Recycled Material Impact On Asphalt Pavement Life Cycle Assessment

As State Agencies are pushed towards developing more sustainable pavement structures, they must find methods to quantify the environmental, economic, and social benefits of their pavement choices.  As a part of the 2012 Test Track, three State Agencies and a Department of Environmental Management sponsored the Green Group experiment which consisted of four six-inch full-depth asphalt pavements.  In an effort to reduce to carbon footprint of the asphalt pavement, the four sponsors chose to incorporate materials such as reclaimed asphalt pavement, recycled asphalt shingles, ground tire rubber, and warm mix asphalt.  A complete life-cycle assessment incorporates 5 phases of a pavement’s life which contains unique contributors affecting the total carbon emitted through the life of the pavement structure: materials, construction, use, rehabilitation and maintenance, and end-of-life.  Using the LCA program RoadPrint ™, the carbon emissions and global warming potential of the four pavement test sections were compared to a virgin asphalt mixture using conventional pavement materials in the materials and construction phases.  Using recycled materials and warm mix reduced the environmental impacts of the pavement structure by up to 22 percent showing that using recycled materials and warm mix significantly reduce a pavement’s effect on the environment.