used as soon as dry shake has absorbed moisture (indicated by darkening of
surface); floating shall be done just sufficiently to bring moisture from
base slab through the shake. Immediately following floating of the first
shake, the remaining one-third of the total specified shake shall be
applied in the same manner and machine floated. Surface shall be further
compacted by a third mechanical floating if time and setting
characteristics will allow. At no time shall water be added to the
surface. As surface further stiffens, indicated by loss of sheen, it shall
be hand or mechanically troweled with blades relatively flat. All marks
and pinholes shall be removed in the final raised trowel operation. Floors
finished with dry shake material shall be cured using a curing compound
recommended by the manufacturer of the dry shake material. Membrane curing
compound shall be applied immediately after the floor surface has hardened
sufficiently so surface will not be marred by the application. Compound
shall be applied uniformly over the entire surface at a coverage which will
provide moisture retention in excess of the requirements of ASTM C 309.
When dry, the coating shall be protected from droppings of plaster, paint,
dirt, and other debris by a covering of scuffproof, non-staining building
paper. Floor shall remain covered and be kept free of traffic and loads
for at least 10 days after completion. Adequate provision shall be made
for maintaining the concrete temperature at 10 degrees C 50 degrees F or
above during the curing period. The curing compound shall remain in place
for not less than 30 days. The curing compound shall be removed by a
manufacturer recommended method prior to turning the facility over to the
Government.
3.12.8
Heavy Duty Floors
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NOTE: Heavy duty floors are to be used only for
floors that will receive major traffic of tracked
vehicles or steel wheeled equipment when the
designer is concerned about wear. Moderate amounts
of such traffic can be accommodated by ordinary
concrete floors. If drawings do not indicate areas
to receive heavy duty finish, they must be specified
here. Delete this subparagraph if not required.
Edit bracketed items. Add to and strengthen this
subparagraph as needed but do not delete any of the
listed requirements.
**************************************************************************
[Areas as indicated on the drawings] [The following areas [_____]] shall
have heavy duty floors constructed as follows:
3.12.8.1
General
Heavy duty floor shall be constructed by placing a heavy duty bonded
topping on a base slab which has had a rough slab finish left 50 mm 2 inches
below final grade. Concrete in the base slab shall be thoroughly hardened
but not more than 30 hours old. The temperature of the fresh concrete
topping shall not vary more than 5 degrees C 10 degrees Fplus or minus from
the temperature of the base slab. The ambient temperature of the space
adjacent to the concrete placement and of the base slab shall be between 10
and 30 degrees C 50 and 90 degrees F.
3.12.8.2
Preparation of Base Slab
The base slab shall be kept continuously damp until topping is placed.
The
SECTION 03300A
Page 56
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