05121 Structural Steel Erection.pdf

Standard Drawings for Doppler (VHF)

Omni Directional Range (DVOR) Counterpoise June 2020

STRUCTURAL STEEL ERECTION 05121-1

SECTION 05121

STRUCTURAL STEEL ERECTION

PART 1 - GENERAL

1.1 Work Included: Furnish all labor and materials, equipment and incidentals necessary to erect structural steel and miscellaneous metals.

1.2 Related Work Covered Elsewhere:

Cast-in-Place Concrete Section 03301

Structural Steel Section 05120

Miscellaneous Metals Section 05500

1.3 QUALITY ASSURANCE:

A. Testing:

1. All shop welds shall be visually inspected and physically tested. Full penetration shop and field welds shall be non-destructive tested by radiographic, ultrasonic, magnetic particle or dye penetrant methods in accordance with AWS B1.10 as approved by the Subcontract Administrator.

Tubular constructions shall be inspected by ultrasonic methods, Class R. All test methods and procedures used shall be determined by the WRPE Designee in advance of welding.

2. Welding shall be inspected by an independent testing agency selected by the Subcontract

Administrator and whose services shall be paid by the Government. The testing agency is the representative of the Government and the Subcontractor shall make all facilities available for inspection at all times, including Shop Fabrication. Inspection of welding shall be in conformance with AWS D1.1 "Structural Welding Code Steel".

3. High Strength Bolts in connections shall be inspected by Governments testing agency in accordance with AISC "Specification for Structural Joints using ASTM A-325 or A-490 Bolts".

Records shall be kept for all testing and shall show date of inspection, location and type of weld, defects encountered and date of repairs.

B. Re-inspection: Subcontractor shall bear costs of re-inspection due to specification non-conformance discovered during tests.

C. Welder’s Qualification:

1. Welds shall be made only by operators who have previously qualified by tests, as prescribed by the "Standard Qualification Procedure" in the "Structural Welding

Code - Steel" by the American Welding Society to perform the type of work required. The

Subcontractor shall provide certification that welders have passed qualification test within six months just prior to performance of work.

2. The techniques of welding employed, the appearance and quality of welds made, and methods used in correcting defective work shall conform to Section 4, "Technique" of the Current Edition of the "Structural Welding Code - Steel" by the American Welding Society.

1.4 Submittals:

Submittals shall be in accordance with general requirements and shall include the following:

A. Certificate of Welder's qualification

B. Schedule of Time Schedule for Shop fabrication

C. Erection Schedule and Description of Erection Procedures

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D. Setting Bolt and Anchor Plate Templates.

1.5 References and Standards:

The applicable provisions of the following references and standards are hereby made a part of this Section as if written herein in their entirety:

A. American Institute of Steel Construction (AISC) Publications: "Specifications for Structural Steel

Buildings"

B. Steel Joist Institute (SJI): "Standard Specifications", Sections 5 and 6.

C. American Welding Society (AWS) Publication: "Code for Arc and Gas Welding in Building

Construction"

AWS D1.1 Structural Welding Code - Steel

AWS B1.10 Guide for Non-Destructive Inspection of Welds

AWS A5.1 Specification for Covered Carbon Steel Arc Welding Electrodes

AWS A5.5 Specification for Low Alloy Steel Covered Arc Welding Electrodes

D. Military Specification: MIL-P-21035, High Zinc Dust Content, Galvanizing Repair.

1.6 Delivery, Handling, and Storage: Deliver steel members and fabricated components to site and store on wood runners or platform raised above grade level. Steel shall not come into contact with groundwater.

1.7 Job Conditions:

A. Erection of steel shall be in proper sequence with the work of other trades. Steel shall be erected in a reasonable sequence and shall be guyed and braced as erected.

B. Obtain complete field dimension prior to fabrication of steel. Re-check dimensions as steel is erected.

Report deficiencies or errors to the Subcontract Administrator in writing in sufficient time to allow for corrections to be made prior to continuing work.

C. Obtain setting bolt templates and setting drawings and install bolts at exact location in the structure.

D. Subcontractor is responsible for maintaining surveying instrument and developing a procedure that permits complete quality control of steel erection. Columns shall be plum and horizontal members shall be level.

