501Structural Steel

Structural Steel

501.1DESCRIPTION

1 This section describes the requirements for structural steel.

501.2MATERIALS

1 Provide and use materials in accordance with the following:

Material Subsection Automatically-End-Welded Studs 815.4 Bolts and Fasteners (other than high-strength) 815.6 Bronze Bearing Plates 815.10 Elastomeric Bearing Pads 815.16 Epoxy Resin Grout 819.2 Galvanized Coating 815.14 High-Strength Anchor Bolts 815.18 High-Strength Bolts, and 815.2 Fasteners Grout 819.1 Paint 809 Preformed Fabric Pads 815.15 Sheet Metal 815.3 Steel Castings 815.12 Steel Pins and Rollers 815.11 Steel Pipe 815.5 Structural Steel 815.1 Welding Materials 815.17

2 Use structural carbon steel.

3 Provide a feeler gauge with each lot of direct tension indicating washers.

501.3EQUIPMENT—V acant

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501.4CONSTRUCTION

501.4.1 Fabrication

501.4.1.1 General

1 Use temperature indicating crayons or infrared devices to determine temperatures of materials.

501.4.1.2 Fabricator Certification

1 Ensure that steel fabricators supplying structural steel components are certified under the American Institute of Steel Construction Quality Certification Program at the time of contract letting and that the certification remains in effect through fabrication. Fabrication includes, but is not limited to, stripping of steel plate, drilling, cutting, and welding.

2 Prior to the start of fabrication submit the certifications for the fabricator to the State Bridge Engineer.

501.4.1.3 Shop Drawings

1 Do not fabricate steel before the State Bridge Engineer approves shop drawings. Ensure that the fabricator gives shop drawings to the State Bridge Engineer in accordance with Subsection 105.2, Working Drawings.

2 With the advance shop drawings, submit, for approval, two copies of the Welding Electrode Certification Conformance, Procedure Qlalification Record, and W elding Procedure Specification in accordance with the current AASHTO/AWS D1.5, Bridge Welding Code. On the drawings, reference weld symbols to “Welding Procedure Specifications.” Identify each piece by AASHTO or ASTM specification; give different assembly and erection marks to pieces of different grades of steel. Give differing piece marks to individual girders and other main members. Show details of proper washer installation on shop drawings.

501.4.1.4 Shop Inspection

1 The fabricator is responsible for quality control; ensure that the fabricator’s inspector is an AWS certified welding inspector, in accordance with AWS QC1, Standard for AWS Certification of Welding Inspectors . Ensure that the primary job of the fabricator’s inspector is quality control, independent of production. Ensure that the fabricator’s inspector reports directly to the fabricator’s top management or chief engineer and works separately from the production unit, performing no production or supervisory work for the project.

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2 Before fabrication, ensure that the fabricator submits to the State Bridge Engineer a written quality control plan outlining quality control tasks the fabricator will follow to ensure that work meets specifications. Include a list of inspection and nondestructive testing personnel and their respective certifications.

3 The department’s inspector will act independently of the fabricator. Review by the department’s inspector does not relieve the fabricator of responsibility for providing materials and finished members as specified. The department may reject deficient or defective materials or members at any time. Replace rejected items promptly at no additional cost to the department.

4 Notify the department’s inspector in writing at least 14 calendar days before starting structural steel fabrication. Before fabrication, give the department ’s inspector one complete copy of the mill test reports, showing chemical and physical properties of the steel. Ensure that the reports indicate, by piece marks, the individual items fabricated for the project. Remove references to unrelated material.

5 Ensure that the fabricator helps in testing and inspection and gives the department ’s inspector access to fabrication and storage areas.

6 E nsure that the fabricator’s inspector verifies that high-strength fasteners and elastomeric bearing pads meet contract requirements by reviewing certifications and performing visual inspection.

7 Submit one copy of the project’s quality control documentation to the State Bridge Engineer after fabrication is complete. Include the measured deviation of the girder camber and blocking ordinates from those specified in the contract.

501.4.1.5 Identification of Steels During Fabrication

1 Properly identify each piece of steel used in fabrication. Use only material identifiable by heat number and mill test report.

2 Stamp flange and web plates in main girders, W- beam girders, and splice plates with the applicable heat numbers at locations visible on the finished structure. Stamp match marks and erection marks showing orientation, direction of members, or both. Use “low-stress” stamps approved by the department’s inspector; apply stamp no closer than 5 ft [1.5 m ] from the ends of girders but not on the edges of plates or flanges. Use a system of assembly marking on individual pieces that maintains the mill test report number. Do not apply marks with paint.

501.4.1.6 Orientation of Plates

1 Cut and fabricate steel plates into structural members so that the primary direction of rolling of the plate parallels the principal stress in the member.

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501.4.1.7 Handling and Storing Materials

1 Place stored material above the ground on platforms, skids, or other supports. Keep material free from dirt, grease and other foreign material, properly drained, and protected from corrosion. Support long members on skids to prevent deflection damage.

2 For shipping and storage, provide softeners for lifting and tie-down chains to prevent damage to corners. When lifting with hooks, ensure sufficient jaw and throat width to prevent damage to flanges or the flange-to-web weld.

501.4.1.8 Straightening and Curving Rolled Beams and Welded Girders

501.4.1.8.1 General

1 The department will reject members made from steel heated higher than 1200 °F [649 °C] or cooled artificially before naturally cooling to 600 °F [320 °C]. Use a cooling method approved by the department’s inspector. For quench and tempered steel, limit application of heat to 1100 °F [590 °C], and perform straightening or curving in accordance with procedures approved by the State Bridge Engineer.

501.4.1.8.2 Straightening Material

1 In the shop, straighten structural steel without damaging the metal and only with the department inspector’s approval. The department will consider kinks and bends that cannot be straightened without damaging the member cause for rejection. Inspect the metal surface for evidence of damage after straightening.

501.4.1.8.3 Curving Rolled Beams and Welded Girders

1 If horizontally curved rolled beams or welded plate girders are specified, curve during fabrication. Fabricate rolled beams as a straight unit; induce required curvature by applying heat to the flange edges on one side. Fabricate welded girders the same way or by thermal-cutting flanges to the required curvature from rectangular plates before fitting and welding to the web. The department will allow cold bending if the proposed methods are approved by the State Bridge Engineer.

2 Perform heat curving of beams or girders in accordance with the following:

stiffeners. Unless provisions are made for girder shrinkage, locate and attach connection plates and bearing stiffeners after curving. If required, curve or thermal- cut longitudinal stiffeners separately and then weld them to the curved girder.

the department’s inspector. Do not mechanically camber rolled beams without the State Bridge Engineer’s approval. For plate girders, cut the web to the prescribed

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camber with suitable allowance for shrinkage. If necessary, correct moderate deviations from specified camber as approved by the department’s inspector.

girder to avoid overturn. When curving with the web in a horizontal position, provide sufficient support to obtain uniform curvature. During heating, place intermediate safety catch blocks at the midlength of the girder within 2 in [50 mm] of the flanges.

edges that will be on the inside of the horizontal curve after cooling. Heat both inside and outside flange surfaces when the flange thickness equals or exceeds 1¼ in [31 mm]; heat both surfaces concurrently.

4.1For the continuous method, heat a strip along the edge of the top and

bottom flange simultaneously; ensure sufficient strip width and temperature to obtain specified curvature.

