Which characteristic of a roller affects both amplitude and frequency?

The characteristic of a roller that affects both amplitude and frequency is drum weight. Drum weight is crucial because it influences the energy imparted to the pavement during compaction. A heavier drum can exert more pressure on the asphalt, leading to a greater amplitude in terms of the depth of the compaction achieved.

Additionally, drum weight affects the frequency of the vibrations produced by the roller. A heavier drum typically generates higher frequency vibrations, which can effectively break down and compact the asphalt mix without damaging it. In contrast, the other characteristics listed—such as drum width, drum height, and roller speed—can influence the overall efficiency and effectiveness of the compaction process, but they do not have the direct relationship to both amplitude and frequency that drum weight possesses.

Thus, understanding the impact of drum weight is vital for achieving optimal compaction results, ensuring the pavement stands up to traffic loads and environmental conditions.