Structural Steel ME- Building Group

Structural Steel ME- Building Group

Structural Steel ME- Building Group

SECTION 05120 - STRUCTURAL STEEL

PART 1 - GENERAL

1.1SUMMARY

  1. This Section includes structural steel.
  2. Related Sections: The following Sections contain requirements that relate to this Section:
  3. Division1 Section "Quality Control Services" for independent testing agency procedures and administrative requirements.
  4. Division5 Section "Steel Deck" for field installation of shear connectors.
  5. Division 9 Section "Structural Metal Primer/Finish" for shop applied coating system.

1.2PERFORMANCE REQUIREMENTS

  1. Structural Performance: Engineer structural steel connections required by the Contract Documents to be selected or completed by the fabricator to withstand design loadings indicated.
  2. Engineering Responsibility: Engage a fabricator who utilizes a qualified professional engineer to prepare calculations, Shop Drawings, and other structural data for structural steel connections.

1.3SUBMITTALS

  1. Shop Drawings detailing fabrication of structural steel components.
  2. Include details of cuts, connections, splices, camber, holes, and other pertinent data.
  3. Indicate welds by standard AWS symbols, distinguishing between shop and field welds, and show size, length, and type of each weld.
  4. Indicate type, size, and length of bolts, distinguishing between shop and field bolts. Identify high-strength bolted slip-critical, direct-tension, or tensioned shear/bearing connections.
  5. Include calculations for connections signed and sealed by a qualified professional engineer responsible for their preparation.
  6. Shop Drawings signed by checker.
  7. Mill test reports signed by manufacturers certifying that their products, including the following, comply with requirements. Submit for Owner information only, no action required.
  8. Structural steel, including chemical and physical properties.
  9. Direct-tension indicators.

1.4QUALITY ASSURANCE

  1. Installer Qualifications: Engage an experienced Installer who has completed structural steel work similar in material, design, and extent to that indicated for this Project and with a record of successful in-service performance.
  2. Fabricator Qualifications: Engage a firm experienced in fabricating structural steel similar to that indicated for this Project and with a record of successful in-service performance, as well as sufficient production capacity to fabricate structural steel without delaying the Work.
  3. Fabricator must participate in the AISC Quality Certification Program and be designated an AISC-Certified Plant as follows:
  4. Category: CategoryI, conventional steel structures.
  5. Comply with applicable provisions of the following specifications and documents:
  6. AISC "Specification for Structural Steel Buildings--Allowable Stress Design and Plastic Design."
  7. AISC "Specification for Allowable Stress Design of Single-Angle Members."
  8. ASTMA6"Specification for General Requirements for Rolled Steel Plates, Shapes, Sheet Piling, and Bars for Structural Use."
  9. Research Council on Structural Connections (RCSC) "Specification for Structural Joints Using ASTMA325 or A490 Bolts."
  10. Professional Engineer Qualifications: A professional engineer who is legally authorized to practice in the jurisdiction where Project is located and who is experienced in providing engineering services of the kind indicated. Engineering services are defined as those performed for projects with structural steel framing that are similar to that indicated for this Project in material, design, and extent.
  11. Welding Standards: Comply with applicable provisions of AWSD1.1 "Structural Welding Code--Steel."
  12. Present evidence that each welder has satisfactorily passed AWS qualification tests for welding processes involved and, if pertinent, has undergone recertification.
  13. Predetailing Conference: Conduct conference at project site. Prior to predetailing meeting, provide typical connection details including truss end connections to attendees.
  14. Preerection Conference: Conduct conference at Project site.

1.5DELIVERY, STORAGE, AND HANDLING

  1. Deliver coated materials to Project site clean and covered to protect against road splatter, and in quantities timed to ensure continuity of installation.
  2. Ship, unload, and store materials to permit easy access for inspection and identification.
  3. Deliver structural steel to Project site clean and covered to protect against road splatter, and in such quantities and at such times to ensure continuity of installation.
  4. Store materials to permit easy access for inspection and identification. Keep steel members off ground by using pallets, platforms, or other supports. Protect steel members and packaged materials from erosion and deterioration.
  5. Store fasteners in a protected place. Clean and relubricate bolts and nuts that become dry or rusty before use.
  6. Do not store materials on structure in a manner that might cause distortion or damage to members or supporting structures. Repair or replace damaged materials or structures as directed.
  7. Steel that becomes soiled or otherwise defaced, shall be washed clean just before erection.
  8. Handle to not damage shop applied coating.