4.2For V-type heating, heat the top and bottom flanges at approximately the

same rate and in regularly spaced truncated triangular areas having their base along the flange edge. On the inside flange surface, end the apex of the truncated triangular area just before the juncture of the web and flange. When the radius of curvature is 1000 ft [300 m] or more, extend the apex of the truncated triangular heating pattern applied to the outside flange surface to the juncture of the flange and web. When the radius of curvature is less than 1000 ft [300 m], extend the apex of the truncated triangular heating pattern of the outside flange surface past the web for a distance equal to one-eighth of the flange width or 3 in [75 mm], whichever is less. Use a truncated triangular pattern with an included angle of approximately 15 to 30 degrees and a base no greater than 10 in [250 mm]. The department’s inspector may approve varying patterns.

are complete and flanges have cooled to a uniform temperature. Check horizontal curvature with the girder in the vertical position by measuring o ffsets from a stringline or wire attached to both flanges or other method approved by the department’s inspector. Check camber with the girder in the horizontal position.

501.4.1.9 Finish

1 Ensure that shearing, thermal-cutting, and chipping of plates leaves edges smooth and free of discontinuities. Break, flatten, or round by grinding all sheared or thermal cut edges and corners that will be exposed in finished members to be painted.

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501.4.1.10 Holes for Fasteners

1 Drill, subdrill and ream, or subpunch and ream holes for fasteners. Make subpunched and subdrilled holes 3 /16 in [5 mm] smaller than the nominal fastener diameter and finished holes 1/16 in [2 mm] larger than the nominal fastener diameter. For structural steel thicker than ¾ in [19 mm] and high-strength steel thicker than ⅝ in [16 mm], drill holes full size or subdrill and ream full size. Remove burs from inside and around the edges.

2 The department considers acceptable holes up to 1 /32 in [1 mm] larger than specified when using a drill or reamer of nominal diameter and slightly conical holes that naturally result from punching.

3 Do not thermal-cut round holes or correct mispunched or misdrilled holes by welding.

4 Thermal-cut slotted holes (whether combined with drilling or punching) are allowed if their dimensions do not exceed more than 1/32 in [1 mm] from specified. The department allows occasional gouges not more than 1/16 in [2 mm] deep in slotted holes in sole plates. Grind thermal-cut bolt slotted hole surfaces in slip critical connections to an ANSI surface roughness of less than 1000 x 10-6 in [25 µm].

5 For holes in field connections and field splices of main members of trusses, arches, continuous beam spans, bents, plate girders, and rigid frames, subpunch or subdrill then ream during assembly, or drill full size through a steel template during assembly. Obtain approval of the assembly, including camber, alignment accuracy of holes, and milled joints, from the department’s inspector. Holes for cross frames may be drilled full size unassembled using a steel template.

6 Ream after pieces are assembled and firmly bolted together with surfaces in close contact. If necessary, take pieces apart before bolting and remove shavings.

7 When drilling members while assembled, hold the parts securely together while drilling, and drill to finish size or subdrill and ream to finish size while all thicknesses of metal are assembled.

8 Match-mark pieces reamed or drilled together so that they may be reassembled in the same position. Provide a diagram showing match-marks on the shop drawings. Do not interchange parts reamed or drilled together.

9 Fabricate holes for floor beam and stringer field connections in accordance with the latest edition of the AASHTO LRFD Bridge Construction Specifications, including applicable interim revisions.

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10 When specified, or approved by the State Bridge Engineer, use oversize, short- slotted, and long-slotted holes in accordance with the following:

Align slots normal to the direction of loading in bearing- type connections.

connection at an individual faying surface. Align slots normal to the direction of loading in bearing-type connections.

Do not exceed the hole dimensions in Table 501.4.1-1, Maximum Hole Sizes.

Table 501.4.1-1 Maximum Hole Sizes Bolt Diameter Standard Diameter Oversize Diameter Short Slot Width × Length Long Slot Width × Length in [mm] ⅝ [16] ¹¹⁄₁₆ [18] ¹³⁄₁₆ [20] ¹¹⁄₁₆×⅞ [18×22] ¹¹⁄₁₆×1⁹⁄₁₆ [18×40] ¾ [19] ¹³⁄₁₆ [22] ¹⁵⁄₁₆ [24] ¹³⁄₁₆×1 [21×26] ¹³⁄₁₆×1⅞ [21×48] ⅞ [22] ¹⁵⁄₁₆ [24] 1¹⁄₁₆ [27] ¹⁵⁄₁₆×1⅛ [24×28] ¹⁵⁄₁₆×2³⁄₁₆ [24×55] 1 [25] 1¹⁄₁₆ [27] 1¼ [31] 1¹⁄₁₆×1⁵⁄₁₆ [27×33] 1¹⁄₁₆×2½ [27×62] 1⅛ [28] 1³⁄₁₆ [30] 1⁷⁄₁₆ [36] 1³⁄₁₆×1½ [30×38] 1³⁄₁₆×2¹³⁄₁₆ [30×70] 1¼ [31] 1⁵⁄₁₆ [33] 1⁹⁄₁₆ [39] 1⁵⁄₁₆×1⅝ [33×41] 1⁵⁄₁₆×3⅛ [33×78]

12 Ensure that the minimum distance from the fastener center to member edges in accordance with Table 501.4.1-2, Minimum Edge Distance for Standard Holes.

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Table 501.4.1-2 Minimum Edge Distance for Standard Holes

Bolt Diameter Sheared Edges Rolled Edges of Plates or Shapes or Gas Cut Edges in [mm] 5/8[16] 11/8 [28] 7/8 [22] 3/4 [19] 11/4 [31] 1 [25] 7/8 [22] 11/2 [38] 11/8 [28] 1 [25] 13/4 [44] 11/4 [31] 11/8 [28] 2 [50] 11/2 [38] 11/4 [31] 21/4 [57] 15/8 [41] 13/8 [35] 23/8 [60] 13/4 [44]

13 For oversized and slotted holes, ensure that there is a clear distance between the edges of the hole and the member, at least equal to the minimum required for a standard hole.

14 The use of oversized holes in diaphragm or cross frame to stiffener connections will be permitted, at no additional cost to the department. Ensure oversized holes are in either cross frame members or stiffeners. Ensure the fabricator details the proposed connection on the shop drawings.

501.4.1.11 Welding and Examination of Welded Joints

501.4.1.11.1 General

1 Weld and inspect welded highway structures in accordance with the current AASHTO/ AWS D1.5, Bridge Welding Code.

2 Ensure that welders hold the specified qualifications for applicable processes, positions, and thicknesses.

3 The department’s inspector requires notice from the fabricator 72 hours before welding inspections are required.

4 Weld structural steel by the manual shielded metal-arc, submerged-arc, flux-cored-arc, or gas metal -arc process. Give written welding procedure specifications to the department’s inspector in accordance with the current AASHTO/AWS D1.5.

5 Do not weld on surfaces that are painted, hot-dipped galvanized, metallized or otherwise deliberately coated with surface protective coatings unless coatings are first removed by

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mechanical means. Remove the entire coating within the weld joint, plus a minimum of 1 in [25 mm] each side beyond the joint prior to welding.

6 Only weld material at locations shown on approved shop drawings.

7 For splices in main members that will be field welded, shop-assemble in proper alignment, and check for correct fit-up dimensions. Do not repair incorrect fit-up by welding without approval from the department’s inspector.

8 The department will reject members on which welds cannot be repaired or replaced in accordance with the current AASHTO/AWS D1.5, Clause 3.7, Repairs, as determined by the department’s inspector. Make repair welds at least 2 in [50 mm] long and at no additional cost to the department.

9 Perform welding on main load-carrying bridge members, including repairs, at a minimum preheat and interpass temperature of 150 °F [65 °C] for material thicknesses less than or equal to 21/2 in [64 mm] and 225 °F [110 °C] for thicker material.

501.4.1.11.2 Ultrasonic Weld Testing

1 Ultrasonically test field and shop butt welds in main members in accordance with the current AASHTO/AWS D1.5. Document the tests in accordance with Clause 6.20 of the current AASHTO/AWS D1.5. Grind butt welds flush before ultrasonic testing . Ensure that testing personnel are qualified in accordance with the American Society of Nondestructive Testing (ASNT) SNT -TC-1A, level II . The department inspector may perform additional testing.

