Which of the following factors is crucial for successful asphalt compaction?

Moisture content is crucial for successful asphalt compaction because it directly affects the density and stability of the asphalt mix. When the moisture content is at the appropriate level, the asphalt can properly bond and achieve optimal compaction, which is essential for creating a durable and long-lasting surface. If the moisture content is too high or too low, it can lead to issues such as improper compaction, increased susceptibility to cracking, and reduced overall performance of the pavement. Maintaining the right moisture balance ensures that the asphalt can be compacted effectively, which ultimately contributes to the longevity and quality of the roadway.

Factors like wind speed, type of asphalt, and time of day, while they may influence certain aspects of the paving process, do not play as fundamental a role in achieving the compaction of asphalt as moisture content does.