LOWER MOUNT INSTALLATION PROCEDURES
Temperatures below 55°F (13°C) slow the hardening process and
keep the grout in a flowable state long enough to permit settlement
and bleeding. Although grouting may be successfully
accomplished at ambient temperatures as low as 45°F (7°C), the
rate of strength gain (hardening) is slow and the required time on-
site may be excessive. To minimize the curing time, it is
recommended that the grout, mixing water, and mount base plates
be warmed to accelerate the curing process. The following
procedure is suggested:
Cold Weather
Grouting
1. Store bags of grout in a sheltered place so that the material will be at
least above freezing, but preferably above 45°F (7°C).
2. Measure the temperature of the base plate and foundation by placing a
thermometer on the surface and covering it with a piece of dry
insulation or dry rags. If the temperature is above 55°F (13°C)
minimum, proceed with grouting following the grouting
procedures. If the temperature is below 55°F (13°C), warm the base
plate and
foundation to bring the temperature above the
minimum, using the following methods:
a. Base plates may be warmed by use of infrared heat lamps or by
building a small enclosure around the base plate and
introducing heat from a convenient source. Warm the mixing
water as necessary to provide mixed grout at a temperature of
60°F (15°C) or above, but avoid use of water hotter than 90°F
(32°C).
b. After installing grout, maintain the temperature of the in-place
grout at 50°F (10°C) or above for a minimum of three hours to
ensure adequate grout hardness for final tightening of the anchor
bolt
nuts.
NOTE
Grout will not harden unless the temperature is maintained
above freezing. The minimum temperature is 40°F (4°C).
Perform the following procedure to grout base plates to foundation
first. Then, grout bottom skin plates to foundation using the
following procedure.
Grouting Procedures
1. Wash work surface with water. Keep surface saturated with water for at
least 24 hours prior to grouting.
NOTE
Grouting must be completed within 10 minutes after mixing.
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42S183D
SERIES 8116/8118 16-/18-METER EARTH STATION ANTENNA
2-33
