3.9.4
Grouting Equipment
3.9.4.1
Grout Pumps
Pumping through aluminum tubes will not be permitted. Pumps shall be
operated to produce a continuous stream of grout without air pockets,
segregation, or contamination. Upon completion of each day's pumping,
waste materials and debris shall be removed from the equipment, and
disposed of outside the masonry.
3.9.4.2
Vibrators
Internal vibrators shall maintain a speed of not less than 5,000 impulses
per minute when submerged in the grout. At least one spare vibrator shall
be maintained at the site at all times. Vibrators shall be applied at
uniformly spaced points not further apart than the visible effectiveness of
the machine. Duration of vibration shall be limited to time necessary to
produce satisfactory consolidation without causing segregation.
3.9.5
Grout Placement
Masonry shall be laid to the top of a pour before placing grout. Grout
shall not be placed in two-wythe solid unit masonry cavity until mortar
joints have set for at least 3 days during hot weather and 5 days during
cold damp weather. Grout shall not be placed in hollow unit masonry until
mortar joints have set for at least 24 hours. Grout shall be placed using
a hand bucket, concrete hopper, or grout pump to completely fill the grout
spaces without segregation of the aggregates. Vibrators shall not be
inserted into lower pours that are in a semi-solidified state. The height
of grout pours and type of grout used shall be limited by the dimensions of
grout spaces as indicated in Table III. Low-lift grout methods may be used
on pours up to and including 1.5 m 5 feet in height. High-lift grout
methods shall be used on pours exceeding 1.5 m 5 feet in height.
3.9.5.1
Low-Lift Method
Grout shall be placed at a rate that will not cause displacement of the
masonry due to hydrostatic pressure of the grout. Mortar protruding more
than 13 mm 1/2 inch into the grout space shall be removed before beginning
the grouting operation. Grout pours 300 mm 12 inches or less in height
shall be consolidated by mechanical vibration or by puddling. Grout pours
over 300 mm 12 inches in height shall be consolidated by mechanical
vibration and reconsolidated by mechanical vibration after initial water
loss and settlement has occurred. Vibrators shall not be inserted into
lower pours that are in a semi-solidified state. Low-lift grout shall be
used subject to the limitations of Table III.
3.9.5.2
High-Lift Method
Mortar droppings shall be cleaned from the bottom of the grout space and
from reinforcing steel. Mortar protruding more than 6 mm 1/4 inch into the
grout space shall be removed by dislodging the projections with a rod or
stick as the work progresses. Reinforcing, bolts, and embedded connections
shall be rigidly held in position before grouting is started. CMU units
shall not be pre-wetted. Grout, from the mixer to the point of deposit in
the grout space shall be placed as rapidly as practical by pumping and
placing methods which will prevent segregation of the mix and cause a
minimum of grout splatter on reinforcing and masonry surfaces not being
immediately encased in the grout lift. The individual lifts of grout shall
SECTION 04200
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