Usually six to nine roller passes are enough to compact an SMA mixture. Moreover, compaction should not cause squeezing of the mastic onto the surface. The number of passes with vibrations should be limited to the indispensable minimum (most frequently, three).
On many construction sites or at the start of a new SMA mixture, it is recommended that the effectiveness of rolling in relation to the number of passes and type of rollers be tested on a specified section. The increase in density with more rolling passes is monitored with, for example, a nuclear density gauge, and the number of passes to reach the desired density is determined.
