Interface contact properties in asphalt pavement using 3D laser scanning technology

Existing research on pavement interlayer bonding has mainly focused on bonding materials and external factors, neglecting the upper and lower interlayer surface characteristics. This study aims to analyze the contact conditions between these surfaces, developing a numerical model to reveal their properties. Five double-layered asphalt systems, including dense-graded asphalt concrete (AC), open-graded friction course (OGFC), and stone mastic asphalt (SMA) mixes, were examined using a nondestructive interlayer separation method and 3D laser scanning. Three indices were proposed to assess interlayer surface characteristics in both 2D and 3D domains. Shear strength tests at room temperature were also conducted, revealing that AC-only systems had lower surface mismatch at the layer interface compared to SMA or OGFC mixes. The study concludes that surface mismatch decreases with greater differences in aggregate coarseness, and systems with significant mismatch gaps have lower shear strength. These findings provide valuable insights for designing durable pavement structures.