Laboratory and Field Evaluation of Warm Mix Asphalt Technology to Determine its Applicability for Massachusetts
Funding Source: Massachusetts Highway Department
ATMC Materials Lab Involvement: Principle Investigator
Start Date: September 2005
End Date: June 2006
Summary:
Some of the most recent innovations in Hot Mix Asphalt (HMA) technology have originated from Europe and migrated to the United States. These include Stone Matrix Asphalt (SMA) and Permeable Friction Courses (PFC). The latest import from Europe is Warm Mix Asphalt (WMA) technology. WMA is a specialized HMA mixture that can be heated to temperatures well below the normal high heating temperatures of conventional HMA. The benefits of using WMA are lower costs of fuel required to heat the asphalt mix in production, reduction in asphalt fumes produced, may permit trucking of loads over longer distances, may allow longer construction season that extends into the winter, and better workability and compaction. Furthermore, it has been reported that this technology can allow for increase in the percentage of Recycled Asphalt Pavement (RAP) in the HMA without negatively impacting the performance of the placed pavement. Because of these benefits, some state DOTs and the FHWA are in the process of evaluating WMA.
Currently, a HMA mixture, identified by MassHighway as a modified SMA, is being placed on Route 95. This SMA will contain a latex stabilizer. It is suggested that this project could be used to begin evaluation of WMA technology for Massachusetts. The SMA designed with WMA technology would be placed in the breakdown lane to allow for an evaluation using a controlled experiment. The mixture will include 1.5% Sasobit® (Sasobit® is one of the products being used by Maryland DOT to produce WMA).
The study proposed herein would assist MassHighway in its efforts evaluating WMA technology in the modified SMA. This study will be limited in its scope; however, it is recommended to conduct a more comprehensive research study on the use of WMA technology with mixtures that contains RAP.
The objectives of this study are:
- Construct SMA (control mix) and WMA specimens at the contractor’s plant.
- Evaluate the performance of the WMA technology in the laboratory using the MMLS and APA.
- Document construction data of the WMA (production and placement).
- Monitor the performance of WMA in the field.