1.6SEQUENCING

  1. Supply anchorage items to be embedded in or attached to other construction without delaying the Work. Provide setting diagrams, templates, instructions, and directions, as required, for installation.

PART 2 - PRODUCTS

2.1MATERIALS

  1. Structural Steel Shapes, Plates, and Bars: As follows:
  2. Wide Flange Steel: ASTM A992, Grade 50.
  3. Channels, Angles, and Plates: ASTM A36.
  4. Cold-Formed Structural Steel Tubing: ASTMA500, GradeB.
  5. Steel Pipe: ASTMA53, Type E or S, GradeB.
  6. Shear Connectors: ASTMA108, Grade1015 through 1020, headed-stud type, cold-finished carbon steel, AWSD1.1, TypeB.
  7. Anchor Rods, Bolts, Nuts, and Washers: As follows:
  8. Unheaded Rods: ASTM A 307.
  9. Headed and Hooked Rods: ASTM A36.
  10. Washers: ASTMA36.
  11. Nonhigh-Strength Bolts, Nuts, and Washers: ASTMA307, GradeA; carbon steel, hex-head bolts; carbon steel nuts; and flat, unhardened steel washers.
  12. Finish: Plain, uncoated.
  13. High-Strength Bolts, Nuts, and Washers: ASTMA325, Type1, heavy hex steel structural bolts, heavy hex carbon steel nuts, and hardened carbon-steel washers.
  14. Finish: Plain, uncoated.
  15. Tension set bolts for slip critical connections.
  16. Welding Electrodes: Comply with AWS requirements.

2.2FABRICATION

  1. Fabricate and assemble structural steel in shop to greatest extent possible. Fabricate structural steel according to AISC specifications referenced in this Section and in Shop Drawings.
  2. Camber structural steel members where indicated.
  3. Identify high-strength structural steel according to ASTMA6 and maintain markings until steel has been erected.
  4. Mark and match-mark materials for field assembly.
  5. Fabricate for delivery a sequence that will expedite erection and minimize field handling of structural steel.
  6. Complete structural steel assemblies, including welding of units, before starting shop-priming operations.
  7. Comply with fabrication tolerance limits of AISC "Code of Standard Practice for SteelBuildings and Bridges" for structural steel.
  8. Thermal Cutting: Perform thermal cutting by machine to greatest extent possible.
  9. Plane thermally cut edges to be welded.
  10. Field burning of structural steel will not be allowed.
  11. Finishing: Accurately mill ends of columns and other members transmitting loads in bearing.
  12. Shear Connectors: Prepare steel surfaces as recommended by manufacturer of shear connectors. Use automatic end welding of headed-stud shear connectors according to AWSD1.1 and manufacturer's printed instructions.
  13. Holes: Provide holes required for securing other work to structural steel framing and for passage of other work through steel framing members, as shown on Shop Drawings.
  14. Cut, drill, or punch holes perpendicular to metal surfaces. Do not flame-cut holes or enlarge holes by burning. Drill holes in bearing plates.
  15. Weld threaded nuts to framing and other specialty items as indicated to receive other work.

2.3SHOP CONNECTIONS

  1. Shop install high-strength bolts.
  2. Shop install and tighten high-strength bolts according to RCSC "Specification for Structural Joints Using ASTMA325 or A490 Bolts."
  3. Bolts: ASTMA325 high-strength bolts, unless otherwise indicated.
  4. Connection Type: Snug tightened, unless indicated as slip-critical, direct-tension, or tensioned shear/bearing connections.
  5. Weld Connections: Comply with AWSD1.1 for procedures, appearance and quality of welds, and methods used in correcting welding work.
  6. Assemble and weld built-up sections by methods that will maintain true alignment of axes without warp.

