TRANSCRIPT OF VIDEO:
There are two main drivers for considering using high RAP, or reclaimed asphalt pavement, in mixes: economic and environmental.
Economically, agencies need to know that using high amounts of RAP can and will provide cost savings over traditional use of virgin materials. Research by the Federal Highway Administration evaluated the various cost inputs affecting roadway construction on a per lane mile of roadway basis. They determined that over 70 percent of costs were attributed to materials including aggregate and bitumen. By reducing the amount of virgin materials in a mix, the total cost per lane mile can be reduced. One way to achieve this can be through the use of higher amounts of lower-cost RAP.
Environmentally, agencies are paying more attention to the impact the materials they use during roadway production have on their overall carbon footprint. The Australian Flexible Pavement Association evaluated greenhouse gas emissions systematically across different percentages of RAP usage. They determined that increasing RAP quantities in a mix can directly reduce the greenhouse gas emissions in a mix, with kilograms of carbon dioxide per ton emissions systematically decreasing as RAP content is increased.