2 Inspect 100 percent of the following ultrasonically:

AASHTO/AWS D1.5 – UT Acceptance - Rejection Criteria – Tensile Stress.

3 In compression areas, inspect 10 percent of the following ultrasonically:

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4 If rejectable defects are found in any partially inspected weld, test the entire weld.

5 Do not test radiographically.

6 Move and brace material as required for proper inspection and personnel safety.

501.4.1.11.3 Other Nondestructive Weld Testing

1 Test welds in girders using the magnetic particle or dye penetrant method as follows:

length; all start/stops; and the ends of the welds . If rejectable discontinuities are found in any test length, test the lesser of the weld’s full length or 5 ft [1.5 m] on either side of the test length.

substructure.

magnetic particle method. Perform hardness testing of arc strikes in accordance with Clause 3.3.7.4 of the current AASHTO/AWS D1.5.

level II.

2 Perform magnetic particle testing in accordance with Clause 6.7.6 of AASHTO/ AWS D1.5 using the yoke method. Perform dye penetrant testing in accordance with Clause 6.7.7 of the current AASHTO/AWS D1.5 . Document magnetic particle testing in accordance with Clause 6.7.6.5 of the current AASHTO/AWS D1.5.

501.4.1.12 Thermal Cutting

1 Thermal-cut structural steel only if a smooth surface free from cracks and notches is obtained using a mechanical guide. Hand-cut only where approved by the department’s inspector.

2 Cut girder flanges 1/4 in [6 mm] wider than specified.

3 A void cutting inside the specified lines. Ensure that thermal-cut surfaces meet requirements of ANSI B46.1 for a surface roughness height of 1000 × 10 -6 in [25 µm]. Ensure that thermal-cut surfaces of members not subject to calculated stress have a surface roughness height of no more than 2000 × 10 -6 in [50 µm].

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4 Fillet re-entrant cuts to a radius of at least 1 in [25 mm].

5 For surface roughness exceeding specification and notches or gouges up to 3/16 in [5 mm] deep, remove by machining or grinding. Fair corrections with the surface of the cut on a minimum bevel of 1:10. Repair gouges of flame-cut edges deeper than 3/16 in [5 mm] by methods approved by the department’s inspecto r. If necessary, weld in accordance with Subsection 501.4.1.11, Welding and Examination of Welded Joints, and test ultrasonically in accordance with the current AASHTO/AWS D1.5. Grind completed welds smooth and flush with the adjacent surface.

6 Before painting thermal -cut surfaces, remove the layer left from resolidification by grinding.

501.4.1.13 Edge Planing

1 Plane sheared edges of plate that are thicker than 5/8 in [16 mm], and that are a, or part of a, design member to a depth of 1/4 in [6 mm].

501.4.1.14 Shop Assembling Steel

1 Before assembling, bolting, or welding, clean steel contact surfaces for connections in accordance with Subsection 501.4.1.24.2, Shop Cleaning. Do not paint contact surfaces before bolting or welding.

2 When specified, shop- assemble entire structures, accurately adjusted to blocking line and camber and with holes for field connections drilled or reamed while assembled.

3 Perform flange-to-web welds on welded plate girders before installing transvers e stiffeners.

4 Assemble field-bolted joints for girders with the abutting members adjusted for alignment and camber. Drill or ream holes for field connections while assembled.

5 Ensure that the fabricator makes bolt assemblies available to the department ’s inspector. Before shipment, replace bolt assemblies deemed improperly lubricated, dirty, weathered, or rusted.

6 Match-mark connecting parts shop-assembled for drilling or reaming holes for field connections. Provide a diagram of such marks on the shop drawings.

501.4.1.15 Facing of Bearing Surfaces

1 Ensure that the surface finish of bearing contact surfaces is in accordance with Table 501.4.1-3, Surface Roughness Requirements.

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Table 501.4.1-3 Surface Roughness Requirements Location Roughness Height (10-6 in [µm]) Plates in contact with elastomeric or Preformed fabric pad 2000 [50] Heavy plates in contact as part of bearing Assemblies to be welded 1000 [25] Milled ends of compression members, milled or ground ends of stiffeners, and fillers 500 [12] Bridge rollers and rockers 250 [6] Pins and pin holes 125 [3] Sliding bearings 125 [3]

2 Ensure that bearing surfaces of bearing assemblies fit within 0.010 in [250 µm] for 75 percent of their area, with no gap elsewhere greater than 1/32 in [1.0 mm].

3 For bearing and base plate surfaces and other metal bearing surfaces that will come in contact with preformed fabric pads, elastomeric pads, or portland cement grout, finish flat to within 1/8-inch tolerance in 12 in [1 mm tolerance in 100 mm] and 1/8-inch [3 mm] tolerance overall.

501.4.1.16 Abutting Joints

1 When specified, face and bring abutting ends in compression members of trusses and columns to an even bearing by milling or saw-cutting. Where joints are not faced, ensure the opening does not exceed ⅜ in [10 mm].

501.4.1.17 End Connection Angles

1 Locate end connection angles of floor beams and stringers flush with each other and accurately set as to position and length of member. Do not finish end connection angles. If angles are milled due to faulty shop assembly, do not reduce thickness by more than 1/16 in [2 mm] or reduce the allowable bearing value below design requirements.

501.4.1.18 Elastomeric Bearing Pads

1 Supply and install elastomeric bearing pads in accordance with shop drawings.

501.4.1.19 Finished Members

1 Ensure that finished members are true to line; free from twists, bends, and open joints; and in accordance with the dimensional tolerance requirements of the current AASHTO/AWS D1.5. Apply these tolerances to the camber in the fabricated pieces before erection .

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501.4.1.20 Stiffeners

1 For bearing and other stiffeners designated as “finish to bear,” mill or grind to achieve at least 75 percent contact with the flange and no gap elsewhere greater than 1/32 in [1.0 mm]. Weld other stiffeners to flanges or “fit tight,” as specified. The department defines “fit tight” stiffeners as having at least one bearing point. The department defines “fit tight” stiffeners as having at least one bearing point on the flange and no clearance at any point greater than 1/16 in [2 mm]. Ensure that stiffeners are perpendicular to flanges, unless otherwise specified.

501.4.1.21 Bent Plates

1 Before plates are bent, round the corners or edges to a radius of 1/16 in [2 mm] throughout the part of the plate to be bent.

2 For cold bending diaphragms, connection plates, and other secondary members, ensure the bend line is perpendicular to the direction of rolling. Ensure a bend radius that will not crack the plate. For bends perpendicular to the direction of rolling, ensure the radius is at least the minimum (measured to the concave face of the metal) shown in Table 501.4.1- 5, Minimum Radius for Perpendicular Bends. For all other cold bending, ensure a minimum radius of 5t.

Table 501.4.1-5 Minimum Radius for Perpendicular Bends Thickness (in [mm]) Minimum Radius (t = thickness of metal to be bent) Up to ½ [12] 2 t Over ½ [12] to 1 [25] 2.5 t Over 1 [25] to 1½ [38] 3 t Over 1½ [38] to 2½ [64] 3.5 t Over 2½ [64] to 4 [100] 4 t

3 If bend lines are parallel to the direction of final rolling, multiply the value shown in Table 501.4.1-5, Minimum Radius for Perpendicular Bends by 1.5. Note reasons for deviating from Subsection 501.4.1.21, paragraph 2 on the shop drawings.

4 Hot-bend low alloy steel thicker than ½ in [12 mm] for small radii if cold-bending cannot feasibly be done.

5 When hot-bending plates, do not apply force when steel temperature is between 300 ° F [150 °C] and 700 °F [370 °C] . Do not allow the steel temperature to exceed 1200 °F (649 °C)

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501.4.1.22 Stress-Relieving

1 Relieve stress in welded bearing assemblies by heat treating in accordance with Clause 4.4 of the current AASHTO/AWS D1.5. Perform finish machining after heat treating. Adequately support the weld assembly in the furnace.

