Remove torn, punctured, or damaged vapor barrier material and provide with
new vapor barrier prior to placing concrete. Concrete placement shall not
damage vapor barrier material. [Place a 50 mm (2 inch) 2 inch layer of
clean concrete sand on vapor barrier before placing concrete.]
3.4.2
Reinforcement Supports
Place reinforcement and secure with galvanized or non corrodible chairs,
spacers, or metal hangers. For supporting reinforcement on the ground, use
concrete or other non corrodible material, having a compressive strength
equal to or greater than the concrete being placed.
[ASTM A 934/A 934M.][ASTM A 775/A 775M.] [Epoxy-coated reinforcing bars
supported from formwork shall rest on coated wire bar supports, or on bar
supports made of dielectric material or other acceptable material. Wire
bar supports shall be coated with dielectric material, compatible with
concrete, for a minimum distance of 50 mm (2 inches) 2 inches from the
point of contact with the epoxy-coated reinforcing bars. Reinforcing bars
used as support bars shall be epoxy coated. Spreader bars, where used,
shall be epoxy coated. Proprietary combination bar clips and spreaders
used in construction with epoxy-coated reinforcing bars shall be made
corrosion resistant or coated with dielectric material. Epoxy-coated bars
shall be tied with plastic-coated tie wire; or other materials acceptable
to the Contracting Officer.]
[3.4.3
Epoxy Coated Reinforcing
Shall meet the requirements of [ASTM A 934/A 934M including Appendix X2,][
ASTM A 775/A 775M including Appendix X1,] "Guidelines for Job Site
Practices" except as otherwise specified herein.
3.4.3.1
Epoxy Coated Reinforcing Steel Placement and Coating Repair
Carefully handle and install bars to minimize job site patching. Use the
same precautions as described in paragraph for reinforcement delivery,
handling, and storage when placing coated reinforcement. Do not drag bars
over other bars or over abrasive surfaces. Keep bar free of dirt and grit.
When possible, assemble reinforcement as tied cages prior to final
placement into the forms. Support assembled cages on padded supports. It
is not expected that coated bars, when in final position ready for concrete
placement, will be completely free of damaged areas; however, excessive
nicks and scrapes which expose steel will be cause for rejection. Criteria
for defects which require repair and for those that do not require repair
are as indicated. Inspect for defects and provide required repairs prior
to assembly. After assembly, reinspect and provide final repairs.
a.
Immediately prior to application of the patching material, any
rust and debonded coating shall be manually removed from the
reinforcement by suitable techniques employing devices such as
wire brushes and emery paper. Care shall be exercised during this
surface preparation so that the damaged areas are not enlarged
more than necessary to accomplish the repair. Damaged areas shall
be clean of dirt, debris, oil, and similar materials prior to
application of the patching material.
b.
Repair and patching shall be done in accordance with the patching
material manufacturer's recommendations. These recommendations,
including cure times, shall be available at the job site at all
times.
SECTION 03300N
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