UFC 4-150-07
19 June 2001
CR-2: MAJOR JOINT AND CRACK REPAIR
Problem: Large cracks or construction joints allow water to penetrate in or leak
through the structure.
Description of Repairs: Sealing of cracks and construction joints to prevent
leakage. This repair is performed after grouting of cracks is completed. Example
given is for drainage and discharge tunnels, and should be modified for less
demanding applications. Repair requires conventional hand and power tools and
a heating bucket.
Materials:
a. Sealant No. 1 - Two-component epoxy coating system. See
Paragraph 3.2.5.2 and CR-4, Applications.
b. Sealant No. 2 - Non-meltable mastic of refined asphalts, resins, and
plasticized compounds reinforced with non-asbestos fiber. Resistant to seawater,
salts, acids, and dilute alkalis.
c. Primer for Sealant No. 2 - Asphaltic liquid primer compatible with
sealant.
d. Sealant No. 3 - Two-component, moisture insensitive epoxy resin
mortar; 1 part mixed epoxy to 7 parts aggregate by volume.
e. Copper Plate - 16 gauge conforming to ASTM B-370-92, Copper
Sheet and Strip for Building Construction.
Preparation: Chip out and saw cut concrete as shown on Figure 7-3. Clean all
surfaces to receive sealants of all loose and deteriorated concrete and marine
growth by chipping, scraping, and sandblasting. Provide clean, sound bond
surfaces. Prepare surfaces to meet sealant manufacturer's requirements.
Repair Procedures:
a. Perform repairs when ambient or water temperature is at least 10C
(50F), depending on whether structure is exposed or submerged.
b. Apply Sealant No. 1 with a brush to cleaned surfaces.
c. Prime all surfaces to receive sealant No. 2 with primer and let dry.
d. Apply three layers of Sealant No. 2 (heat sealant) as shown in
Figure 7-3. Pound each layer during and after cooling.
e. Fasten copper strip in place for placement of sealant No. 3. Do not
use fasteners of dissimilar metal.
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