The following sections outline some considerations regarding the operation of rollers once the roller combination for a specific job has been determined.
In standard conditions, rollers should follow as closely as possible behind the paver. If it is not possible for the rollers to keep up with the paver, the speed of the paver should be reduced or the number of rollers increased. The method of rolling and positions of the different rollers are thoroughly discussed in the USACE Handbook 2000, Dynapac Handbook, and German DAV Handbook (Milster et al., 2004), where detailed directives can be found.
Rolling thin SMA layers should be executed with great caution, with vibration only rarely applied. The use of slightly lighter rollers instead of heavy ones is recommended.
The quantity of so-called SMA roll down (i. e., the change in thickness of a spread layer due to rolling) may be estimated as 10-15% of a layer thickness. It depends, among other things, on the design gradation curve that forms the aggregate skeleton.
