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March 29, 2018

Asphalt: the go-to material for green paving projects

  • The asphalt industry reuses and recycles nearly 75 million tons of its own product annually, lowering carbon emissions and taking a burden off landfills.
  • By KAREN DEAL and TAMARA HUDDLESTON
    Lakeside Industries

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    Deal

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    Huddleston

    Asphalt might not sound like a green word, but it is a green product that packs the potential to reduce carbon dioxide emissions, improve air quality and keep our water clean.

    Over the years, asphalt has become the go-to material for constructing green pavements and is used for everything from fish hatcheries to lining our drinking water reservoirs. From the production of the paving material to the placement of the pavement on the road, to rehabilitation through recycling, asphalt pavement minimizes the impact on the environment.

    The low consumption of energy for production and construction, low emissions of greenhouse gases, and conservation of natural resources help to make asphalt the environmental pavement of choice. As both private companies and public agencies look for ways to be more sustainable and reduce their environmental impact, they can start by looking from the ground up.

    Lakeside Industries has been recognized by various organizations and received awards and accolades for our environmental contributions. We work hard to find solutions for our clients to increase sustainability within their own organization.

    We received a King County Green Globe award in 2013 for our production of sustainable pavements by using recycled asphalt shingles in our paving mix. We were also recognized for our work with the Washington State Department of Transportation on a new pavement specification for evaluating pavements containing recycled asphalt shingles on state roads.

    Recycling roads

    Photo provided by Lakeside Industries [enlarge]
    A Lakeside Industries asphalt plant in Monroe.

    In order to be green, we have committed to producing a product that incorporates recycled materials into our asphalt mixes. Reclaimed asphalt pavement (RAP) is the term given to removed and reprocessed pavement materials containing asphalt and aggregates.

    These materials are generated when asphalt pavements are removed for reconstruction, resurfacing or to obtain access to buried utilities. RAP has multiple applications and can be crushed and incorporated into hot- or warm-mix asphalt that is used for new paving projects and utilized as an aggregate for various construction uses.

    According to the Environmental Protection Agency and Federal Highway Administration, RAP is recognized as America's number-one recycled product, and the asphalt industry reuses and recycles nearly 75 million tons of its own product every year. This takes a significant burden off landfills and helps to ensure that untapped mineral resources will be available to future generations.

    Use of RAP also helps to lower greenhouse gas emissions. According to an EPA study, adding 20 percent RAP to new asphalt pavements reduces greenhouse gas emissions by 14 percent.

    Porous pavement

    Use of recycled materials and construction of porous asphalt pavements in major projects helps organizations reach their sustainability goals and can be a significant factor when being considered for various awards and designations. Lakeside helps these businesses by producing high-quality paving materials that help them meet these awards requirements.

    Greenroads, for example, is a foundation that advances sustainability education and incentives for transportation infrastructure.

    They have developed a rating system for projects designed and constructed to a level of sustainability higher than standard industry practices. This is a distinguished designation for a project to achieve, as it must pass a rigorous review using the Greenroads Rating System. Recycled and recovered content, use of local materials, materials preservation and reuse, and water runoff flow control are some of the metrics used in determining whether a project is eligible for the designation.

    When contractors use asphalt containing significant levels of RAP or select porous pavements for their paving projects, they can more effectively meet their sustainability goals, helping them meet the requirements of this designation.

    Lakeside is a major producer and supplier of porous asphalt mix. Porous asphalt is produced using the same process as other asphalt design mixes, but with a lower concentration of finer materials. Typically, a porous asphalt pavement is constructed with three layers: a surface layer, a filter layer and a reservoir layer.

    The result is a pavement that allows water to drain through the surface into a recharge bed, where it slowly filters to the soils below. This is beneficial when considering stormwater runoff management design, as it can significantly reduce the amount of untreated runoff reaching open waterways and prevent flooding on roads and in parking lots.

    Porous asphalt pavements are being used successfully throughout the U.S. in every type of climate and geography. They are recognized by the EPA as a best practice for stormwater management.

    LEED friendly

    In addition to paving projects, developers are increasingly looking to find ways to build using recycled products and materials in their projects. Use of asphalt containing RAP in driveways, parking lots and other structures can be a major factor in achieving green building certification credits.

    The LEED green building rating system serves as a benchmark or scorecard for the design, construction and operation of green buildings. It was designed to encourage the adoption of sustainable building and development practices.

    Incorporating porous asphalt pavements, open-graded surfacing or light-colored asphalt into a building project are some of the areas that are eligible for credits under the LEED sustainable sites criteria.

    The recyclable nature of asphalt pavement, the use of asphalt with high percentages of RAP, and the requirement that asphalt must be produced locally can also make a project eligible for credits under LEED criteria. Additionally, innovation and design credits can be awarded for use of warm-mix and high-RAP-mix asphalt pavements.

    When all these factors are considered, asphalt pavements can contribute more LEED credits than any other pavement type.

    Supporting society

    The world needs asphalt, and we're proud of the product we're able to deliver to our customers to build schools, airports, highways, city streets, private developments and fish hatcheries, to name a few.

    Through investments in technology and leading in industry trends, we work to continually improve our practices to exceed the requirements established by state and local environmental agencies. When your product is integral to the infrastructure that supports our society, you should work even harder to protect the world our society lives in.


    Karen Deal is the environmental and land use director at Lakeside Industries. Tamara Huddleston is a technical administrative assistant at Lakeside.


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