Visible small cracks that run perpendicular to the drum indicate what condition?

When small cracks are visible that run perpendicular to the drum, this condition typically signifies potential issues with the compaction of the Hot Mix Asphalt (HMA). Proper compaction is essential in the paving process because it influences the performance characteristics of the asphalt layer, including its durability, resistance to deformation, and moisture susceptibility. When compaction is insufficient, it can lead to air voids and inadequate density, resulting in the formation of cracks as the asphalt layer may not be adequately bonded or supported.

The presence of these perpendicular cracks serves as an indicator that the material may not have achieved the necessary density required for optimal performance, suggesting that the compaction efforts during the paving process might have been inadequate. Recognizing these signs helps inspectors identify maintenance needs and make informed decisions regarding repair or further compaction efforts.