PPRC 11 SPE: Laboratory and Accelerated Pavement Testing (APT) of Gap-Graded Rubberized Mixes (Hot Mix Asphalt and Warm Mix Asphalt) for the Department of Resources Recycling and Recovery (CalRecycle)

Warm Mix Asphalt (WMA) is a suite of technologies that allows a reduction in temperatures for traditional hot-mix asphalt (HMA) production and paving. There are currently four different WMA categories (organic additives, inorganic additives, chemical foaming processes, and mechanical foaming processes), with more than 20 known technologies currently available in the United States. The California Department of Transportation (Caltrans), local government road authorities, and the construction industry are interested in evaluating WMA technologies used in conventional rubberized, and polymer modified asphalt mixes for: (1) Worker health and safety benefits (lower temperatures, less fumes); (2) Environmental benefits (reduced stack and construction emissions due to lower temperatures), (3) Opportunities to extend the paving season, undertake more night time paving, and to allow longer hauls of HMA, (4) Reduced greenhouse gas emissions due to reduced energy inputs (lower temperatures), (5) Potential increased pavement service life from improved compaction, and (6) Higher productivity at asphalt plants. Caltrans, through the University of California Pavement Research Center (UCPRC), has been evaluating WMA technologies in a phased research program under a variety of applications. The UCPRC research program includes laboratory testing, accelerated pavement testing, and field tests throughout the state. This program is a comprehensive, controlled study that will provide an indication of longer-term performance in a relatively short time period, thereby reducing the risk for road authorities in implementing the use of WMA technology on higher traffic roads. This Scope of Work (SOW) will assist Caltrans in completing its phased research of WMA technologies.