Use of a Hot-Mix Asphalt Plant to Produce a Cold Central Plant Recycled Mix: Production Method and Performance

Cold central plant recycling (CCPR) of asphalt mixtures continues to grow in interest among agencies and asphalt mixture suppliers. However, one implementation challenge has been the need to invest in new equipment to produce the mixture. In 2015, the National Center for Asphalt Technology (NCAT) worked with a local contractor to produce a CCPR mixture through a standard hot-mix asphalt (HMA) plant. The mix was then placed in a test section on the NCAT Pavement Test Track with a highly modified dense graded HMA overlay. The process used to produce the mixture in the HMA plant is outlined along with the performance of the mixture after heavy truck loading in comparison with a control section with a highly modified dense graded hot-mix asphalt in lieu of CCPR. After 17 million equivalent single axle loads the test section containing the CCPR mixture is performing as well as the control section. This shows that CCPR can be successfully produced using an HMA plant, which may encourage mix suppliers and agencies to conduct trial projects with CCPR, implement CCPR into standard practice, and further justify new CCPR equipment investments.