SECTION 05 12 00 — STRUCTURAL STEEL FRAMING

PART 1 — GENERAL

1.1 SUMMARY

A. Section includes structural steel framing members including:
   1. Steel columns, beams, and girders
   2. Steel trusses and bracing
   3. Connection hardware and anchor bolts

1.2 REFERENCES

A. AISC 360-22 — Specification for Structural Steel Buildings
B. AISC 341-22 — Seismic Provisions for Structural Steel Buildings
C. ASTM A992/A992M — Standard Specification for Structural Steel Shapes
D. ASTM A325 — Standard Specification for Structural Bolts
E. ASTM A572/A572M — Standard Specification for High-Strength Low-Alloy Steel
F. AWS D1.1/D1.1M — Structural Welding Code — Steel
G. IBC 2021, Chapter 22 — Steel
H. ASCE 7-22 — Minimum Design Loads and Associated Criteria

1.3 SUBMITTALS

A. The contractor shall submit shop drawings for all structural steel members within 30 calendar days of Notice to Proceed.
B. Shop drawings shall include member sizes, connection details, bolt patterns, and weld symbols per AWS D1.1.
C. Calculations shall be stamped by a Professional Engineer licensed in the State of Colorado.

1.4 QUALITY ASSURANCE

A. Fabricator shall be AISC-certified in the appropriate category.
B. All welding shall be performed by AWS-certified welders.
C. Independent inspection required per IBC 2021 Section 1705.

PART 2 — PRODUCTS

2.1 STRUCTURAL STEEL

A. Wide-flange shapes: ASTM A992, Fy = 50 ksi minimum.
B. HSS sections: ASTM A500 Grade C, Fy = 50 ksi.
C. Plates and bars: ASTM A572 Grade 50.

2.2 BOLTS AND CONNECTORS

A. High-strength bolts: ASTM A325, Type 1.
B. Anchor rods: ASTM F1554, Grade 55.
C. Minimum bolt diameter shall not be less than 3/4 inch.

2.3 WELDING MATERIALS

A. Electrodes: AWS A5.1, E70XX series.
B. All filler metals shall match or exceed base metal strength.

PART 3 — EXECUTION

3.1 ERECTION

A. The contractor shall erect structural steel in accordance with AISC 303 Code of Standard Practice.
B. Maximum erection tolerance: 1/4 inch per story height, not to exceed 1 inch total.
C. Temporary bracing shall be maintained until permanent connections are complete.

3.2 FIELD WELDING

A. All field welding shall comply with AWS D1.1.
B. Preheat requirements per AWS D1.1 Table 3.3 shall be strictly followed.
C. Visual inspection required for all welds. Ultrasonic testing required for complete joint penetration welds.

3.3 BOLTED CONNECTIONS

A. Snug-tight condition required for all bearing-type connections.
B. Slip-critical connections shall be pretensioned per AISC Specification Table J3.1.
C. Direct tension indicators per ASTM F959 may be used as an alternative tensioning method.

3.4 FIRE PROTECTION

A. Structural steel shall achieve minimum fire resistance ratings per IBC 2021 Table 601.
B. Type I-A construction: 3-hour rating for structural frame.
C. Type II-B construction: 0-hour rating (unprotected).
D. Spray-applied fire-resistive material shall comply with ASTM E119.

3.5 SAFETY

A. Life safety systems shall not be compromised during erection.
B. Seismic design categories D, E, and F require special moment frame connections per AISC 341-22.
C. All connections in the seismic force-resisting system shall be prequalified per AISC 358.
D. Collapse prevention shall be verified for the Maximum Considered Earthquake (MCE).

3.6 CONTRACT REQUIREMENTS

A. Contract value: $2,450,000.00 for structural steel package.
B. Retainage: 10% until substantial completion.
C. Liquidated damages: $1,500 per calendar day for delays beyond the scheduled completion date of 06/15/2026.
D. Warranty period: 2 years from date of substantial completion.
E. The contractor shall indemnify the Owner against claims arising from the contractor's negligence.
F. Force majeure provisions per Article 8.3 of the General Conditions shall apply.

END OF SECTION 05 12 00