2.4SHOP COATING

  1. Refer to Division 9 Section "Structural Metal Primer/Finish"
  2. Hot-Dip Galvanized Finish: Apply zinc coating by the hot-dip process to structural steel according to ASTMA123/A123M.
  3. Galvanize CoolingTower grillage steel components.

2.5SOURCE QUALITY CONTROL

  1. Engage an independent testing and inspecting agency to perform shop inspections and tests and to prepare test reports.
  2. Testing agency will conduct and interpret tests and state in each report whether test specimens comply with or deviate from requirements.
  3. Provide testing agency with access to places where structural steel Work is being fabricated or produced so required inspection and testing can be accomplished.
  4. Testing agency shall inspect each fabrication shop a minimum of once to observe and verify the shop’s quality control program.
  5. Correct deficiencies in or remove and replace structural steel that inspections and test reports indicate do not comply with specified requirements.
  6. Additional testing, at Contractor's expense, will be performed to determine compliance of corrected Work with specified requirements.
  7. Shop-bolted connections will be tested and inspected according to RCSC "Specification for Structural Joints Using ASTMA325 or A490 Bolts."
  8. Direct-tension indicator gaps will be verified to comply with ASTM F 959, Table2.
  9. Shop-welded connections will be inspected and tested according to AWSD1.1 and the inspection procedures listed below:
  10. Inspections: Visually inspect 100 percent of welds.
  11. Tests: Test minimum of 25 percent of all full penetration welds with one of the following procedures:
  12. Liquid Penetrant Inspection: ASTME 165.
  13. Magnetic Particle Inspection: ASTME709; performed on root pass and on finished weld. Cracks or zones of incomplete fusion or penetration will not be accepted.
  14. Radiographic Inspection: ASTME94 and ASTME142; minimum quality level "2-2T."
  15. Ultrasonic Inspection: ASTME164.

PART 3 - EXECUTION

3.1EXAMINATION

  1. Before erection proceeds, and with the steel erector present, verify elevations of concrete bearing surfaces and locations of anchorages for compliance with requirements.
  2. Do not proceed with erection until unsatisfactory conditions have been corrected.

3.2PREPARATION

  1. Provide temporary shores, guys, braces, and other supports during erection to keep structural steel secure, plumb, and in alignment against temporary construction loads and loads equal in intensity to design loads. Remove temporary supports when permanent structural steel, connections, and bracing are in place, unless otherwise indicated.
  2. Surfaces to be high-strength bolted with slip-critical connections shall be coated with the certified coating specified.
  1. Remove tape or film applied in the shop for protection just before erection.

3.3ERECTION

  1. Set structural steel accurately in locations and to elevations indicated and according to AISC specifications referenced in this Section.
  2. Base and Bearing Plates: Clean concrete bearing surfaces of bond-reducing materials and roughen surfaces prior to setting base and bearing plates. Clean bottom surface of base and bearing plates.
  3. Set base and bearing plates for structural members on wedges, shims, or setting nuts as required.
  4. Tighten anchor bolts after supported members have been positioned and plumbed. Do not remove wedges or shims but, if protruding, cut off flush with edge of base or bearing plate prior to packing with grout.
  5. Pack grout solidly between bearing surfaces and plates so no voids remain. Finish exposed surfaces, protect installed materials, and allow to cure.
  6. Comply with manufacturer's instructions for proprietary grout materials.
  7. Maintain erection tolerances of structural steel within AISC "Code of Standard Practice for SteelBuildings and Bridges."
  8. Align and adjust various members forming part of complete frame or structure before permanently fastening. Before assembly, clean bearing surfaces and other surfaces that will be in permanent contact. Perform necessary adjustments to compensate for discrepancies in elevations and alignment.
  9. Level and plumb individual members of structure.
  10. Establish required leveling and plumbing measurements on mean operating temperature of structure. Make allowances for difference between temperature at time of erection and mean temperature at which structure will be when completed and in service.
  11. Splice members only where indicated.
  12. Do not enlarge unfair holes in members by burning or by using drift pins. Ream holes that must be enlarged to admit bolts.

