Amplitude is a setting for which type of roller?

Amplitude is a key setting specifically associated with vibratory rollers. These rollers utilize vibration to enhance the compaction process of hot mix asphalt. The amplitude setting determines the extent of the roller's vibrating action, which affects the depth of the compaction and the effectiveness in achieving a dense mat. In vibratory rollers, adjusting the amplitude can optimize performance based on the type of material being compacted and the desired outcomes.

Static rollers, on the other hand, rely solely on the weight of the roller for compaction and do not utilize vibration, so they do not have an amplitude setting. Pneumatic rollers use air-filled tires to compact asphalt, also without reliance on vibrating mechanisms, thus they do not incorporate amplitude as a setting.

Therefore, the focus on amplitude directly connects to the compaction effectiveness and operational versatility provided by vibratory rollers, solidifying why this is the correct choice.