Full depth reclamation (FDR) of distressed asphalt pavements with foamed asphalt is a promising highway rehabilitation strategy. In the FDR process observed in California, the distressed pavement and the upper portion of the underlying granular material (reclaimed granular base thickness is dependent on the thickness of the asphalt pavement, but typically at least 25 mm) is milled in place with a customized recycler. This recycler
produces foamed
asphalt (or asphalt foam) by mixing hot asphalt binder, cold water, and compressed air in an expansion chamber and then injects the mixture into the pulverized material in a separate mixing chamber through special nozzles. The combined pulverized asphalt pavement (PAP) and asphalt foam is termed foamed asphalt stabilized material, or simply foamed asphalt mixes in this paper. Foamed asphalt mixes are compacted immediately after mixing, and used as a stabilized base layer underneath a new, thin layer of hot mix asphalt (HMA) surfacing. Compared to alternative strategies, the benefits of FDR-foamed asphalt include faster rehabilitation, reduced cost, and reduced traffic delays. This rehabilitation approach also has less negative impact on the environment, primarily by eliminating the disposal of old pavement materials and minimizing
the use and transport of virgin aggregate. The bitumen content shall be between 2 to 3.5% and cement content up to 1%. Our cold recycler is equipped to the most advanced foamed bitumen system in comparison to the similar equipment in the market.