Cracks perpendicular to the pavement’s centerline or laydown direction. Usually a type of thermal cracking.
Allows moisture infiltration, roughness
- Shrinkage of the HMA surface due to low temperatures or asphalt binder hardening
- Reflective crack caused by cracks beneath the surface HMA layer
- top-down cracking
Strategies depend upon the severity and extent of the cracking:
- Low severity cracks (< 1/2 inch wide and infrequent cracks). Crack seal to prevent (1) entry of moisture into the subgrade through the cracks and (2) further raveling of the crack edges. HMA can provide years of satisfactory service after developing small cracks if they are kept sealed (Roberts et. al., 1996).
- High severity cracks (> 1/2 inch wide and numerous cracks). Remove and replace the cracked pavement layer with an overlay.
Footnotes (↵ returns to text)
- Hot Mix Asphalt Materials, Mixture Design, and Construction. National Asphalt Paving Association Education Foundation. Lanham, MD.↵