equipment shall be present on the jobsite when base-coat plastering begins,
and until completion. Testing of the mix shall be the responsibility of
the Contractor, but equipment shall be available for use by the Government.
Additional water shall not be added to the mix to allow pumping through
extended hose lines to the plastering nozzle. The amount of water added to
each batch of plaster shall be that quantity which results in a plaster
slump of not more than 75 mm 3 inches for gypsum and 65 mm 2-1/2 inches for
portland cement using a standard plaster slump cone or 150 mm 6 inches for
gypsum and 125 mm 5 inches for portland cement using a concrete slump cone.
Application of plaster shall conform to the provisions of ASTM C 842.
3.15
QUALITY CONTROL
Fluidity or stiffness of plaster shall be tested with a standard 50 x 100 x
150 mm 2 x 4 x 6 inch plaster slump testing cone or by a 100 x 200 x 300 mm
4 x 8 x 12 inch concrete slump testing cone. Method of making slump test
shall be as follows:
a.
Place cone on center of dry base plate located on a level, firm
surface. Hold cone tightly against plate.
b.
Fill the cone with plaster obtained from the hose or nozzle,
without air on the nozzle, puddling with tamping rod during the
operation to eliminate air bubbles or voids.
c.
Screed plaster level with top of cone.
d.
Lift cone straight up from base plate in a slow and uniform
motion, and place it on the base plate next to plaster sample.
e.
Lay a straightedge across top of cone, being careful not to
disturb or jostle the plate, and measure the slump in mm inches
from the bottom of the straightedge to the top of the plaster
sample.
3.16
APPLICATION OF FINISHES
The finish coat may be omitted back of projecting bases, wainscots,
structural-glass wall finish, cabinets, chalkboards, tackboards, bulletin
boards, acoustic treatments, fixed equipment, and other locations where
indicated. Finish coats shall not be applied above wainscots until
wainscots have been installed. Plaster shall have a [[smooth-trowel]
[texture] finish] [finish as shown].
3.16.1
Interior Gypsum Plaster
Application of interior gypsum plaster (full thick) shall be in accordance
with ASTM C 842. Nominal plaster thickness shall be [as shown] [[_____] mm
inches].
3.16.2
Gypsum Veneer Plaster
Application of gypsum veneer plaster shall be in accordance with ASTM C 843.
Plaster shall be [[one-component system] [two-component system]] [system
as shown].
3.16.3
Lime-Putty Finish
Lime-putty finish shall be applied over gypsum plaster base coats in
SECTION 09200A
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