3.6
FINISHING
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NOTE: Edit bracketed items as appropriate. Retain
slipform paving subparagraph except when it is
prohibited elsewhere. Delete Other Types of
Finishing Equipment here and in PART 1, if not
wanted. Hand finishing is to be allowed only for
isolated, small, odd-shaped slabs or places
inaccessible to the paver.
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Finishing operations shall be a continuing part of placing operations
starting immediately behind the strike-off of the paver. Initial finishing
shall be provided by the transverse screed or extrusion plate. The
sequence of operations shall be transverse finishing, longitudinal machine
floating if used, straightedge finishing, texturing, and then edging of
joints. Finishing shall be by the machine method. The hand method shall
be used only on isolated areas of odd slab widths or shapes and in the
event of a breakdown of the mechanical finishing equipment. Supplemental
hand finishing for machine finished pavement shall be kept to an absolute
minimum. Any machine finishing operation which requires appreciable hand
finishing, other than a moderate amount of straightedge finishing, shall be
immediately stopped and proper adjustments made or the equipment replaced.
Every effort shall be made to prevent bringing excess paste to the surface
and any operations which produce more than 3 mm 1/8 inch of paste (mortar,
water, laitance, etc.) over the top layer of coarse aggregate shall be
halted immediately and the equipment, mixture, or procedures modified as
necessary. Compensation shall be made for surging behind the screeds or
extrusion plate and settlement during hardening and care shall be taken to
ensure that paving and finishing machines are properly adjusted so that the
finished surface of the concrete (not just the cutting edges of the
screeds) will be at the required line and grade. Finishing equipment and
tools shall be maintained clean and in an approved condition. At no time
shall water be added to the surface of the slab with the finishing
equipment or tools, or in any other way, except for fog (mist) sprays
specified to prevent plastic shrinkage cracking.
3.6.1
Machine Finishing With Fixed Forms
The machine shall be designed to ride the forms and shall be operated to
screed and consolidate the concrete. Machines that cause displacement of
the forms shall be replaced. The machine shall make only one pass over
each area of pavement. If the equipment and procedures do not produce a
surface of uniform texture, true to grade, in one pass, the operation shall
be immediately stopped and the equipment, mixture, and procedures adjusted
as necessary.
3.6.2
Machine Finishing with Slipform Pavers.
The slipform paver shall be operated so that only a very minimum of
additional finishing work is required to produce pavement surfaces and
edges meeting the specified tolerances. Any equipment or procedure that
fails to meet these specified requirements shall immediately be replaced or
modified as necessary. A self-propelled nonrotating pipe float may be used
while the concrete is still plastic, to remove minor irregularities and
score marks. Only one pass of the pipe float shall be allowed. If there
is concrete slurry or fluid paste on the surface that runs over the edge of
the pavement, the paving operation shall be immediately stopped and the
SECTION 02753
Page 63
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