As the industry’s use of warm-mix asphalt (WMA) increases, options for foaming the liquid asphalt cement (AC) meet new technology. The team from Astec Industries, Chattanooga, Tennessee, released the Generation 3 warm-mix system December 2017 to allow producers to make WMA mix designs without chemical additives. Here’s how it works.
The Gen3 apparatus is installed inline so the heated liquid AC enters the system easily. It uses a flow splitter plate to ensure the AC encounters both water spray nozzles in the system.
As the liquid AC enters the Gen3 manifold, it is directed above the splitter plate adjacent to two water injection valves. Electric over air solenoids open and close self-cleaning water valves to inject water supplied via an aluminum manifold.
As water flashes to steam and mixes with liquid AC, it foams and expands through an orifice plate and into the mixing device.
For more information, contact Astec Parts at (800) 251-6042.