NCAT Mix Design Training

When you need a course on how to make a new mix design, sometimes it’s easier to have the trainer come to you. Consultants in the paving business have been following that model for decades. The engineers at the National Center for Asphalt Technology (NCAT) at Auburn University offer this as well. If you need to train a set of lab techs, NCAT can bring their course to you.

For example, when dealing with a stone mastic asphalt (SMA) mix, your team might need hands-on help. In the course from NCAT, “Participants will work through a typical SMA mix design and will perform hands-on lab testing to determine the voids in coarse aggregate (VCA) of the dry-rodded aggregate and VCA properties of the compacted mixture,” Don Watson of NCAT explained. “This VCA testing is performed to determine whether the mix has stone-on-stone contact of the coarse aggregate portion of the mixture as this characteristic has been associated with successful rutting resistance of SMA mixtures. A rich asphalt mortar provides improved service life of SMA over other mix types. A drain-down test is required to evaluate the resistance of the thick binder film coating to draining from the aggregate particle. A demonstration of this test will be performed.”

Another mix design the NCAT course covers is that of open graded friction course (OGFC). “The service life of OGFC pavements can be extended by reducing the potential for raveling,” Watson shared. “One of the lab tests for this evaluation is the Cantabro test procedure. Participants will test samples to determine the effect of different mix properties on resistance to raveling. OGFC mixtures are typically used for the safety benefits provided by draining water through the layer rather than having water flow over the mix surface as is done with other mixes. Permeability testing will be demonstrated as it is an important measure of the ability of the mix to drain water.”

To set up the course, you don’t have to be in a lab as sophisticated as the one at Auburn University. Merely contact NCAT to discuss what you have available at your facility. “The instructor will coordinate with the workshop host to determine the equipment and test samples needed for the workshop,” Watson explained. “If a laboratory is not available, the instructor will provide slides or videos demonstrating the procedures. Companies or agencies may also conduct only the SMA or OGFC workshops independently if desired.”

For more information, you can reach NCAT at (334) 844-7306.