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26 Νοε 2013 (πριν από 3 χρόνια και 6 μήνες)

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SPECIAL PROVISIONS

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SECTION I



1



1.

PRECAST PRESTRESSED
DECK SECTIONS (REVIS
ED 6
-
27
-
11)

A.

Description. These are precast, prestressed concrete deck sections intended to form
both the structural support and riding surface of a bridge. These sections must meet the require
ments
of Section 553

of the Standard Specifications and the requirements of this provision.

B.

Materials. The following requirements are in addition to those of Section 553.02 of the
Standard Specifications:

1)

Class Pre Concrete, Air Entrainment. Ensure that the Class Pre concre
te used in the
deck sections includes from 4% to 6% entrained air. Maintain all other properties for Class Pre
Concrete shown on Table 551
-
1.

2)

Deck Sealer. Use Baracade Silane 40 IPA, Protectosil CHEM
-
TRETE 40 VOC, Hydrozo
Silane 40 VOC sealer or other ap
proved silane sealer.

3)

Leveling Inserts. Equip all deck sections with leveling inserts. Use ¾ in. (19

mm)
minimum diameter structural connection type leveling inserts. The inserts must be designed for a
minimum working tension of 5,500 lbs (24.4 kN) and
have machine threaded ferrules.

C.

Construction Requirements. The following requirements are in addition to Section 553
of the Standard Specifications:

1)

General. Once the deck sections are placed on the supports, some adjustments may be
necessary to obtain a
n acceptable riding surface. Make these adjustments by use of a leveling beam
and jack assembly. Attach the leveling beam to the inserts and jack the deck sections so that the riding
surface meets the tolerance outlined below.

2)

Leveling Inserts. Indicate

the leveling insert locations on the shop drawings for approval.
Locate the inserts so that the specified camber corrections are achieved by the methods described
herein. Center the leveling inserts over the beam's web, install a minimum of
1
/
8

in. (3

mm) below the
finished deck surface, and cast into the member. After all adjustments are complete and the deck
sections are in their final position, fill all leveling insert holes with an approved non
-
shrink epoxy grout.

3)

Leveling Beam. Have avail
able a leveling beam and suitable jacking assemblies for
attachment to the leveling inserts of adjacent beams. Adjust the deck sections to the tolerances
described herein. Submit drawings of the proposed leveling system for approval prior to beginning
le
veling operations. More than one leveling beam with jacking assemblies may be necessary in order
to adjust the adjacent sections to the required tolerance.

4)

Fabrication Camber Control. Schedule fabrication so that camber differences between
adjacent deck
sections are minimized. Measure camber on each deck section immediately after
transfer of prestress forces. At transfer of prestress, the difference in camber between adjacent deck
sections of the same design must not exceed ¼ in. (6

mm) per 10 ft. (3 me
ters) of span length or a
maximum difference of ¾ in. (19

mm), whichever is less.

SPECIAL PROVISIONS

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SECTION I



2



5)

Field Leveling. Use the approved leveling system to adjust adjacent deck sections to
within
3
/
8

in. (9

mm) at the center of the span prior to placement of the weld tie conne
ctions and
diaphragms. If the prescribed adjustment tolerance between deck sections can not be attained by use
of the approved leveling system, employ other methods to achieve the prescribed tolerance. Shim the
bearings of the deck sections or use other
means as approved so the deck sections match within
3
/
8

in.
(9

mm) throughout the span.

6)

Remove any grease, oil or other contaminants on the deck surface by sandblasting.
After sandblasting, power
-
wash the entire deck surface to remove concrete swarf, dirt
, dust and other
debris. Allow the deck to dry until it is visibly dry with no ponding or dark areas indicating moisture in
the concrete surface. Apply Deck Sealer by spray until refusal to the cleaned, dry deck. Refusal
means that additional spray appl
ications remain on the surface of the concrete and do not soak in.
Insure that a minimum of 28 calendar days have passed from the time the deck is cast to the
application of the Deck Seal. Prevent chloride contamination of the deck during all stages of
c
onstruction.

D.

Basis of Payment. Include all costs associated with this work in the unit price bid for
Prestressed Beam
-

Bulb
-
Tee, Prestress Beam
-

Tri Deck or Prestress Beam


Rib Deck.