Which type of cracking results from hardening or shrinking of asphalt?

Block cracking is a type of distress that occurs in asphalt pavements due to the hardening and shrinking of the asphalt material over time. This process can be exacerbated by factors such as temperature fluctuations and aging, which lead to the asphalt binder losing its flexibility. As the asphalt contracts and shrinks, it can create larger cracks in a block-like pattern, typically resulting in rectangular or square shapes in the surface.

The significance of block cracking lies in its impact on the pavement's structural integrity and its ability to protect the subgrade layers from water infiltration and other environmental factors. Early identification and appropriate maintenance measures are essential to mitigate further deterioration and preserve the pavement's longevity.

In contrast, raveling is associated with the loss of aggregate material from the surface, transverse cracking relates to cracking that occurs perpendicular to the pavement's centerline due to temperature-induced expansion and contraction, and alligator cracking is indicative of fatigue from repeated loading and is characterized by interconnected cracks resembling an alligator's skin. Each of these types of cracking has distinct causes and implications for pavement management.