applications. After the concrete has been placed, consolidated, struck
off, and leveled to a Class C tolerance as defined below, the surface shall
be roughened with stiff brushes of rakes before final set.
3.8.1.2
Floated
Use for [surfaces to receive [roofing,] [waterproofing membranes,] [sand
bed terrazzo,]][_____] [and] [exterior slabs where not otherwise
specified.] After the concrete has been placed, consolidated, struck off,
and leveled, do not work the concrete further, until ready for floating.
Whether floating with a wood, magnesium, or composite hand float, with a
bladed power trowel equipped with float shoes, or with a powered disc,
float shall begin when the surface has stiffened sufficiently to permit the
operation. During or after the first floating, surface shall be checked
with a 3 meter (10 foot) 10 foot straightedge applied at no less than two
different angles, one of which is perpendicular to the direction of strike
off. High spots shall be cut down and low spots filled during this
procedure to produce a surface level within [6] [_____] mm in 3 m ([1/4]
[_____] inch in 10 feet) [1/4] [_____] inch in 10 feet.
[3.8.1.3
Concrete Containing Silica Fume
Finish using magnesium floats or darbies.
[Finish using techniques
demonstrated in the sample installation.]
]3.8.1.4
Steel Troweled
**************************************************************************
NOTE: ACI 302.1R suggests power troweling three
times for Class 5 floors and where increased wear
resistance is needed.
**************************************************************************
Use for floors intended as walking surfaces[,] [and] for reception of floor
coverings[, and] [_____]. First, provide a floated finish. The finish
shall next be power troweled [two] [three] [_____] times, and finally hand
troweled. The first troweling after floating shall produce a smooth
surface which is relatively free of defects but which may still show some
trowel marks. Additional trowelings shall be done by hand after the
surface has hardened sufficiently. The final troweling shall be done when
a ringing sound is produced as the trowel is moved over the surface. The
surface shall be thoroughly consolidated by the hand troweling operations.
The finished surface shall be essentially free of trowel marks and uniform
in texture and appearance. The finished surface shall produce a surface
level to within [6] [_____] mm in 3 m ([1/4] [_____] inch in 10 feet) [1/4]
[_____] inch in 10 feet. On surfaces intended to support floor coverings,
any defects of sufficient magnitude to show through the floor covering
shall be removed by grinding.
[3.8.1.5
Nonslip Finish
**************************************************************************
NOTE: Include when nonslip finish using dry shake
aggregate is desired.
**************************************************************************
Use on surfaces of exterior platforms, steps, and landings; and on exterior
and interior pedestrian ramps. Apply dry shake aggregate of [ceramically
bonded aluminum oxide] [_____] to the surface at a minimum rate of 1.2 kg
SECTION 03300N
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