Section 2404. Reinforcement
2404.01 DESCRIPTION.
This work shall consist of furnishing and placing all reinforcing bars and fabrics used
in concrete in accordance with the contract documents.
2404.02 MATERIALS.
Reinforcement shall meet requirements of Section 4151.
2404.03 CLEANING.
At the time reinforcement comes into contact with concrete, it shall be free
from dirt, detrimental scale, rust, paint, oil, or other foreign substances.
For uncoated bars, thin powdery rust and tight rust is not considered detrimental
and need not be removed. Any appreciable reduction in section caused by corrosion
will be sufficient cause for rejection of reinforcement.
2404.04 FABRICATION.
Care shall be exercised so that reinforcement is not damaged during bending, and only
proper appliances and competent workers shall be employed on the work. Except in shops
where accurate control of temperature is provided, reinforcement shall be bent cold.
Deformed bars of Grade 60 (Grade 400) or higher and all bars of No. 8 (No. 25) size and
larger shall be bent in the shop. Reinforcement shall be bent accurately to the dimensions
and shapes shown in the contract documents. Bars partially embedded in concrete shall not
be field bent except as shown in the contract documents.
When galvanized reinforcement is required, all cutting and bending shall be done before galvanizing.
When epoxy coated reinforcement is required, the fabrication shall be in accordance with Article 4151.03, B.
Fabrication of reinforcement, including bending details, shall be in accordance with ACI Code 318.
Bar reinforcement shall be shipped in standard bundles, tagged and marked in accordance with the Code of Standard Practice of the CRSI.
2404.05 STRAIGHTENING.
Reinforcement that may have become bent during shipment or handling shall be
straightened before being placed in the work. Straightening shall be done
without heating and in a manner that will minimize damage to any coating.
2404.06 PLACING AND FASTENING.
Reinforcement shall be placed in the position indicated in the contract
documents and shall be held securely in place during placing and hardening
of the concrete. Bars shall be tied at all intersections except where spacing
is less than 1 foot (300 mm) in each direction, in which case alternate
intersections shall be tied. The locations, fastening, and condition of
reinforcement shall be inspected and approved by the Engineer before concrete
is placed around it. Welding of reinforcing steel will not be permitted unless
specified in the contract documents or approved by the Engineer.
In the floors of culverts and in other footings without piling, reinforcement shall be suspended from cross wales above the tops of the forms or shall be supported on steel stakes driven into the subgrade or on chairs.
Installation of dowels, deformed bars, inserts, or other articles into existing pavements and structures shall be as shown in the contract documents. When installed with epoxy material, the procedure shall be in accordance with Article 2301.12. Cutting of reinforcing steel in the field shall be by mechanical methods and not by flame cutting.
2404.07 REINFORCING SUPPORTS AND SPACERS.
All horizontal reinforcement shall be supported using support devices or tied
to vertical reinforcing steel. All vertical reinforcement shall be positioned
using side-form spacers. Support devices and side-form spacers, either plastic
or steel, shall meet the requirements of
Materials I.M. 451.01. Epoxy coated reinforcing steel shall be held in place
with epoxy or plastic coated bar supports, and epoxy or plastic coated tie wires.
Concrete block inserts, bricks, stones, wood blocks, wood stakes, and similar
materials shall not be used for supporting reinforcement if the manner of their
use is such that these materials are likely to become embedded in the concrete.
Support devices shall be spaced in accordance with the manufacturer's recommendations or as recommended by the current Concrete Reinforcing Steel Institute's Manual of Standard Practice. The support system spacing shall not exceed 4 feet (1.2 m) in each direction for bolsters or continuous high chairs and 3 feet (0.9 m) in each direction for individual bar chairs. The base of all chairs and support bolsters shall rest on the supporting false work. Supporting chairs shall have either upturned legs or a horizontal bar spot welded at the base of the leg. If necessary to prevent spreading of upturned legs, the legs shall be cross-tied at their bases or nailed to the forms. For situations where two or more separate mats of reinforcing steel are required, each mat shall be independently supported by an approved support system.
Side-form spacers shall be placed at intervals sufficient to ensure that all reinforcing is at the required clearance.
2404.08 SPLICING.
Reinforcement shall be spliced only at points shown in the contract documents or
approved by the Engineer. When lapped splices are used in reinforcement in which
the critical design stress is tensile, splices shall not be used at points of
maximum stress. Bars shall be placed in close contact and wired tightly in a
manner that the specified clear distance to the surface of the concrete is
maintained.
The minimum length of lap for reinforcing steel shall be in accordance with that specified in AASHTO Standard Specifications for Highway Bridges.
2404.09 METHOD OF MEASUREMENT.
The Engineer will compute the weight (mass) in pounds (kilograms) of reinforcement
from the theoretical weight (mass) of the nominal sizes and actual lengths of the
various sizes of reinforcement shown in the contract documents. No adjustment will
be made for galvanizing or epoxy coating. If a greater or lesser quantity of
reinforcement than that shown in the contract documents is ordered by the Engineer,
the quantity will be recomputed from the theoretical weight (mass) of the reinforcement
actually used.
The weight (mass) of reinforcement, shown in the contract documents, shall be presumed to be correct and will provide the quantity used as the basis of payment; however, if the Contractor presents evidence that the weight (mass) computed is in error by more than 1.0%, the weights (mass) will be recomputed by the Engineer.
2404.10 BASIS OF PAYMENT.
The weight (mass) of steel reinforcing, galvanized steel reinforcing, and epoxy
coated steel reinforcing, computed as specified above, will be paid for at the
contract unit price per pound (kilogram). This payment shall be full compensation
for furnishing and placing the reinforcement, ties, and supports as may be required
to hold the reinforcement in proper position.