15 March 2001
6.1. Description. Concrete crack repair sealants are essentially the same as joint sealants and
are designed to mitigate two problem areas, moisture intrusion into the pavement base and
debris retention in the crack opening. The influx of moisture through a crack into the pavement
base layer can seriously reduce the strength of the base and the ability to sustain a load. It can
also erode underlying material and cause pumping. Debris retention is a particular problem due
to thermal movement of the slab at the joint. If incompressible material is present in the joint and
the slab expands due to thermal changes, spalling may result due to the inability of the stress to
be relieved through movement of the slab at the crack.
6.2. Fuel and Blast Resistance. Additional considerations for the crack repair material are jet
fuel and jet blast resistance. The crack to be repaired may be located in an area in which fuel or
lubricating or hydraulic fluid spillage may occur or in an area subjected to high temperature from
jet blast or exhaust from auxiliary power units. The repair material must conform to ASTM
specifications designated for joint and crack sealants for use in these areas, as listed in Table
1.1. under "Joint and Crack Repair."
6.3. Navy Regulations. Naval regulations require that all materials used on U.S. Navy facilities
must conform to NFGS-02982 (Reference 1.3.3.). The Navy recommends use of silicone
sealants on all Naval facilities and as an alternative to materials meeting ASTM D 5893, if
approved by the local base engineer. Silicone sealants may be used in place of neoprene
sealants for new joints if cost becomes a major factor in placement of neoprene sealant
(Refernces 1.3.3. and 1.3.4.).