3.4FIELD CONNECTIONS

  1. Install and tighten high-strength bolts according to RCSC "Specification for Structural Joints Using ASTMA325 or A490 Bolts."
  2. Bolts: ASTMA325 high-strength bolts, unless otherwise indicated.
  3. Connection Type: Snug tightened, unless indicated as slip-critical, direct-tension, or tensioned shear/bearing connections.
  4. Weld Connections: Comply with AWSD1.1 for procedures, appearance and quality of welds, and methods used in correcting welding work.
  5. Comply with AISC specifications referenced in this Section for bearing, adequacy of temporary connections, alignment, and removal of paint on surfaces adjacent to field welds.
  6. Assemble and weld built-up sections by methods that will maintain true alignment of axes without warp.

3.5FIELD QUALITY CONTROL

  1. Engage an independent testing and inspecting agency to perform field inspections and tests and to prepare test reports. Contractor to indicate testing agency they will be using with bid submittal.
  2. Testing agency will conduct and interpret tests and state in each report whether tested Work complies with or deviates from requirements.
  3. Correct deficiencies in or remove and replace structural steel that inspections and test reports indicate do not comply with specified requirements.
  4. Additional testing, at Contractor's expense, will be performed to determine compliance of corrected Work with specified requirements.
  5. Field-bolted connections will be tested and inspected according to RCSC "Specification for Structural Joints Using ASTMA325 or A490 Bolts."
  6. Direct-tension indicator gaps will be verified to comply with ASTMF959, Table2.
  7. Inspect 10 percent of high strength bolted connection, and not less than two bolts per connection, in accordance with Section 6 of AISC “Specification for Structural Joints, using ASTM A325 or A490 Bolts”.
  8. Inspect 100 percent of the slip critical connections.
  1. Field-welded connections will be inspected and tested according to AWSD1.1 and the inspection procedures listed below:
  2. Inspections: Visually inspect 100 percent of field welds.
  3. Tests: Test minimum of 25 percent of all full penetration welds with one of the following procedures:
  4. Liquid Penetrant Inspection: ASTME165.
  5. Magnetic Particle Inspection: ASTME709; performed on root pass and on finished weld. Cracks or zones of incomplete fusion or penetration will not be accepted.
  6. Radiographic Inspection: ASTME94 and ASTME142; minimum quality level "2-2T."
  7. Ultrasonic Inspection: ASTME164.
  8. Field-welded shear connectors will be inspected and tested according to requirements of AWSD1.1 for stud welding and as follows:
  9. Inspections: Visually inspect 100 percent of shear connectors.
  10. Tests: Perform bend tests when visual inspections reveal either less than a continuous 360-degree flash or welding repairs to any shear connector.
  11. Weld Fracture: Conduct additional tests, according to AWS D1.1, when weld fracture is observed before, during, or after testing.

3.6CLEANING/TOUCH-UP COATING

  1. Wash and clean steel prior to erection and/or after erection to Owner’s satisfaction.
  2. Immediately after erection, clean field welds, bolted connections, exposed slip-critical connection coating, and abraded areas of shop coat, for touch-up, using the same material and color as applied as the shop coating.
  3. Perform touch-up when ambient temperature is 32 degF and rising, unless otherwise allowed by the coating manufacturer.
  4. Prepare surfaces per coating manufacturer's recommendations, or as a minimum, per SSPC SP-2 Specification (Hand Tool Cleaning).
  5. Apply coating by brush to provide a minimum dry film thickness of 3 mils.
  6. Repair damaged galvanized coatings on galvanized items with galvanized repair paint according to ASTMA780 and manufacturer's written instructions.

END OF SECTION

Page 1 of 8

Revision Date: 12/17/04 Project & Bid Package

File name:05120StructuralSteel.doc

Top View