2 Ensure the provision of an accurate recording pyrometer with thermocouple junctions at the hottest and coolest points on the assembly but not in the direct path of heating flames. Ensure that the recording device provides a continuous permanent record of the temperatures. Give the department’s inspector two copies of the records.

501.4.1.23 Pins and Rollers

501.4.1.23.1 General

1 Use pins and rollers that are straight, smooth, free of flaws, and finished in accordance with Subsection 501.4.1.15, Facing of Bearing Surfaces.

501.4.1.23.2 Boring Pin Holes

1 Bore pin holes true to detail dimensions, smooth, straight, and at right angles to the axis of the member and parallel to each other. Always make a finishing cut. Ensure that the length outside-to-outside of holes in tension members and inside-to-inside of holes in compression members does not vary from detailed dimensions more than 1/32 in [1 mm]. Bore holes in built-up members after shop bolting and welding.

501.4.1.23.3 Pin Clearance

1 Ensure that the pin hole diameter does not exceed that of the pin by more than 1/50 in [500µm] for pins 5 in [125 mm] or less in diameter or 1/32 in [1 mm] for larger pins.

501.4.1.23.4 Pilot and Driving Nuts

1 Furnish two pilot nuts and two driving nuts for each size of pin.

501.4.1.24 Painting

501. 4.1.24.1 General

1 Paint new structural steel work. Do not paint aluminum; weathering steel meeting ASTM A 709, grades 50W or 70W [ASTM A 709M, grades 345W or 485W]; galvanized; or bronze surfaces, unless specified. Apply the shop coat after fabrication and after surfaces have been prepared. Apply field coats after erection is complete.

2 Ensure that paint is delivered in original, unopened containers with intact labels identifying the paint and showing the date of manufacture and batch number.

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3 Paint only dry, clean surfaces. Do not paint frosted or ice-coated surfaces; when steel, paint, or air temperature is below 40 °F [4 °]; in rain, wind, snow, fog, mist; or when the steel surface temperature is less than 5 °F [3 °C] above the dew point. If a thin film of water applied to the cleaned surface with a damp cloth evaporates within 15 minutes, the dew point requirement is satisfied.

4 Perform blast cleaning and painting in well lighted areas.

5 Mix paint thoroughly with mechanical mixers to keep the pigments in suspension and continue stirring while paint is applied. Furnish and install a water trap or separator on air-supplied equipment used in spray painting.

6 Apply paint with spray guns, rollers, or brushes. If sprayed, brush out the paint where necessary. When brushed, ensure a uniform, even coating. Work paint into joints and open spaces. On otherwise inaccessible surfaces, apply paint with sheepskin daubers.

7 Ensure that the completed coat of paint provides a uniform appearance. Protect painted surfaces while drying.

501.4.1.24.2 Shop Cleaning

1 After fabrication, blast -clean the surface of new structural steel to be painted in accordance with the following for the selected paint system:

blast profile of from 2.0 mil to 3.0 mil [50 μm to 75 μm], when tested by profilometer.

2 After fabrication, prepare unpainted weathering steel bridge girders and faying surfaces of bolted connections in accordance with SSPC -SP 6 —Commercial Blast Cleaning . Ensure that the final surfaces of other unpainted weathering structural steel meet or exceed the standards of SSPC-SP 2—Hand Tool Cleaning.

501.4.1.24.3 Shop Painting

1 Before applying the shop coat, stamp match and erection marks for field identification of members and weight marks in accordance with Subsection 501.4.1.5, Identification of Steels During Fabrication.

2 After acceptance of steel work by the department’s inspector and before shipment, blast- clean, and before surfaces rust, apply one coat of approved shop primer . Reclean if surfaces rust or are contaminated before painting.

3 Do not paint surfaces to be embedded in concrete, except edges of top flanges; apply one coat of shop primer to them. Apply one coat of primer to machined surfaces.

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4 Paint structural steel surfaces in accordance with the following for the selected paint system:

5 Before surfaces rust, apply paint with airless spray equipment to a dry film thickness of from 2.0 mil to 5.0 mil [50 µm to 130 µm]. If necessary to achieve minimum dry film thickness, recoat in accordance with the manufacturer’s recommendations. Brush or daub touch-up as necessary to obtain a smooth surface.

6 During application and curing, ensure that the temperature is from 40 °F to 115 °F [4 °C to 46 °C], that the steel temperature is at least 5 °F [3 °C] above the dew point, and that the relative humidity is between 45 and 90 percent. Apply primer at lower humidities in accordance with applicable recommendations from the manufacturer.

7 Do not load members for shipment sooner than 14 calendar days after painting and until thoroughly dry. Consider paint dry when it cannot be scraped off with a thumbnail. Protect structural steel members while paint dries, and repair paint damage at no additional cost to the department.

501.4.1.25 Galvanizing

1 Galvanize steel after it is fabricated into the largest practical sections. Fabrication includes bending and welding. Before galvanizing, blast-clean welds in accordance with SSPC- SP 5 — White Metal Blast Cleaning. Galvanize components of bolted assemblies separately before assembly. Perform any straightening after galvanizing without damaging the coating.

2 Repair damaged areas of galvanizing in accordance with ASTM A 780. Perform shop repairs by metalizing or soldering with zinc-based alloys in rod or powder form.

501. 4.1.26 Shipping Materials

1 Mark the weight [mass] on members weighing more than 3 ton [2.7 t]. Block projecting parts with wood or otherwise protect them from damage. Do not bend, scrape, or overstress pieces while handling and shipping. The department will reject bent or otherwise damaged pieces.

2 Ensure that material shipped to the project is accompanied by a manufacturer’s certification listing each separate piece by name and piece mark along with two copies of the mill test reports and the fabricator’s quality control records.

3 Ship small parts, such as bolts, nuts, washers, pins, fillers, and small connecting plates or angles in boxes, crates, kegs, or barrels. Include an itemized list and description of the contents on the outside of each package.

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4 Keep the metal clean and undamaged during loading, transporting, and unloading. Ship girders upright unless otherwise approved by the State Bridge Engineer.

501.4.2 Field Work

501.4.2.1 General

1 Use temperature-indicating crayons or infrared devices to determine temperatures of materials.

2 Assemble structural steel as specified, following all match-marks. Handle material without damaging parts. Do not damage or distort members by hammering. Clean bearing and permanent contact surfaces before members are assembled. Provide sufficient bracing to prevent lateral buckling of girders during field erection.

3 Round corners and edges that are marred, cut, or roughened in handling or erection by grinding or other approved methods. Perform field straightening using only approved methods.

4 Tighten high- strength bolts in accordance with Subsection 501.4.2.3.4, Installation, before the superstructure concrete is placed.

501.4.2.2 Drifting of Holes

1 As necessary, drift holes to bring parts into proper alignment without enlarging the holes or otherwise distorting the metal. Do not ream holes that need enlarging by more than 1/16 in [2 mm] greater than the nominal bolt diameter to admit fasteners unless approved by the State Bridge Engineer.

501.4.2.3 Connections Using High Strength Bolts

501.4.2.3.1 General

1 This subsection covers the assembly of slip-critical structural joints using high- strength bolts, nuts, and washers for structural steel joints or equivalent fasteners tightened to a high tension.

2 Use slip-critical bolted connections. Use ⅞ in [22 mm] diameter high-strength bolts with a direct tension indicating washer, twist-off control element, or use lock-pin and collar fasteners.

