427 SECTION 602 – STEEL STRUCTURES
602.01 Description ................................ ................................ ................... 428
602.02 Materials ................................ ................................ ...................... 428
602.03 Reserv ed ................................ ................................ ....................... 429
602.04 Shop Inspection ................................ ................................ ............ 429
602.05 General ................................ ................................ ......................... 430
602.06 Bolt Holes ................................ ................................ .................... 435
602.07 Punched Holes ................................ ................................ ............. 436
602.08 Re amed or Drilled Holes ................................ .............................. 436
602.09 Preparation of Field Connections ................................ ................. 436
602.10 Accuracy of Punched and Drilled Holes ................................ ...... 437
602.11 Accuracy of Reamed and Drilled Holes ................................ ....... 437
602.12 Fitting for Bolting ................................ ................................ ........ 438
602.13 Shop Assembling ................................ ................................ ......... 438
602.14 Drifting of Holes ................................ ................................ .......... 440
602.15 Match -Marking ................................ ................................ ............ 440
602.16 Bolts and Bolted Connections ................................ ...................... 441
602.17 Connections Using High Strength Bolts ................................ ...... 442
602.18 Plate Cut Edges ................................ ................................ ............ 460
602.19 Welds ................................ ................................ ........................... 460
602.20 Facing of Bearing Surfaces ................................ .......................... 462
602.21 Abutting Joints ................................ ................................ ............. 462
602.22 End Connection Angles ................................ ............................... 462
602.23 Lacing Bars ................................ ................................ .................. 462
602.24 Fabrication of Members ................................ ............................... 463
602.25 Web Plates ................................ ................................ ................... 463
602.26 Bent P lates ................................ ................................ ................... 463
602.27 Fit of Stiffeners ................................ ................................ ............ 464
602.28 Eyebars ................................ ................................ ......................... 464
602.29 Annealing and Stress Relieving ................................ ................... 465
602.30 Pins and Rollers ................................ ................................ ........... 465
602.31 Boring Pin Holes ................................ ................................ .......... 466
602.32 Pin Clearances ................................ ................................ .............. 466
602.01 428 602.33 Threads for Bolts and Pins ................................ ........................... 466
602.34 Pilot and Driving Nuts ................................ ................................ . 466
602.35 Identification of Steels During Fabrication ................................ .. 466
602.36 Weighing of Members ................................ ................................ .. 467
602.37 Full Size Tests ................................ ................................ .............. 467
602.38 Marking and Shipping ................................ ................................ .. 468
602.39 Erection ................................ ................................ ........................ 470
602.40 Handling and Storing Materials ................................ ................... 470
602.41 Temporary Supports ................................ ................................ ..... 471
602.42 Method and Equipment ................................ ................................ 471
602.43 Straightening Bent Material and Cambering ................................ 471
602.44 Misfits ................................ ................................ .......................... 472
602.45 Assembling ................................ ................................ ................... 472
602.46 Pin Connections ................................ ................................ ........... 473
602.47 Setting Shoes and Bearings ................................ .......................... 473
602.48 Painting ................................ ................................ ........................ 474
602.49 Method of Measurement ................................ .............................. 474
602.50 Basis of Payment ................................ ................................ .......... 477
DESCRIPTION
602.01 Description
This work consists of furnishing the various materials for the fabrication, erection, and painting of bridges and such other parts of bridges that are composed of structural steel and miscellaneous metals, except steel piling or metal reinforcement for con crete. MATERIALS
602.02 Materials
Provide materials as specified in: Structural Steel and Appurtenant Materials ................................ 908 Paint ................................ ................................ ............................ 910 602.03 429 For materials not covered by these Specifications, comply with th e AASHTO Bridge Specifications identified on the Plans. Refer to the Plans for testing requirements and dimensions of materials.
602.03 Reserved
CONSTRUCTION REQUIREMENTS – FABRICATION
602.04 Shop Inspection
A.AISC Certification for Steel Fabricators Fabricators of steel bridges shall hold the following certifications in accordance with the AISC Certification Program for Structural Steel Fabricators – Standard for Steel Bridges:
1.As a minimum, all fabricators shall be certified in the category of intermediate bridges with applicable supplemental requirements.
