 |
|
Construction Specification
81. METAL FABRICATION AND INSTALLATION
1. SCOPE
The work shall consist of furnishing, fabricating and erecting metalwork, including the metal parts and fasteners of the composite structures.
2. MATERIALS
Unless otherwise specified, materials shall conform to the requirements of Material Specification 581, Metal. Steel shall be structural quality unless otherwise specified. Castings shall be thoroughly cleaned and subjected to careful inspection before installation. Finished surfaces shall be smooth and true to assure proper fit. Galvanizing shall conform to the requirements of Material Specification 582, Galvanizing.
3. FABRICATION
Fabrication of structural steel shall conform to the requirements of "Specification for the Design, Fabrication and Erection of Structural Steel for Buildings (Riveted, Bolted and Arc-Welded Construction)," American Institute of Steel Construction.
Fabrication of structural aluminum shall conform to the requirements in the ‘Aluminum Design Manual’, available from The Aluminum Association.
4. ERECTION
The frame of metal structures shall be installed true and plumb. Temporary bracing shall be placed wherever necessary to resist all loads to which the structure may be subjected, including those applied by the installation and operation of equipment. Such bracing shall be left in place as long as may be necessary for safety.
As erection progresses the work shall be securely bolted up, or welded, to resist all dead load, wind and erection stresses. The Contractor shall furnish such installation assisting bolts, nuts and washers as may be required.
No riveting or welding shall be performed until the structure is stiffened and properly aligned.
Rivets driven in the field shall be heated and driven with the same care as those driven in the shop.
All field welding shall be performed in conformance to the requirements for shop fabrication, except those that expressly apply to shop conditions only.
5. PROTECTIVE COATINGS
Items specified to be galvanized shall be completely fabricated for field assembly before the application of the zinc coatings. Galvanized items shall not be cut, welded or drilled after the zinc coating is applied.
Items specified to be painted shall be painted in conformance to the requirements of Construction Specification 82 for the specified paint systems.
6. MEASUREMENT AND PAYMENT
Method 1 The work will not be measured. Payment for metal fabrication and installation will be made at the contract lump sum price in the contract. Such payment will constitute full compensation for all labor, equipment, materials and all other items necessary and incidental to the completion of the work, including connectors and appurtenances such as rivets, bolts, nuts, pins, studs, washers, hangers and weld metal.
Method 2 The weight of metal installed complete in place shall be determined to the nearest pound. Unless otherwise specified, the weight of metal shall be computed by the method specified in Section 3 of the "Code of Standard Practice for Steel Buildings and Bridges," American Institute of Steel Construction, except that the following unit weights shall also be used, as appropriate, as the basis of computation:
Material Unit Weight (lbs./ft3) Aluminum alloy 173.0 Bronze or copper alloy 536.0 Iron, malleable 470.0 Iron, wrought 487.0
Payment for furnishing, fabricating and installing metalwork will be made at the contract unit price for the specified types of labor, materials, equipment and all other items necessary and incidental to the completion of the work.
Method 3 The work will not be measured. Payment for furnishing, fabricating and installing each item of metalwork will be made at the contract price for that item. Such payment will constitute full compensation for all labor, equipment, materials and all other items necessary and incidental to the completion of the work, including connectors and appurtenances such as rivets, bolts, nuts, pins, studs, washers, hangers and weld metal.
All Methods The following provisions apply to all methods of measurement and payment. Compensation for any item of work described in the contract but not listed in the bid schedule will be included in the payment for the item of work to which it is made subsidiary. Such items and the items to which they are made subsidiary are identified in Section 7 of this specification.