PART 2 - PRODUCTS

2.1 Materials:

A. Unfinished Bolts and Nuts: Unfinished bolts and nuts shall conform to ASTM Standard A-307 and shall be the regular hexagon-bolt type.

B. Turned Bolts and Nuts: Bolts and nuts shall conform to ASTM A - 307.

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C. High Strength Bolts and Nuts: Bolt and nuts shall conform to ASTM Specification A-325. Bolt and nut dimensions and threads shall be in accordance with American Standard B 18.22 for regular semi-finished hexagon bolts and heavy semi-finished hexagon nuts.

D. Washers: Round washers shall conform to American Standard B27.2 Type B. Washers in contact with high-strength bolt heads and nuts shall be hardened in accordance with ASTM Standard A-325.

Beveled washers shall be square, smooth, and sloped so that contact surfaces of bolt head and nut are parallel. The diameter of the hole of square-beveled washers shall be 1/16" greater than the bolt size for bolts not larger than 1", and 1/8" greater than the bolt size for bolts larger than 1".

E. Filler Metal for welding: Welding electrode for manual schedules metal arc-welding shall conform to AWS Specifications. Bare electrodes and granular flux used in submerged-arc process shall conform to Section A.3.6 of AISC "Specifications for Structural Steel Buildings". Only E70 Series electrodes for manual arc welding and electrodes conforming to AWS A5.17-80 for submerged arc process shall be used for welding A-36 steel.

F. Shop Paint: Rust inhibitive primer; TNEMEC 99 Series, or equal conforming to top coat as specified in Section 09900 PAINTING.

G. Cold Galvanized Compound: High zinc content compound conforming to Military Specifications

MIL-P-21035.

PART 3 EXECUTION

3.1 Erection:

A. The framing shall be carried up true and plumb and temporary bracing shall be introduced wherever necessary to take care of the loads to which the structure may be subjected, including erection equipment and its operation. Such bracing shall be left in place as long as may be required for safety.

It shall finally be removed by the Subcontractor as part of his equipment. As erection progresses, the work shall be securely connected to take care of all dead load, wind, and erection stresses.

B. Set columns in exact position, in alignment, plumb and at proper elevations. Center of base plate shall be within 1/16 inch of true center line. Height shall be shimmed and grouted to 1/32 inch true height.

Support base plate on leveling nuts until grouted and set.

C. Erection bolts used as temporary anchorage for fully welded joints shall be removed after welds are complete and approved. In visible locations holes shall be plug welded solid. Bolted connections using machine bolts shall be peened to deface threads after bolts have been tightened.

D. Furnish templates for setting anchor bolts or anchor plates that are to be cast into concrete. Furnish instructions for setting of anchors, connection details, length of exposed bolts, and other information necessary for the proper setting of embedded components.

3.2 Bolted Field Connections:

A. Correction of mis-aligned holes at connections and base plates must be by methods approved by the

Subcontract Administrator. Enlarged holes, when permitted, must be reamed to larger size. Do not burn holes to larger diameter. Mis-matched holes in any number makes the complete member subject to rejection without further comment.

B. ASTM A-325 high strength bolts shall have suitable identification mark on heads. Tightening of nuts shall be in accordance with AISC "Structural Joints using ASTM A-325 or A-490 Bolts". Minimum

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bolt tension for the size of bolt uses shall be in accordance with tables listed in referenced standards.

Tightening shall be accomplished using "calibrated wrench" method.

C. When assembled, joint surfaces, including those adjacent to the washers, shall be free of scale except tight mill scale. They shall be free of dirt, loose scale, burrs, and other defects that would prevent solid seating of the parts. Contact surfaces with friction-type joints shall be free of oil, paint, lacquer or galvanizing.

3.3 Welded Field Connections:

A. Each welder shall place his identification mark with paint (or stamp) near the welds he constructed, so that all weldments can be properly identified and associated with the correct welder.

B. Surfaces to be welded shall be free from loose scale, slag, rust, grease, paint, and any other foreign material except that mill scale withstanding vigorous wire brushing may remain. Joint surfaces shall be free from fins and tears. Preparation of edges by gas cutting shall, wherever practicable, be done by mechanically guided torch.

