Blowups

are caused by expansion of concrete to the point where the stress causes the concrete to be raised. This can result in a problem ranging from a small bump to a shattering of concrete as if an explosion occurred. When blowups occur, the loose material should be removed and temporary repairs should be made until permanent repairs are practical.

Cracks

, both longitudinal and transverse, may occur in concrete pavement. Transverse cracks are meant to occur in continuously reinforced concrete pavement (CRCP) and should not be sealed. These cracks have little effect on ride quality and should not allow moisture to enter underlying layers and lead to other distress. However, transverse cracks on jointed concrete pavement tend to be wider and will allow moisture into the pavement and should be sealed.

Failures

are punchouts, corner breaks and other major distresses that can cause very uncomfortable ride and in severe conditions could result in vehicle damage. Make repairs whenever areas of the pavement become cracked or broken to the extent that ride quality and structural integrity of the pavement is lost.

Joint failures

(jointed pavements) occur at various spacing on jointed concrete pavement and can cause an unpleasant ride if not properly maintained. Joint failures appear in many forms from minor to major spalling to blowups. Deep spalls and failures may affect vehicle contact with the pavement and should be repaired as soon as possible. Joints should be inspected routinely and should be maintained to exclude foreign material and to preserve the integrity of the joint. When excessive foreign material or infiltration of water is evident, cleaning which includes the repairing and sealing of the joints should be scheduled. This should be done in accordance with "Standard Specification Item 438 Cleaning and/or Sealing Joints and Cracks" (Portland Cement Concrete).

Settlement, heave, and/or faulting

can

occur in jointed pavement. Settlement and heave are normally gradual changes and can lead to an uncomfortable ride. Faulting can occur rather suddenly when a slab rises or lowers. Repairs should be made as soon as practical when the ride quality becomes objectionable. Severe faulting that may affect vehicle control should be repaired as soon as possible.

Surface deterioration

such as raveling, popouts, joint spalling and other surface type deterioration allows moisture to penetrate to steel reinforcing, causing further distress. Ride quality also becomes uncomfortable. Repairs are to be made as soon as possible when a section of a roadway is considered to have a severe condition of this type.