501. 4.2.3.2 Bolts, Nuts, and Washers

1 Determine bolt lengths in accordance with Table 501.4.2-1, Bolt Length.

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Table 501.4.2-1 Bolt Length Bolt Size (in [mm]) Add to Grip (1) to Determine Bolt Length (in [mm]) ⅝ [16] ⅜ [22] ¾ [19] 1 [25] ⅞ [22] 1⅛ [28] 1 [25] 1¼ [31] 1⅛ [28] 1½ [38] 1¼ [31] 1⅝ [42] (1)Grip is thickness of material to be connected exclusive of washers.

NOTES:

5/16 in [8 mm]

the washers.

2 Determine lengths of lock-pin fasteners in accordance with the manufacturer’s recommendations.

3 Use direct tension indicating washers that provide a method to evaluate induced bolt tension during and after tightening. Evaluate tension from measurements of the residual gap after protrusions have been flattened.

4 For fasteners with twist-off control or indicator elements, use a type with a splined end extending beyond the threaded portion of the bolt, which is then gripped by a special design wrench chuck, providing a means for turning the nut relative to the bolt until the splined end is sheared off.

5 Do not mix nuts and bolts from different lots.

501.4.2.3.3 Bolted Parts

1 Field-drill holes for bolted parts in accordance with Subsection 501.4.1.10, Holes for Fasteners.

2 Ensure that the surface slope of bolted parts in contact with the bolt head and nut does not exceed 1V:20H with respect to a plane perpendicular to the bolt axis. Ensure that

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bolted parts fit solidly together when assembled and are not separated by gaskets or interposed compressible material.

3 Lubricate galvanized nuts with a lubricant dyed so that a visual check for lubricant can be made during field installation. Ensure that black bolts are “oily” to the touch when installed.

4 Ensure that, when assembled, joint surfaces are free of dirt, loose scale, other foreign material, burrs, and other defects preventing solid seating of the parts. Ensure that contact surfaces within slip-critical type joints are free of oil, intermediate and top coat paint (including overspray), lacquer , rust inhibitor , and other foreign material. Primer meeting Class B slip coefficient is acceptable on faying surfaces of slip critical connections. Roughen galvanized contact surfaces by hand wire brushing; do not use power wire brushing.

5 Install bolt, nut, and washer combinations from the same rotational-capacity lot.

501.4.2.3.4 Installation

501.4.2.3.4.1 Bolt Tension

1 Tighten fasteners to at least the bolt tensions shown in Table 501.4.2-2, Bolt Tension.

Table 501.4.2-2 Bolt Tension Bolt Size (in [mm]) Minimum Bolt Tension(1) 103 lb [kN] ⅝ [16] 19 [94.2] ¾ [19] 28 [147] ⅞ [22] 39 [182] 1 [25] 51 [212] 1⅛ [28] 56 [275] 1¼ [31] 71 [337] (1) Equal to the proof load (length measurement method) given in AASHTO M 164 [AASHTO M 164M] and ASTM F3125.

2 Use impact wrenches that can tighten bolts in a maximum of ten seconds. Do not tighten high-strength bolts installed in or through concrete to the required tension in Table 501.4.2-2, Bolt Tension. Install with lock washers and tighten only snug -tight with lock washers flattened.

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501.4.2.3.4.2 Washers

1 For slip-critical, high-strength bolted connections, provide and use washers as follows:

respect to a plane perpendicular to the bolt axis, use a hardened beveled washer to compensate for the lack of parallelism.

bolts are installed and tightened in an oversized or short slotted hole in an outer ply unless meeting Subsection 501.4.2.3.4.7, Installation of Twist-off Fasteners are used.

where AASHTO M 164 [AASHTO M 164M] or ASTM F1325 bolts are installed and tightened in a long slotted hole in an outer ply. This washer need not be hardened. Ensure that the washer or bar completely covers the slot after installation and is of structural grade material. Place hardened washers over the outer surface of the plate washer or bar.

501.4.2.3.4.6, Direct Tension Indicating Washer Installation.

501.4.2.3.4.3 Tension Calibrator

1 The engineer will provide a Skidmore- Wilhelm Calibrator or an acceptable equivalent tension measuring device where bolts are being installed and tightened. Use it to confirm the following:

satisfy the requirements of Table 501.4.2-2, Bolt Tension;

501.4.2.3.4.4 Verification Test Procedure

1 On site, demonstrate the ability to achieve required fastener tension by testing, in a tension calibrator, a representative sample of at least three fasteners of each diameter and length to be used. Test assemblies that include flat washers arranged as those in actual connections to be tensioned. The department requires that each fastener tested develops a tension at least 5 percent greater than the tension required by Table 501.4.2-

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2, Bolt Tension. The department does not require testing on projects using less than 100 high-strength fasteners or on fasteners too short for the calibrator.

501.4.2.3.4.5 General Installation

1 Install fasteners in all holes in the connection and bring to a snug-tight condition. The department defines snug-tight as the tightness existing when the plies of the joint are in firm contact. Snug-tighten from the center of the connection to the free edges, then retighten in a similar systematic manner , as necessar y, until all fasteners are simultaneously snug-tight and all plies of the connection are in full contact.

2 After snug-tightening, tighten fasteners in the connection to achieve the minimum tension shown in Table 501.4.2-2, Bolt Tension. Progress systematically from the center of the joint to its free edges.

501.4.2.3.4.6 Direct Tension Indicating Washer Installation

1 Direct tension indicating washers may be used to ensure proper bolt tension, as specified in Table 501.4.2-2, Bolt Tension. Place the direct tension indicating washer on the bolt with the protrusions bearing against the underside of the bolt head; turn the nut. If the bolt head is turned, due to bolt entering and wrench clearance, place a hardened round washer on the bolt under the bolt head, and place the direct tension indicating washer on the bolt with the protrusions against the hardened round washer.

2 If it is necessary to place the direct tension indicating washer at the nut end, place it on the bolt with protrusions facing toward the nut. Place a hardened round washer on the bolt against the protrusions, and install the nut. Turn the nut. When beveled washers are required, they may be used in conjunction with the direct tension indicating washer.

3 Ensure that the surface contacting the protrusions does not turn during installation. Where a direct tension indicating washer is used with a hardened round washer , some slight movement of the round washer is acceptable.

4 For oversize or slotted holes, use hardened washers in accordance with Subsection 501.4.2.3.4.2, Washers. Do not substitute direct tension indicating washers for required hardened washers; use them in conjunction.

5 Do not reuse direct tension indicating washers.

6 Hold the stationary element with a hand wrench to prevent turning when tightening. Tighten the bolt until the average gap is less than 0.005 in [130 µm] as determined by a feeler gauge. If the gap around the circumference of the direct tension indicating washer is not uniform because the wrench pulls the bolt off-center in the hole and results in protrusions not compressing uniformly, the department will consider the criteria met when gaps are measured in accordance with Table 501.4.2-3, Direct Tension Indicating Washer Inspection Criteria.

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Table 501.4.2-3 Direct Tension Indicating Washer Inspection Criteria Number of Spaces in Washer (Between protrusion) Minimum Number of Spaces (gauge in refused) 5 2 5 3 6 3 7 4 8 4

7 After all bolts in a joint have been tightened, inspect the bolts to ensure that they have not slackened during tightening. If necessar y, restore the tension on these bolts by tightening so that gaps are less than originally measured.

501.4.2.3.4.7 Installation of Twist-Off Fasteners

1 Under the nut, use twist-off bolt assemblies that include a hardened washer specifically designed for twist-off fasteners. On oversize or slotted holes, the department does not require a hardened washer under the bolt head if the diameter of the bolt head is at least as large as the hardened washer . Proper bolt installation tension is indicated when the bolt tip shears off. Replace twist-off bolts that do not meet installation requirements. Do not use or re-torque twist-off bolts that have the bolt tip sheared off.

