Which factor causes an increase in compactive effort during asphalt paving?

The hardness of the aggregate significantly influences the compactive effort required during asphalt paving. When using harder aggregates, more compactive effort is necessary to achieve the desired density and ensure proper bonding between the asphalt mixture and the aggregates. Hard aggregates tend to resist deformation and require additional force to effectively compact the asphalt layer.

For instance, when aggregates are softer, they can be compressed more easily, which means that less energy or effort is needed to achieve the necessary level of compaction. Thus, the hardness of the aggregates directly correlates with the intensity and duration of compaction needed to achieve an optimal pavement structure that meets performance specifications.

In this context, while the size of the equipment, the number of workers on site, and environmental conditions do play roles in the overall paving process, they do not directly affect the effort required for compaction as the characteristics of the aggregates do. Hence, understanding the qualities of the aggregates is crucial for planning the requisite compactive effort during the paving operation.