US Hwy 12/18/151 at Verona Road-Beltline: Recycled Materials Case Study

The eastbound Beltline Highway (US 12/18) from Whitney Way to Seminole Highway, a 1.5 mile stretch, is undergoing a reconstruction and expansion three lanes from fall 2014 to spring 2016. The RMRC research team proposes to use this project to better determine a methodology for gathering the data needed for the inputs of the life cycle assessment (LCA) and life cycle cost analysis (LCCA) tool, PaLATE, as well as assess the benefits of using recycled materials in the project. The project will be used in preparation for more analyses of member-state roads. Examples of user inputs include material volumes, road dimensions, equipment used, etc. During past research, the research team has been unable to utilize LCA and LCCA technology without making significant assumptions for the inputs. The Beltline project offers an opportunity to develop a method for data collection that could eliminate assumptions from the analyses.

For more information:

RMRC SOW – Beltline

I-94 Recycled Materials Case Study

The Recycled Materials Resource Center (RMRC) analyzed the environmental benefits of incorporating recycled material in the reconstruction of Interstate 94 (I-94) in Kenosha County, WI, using Building Environmentally and Economically Sustainable Transportation-Infrastructure-Highway (BE2ST-in-Highways) code. BE2ST-in-Highways integrates various supporting databases and uses life cycle assessment (LCA) and life cycle cost analysis (LCCA) techniques to evaluate the overall impact of highway construction projects. An alternative construction project that contains recycled materials is typically analyzed in comparison to a reference project that contains virgin materials. With the goal of quantitatively determining the environmental benefits of using recycled materials, the RMRC targeted a one-mile stretch of the Kenosha County portion of the I-94 North-South Freeway Project because it incorporates recycled materials in its reconstruction. Recycled materials used in the project include fly ash, bottom ash, foundry sand, recycled concrete aggregate (RCA), and recycled asphalt pavement (RAP). BE2ST-in-Highways’s rating system targets criteria including energy use, greenhouse gas (GHG) emissions, materials reuse/recycling, water consumption, social carbon cost, and hazardous waste generation. This analysis, based on a fifty-year window, calculates the environmental impact of the initial road construction and maintenance in three parts: materials production, materials transportation, and processes (equipment). Preliminary results of the BE2ST-in-Highways analysis of the I-94 mainline reconstruction show that the use of recycled materials reduces the environmental impact of the highway construction in all criteria over its lifetime. The RMRC recommends that using recycled materials should be made a priority by state departments of transportation.

For more information:

I-94 SOW

Upcycling: Connecting Producers to Consumers Website

Over half a billion tons of recyclable material such as foundry sand, coal combustion products and construction and demolition debris, are produced each year in the United States. Many of these materials have beneficial use in transportation construction projects. Unfortunately, the widespread use of these materials is hindered by a lack of information; either an understanding of the beneficial use of the recycled material or simply finding an adequate source of the recycled material.

Providing potential consumers of recycled materials an on-line location-based information system that includes recycled material sources, past projects that used recycled material, and regulations pertaining to the use of recycled material in construction projects is needed. Information about recycled material including: type(s) of material, availability, producer throughput, cost, and material characteristics should be included in the site. In addition to the map of recycled material sources, two additional map layers: case studies and regulations, need to be available on the site. The case study layer will focus on past projects that employed recycled material in the design and construction. The regulations layer will display state regulations pertaining to the beneficial use of recycled material. By providing locations and quantities of available recycled materials, examples of past case studies, and regulations governing recycled material, a single source to promote the use of recycled material will be created.

For more information:

RMRC SOW – Web Map to Link Materials

Use of Recycled Materials Behind MSE Walls

To ensure long-term integrity of MSE walls, reinforced backfills consisting predominantly of coarse-grained materials have been recommended and used. This limitation on material type can significantly increase the cost of construction on some projects because of the cost of transporting select material to the construction site when local select fill is not available. At the same time, industrial operations and construction activities create coarse-grained materials that must be disposed. Again, producers of such materials must pay transportation costs, as well as disposal fees, to discard these materials. One solution is to recycle these materials and use them as alternative reinforced backfill.

Throughout the U.S., substantial amounts of recycled asphalt pavement (RAP) and recycled concrete aggregate (RCA) are being produced through reconstruction activities as well as granular industrial byproducts such as foundry sand/slag, bottom ash, and iron/steel slag. If these materials were used as reinforced backfill for MSE walls, transportation and disposal costs for these materials could be greatly reduced, translating into significant savings for state departments of transportation. Furthermore, such activities would promote sustainable construction, preserve natural resources, and reduce carbon footprint and landfill disposal in highway construction. There are reports of the use of these materials as reinforced backfill as well as research on their properties relevant to reinforced backfill requirements. Further focused research of recycled materials needs to be done to determine if their use as MSE wall reinforced backfill is considered suitable for a more sustainable and potentially economical design and develop design and construction recommendations.

For more information:

RMRC RFP3 – Recycled Matls as MSE Wall Fill

Statewide Materials Use Study

RMRC and various governmental agencies have developed fact sheets on various recycled materials and industrial byproducts for their use in highway construction applications. However, these fact sheets often lack direct information on sustainability assessment characteristics, i.e., greenhouse emissions, energy and water consumption and life cycle cost benefits. Although state transportation departments have been in the forefront of introducing recycled materials, they have not been able to clearly convey the benefits in a quantitative and transparent manner using easily understood metrics.

The first objective of this study is to develop/update factsheets on various recycled materials and industrial byproducts that are being used in highway construction. New information generated in recent years relative to their engineering properties and environmental impact questions will be added as well as relevant life cycle assessment data. The second objective of this study is to develop a tool by which the state system-wide material use quantities can be used to calculate the life cycle benefits associated with the incorporation of recycled materials and industrial byproducts to highway pavement construction.

For more information:

RMRC SOW – Systemwide Life Cycle Benefits of Recycled Materials