Do not re-lubricate bolt assemblies in the field. The type and amount of lubrication applied by the manufacturer is critical to performance. Do not use bolt assemblies requiring re- lubrication.

501.4.2.3.4.8 Installation of Lock-Pin and Collar Fasteners

1 If slotted or oversize holes are specified, use hardened flat washers. Proper installation tension is indicated when the pintail separates.

501.4.2.3.4.9 Reuse of Bolts

1 Do not reuse galvanized AASH TO M 164 [AASH TO M 164M] or ASTM F3125 bolts. Ungalvanized AASHTO M 164 [AASHTO M 164M] or ASTM F3125 bolts may be reused once, provided no significant permanent elongation or “stretch” has occurred in the threads (as determine by assembling the nut on the bolt). The bolt may be reused if the nut runs freely the full length of the threads. Do not reuse twist-off fasteners with a sheared-off tip or lock-pin fasteners without the pintail.

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501.4.2.3.5 Inspection

1 The engineer may use the following inspection procedures:

a metal feeler gauge to inspect direct tension indicating washers and at least 10 percent of the bolts but not less than two bolts selected at random in each connection. The engineer will accept the connection as properly tightened if gaps on all the inspected bolts are in accordance with Subsection 501.4.2.3.4.6, Direct Tension Indicating Washer Installation. If any gaps checked are in excess of the specified average gap, reinspect each bolt in the connection, retighten as required, and resubmit the connection for inspection.

will use a manual torque wrench that indicates torque on a dial or that can be adjusted to show that the “job-inspecting torque,” as defined below, has been reached.

Tighten a representative sample of five bolts of the diameter and length, with washers, used in the work and arranged as in the work, to an initial condition of approximately 15 percent of the required fastener tension and then to the tension specified in Table 501.4.2-2, Bolt Tension, using a tension measuring device. Then apply the inspecting wrench to the tightened bolt in the calibrator. Determine the torque necessary to turn the nut or head 5 degrees (approximately 1 inch at a 12- inch radius [90 mm at 1 m]) in the tightening direction. The average of the three middle values will determine the job-inspecting torque.

I nspect bolts represented by the sample in the preceding paragraph that have been tightened in the structure by applying, in the tightening direction, the inspecting wrench with the job-inspecting torque to 10 percent of the bolts (at least two bolts) selected at random in each connection in question. If no nut or bolt head is turned by application of the job-inspecting torque, the engineer will accept the connection as properly tightened. If any nut or bolt head is turned with the job- inspecting torque, retighten all of bolts in the connection and resubmit the connection for inspection.

collar fasteners.

501.4.2.4 Bolted Connections Other Than High-Strength

1 For permanent connections not requiring high-strength bolts, use regular hexagon head bolts with hexagon nuts in accordance with Subsection 815.6, Bolts and Fasteners.

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501.4.2.5 Field Welding

501.4.2.5.1 General

1 In the field, weld by the shielded metal-arc process using electrodes in accordance with the current AASHTO/AWS classification E7018 or E8018 unless otherwise approved, in writing, by the State Bridge Engineer. Use electrodes in hermetically sealed contai ners and in accordance with the current AASHTO/AWS D1.5 Clause 4.5 - Electrodes for SMAW.

2 Submit 14 calendar days prior to welding a written welding procedure specification to the State Bridge Engineer. The specification will be in accordance with the current AASHTO/AWS D1.5, Clause 5 – Qualification, and follow Form O -2 shown in Annex O, Suggested Sample Welding Forms. Ensure the welding procedure includes the voltage, current, travel speed, minimum pre- heat/interpass temperature, maximum interpass temperature, electrode size, process type, joint design, electrode manufacturer, and electrode classification/specification. Obtain the engineer’s approval before beginning welding or erection.

3 Ensure welders are qualified in accordance with Subsection 501.4.1.11.1, General. Ensure 100 percent of the welds are visually inspected by an AWS Certified Welding Inspector (CWI) in accordance with the current AASHTO/AWS D1.5 and Subsection 501.4.2.5.3 Quality of Welds. Report results to the engineer.

4 Unless otherwise identified in the contract, test 100 percent of all fillet welds in accordance with Subsection 501.4.1.11, Welding and Examination of Welded Joints, using magnetic particle testing in accordance with Clause 6.7.6 of the current AASHTO/AWS D1.5 using the yoke method. Ensure that testing personnel are qualified in accordance with the American Society of Nondestructive Testing (ASNT) SNT-TC-1A, level II. Test 100 percent of all full-penetration welds ultrasonically in accordance with the current AASHTO/AWS D1.5, Table 6.3, UT Acceptance – Rejection Criteria – Tensile Stress. Submit test results to the State Bridge Engineer 14 calendar days after welding is performed.

6 Repair defects in welds in accordance with the current AASHTO/AWS D1.5, Clause 3.7, Repairs, as determined by the State Bridge Engineer.

501.4.2.5.2 Workmanship and Technique

501.4.2.5.2.1 General

1 Make field splice welds with the members properly aligned relative to each other. Obtain the engineer’s approval of the alignment before beginning welding.

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2 Do not weld when the air temperature is lower than 0 °F [-18 °C] or when surfaces are wet or exposed to rain, snow , or high wind velocities. Do not make welds other than those specified and approved.

3 Work upward on vertical passes for all welding, including repairs.

4 Back-gouge by air carbon-arc gouging or grinding.

5 Use extension bars or run-off tabs on flange and web splice welds. Ensure that extension bars or run-off tabs for flanges have the same joint preparation and thickness as the flanges and that they fit accurately with no gaps.

501.4.2.5.2.2 Preparation of Base Metal

1 Do not weld on surfaces that are painted, hot dipped galvanized or metalized. Remove all protective coatings by mechanical means such as grinding, blasting, etc. before welding. Remove the entire coating within the weld joint, plus a minimum of 1 in [25.4 mm] beyond the joint prior to welding. Ensure that surfaces, including those nearby, are free from loose or thick scale, slag, rust, moisture, grease, or other foreign material. The department will allow mill scale that can withstand vigorous wire brushing.

501.4.2.5.2.3 Assembly

1 Bring parts to be joined by fillet welds as close together as possible. Do not allow the root opening to exceed 3/16 in [5 mm]. If the root opening is greater than in 1/16 [2 mm], increase the leg of the fillet weld by the amount of root opening. Do not allow the root openings of groove welds without backing to exceed 3/16 in [5 mm]. For groove welds with backing, ensure a root opening of at least 3/16 in [5 mm] but no more than 1/2 in [12 mm]. Do not allow a separation between base metal and backing bars greater than 1/32 in [1 mm]. Do not use fillers.

2 Ensure that the engineer inspects and approves joint preparation before welding.

501.4.2.5.2.4 Preheat and Interpass Temperature Requirements

1 Use a preheat and interpass temperature sufficient to prevent cracking but not less than indicated in Table 501.4.2-4, Minimum Preheat and Interpass Temperature for Field Welding.

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Table 501.4.2-4 Minimum Preheat and Interpass Temperature for Field Welding

Type of Welding Material Thickness (1)

Distance (2)

from Weld Up to 2½ in [64 mm] Over 2½ in [64 mm] Main girder 200 °F [93 °C] 225 °F [110 °C] 6 in [150 mm] Other 150 °F [65 °C] 225 °F [110 °C] 3 in [75 mm] (1)Thickest part at point of welding.

(2) Preheat the base metal so that the surfaces on which the weld metal is being deposited are at or above the specified minimum temperature for the distance shown in all directions from the point of welding, including the side opposite to that being welded.

501.4.2.5.2.5 Tack Welding

1 The same quality requirements apply to tack welds as to final welding, except that discontinuities need not be repaired if they will be consumed by the finished weld. Make tack welds with electrodes that meet the requirements for the final weld. Perform tack welding within the joint so that all tack welds will be consumed by the final weld. Thoroughly clean tack welds before performing the final weld. Ensure multiple- pass tack welds have cascaded ends.