2.Fabricators of advanced type bridges, as defined in the AISC Standard for Steel Bridges, shall be certified in the category of advanced bridges with applicabl e supplemental requirements.
3.Fabricators of diaphragms, cross -frames, floor beams, stringers (rolled beams) and laterals shall be certified in the category of Intermediate bridges, as a minimum.
4.Fabricators of bridge bearings, expansion joints, sign struc tures and other metal highway components as listed in the AISC standard shall hold certification under the AISC Certification Program – Standard for Bridge and Highway Metal Component Manufacturers. As an alternative, fabricators of bridge bearing or expa nsion joints may hold certification in the category of Intermediate bridges under the Standard for Steel Bridges.
B.Quality Assurance (QA) Shop Inspection At least 6 weeks before starting shop fabrication, provide written notification to the Division of Str uctures, with a copy to the Engineer, as to the location and schedule of the fabrication of structural steel, so that the Department may arrange for QA shop inspection. 602.05 430 The Department will pay for the cost of this QA inspection, limited to the rates set forth in the Special Provisions for each weight range. To establish the maximum inspection cost to be paid by the Department, the Department will multiply the per pound inspection cost for each specified weight range by the applicable steel poundage within its weight range. The Department will deduct the cost of all structural steel inspection (QA) in excess of this maximum cost from monies due the Contractor. The cost for structural steel inspection (QA) includes the cost of an inspection agency hired by the Department to perform shop inspection (QA) of steel fabrication. The Contractor may obtain a detailed description of the duties of an inspection agency from the Engineer. The shop inspection performed by the inspection agency hired by the Department is intended as QA to assure to the Department that the fabricator is following all quality control requirements and is providing a product conforming to the Contract requirements. The inspection agency is not instructed or expected to replace the fabricat or’s quality control. The inspection and acceptance of the work performed by the Department’s inspection agency does not relieve the fabricator of providing materials and finished products as specified. The Department may reject defective or non -conforming materials at any time. Replace rejected materials promptly at no additional cost to the Department. Include the cost of nondestructive testing in the lump sum bid price for steel structures.
602.05 General
A.Type of Construction The type of construction shall be welded or bolted, as shown on the Plans.
B.Workmanship and Finish Workmanship and finish shall be in accordance with the American Institute of Steel Construction ( AISC) best general practices in modern bridge shops . Provide a neat finish to portions of the work exposed to view. 602.05 431 C. Storage of Materials Store material, either plain or fabricated, above the ground on platforms, skids, or other supports. Keep materials free from dirt, grease, or other foreign matter, and provide appropriate protect ion from corrosion.
D.Straightening Material Ensure that rolled material, before being laid off or worked, is straight. If straightening is necessary, use methods that will not damage the metal. Only perform heat straightening of ASTM A709, Grade 100W, 24 4 (ASTM A514) or ASTM A517 steel under rigidly controlled procedures, with each application subject to the Engineer’s approval. Do not allow the maximum temperature of the steel to exceed 1100 °F as set forth in the AASHTO Guide Specifications for Highway Bridge Fabrication with High Performance Steel , current edition, and the AASHTO Bridge Welding Code , current edition. The Engineer will reject material with sharp kinks and bends. To straighten plates, angles, other shapes, and built -up members when permitted by the Engineer, use methods that will not fracture or otherwise damage the metal. Straighten distorted members by mechanical means or, if approved by the Engineer, by carefully planned procedures and supervised application of a limited amount of localized heat. However, to heat straighten AASHTO M 270 (ASTM A709) Grades HPS70W and 100W steel members, adhere to the AASHTO Guide Specification for Highway Bridge Fabrication with High Performance Steel , current edition, and the AASHTO Bridge Welding Code, current edition, with each application subject to the Engineer’s approval. Do not exceed the maximum temperatures specified in Table 602.05 -1. 602.05 432 Table 602.05-1: Heat Straightening Grade Maximum Temperature, degrees F Grade HPS 70W > 6 inches from weld 1100 °F Grade HPS 70W < 6 inches from weld 900 °F Grade 100W > 6 inches from weld 1100 °F Grade 100W < 6 inches from weld 950 °F In all other steels, do not allow the temperature of the heated area to exceed 1200 F, as controlled by temperature indicating crayons, liquids, or either contact or non -contact infrared thermometers. Heating in excess of the limits shown will be cause f or rejection, unless the Engineer allows testing to verify material integrity. Keep parts to be heat straightened substantially free of stress and from external forces, except stresses resulting from mechanical means used in conjunction with the applicatio n of heat. The Engineer will reject pieces showing evidence of fracture following straightening of a bend or buckle.
