Corrugation and Shoving

Description

A form of plastic movement typified by ripples (corrugation) or an abrupt wave (shoving) across the pavement surface. The distortion is perpendicular to the traffic direction. Usually occurs at points where traffic starts and stops (corrugation) or areas where HMA abuts a rigid object (shoving).

Corrugations on a steep city street
Figure 1: Corrugations on a steep city street

Shoving at a busy intersection
Figure 2: Shoving at a busy intersection

Shoving in the parking lane of a collector road.
Figure 3: Shoving in the parking lane of a collector road.

Problem

Roughness

Possible Causes

Usually caused by traffic action (starting and stopping) combined with:

  • An unstable (i.e. low stiffness) HMA layer (caused by mix contamination, poor mix design, poor HMA manufacturing, or lack of aeration of liquid asphalt emulsions)
  • Excessive moisture in the subgrade

Repair

A heavily corrugated or shoved pavement should be investigated to determine the root cause of failure. Repair strategies generally fall into one of two categories:

  • Small, localized areas of corrugation or shoving. Remove the distorted pavement and patch.
  • Large corrugated or shoved areas indicative of general HMA failure. Remove the damaged pavement and overlay.