501.4.2.5.2.6 Weld Cleaning

1 Before welding over previously deposited metal, remove slag, and brush the weld and adjacent base metal clean. Remove slag from completed welds, and clean the weld and adjacent base metal by brushing or other approved means.

501.4.2.5.3 Quality of Welds

1 Do not paint welded joints until after welding and cleaning and the weld has been approved by the engineer. Ensure the welds meet the following criteria:

fused.

other welding.

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AASHTO/AWS D1.5, Figure 3.4 (A) and (B), with none of the unacceptable profiles shown in the current AASHTO/AWS D1.5, Figure 3.4 (C).

of butt and corner joints:

8.1The face reinforcement does not exceed ⅛ in [3 mm] in height and has a

gradual transition to the plane of the base metal, in accordance with the current AASHTO/AWS D1.5, Figure 3.4 (D).

8.2They are free of the discontinuities shown for butt joints in the current

AASHTO/AWS D1.5, Figure 3.4 (E).

8.3Butt joint surfaces required to be ground flush are finished so that the

thickness of the base metal is not reduced by more than required in the current AASHTO/AWS D1.5, Clause 3.6.2.1.

2 Measure fillet welds with a fillet gauge.

501.4.2.5.4 Weld Repairs

1 Remove entirely and replace or repair welds not meeting the requirements of Subsection 501.4.2.5.3, Quality of Welds, at no additional cost to the department. When repairing a weld, correct as follows:

1 Remove entirely and replace or repair welds not meeting the requirements of Subsection 501.4.2.5.3, Quality of Welds, at no additional cost to the department. When repairing a weld, correct as follows:

metal.

portions and rewelding.

metal for the full length of the crack plus 2 in [50 mm] at each end and rewelding.

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2 Remove weld metal by air carbon-arc gouging or grinding. Preheat repair welds in accordance with Subsection 501.4.2.5.2.4, Preheat and Interpass T emperature Requirements, and ensure a minimum length of 2 in [50 mm].

501.4.2.5 Preparation of Bearing Areas

1 Ensure that column bases, truss and girder pedestals, base plates, and masonry plates have a full and uniform bearing on the substructure concrete and are rigidly and permanently located to the correct alignments and elevations. Do not place on improperly finished, deformed, or irregular bridge seat areas of piers or abutments. Place steel pedestals, base plates, and masonry plates on preformed fabric pads.

501.4.2.6 Setting Anchor Bolts

1 Drill or form anchor bolt holes perpendicular to the plane of the bridge seat. Set the anchor bolts with an adhesive anchorage system unless otherwise approved by the engineer. Before setting, drop anchor bolts into dry holes to ensure a proper fit. Immediately before placing, clean holes thoroughly. Ensure that anchor bolts are free of contaminating substances. Remove oil or grease by washing with solvent.

2 Heat anchor bolts installed in temperatures below 50 °F [10 °C] in clean boiling water for at least five minutes. Dry with a clean cloth and immediately set in adhesive anchorage system.

3 Place anchor bolts and adhesive anchorage system in accordance with the manufacturer’s recommendations. Hold the bolts in their proper position during the curing period.

4 At no additional cost to the department, replace any bolt disturbed during curing. Remove existing anchorage adhesive from the hole and replace bolt in accordance with the above procedure.

5 Do not leave anchorage adhesive in slotted holes in expansion rockers, rollers, plates, or on any metal surface. Place anchor bolts in correct position, with expansion bearings properly adjusted, before placing the superstructure concrete. Based on the prevailing temperature, the engineer will give instruction for varying location of the anchor bolts in relation to slotted holes in sliding expansion shoes or plates. Ensure that the nuts on anchor bolts at the expansion ends of spans allow free movement of the span. To ensure proper location and elevation, use templates to set anchor bolts in concrete before erection of the superstructure.

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501.4.2.7 Field Painting

501.4.2.7.1 General

1 Repair shipping damage to paint at no additional cost to the department. Ensure the repairs have a uniform appearance and a dry film thickness not less than the original shop coat.

501.4.2.7.2 Field Cleaning

1 After erection, remove foreign matter from unpainted areas by blast-cleaning or with hand tools. Clean areas of steel coated with shop primer using a pressure water wash.

501.4.2.7.3 Field Paint Application

1 After field erection paint all steel in accordance with the specified paint system.

2 Protect the structure against disfigurement by overspray spatters, splashes and smirches of paint, or by paint materials. Paint without damaging vehicles, persons or property, including plants and animals. Prevent dust from accumulating on freshly painted surfaces. Remove overspray.

3 Field-paint structural steel surfaces in accordance with applicable portions of Subsection 501.4.1.24.1, General, and the following requirements for the selected paint system:

Cover unpainted surfaces; field bolts; surfaces where paint is worn off, removed or defective; and shipping and erection marks with one coat of shop primer.

When paint applied for touching up bolts and abraded surfaces has thoroughly dried, apply the first and second field coats. Ensure a minimum film thickness for each coat of 1.5 mil [40 µm], measured dry with a calibrated magnetic film thickness gage in accordance with SSPC -PA 2—Measurement of Dry Coating Thickness with Magnetic Gages.

Let eac h coat of paint dry before applying the next coat. Consider paint dry enough for recoating when an additional coat can be applied without causing detrimental film irregularities, such as lifting, wrinkling, or loss of adhesion of the undercoat. Do not apply additional coats less than 48 hours from the application of the previous coat. Fill small cracks and cavities that have not been sealed watertight by the first field coat with a pasty mixture of first field coat paint before the second field coat is applied. Give surfaces inaccessible after field assembly two coats of second field coat paint before assembly except on surfaces that will be embedded in concrete.

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cleaning structural steel, overcoat all surfaces with one application of the field- applied coating(s) as noted in Table 501.4.2.7-1, Field Paint Application. Mix paint per manufacturer’s recommendations . If allowed based on manufacturer’s recommendations, apply an initial mist coat, let dry for at least 15 minutes, and apply again to provide a final dry film thickness as noted in Table 501.4.2.7-1, Field Paint Application. Measure the final dry film thickness with calibrated magnetic film thickness gage in accordance with SSPC-PA 2—Measurement of Dry Coating Thickness with Magnetic Gages . Ensure paint is free of gas bubbles, blowouts, and voids.

Before applying top coat, ensure surface is cured, clean, sound, dry, and free of contamination. Mix top coat per manufacturer’s recommendations. Brush, roll, or spray top coat to a wet film thickness or a dry film thickness as noted in Table 501.4.2.8-1, Field Paint Application, to produce a smooth surface free from runs, sags, streaks, flashes, laps, pinholes, fisheyes, or craters.

Table 501.4.2.7-1, Field Paint Application Paint System Type B C Overcoat Coating(s) 1. Primer and,

Re-Coat Time Between 4 hours and 1 year Final Dry Film Thickness 5.0 mil to 8.0 mil [130 µm to 200 µm] Topcoat Type Acrylic Latex Polyurethane Wet Film Thickness 5.0 mil to 7.0 mil [130 µm to 180 µm] 3.0 mil to 6.0 mil [75 µm to 150 µm] Dry Film Thickness 2.0 mil to 3.0 mil [50 µm to 75 µm]

501.4.2.8 Repair of Galvanizing

1 Repair damaged areas of galvanizing in the field with zinc-rich paint and in accordance with ASTM A 780.

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501.4.2.9 Falsework

1 Where falsework is supported on structural steel members, ensure that there is no rotation of the member when loads are applied. Do not weld, cut, or drill holes in structural steel to support falsework. Design and construct falsework to support loads that will be applied.

