of TRB activities. Submissions of manuscripts for possible publication are accepted at any time.

Copies of the TR News may be purchased individually or ordered on an annual subscription basis.

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