C. Clean tack welds and thoroughly fuse with final weld. Remove defective, cracked, or broken tack welds before final welding. Tack welds must be removed from joints where stress is primary, if welding is to be manual.

D. Weld metal shall be completely sound and free of cracks in any weld or weld pass. Fill all craters to the full cross-section of the weld. Remove weld scale or slag, spatter, burrs, and other sharp or rough projections to leave the surface suitable for non-destructive testing, cleaning, and painting.

E. Cut apart and reweld improperly fitted and misaligned parts. Remove cracked welds throughout their length.

F. Straighten members distorted by heat of welding using mechanical means or by carefully supervised application of a limited amount of localized heat. Heated areas shall not exceed 1,200 degrees

Fahrenheit as measured by Tempilsticks. Parts to be heated for straightening shall be free from external stress forces, except when mechanical means are used in conjunction with heat application.

G. If faulty welding or its removal for rewelding damages the base metal so that, in the WRPE Designee's judgement, it is not in accordance with the intent of the drawings and specifications, remove and replace the damaged material and compensate for the deficiency in a manner acceptable to the WRPE

Designee.

H. Where work performed subsequently to the making of the deficient weld has rendered the weld inaccessible, or has caused new conditions which make connection of the deficiency dangerous or ineffectual, restore the original conditions by removing welds or members, or both before making the necessary corrections. Another option is to compensate for the deficiency with additional work according to the revised design, approved by the WRPE Designee.

I. Beam flanges employing full penetration welds shall have 1-1/4" x 3/16" backup plate. Back gouge root pass and weld flush on backside of beam webs where full penetration is specified.

J. Protect finish material from damage. Shield operations from wind currents. Do not perform welding operation during rainy weather or when temperature is below 40o degree F.

K. Field weld joints which are to remain exposed shall be welded continuously regardless of strength requirements. Other joints may be skip welded as necessary to develop strength requirements. In all cases, connection shall be adequate to develop the full strength of largest member connected, regardless of actual requirements.

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3.5 Steel Joist: Steel Joists shall be erected in accordance with Section 05210.

3.6 Field Quality Control:

A. Corrective measures shall be taken when welding is unsatisfactory or indicates inferior workmanship.

Chip and grind if the removal of part of the weld or a portion of the base metal is required. Where deposition of additional weld material is necessary, the sides of the area to be welded shall have no less than one to one slope to allow room for depositing new material. Correct defective or unsound welds by the removal and replacement of the entire weld using the following procedures:

1. Excessive Convexity: Remove excess weld metal by grinding.

2. Shrinkage Cracks, Cracks in Base Metal, Craters and Excessive Porosity: Remove defective portions of base and weld material down to sound metal, and deposit additional sound material.

3. Undercutting, Undersize, and Excessive Concavity: Clean and deposit additional weld metal.

4. Overlapping and Incomplete Fusion: Remove and replace the defective portion of the weld.

5. Slag Inclusion: Remove those parts of the welds containing slag. Fill with sound weld metal.

6. Removal of Adjacent Base Metal during Welding: Clean and form full size by depositing weld material.

B. Field connections shall be visually inspected and physically tested as described above. Every connection must be identified by number and shall be approved by the WRPE Designee or

Government's testing agency. Procedure for identifying faulty connections shall be determined by the

WRPE Designee.

3.7 Field Painting:

A. Shop painting shall be in accordance with the individual section of the specification. Finished painting shall be as specified in Section 09900 PAINTING. Apply one coat of paint to field welds, and bolts and as necessary to touch up damaged primer. Remove rust and apply same primer as specified.

B. Galvanized metals shall be repaired with a cold applied zinc-rich paint. Coat welds, bolts damage to galvanized surfaces, and surface cuts made in the field.

3.8 Clean and Adjust:

After inspection and approval, the steel work shall be thoroughly cleaned of loose scale, rust, splatter, slag, flux, deposit, oil, dirt, and other foreign matter. Exposed steel shall be painted as specified in Section 09900

PAINTING.

END OF SECTION