E.Heat Curving Rolled Beams and Welded Girders
1.Materials. Do not perform heat -curving in steels that are manufactured to a specified minimum yield point greater than 70,000 pounds per square inch.
2.Type of Heating. Curve beams and girders by either continuous or V-type heating as approved by the Engineer. 602.05 433 a. Continuous Method. For the continuo us method, heat a strip along the edge of the top and bottom flanges simultaneously. Ensure that the strip is of sufficient width and temperature to obtain the required curvature.
b.V-type Heating. For V-type heating, heat the top and bottom flanges at a pproximately the same rate and in regularly spaced truncated triangular or wedge -shaped areas having their base along the flange edge. Determine the spacing and temperature of areas necessary to obtain the required curvature. On the inside flange surface , terminate the apex of the truncated triangular area just before the juncture of the web and the flange. To avoid web distortion, take special care when heating the inside flange surfaces (the surfaces that intersect the web) so that heat is not applied directly to the web. When the radius of curvature is 1,000 feet 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 1, 000 feet, extend the apex of the truncated triangular heating pattern applied to the outside flange surface past the web for a distance equal to 1/8 of the flange or 3 inches, whichever is less. The truncated triangular pattern shall have an included angl e of approximately 15 to 30 degrees and a base of no greater than 10 inches. The Engineer may approve variations in these patterns. For both types of heating, the flange edges to be heated are those that will be on the inside of the horizontal curve after cooling. Heating both inside and outside flange surfaces is only required when the flange thickness is 1 -1/4 inches or greater, in which case, heat the two surfaces concurrently.
3.Temperature. Conduct the heat -curving operation so that the temperature of the steel does not exceed 1200 °F for Grades 36, 50, 50W, and HPS50W; and 1100 °F for Grades HPS70W and 100W, as measured by temperature -indicating crayons or other suitable means. Do not artificially cool the girder until after it has naturally cooled to 600 F; the method of artificial cooling is subject to the Engineer’s approval.
4.Position for Heating. The girder may be heat -curved with the web in either a vertical or a horizontal position. 602.05 434 When curving girders with the web in the vertical positio n, brace or support the girder to prevent it from overturning. When curving with the web in the horizontal position, support the girder near its ends and at intermediate points, if required, to obtain uniform curvature. Do not allow the bending stress in the flanges due to the dead weight of the girder and externally applied loads to exceed the usual allowable design stress. During heating, maintain intermediate safety catch blocks at the mid -length of the girder within 2 inches of the flanges to avoid a sudden sag due to plastic flange buckling.
5.Sequence of Operations. Heat -curve the girder before painting, and either before or after completing all the required welding of transverse intermediate stiffeners. However, unless provisions are made for girder shrinkage, locate and attach connection plates and bearing stiffeners after heat curving. If longitudinal stiffeners are required, heat -curve or oxygen -cut them separately, and then weld them to the curved girder. When attaching cover plates to rolled beams, attach them before heat curving if the total thickness of one flange and cover plate is less than 2 -1/2 inches and the radius of curvature is greater than 1,000 feet. For other rolled beams with cover plates, heat -curve the beams before attaching th e cover plates. Either heat -curve or oxygen -cut cover plates separately, and then weld them to the curved beam.
6.Camber. Camber girders before heat curving. Camber rolled beams by heat -cambering methods approved by the Engineer. For plate girders, cut the web to the prescribed camber with suitable allowance for shrinkage due to cutting, welding, and heat curving. If necessary, correct moderate deviations from specified camber by a carefully supervised application of heat, as approved by the Engineer.
