showing that the dowels [and tie bars] are installed within specified
tolerances.
3.5.8.2
Construction Joints-Fixed Form Paving
Installation of dowels [and tie bars] shall be by the bonded-in-place
method. Installation by removing and replacing in preformed holes will not
be permitted. Dowels [and tie bars] shall be prepared and placed across
joints where indicated, correctly aligned, and securely held in the proper
by means of devices fastened to the forms. The spacing of dowels [and tie
bars] in construction joints shall be as indicated, except that, where the
planned spacing cannot be maintained because of form length or interference
with form braces, closer spacing with additional dowels [or tie bars] shall
be used.
3.5.8.3
Dowels Installed in Hardened Concrete
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NOTE: The first option is for "Cylinders/Beams" and
the second option is for "Beams".
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Dowels installed in hardened concrete shall be installed by bonding the
have cured for 7 days or reached a minimum compressive strength of 17 MPa
2500 psi flexural strength of 3.1 MPa 450 psi before drilling commences.
Holes approximately 3 mm 1/8 inch greater in diameter than the dowels shall
during drilling shall be repaired as directed; continuing damage shall
require modification of the equipment and operation. Dowels shall be
bonded in the drilled holes using epoxy resin. Epoxy resin shall be
injected at the back of the hole before installing the dowel and extruded
to the collar during insertion of the dowel so as to completely fill the
void around the dowel. Application by buttering the dowel will not be
permitted. The dowels shall be held in alignment at the collar of the
hole, after insertion and before the grout hardens, by means of a suitable
metal or plastic grout retention ring fitted around the dowel. Dowels
required to be installed in any joints between new and existing concrete
shall be grouted in holes drilled in the existing concrete, all as
specified above. [Where tie bars are required in longitudinal construction
joints of slipform pavement, bent tie bars shall be installed at the paver,
in front of the transverse screed or extrusion plate. If tie bars are
required, a standard keyway shall be constructed, and the bent tie bars
shall be inserted into the plastic concrete through a 0.45 to 0.55 mm 26
gauge thick metal keyway liner. Tie bars shall not be installed in
preformed holes. The keyway liner shall be protected and shall remain in
place and become part of the joint. When bending tie bars, the radius of
bend shall not be less than the minimum recommended for the particular
grade of steel in the appropriate material standard. Before placement of
the adjoining paving lane, the tie bars shall be straightened, using
procedures which will not spall the concrete around the bar.]
3.5.8.4
Lubricating Dowel Bars
The portion of each dowel intended to move within the concrete or expansion
cap shall be wiped clean and coated with a thin, even film of lubricating
oil before the concrete is placed.
SECTION 02753
Page 62