Spalling

Description

Cracking, breaking or chipping of joint/crack edges. Usually occurs within about 0.6 m (2 ft.) of joint/crack edge.

Figure 1: Spalling along a linear (panel) crack.

Figure 2: Onset of spalling up close.

Figure 3: Bad construction joint spalling.

Problem

Loose debris on the pavement, roughness, generally an indicator of advanced joint/crack deterioration

Possible Causes

Possible causes are (AASHTO, 1993[1]):

  • Excessive stresses at the joint/crack caused by infiltration of incompressible materials and subsequent expansion (can also cause blowups).
  • Disintegration of the PCC from freeze-thaw action or “D” cracking.
  • Weak PCC at a joint caused by inadequate consolidation during construction. This can sometimes occur at a construction joint if (1) low quality PCC is used to fill in the last bit of slab volume or (2) dowels are improperly inserted.
  • Misalignment or corroded dowel.
  • Heavy traffic loading.

Repair

Spalling less than 75 mm (3 inches) from the crack face can generally be repaired with a partial-depth patch. Spalling greater than about 75 mm (3 inches) from the crack face may indicated possible spalling at the joint bottom and should be repaired with a full-depth patch.



Footnotes    (↵ returns to text)
  1. AASHTO Guide for Design of Pavement Structures.  American Association of State Highway and Transportation Officials.  Washington, D.C.

 

 

 

Check out the new Pavement Interactive at beta.pavementinteractive.org

We have been working hard to improve the Pavement Interactive experience.

The improvements include: