UFC 3-270-04
15 March 2001
other elevation differences. If the temperature is high, the concrete may be in compression at the
slab ends and may not be free to move. This may require freeing the joints by sawing to
complete the lifting process.
6.7. Elevation Control During Jacking. Before slabjacking operations are started, some
method of controlling the amount the slab is to be raised and the finished elevation of the
pavement should be determined. For correcting faulted slabs, a straight edge may be used. For
short dips up to approximately 50 feet (18.3 meters) in length, a tight stringline is adequate
provided the joints are true and plane with those of the adjacent pavement (Figure 6.4.). For dips
in excess of 50 feet (18.3 meters) in length, an engineer's level and rod should be used to check
the profile well beyond the dip. This will avoid building a bulge into the pavement.
6.8. Plugging and Cleanup. After slabjacking has been completed in a hole and the discharge
pipe removed, the hole should be plugged immediately. Tapered wooden plugs are temporarily
placed into the injection hole to retain the pressure of the grout and stop any return flow of the
mixture.
When slabjacking to the desired elevation has been accomplished, the temporary plugs are
removed and the injection holes are filled with a stiff one-part-water, three-part-cement grout or
approved concrete mixture. These areas are then finished to an approximate match with the
existing pavement. Surfaces adjacent to the grouting operation should be kept clean of excess
grout and other materials. Grout and cement slurry on the pavement should be broomed and
washed off to avoid unsightly discoloration and to remove the grout slurry before it bonds to the
surface.
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