4. SIDEWALK DEFICIENCIES (Concrete & Asphalt)

4.1 Cracking

• 4.1.1 Transverse Cracks

  Transverse cracks are the result of non-uniform sub grade compaction. They also occur on sidewalks subjected to high vehicle loads, such as sections running through driveways. Transverse cracks are parallel to the joints, and therefore perpendicular to the direction of travel of the sidewalk. They span the entire width of the sidewalk in a relatively straight path. (see Figure 4.1.1 for a diagram of transverse cracking)

Fig. 4.1.1: Transverse Cracking of Concrete  (  http://irc.nrc-cnrc.gc.ca  )

• 4.1.2 Longitudinal Cracks

  Longitudinal cracks run parallel to the traveling direction of the sidewalk, typically within the middle third of the sidewalk. These cracks are most often caused by non-uniform sub grade compaction but may sometimes be caused by vehicle loads. Longitudinal cracks usually start and end at panel joints or transverse cracks, however, they can extend through numerous expansion joints without stopping (as shown in Figure 4.1.2).