3.3.5.4
Blocked Pipes
Care shall be exercised to avoid blocking grout insert pipes by avoiding
interruptions in pumping; however, when a pipe becomes blocked, it shall be
withdrawn immediately until the end is at least 600 mm 2 feet above the
level of the grout before an attempt is made to unblock it by washing out
the line. In no case shall washing be attempted with the end of the grout
line inserted in the grout.
3.3.5.5
Placing Temperature
Intrusion grout shall not be placed when the ambient temperature is below 2
degrees C 35 degrees F, unless specifically approved by the Contracting
Officer. The preplaced-aggregate concrete, without special protection,
shall not be subjected to freezing temperatures before grout reaches a
unconfined compressive strength of 3500 kPa 500 psi. Grout which is
intruded during cold weather shall have a temperature of not less than 5
degrees C 40 degrees F nor more than 15 degrees C 60 degrees F. Heating of
the mixing water or fine aggregate will not be permitted until the
temperature of the grout has decreased to 7 degrees C 45 degrees F. All
methods and equipment for heating shall be subjected to approval.
3.4
FINISHING
**************************************************************************
NOTE: Consult the appropriate DM for those surfaces
to receive a trowel finish, abrasive aggregate
finish, or broom finish. Be sure those special
finishes are shown.
**************************************************************************
The ambient temperature of spaces adjacent to surfaces being finished shall
be not less than 10 degrees C 50 degrees F. In hot weather when the rate
of evaporation of surface moisture, as determined by use of Figure 2.1.5 of
ACI 305R, may reasonably be expected to exceed 1 kg/square meter 0.2 psf
per hour, provisions for windbreaks, shading, fog spraying, or wet covering
with a light-colored material shall be made in advance of placement. Such
protective measures shall be taken as quickly as finishing operations will
allow. All unformed surfaces that are not to be covered by additional
concrete or backfill shall have a float finish. Additional finishing shall
be as specified below and shall be true to the elevation shown in the
drawings. Surfaces to receive additional concrete or backfill shall be
brought to the elevation shown in the drawings and left true and regular.
Exterior surfaces shall be sloped for drainage unless otherwise shown in
the drawing or as directed.
3.4.1
[Formed Top Surface
A venting form constructed of muslin shall be used to produce the finished
surface. The venting form shall be placed on top of the aggregate and
backed up by fly screen, diamond metal lath, and sheeting boards spaced
from 13 to 25 mm 1/2 to 1 inch apart. The form shall be tied down against
uplift pressure.]
3.4.2
[Screeded or Trowelled Surface
The grout shall be brought up to flood the aggregate surface and any
diluted surface grout shall be removed by brooming. Following this, a thin
layer of pea gravel or 9.5 to 12.5 mm 3/8 to 1/2 inch crushed aggregate
SECTION 03372
Page 27
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