7.Measurement of Curvature and Camber. The Engineer will measure horizontal curvature and vertical camber for final acceptance after all welding and heating operations are completed and the flanges have cooled to a uniform temperature. The Engineer will check horizontal curvature with the girder in the vertical position. 602.06 435 8. Finish. Provide a neat finish to exposed portions of th e work. Perform shearing, flame cutting, and chipping carefully and accurately.
602.06 Bolt Holes
A.Holes for High Strength Bolts and Unfinished Bolts1 Punch or drill all bolt holes. Material forming parts of a me mber composed of not more than five thicknesses of metal may be punched 1/16 inch larger than the nominal diameter of the bolts where the thickness of the material is not greater than ¾ inch for structural steel, 5/8 inch for high -strength steel, or ½ inch for quenched and tempered alloy steel, unless sub -punching and reaming is required under 602.09. Where there are more than five thicknesses, or when any of the main material is thicker than ¾ inch for structural steel, 5/8 inch for high - strength steel, or ½ inch for quenched and tempered alloy steel, either sub-drill and ream or drill holes full size. If required under 602.09, either sub -punch or sub -drill (sub -drill if thickness limitation governs) all holes 3/16 inch smaller, and, after assembling, ream 1/16 inch larger, or drill full size to 1/16 inch larger than the nomin al diameter of the bolts. The Department will only allow use of enlarged or slotted holes with high-strength bolts 5/8 inch or larger in diameter where shown on the design drawings.
B.Holes for Ribbed Bolts, Turned Bolts or ot her Approved Bearing Type Bolts The Fabricator may either sub -punch or sub -drill all holes for ribbed bolts, turned bolts, or other approved bearing -type bolts 3/16 inches smaller than the nominal diameter of the bolt, and then ream, assemble or drill to a steel template or, after assemb ly, drill from the solid. In any case, ensure that the finished holes provide a driving fit as shown on the Plans or specified in the Special Provisions. 1 See 602.16 for bolts included in designation "Unfinished Bolts." 602.07 436 602.07 Punched Holes Use a die diam eter that is not more than 1/16 inch larger than the punch diameter. Ream holes that must be enlarged to admit bolts. Ensure that holes are cleanly cut without torn or ragged edges. Poor matching of holes will be cause for rejection.
602.08 Reamed or D rilled Holes
Ream or drill holes so they are cylindrical and perpendicular to the member and sized to comply with 602.06. Where prac ticable, direct reamers using mechanical means. Remove burrs on the outside surfaces. Poor matching of holes will be cause for rejection. Ream and drill holes with twist drills. If required by the Engineer, take apart assembled pieces to remove burrs c aused by drilling. Assemble and securely hold together connecting parts that are being reamed or drilled and match -mark before disassembling.
602.09 Preparation of Field Connections
A.Sub-punching a nd Reaming of F ield Connections Unless otherwise specified in the Special Provisions or shown on the Plans, sub -punch (or sub -drill if sub -drilling is required) the holes in all field connections and field splices of main members of trusses, arches, continuous beam spans , bents, towers (each face), plate girders, and rigid frames, as specified in 602.06, and subsequently ream while assembled or to a steel template, as specified in 602.13. Sub-punch all holes for floor beam and stringer field connections, and ream to a steel template or while assembled. When reaming or drilling full size field connection holes through a steel template, accurately locate and position the template and firmly bolt in place before drilling. Ensure that templates used for reaming matching members, or the opposite faces of a single member, are exact duplicates. Accurately locate templates used for connections on like parts or members so that the parts or members are duplicat es and require no match-marking. For any connection, instead of sub -punching and reaming or sub -drilling and reaming, the Fabricator may drill holes full size with all thicknesses of material assembled in proper position. 602.10 437 The Special Provisions or the Plan s will identify if any additional sub - punching and reaming is required.
B.Numerically Controlled (N/C) Drilled Field Connections
1.General. For any connection or splice specified in 602.09.A, instead of drilling undersized holes a nd reaming while assembled, or drilling holes full size while assembled, the Contractor may use N/C drilling equipment to drill bolt holes full -size in unassembled pieces and/or connections including templates for use with matching undersized and reamed ho les. If N/C drilling equipment is used, the Engineer, unless otherwise stated in the Special Provisions or shown on the Plans, may require the Contractor, by means of check assemblies, to demonstrate that this drilling procedure consistently produces holes and connections meeting 602.11 and 602.13. Submit to the Engineer for approval a detailed outline of the proposed procedures for accomplishing the work, from initial drilling through check assembly, if req uired. Identify in the submittal the specific members of the structure that may be N/C drilled, the sizes of the holes, the location of common index and other reference points, composition of check assemblies, and all other pertinent information.
