Blowup

Blowups occur in hot weather, usually at a transverse crack or joint that is not wide enough to permit expansion of the concrete slabs. The insufficient width is usually caused by inflation of incompressible materials into the joint space. When expansion cannot relieve enough pressure, a localized upward movement of the slab edges (buckling) or shattering will occur in the vicinity of the joint. Blowups can also occur at utility cuts and drainage inlets. This type of distress is almost always repaired immediately because of severe damage potential to aircraft. The main reason blowups are included here is for reference when closed sections are being evaluated for reopening.

Severity	Distress Example	Description
Low		Buckling or shattering has not rendered the pavement inoperable, and only a slight amount of roughness exists.
Medium		Buckling or shattering has not rendered the pavement inoperable, but a significant amount of roughness exists.
High		Buckling or shattering has rendered the pavement inoperable.