2 Remove falsework materials completely except for piling. Remove falsework piling to at least 24 in [600 mm] below the surface of the original ground, finished groundline, channel bottoms, streambed, or bottom and side slopes of excavated areas.

501.4.3 Automatically End-Welded Studs

501.4.3.1 General

1 Perform automatically end- welded studs in accordance with Clause 7 of the current AASHTO / AWS D1.5.

2 Studs that are applied in the flat position are deemed prequalified and no further testing is required. Flat position is defined as from 0 to 15 degrees from horizontal. Stud application qualification requirements per Clause 7.6 of the current AASHTO / AWS D1.5 are to be performed for all other positions.

3 Use an arc shield (ferrule) of heat -resistant ceramic or other suitable material as recommended by the manufacturer with each stud.

4 Furnish a suitable deoxidizing and arc stabilizing flux for welding with each stud of 5/16 in [8 mm] diameter or larger. Studs less than 5/16 in [8 mm] may be furnished with or without flux.

5 Ensures tuds are free from laps, fins, seams, cracks, twists, bends, or other discontinuities. Radial cracks or bursts in the head of a stud are not cause for rejection, provided the cracks or bursts do not extend more than half the distance from the head periphery to the shank.

6 Do not use direct current welding power sources with a constant voltage characteristic. Connect automatically timed stud welding equipment to a source of direct current electrode negative (DCEN) power. Set welding voltage, current, time, and gun settings for lift and plunge at optimum settings, based on past practice and recommendations of stud and equipment manufacturer.

501.4.3.2 Workmanship and Technique

1 Keep arc shields dry. If arc shields show signs of surface moisture, discard them or dry them in an oven at 250 °F [121 °C] for a minimum of two hours before use.

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2 Do not weld studs when the surface of the base metal is wet or exposed to precipitation.

3 Do not paint, galvanize, or plate stud base prior to welding.

4 Do not use studs displaying corrosion, pitting, scale, oil, moisture, and other deleterious matter that would adversely affect the welding operation. R emove scale, corrosion, moisture, and other deleterious material from the base metal to obtain satisfactory welds at all stud locations . Clean these areas by wire brushing, scaling, prick -punching, or grinding.

5 Do not vary the longitudinal and lateral spacing of studs with respect to each other and to edges of beam or girder flanges more than 1 in [25 mm] from the locations shown in the contract. Maintain a minimum of 1½ in [38 mm] from the edge of a stud base to the edge of a flange.

6 Interlock the guns if two or more stud welding guns are to be operated from the same power source so that only one can operate at a time and the power source has fully recovered from making one weld before another weld is started. While in operation, hold the welding gun in position without movement until the weld metal has solidified.

7 Break arc shields free from the studs after welding and remove the broken pieces. Ensure studs are free of discontinuities or substances, such as remaining portions of arc shields that would interfere with their intended function. The stud weld flash may have nonfusion in its vertical leg and overlap on its horizontal leg, and it may contain occasional small shrink fissures or other discontinuities that usually form at the top of the weld flash with essentially radial or longitudinal orientation, or both, to the axis of the stud. Such nonfusion on the legs of the flash and small fissures are acceptable.

8 Do not use fillet welding to attac h studs on a production basis. Use fillet welding only for attaching a minor number of studs neglected in production welding, or to repair or replace studs with the approval of the engineer. Use a minimum sized fillet weld in accordance with Table 501.4.3.6-1, Minimum Fillet Weld Size for Studs. Use the shielded metal arc process with low-hydrogen electrodes for fillet welding. Prior to attaching new studs with a fillet weld, prepare the base of the stud to fit flat against the base metal.

501.4.3.3 Preheat Temperature Requirements

1 Preheat the base metal to a minimum of 150 ºF [66 ºC] when the air temperature is below 32 ºF [0 ºC] prior to performing the automatic stud welding.

2 For fillet weld repairs of stud connections, ensure base metal is preheated in accordance with Subsection 501.4.2.5.2.4, Preheat and Interpass Temperature Requirements.

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501.4.3.4 Stud Pre-Production Testing

1 Weld and test a minimum of two studs prior to production welding at the beginning of each day's or shift's production and with each change in welding set-up. Set-up changes include changes in stud gun, power source, size and type of stud, gun lift and plu nge, total welding lead length, or changes greater than ± 5% in current (amperage) and time.

2 Weld test studs on the girder or on a piece of material similar to the production member in thickness and properties. If actual production thickness is not available, the thickness may vary by plus or minus 25 percent. Weld all test studs in the same general position as required on the production member (flat, vertical, or overhead).

3 Perform the following on test studs prior to production:

approximately 30 degrees from their original axes by either striking the st uds on the head with a hammer or by placing a pipe or other suitable hollow device over the stud and manually or mechanically bending the stud. When the base metal temperature is below 50 °F [10 °C], bend the studs with a slow continuous application of load.

zone of either stud after bending, correct the welding procedure and weld two additional studs to the production member or on separate material. If either of the second set of test studs fails, continue additional welding on separate plates until two consecutive studs are tested and found to be satisfactory. Remove and replace failed test studs on the production members.

501.3.4.5 Stud Production Testing and Inspection

1 Once production welding has begun, any changes made to the welding setup require the testing in Subsection 501. 4.3.4, Stud Pre-Production Testing be performed prior to resuming production welding.

2 The engineer will inspect installed studs and identify those showing less than a full 360 degrees of flash. Bend studs to an angle of approximately 15 degrees from its original axis. Repair of any stud by fillet welding prior to bending is optional. Whether repaired or not, test all studs by bending to an angle of 15 degrees from its original axis in the direction opposite the repair or incomplete flash.

3 In addition to all studs with incomplete flash, the engineer may select other random studs to be subjected to the bend test described above. Bent shear stud connectors showing no sign of failure are acceptable for use. Leave studs in the bent position.

Structural Steel SECTION 501

4 Remove and replace any stud that fails the bend test. After removal of the stud, grind the area flush with the surface of the base metal.

501.3.4.6 Stud Repairs

1 Should failure of a stud result in pulling out portions of the base metal during testing, do not fill the divot solely using another stud weld. Fill the resulting divots by welding with SMAW low -hydrogen electrodes. Grind the repair level with the surface of the surrounding base metal.

2 When the depth of the discontinuity is the lesser of 1/8 in [3 mm] or 7% of the base metal thickness, the discontinuity may be faired by grinding in lieu of filling with weld metal.

3 Perform magnetic particle testing of all divots and weld repaired areas, and repair any resulting defects prior to installing a new stud.

4 In production, studs on which a 360 degree flash is not obtained may, at the option of the contractor, be repaired by adding the minimum sized fillet weld in accordance with Table 501.4.3.6-1 , Minimum Fillet Weld Size for Studs, in place of the missing flash. Extend the repair weld at least 3/8 in [10 mm] beyond each end of the discontinuity being repaired.

5 Weld with electrodes 5/32 in [10 mm] or 3/16 in [4.8 mm] in diameter except that a smaller diameter electrode may be used for out of position welds.

6 Visually inspect fillet weld repairs in accordance with Subsection 501.4.2.5.3,Quality of Welds.

Table 501.4.3.6-1 Minimum Fillet Weld Size for Studs Stud Diameter (in [mm]) Minimum Fillet Weld Size (in [mm]) Up to 1 in [25 mm] 5/16 in [8 mm] Over 1 in [25 mm] 3/8 in [10 mm]

501.5MEASUREMENT and PAYMENT

1 The engineer will measure Structural Steel as one complete unit or by the pound [kilogram]. Payment by the pound [kilogram] will be based on the invoice(s) for the material incorporated into the work.

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2 The department will pay as follows:

Pay Item

Pay Unit Measure to the Nearest Pay to the Nearest Structural Steel LS, LB [LS, kg] LS, lb [LS, kg] LS, 20 LB [LS, 10 kg]