shall be no abrupt offset either horizontally or vertically in the
completed keyway. The keyway liner shall be protected and shall remain in
place and become part of the joint.]
3.5.6.2
Guideline for Slipform Paving
Guidelines shall be accurately and securely installed well in advance of
concrete placement. Supports shall be provided at necessary intervals to
eliminate all sag in the guideline when properly tightened. The guideline
shall be high strength wire set with sufficient tension to remove all sag
between supports. Supports shall be securely staked to the underlying
material or other provisions made to ensure that the supports will not be
displaced when the guideline is tightened or when the guideline or supports
are accidentally touched by workmen or equipment during construction. The
appliances for attaching the guideline to the supports shall be capable of
easy adjustment in both the horizontal and vertical directions. When it is
necessary to leave gaps in the guideline to permit equipment to use or
cross underlying material, provisions shall be made for quickly and
accurately replacing the guideline without any delay to the forward
progress of the paver. Supports on either side of the gap shall be secured
in such a manner as to avoid disturbing the remainder of the guideline when
the portion across the gap is positioned and tightened. The guideline
across the gap and adjacent to the gap for a distance of 60 m 200 feet
shall be checked for horizontal and vertical alignment after the guideline
across the gap is tightened. Vertical and horizontal positioning of the
guideline shall be such that the finished pavement shall conform to the
alignment and grade elevations shown on the drawings within the specified
tolerances for grade and smoothness. The specified tolerances are intended
to cover only the normal deviations in the finished pavement that may occur
under good supervision and do not apply to setting of the guideline. The
guideline shall be set true to line and grade.
3.5.6.3
If the Contractor proposes to use any type of automatic laser controls, a
detailed description of the system shall be submitted and a trial field
demonstration shall be performed in the presence of the Contracting Officer
at least one week prior to start of paving. Approval of the control system
will be based on the results of the demonstration and on continuing
satisfactory operation during paving.
3.5.7
Placing Reinforcing Steel
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NOTE: Delete bracketed item if CRCP is not being
constructed.
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The type and amount of steel reinforcement shall be as shown on the
drawings. For pavement thickness of 300 mm 12 inches or more, the
reinforcement steel shall be installed by the strike-off method wherein a
layer of concrete is deposited on the underlying material, consolidated,
and struck to the indicated elevation of the steel reinforcement. The
reinforcement shall be laid upon the prestruck surface, and the remaining
concrete shall then be placed and finished in the required manner. When
placement of the second lift causes the steel to be displaced horizontally
from its original position, provisions shall be made for increasing the
thickness of the first lift and depressing the reinforcement into the
unhardened concrete to the required elevation. The increase in thickness
SECTION 02753
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