"We had used oscillation compaction on another project and knew how it would perform," Pine says. "The main advantage to oscillating and not vibrating the mix is the lack of degradation to the aggregate structure. There is no breakage of aggregate under the roller.
"It seems like a very good process, especially for a mix that may exhibit some tenderness at times," Pine says. "But for SMA, from what we've seen, it works best in an intermediate position for us to obtain density, because at that point, you generally couldn't vibrate with a conventional vibratory roller because the mat would be too cool and you would risk aggregate degradation in trying to get compaction."