UFC 3-270-02
15 March 2001
7.3.2. HCA heat lance. The HCA heat lance should only be used when the pavement is wet
and/or cold (pavement temperature below 50 degrees Fahrenheit (10 degrees Celsius)).
Extreme care should be used to ensure the crack faces do not become overheated or burned.
Overheating of the crack faces can greatly reduce the life expectancy of the sealant and adjacent
pavement. The expected failures may be in the form of adhesion failure of the sealant or
additional cracking of the pavement between the area that was overheated and the remainder of
the pavement.
7.3.3. Wire brushes. Wire brushes are commonly used during sealing projects; however, wire
brushes are not always capable of removing debris from the crack faces, and this debris can
cause adhesion failures. Careful inspections should be conducted to ensure that the wire
brushes are not worn and that all debris and dust have been removed.
7.4. Debris Removal. The recommended procedure to remove debris from the crack is to rout
the crack. This method normally removes the debris more effectively with less chance of
pavement damage. The rotary impact router equipped with carbide-tipped bits is generally faster
than the spindle router. The precautions mentioned previously should always be observed.
7.5. Final Crack Cleaning. Once the old sealant and debris have been removed from the crack,
the crack is cleaned with compressed air. The compressed air is blown into the crack to remove
sand or any debris that was loosened during the initial cleaning. The compressed air also aids in
the removal of moisture.
7.6. Inspection. Inspection is the final phase of crack preparation. The crack must be inspected
for cleanliness and dryness. It is essential for the crack to be clean and dry so that the sealant
will adhere to the pavement. One method to check for cleanliness is to rub one's finger along the
crack face. If a dusty residue is left on the finger, the crack should be recleaned. If there is no
residue, the crack is ready for sealing.
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