Joint Seal Damage

Joint sealant damage is any joint seal condition that enables soil or rocks to accumulate in the joints, or allows significant infiltration of water. Accumulation of incompressible materials prevents the slabs from expanding and may result in buckling, shattering, or spalling. A pliable joint filler bonded to the edges of the slabs protects the joints from accumulation of materials, and also prevents water from seeping down and softening the foundation supporting the slab. Typical types of joint seal damage are: (1) stripping of joint sealant, (2) extrusion of joint sealant, (3) weed growth, (4) hardening of the filler (oxidation), (5) loss of bond to the slab edges, and (6) lack or absence of sealant in the joint.

Severity Distress Example Description
Low Close-up photo of a transverse joint with low-severity joint seal damage.  The silicone sealant in the photo           is in good condition, but it is noticeably debonded from one side of the joint. Joint sealer is in generally good condition throughout the sample. Joint seal damage is at low severity if a few of the joints have sealer which has debonded from, but is still in contact with the joint edge. This condition exists if a knife blade can be inserted between sealer and joint face without resistance.
Medium Close-up photo of a transverse joint with medium-severity joint seal damage.  The asphalt sealant in the photo is           not in good condition, and noticeably debonded from the sides of the joint. Joint seal damage is at medium severity if a few of the joints have any of the following conditions: (1) joint sealer is in place, but water access is possible through visible openings no more than 1/8 in (3 mm) wide; if a knife blade cannot be inserted easily between sealer and joint face, this condition does not exist; (2) pumping debris are evident at the joint; (3) joint sealer is oxidized and "lifeless" but pliable (like a rope), and generally fills the joint openings; (4) vegetation in the joint is obvious, but does not obscure the joint opening. Sealant needs replacement within two years.
High Close-up photo of a transverse joint with high-severity joint seal damage.  The joint in the photo is fairly wide,           and the sealant is noticeably debonded from both sides of the joint. Joint sealer is in generally poor condition over the entire surveyed sample. Joint seal damage is at high severity if 10% or more of the joint sealer exceeds limiting criteria listed above, or if 10% or more of sealer is missing. Sealant needs immediate replacement.