Surface distortions in flexible pavements

Pavement surface distortions are generally distresses related to pavement unevenness in the longitudinal or transverse direction. Surface evenness affects traffic safety and comfort. Distortions may be accompanied by cracking, which then affects the structural performance of the pavement. 

Surface distortions may be caused by one or more of the following reasons (a) viscoelastic behaviour of the asphalt, (b) low resistance to deformability of the asphalt, (c) poor compaction of one or some of the pavement layers and (d) subgrade settlement. 

For effective pavement distortion repair/maintenance, as in all pavement defects, it is absolutely necessary to determine the cause. 

Generally, the repair/maintenance of surface distortions may range from hot asphalt filling, complete removal of the affected area and replacement with new material, thin or full-depth patching or application of micro-surfacing. 

The treatment for rutting after a long period may consist of one of the following actions, depending on the cause  

---