4.9 KiB
4.9 KiB
Structural Steel Specifications
General
Fabrication and Erection
- All structural steel shall be fabricated and erected in accordance with the latest edition of AISC 360 – Specification for Structural Steel Buildings.
Protection
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Steel within permanently conditioned, non-corrosive spaces inside the building envelope does not require shop painting unless exposed to the elements for one year or more during construction.
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Steel in unconditioned spaces or outside the building envelope must be either:
- Hot-dip galvanized, or
- Painted with zinc-rich paint.
The contractor shall prepare steel according to the selected protection method.
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Galvanization Requirements:
- Steel members, fabrications, and welded assemblies shall be galvanized after fabrication via hot-dip in accordance with ASTM A123.
- Zinc coating weight shall meet ASTM A123 or ASTM A386 (“Weight of Coating”) requirements.
- Field-welded portions of galvanized assemblies shall be repaired with zinc-rich corrosion-resistant paint.
- Closed shapes (e.g., tubes, pipes) requiring holes for fabrication shall have the hole filled with weld material and repaired after galvanization, or sealed with exterior-grade sealant.
Fireproofing
- Steel members to receive fireproofing shall not be primed or painted.
- Fireproofing thickness shall be increased for members not meeting minimum UL-rated sizes or for unrestrained members, per the UL Fire Resistance Directory – Volume 1.
Camber
- Beams shall be cambered upward where indicated in the contract documents.
- If no camber is shown, any mill camber shall be detailed upward.
Notifications and Penetrations
- Notify the structural engineer of misfabricated steel prior to erection.
- Penetrations shall not be cut unless shown on the drawings or approved by the engineer.
Materials
- All hot-rolled steel plates, shapes, and bars shall be new and conform to ASTM A6 (latest edition).
| Member Type | Specification |
|---|---|
| W-Shapes | A992 |
| Channels, Angles, Plates | A36 |
| Rectangular HSS | A500, Gr. C (Fy = 50 ksi) |
| Round HSS | A500, Gr. B (Fy = 42 ksi) |
Submittals
- Structural steel submittals must be accompanied by the SDS/2 or Tekla model for visual reference to the shop drawings.
- Shop drawings must comply with the AISC Code of Standard Practice.
Connections
Connection Design
- All steel connections not fully detailed in the drawings shall be designed by a contractor-hired connection engineer who is a licensed professional in the project state.
- Connection details shown are conceptual; the final design, including plate/angle thickness and bolt quantity, is the responsibility of the connection engineer.
Structural Bolts
- Conform to ASTM A325 Type 1, unless noted otherwise.
Threaded Rods
- Conform to ASTM F1554 Gr. 55 S1.
Welding
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Electrodes shall conform to:
- SMAW – E70XX
- SAW – F7XX-EXX
- GMAW – ER70S-X
- FCAW – E8XT-X
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Field welds must be performed by certified welders under continuous special inspector supervision.
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Shop welds must be executed in a fabrication shop certified by the AHJ.
Anchor Rods
- Conform to ASTM F1554, typical size 3/4" Ø, embedded min. 1'-0", with heavy hex nut unless noted otherwise.
- Grade 55 S1 unless otherwise specified.
Grout
- Use non-metallic, non-shrink grout with minimum compressive strength 6,000 psi when bearing on ≤3,000 psi concrete.
Splicing
- Steel splicing not shown on drawings is prohibited without EOR approval.
Headed Concrete Stud Anchors (HSA)
- Use Nelson or KSM anchors (or approved alternative), per ASTM A108, Grades C-1010 to C-1020.
- Anchors shall be automatically end-welded using suitable shop or field welding equipment.
Deformed Bar Anchors (DBA)
- Use Nelson or KSM anchors (or approved alternative), made from cold-drawn wire per ASTM A496, minimum yield 70 ksi.
- Anchors shall be automatically end-welded per manufacturer recommendations.
Fillet Weld Sizes (Minimum, unless noted)
| Thinner Material Thickness (T) | Fillet Weld Size |
|---|---|
| 3/16" | 3/16" |
| 1/4" | 3/16" |
| 5/16" | 1/4" |
| 3/8" | 5/16" |
| 7/16" | 3/8" |
| 1/2" | 7/16" |
| 3/4" | 1/2" |
| >3/4" | 5/8" |