Pavement Inspection

Raveling

Raveling is the dislodging of coarse aggregate in the surface of a pavement. The pavement may be showing signs of ageing and hardening and may result in the production of FOD.

Severity Distress Example Description
Low Close-up photo of a small area of asphalt pavement surface with a few missing pieces of aggregate. Dense Mix Asphalt Pavement (shown in photo): One of the following conditions exists: (1) In a square yard (square meter) representative area, the number of coarse aggregate pieces missing is between 5 and 20, and/or (2) missing aggregate clusters are less than 2 percent of the examined area. In low-severity raveling, there is little or no FOD potential.

Surface Treatment: One of the following conditions exists: (1) Scaled area is less than 1 percent of the examined area, and/or (2) in case of cold tar where pattern cracking has developed, the tar surface cracks are less than 1/4 in (6 mm) wide.

Porous Friction Courses: One of the following conditions exists: (1) number of missing aggregate pieces is between 5 and 20, and/or (2) the number of missing aggregate clusters does not exceed 1.
Medium Close-up photo of a small area of asphalt pavement surface with 30 to 40 missing pieces of aggregate. Dense Mix Asphalt Pavement (shown in photo): One of the following conditions exists: (1) In a square yard (square meter) representative area, the number of coarse aggregate pieces missing is between 21 and 40, and/or (2) missing aggregate clusters are between 2 and 10 percent of the examined area.

Surface Treatment: One of the following conditions exists: (1) Scaled area is between 1 and 10 percent of total area, and/or (2) in case of cold tar where pattern cracking has developed, the tar surface cracks are 1/4 in (6 mm) wide or greater.

Porous Friction Courses: One of the following conditions exists: (1) number of missing aggregate pieces is between 21 and 40, and/or (2) the number of missing aggregate clusters is greater than 1 but less than or equal to 25 percent of the examined area.
High Close-up photo of a small area of asphalt pavement where the majority of the surface has missing aggregate. Dense Mix Asphalt Pavement (shown in photo): In a square yard (square meter) representative area, the number of coarse aggregate particles missing is over 40, and/or (2) missing aggregate clusters make up more than 10 percent of the examined area.

Surface Treatment: One of the following conditions exists: (1) Scaled area is over 10 percent, and or (2) in case of cold tar, the tar surface is peeling off.

Porous Friction Courses: One of the following conditions exists: (1) number of missing aggregate pieces is greater than 40, and/or (2) the number of missing aggregate clusters is greater than 25 percent of the examined area.