2.Holes. Ensure that holes drilled by N/C drilling equipment are drilled to appropriate size either through individual pieces or any combination of pieces held tightly together.
602.10 Accuracy of Punched and Drilled Holes
Punch holes so that, after assembling (before any reaming is done), a cylindrical pin 1/8 inch smaller in diameter than the nominal size of the punched hole may be entered perpendicular to the face of the member, without drifti ng, in at least 75% of the contiguous holes in the same plane. The Engineer will reject pieces that do not meet this requirement. The Engineer will also reject all holes that will not pass a pin 3/16 inch smaller in diameter than the nominal size of the punched holes.
602.11 Accuracy of Reamed and Drilled Holes
When holes are reamed or drilled, 85% of the holes in any contiguous group shall, after reaming or drilling, show no offset greater than 1/32 inc h between adjacent thicknesses of metal. Use steel templates having hardened steel 602.12 438 bushings in holes accurately dimensioned from the center lines of the connection as inscribed on the template. Use the center lines when locating the templates from the mi lled or scribed ends of members.
602.12 Fitting for Bolting
Clean surfaces of metal in contact before assembling. Before reaming, ensure that the parts of a member are assembled, well pinned, and firmly drawn together with bolts. When necessary, take as sembled pieces apart to remove burrs and shavings produced by the reaming operation. Ensure that members are free from twists, bends, and other deformation.
602.13 Shop Assembling
Assemble the field connections of main members of trusses, arches, continuous beam spans, bents, towers (each face), plate girders, and rigid frames in the shop with milled ends of compression members in full bearing, and then ream their su b-size holes to the specified size while the connections are assembled. Assembly may be full truss or girder assembly, progressive truss or girder assembly, full chord assembly, progressive chord assembly, or special complete structure assembly unless oth erwise specified in the Special Provisions or shown on the Plans. Fabricate check assemblies with numerically controlled (N/C) drilled field connections as specified in 602.13.F. Obtain the Engineer’s approval of each assembly, including camber, alignment, accuracy of holes, and fit of milled joints, before starting reaming or before dismantling an N/C drilled check assembly. The Fabricator shall submit to the Engineer a camber diagram showing the camber at each panel point for trusses or arch ribs and at the location of field splices and fractions of span length (1/4 points minimum, 1/20 points maximum) for continuous beam and girders or rigid frames. When the shop assembly is Full Truss or Girder Assembly or Special Complete S tructure Assembly, the camber diagram shall show the camber measured in assembly. For the other shop assembly methods, the camber diagram shall show calculated camber. 602.13 439 A. Full Truss or Girder Assembly Full Truss or Girder Assembly shall consist of assembling all members of each truss, arch rib, bent, tower face, continuous beam line, plate girder, or rigid frame at one time.
B.Progressive Truss or Girder Assembly Progressive Truss or Girder Assembly shall consist of assembling initially for each truss, arch rib , bent, tower face, continuous beam line, plate girder, or rigid frame at least three contiguous shop sections or all members in at least three contiguous panels but not less than the number of panels associated with three contiguous chord lengths (i.e., l ength between field splices) and not less than 150 feet in the case of structures longer than 150 feet. Add at least one shop section or panel or as many panels as are associated with a chord length at the advancing end of the assembly before removing any member from the rearward end, so that the assembled portion of the structure is never less than that specified above.
C.Full Chord Assembly Full Chord Assembly shall consist of assembling, with geometric angles at the joints, the full length of each chord o f each truss or open spandrel arch, or each leg of each bent or tower, then reaming their field connection holes while the members are assembled and reaming the web member connections to steel templates set at geometric (not cambered) angular relation to t he chord lines. Ream field connection holes in web members to steel templates. Ensure that at least one end of each web member is milled or scribed normal to the longitudinal axis of the member. Accurately locate the templates at both ends of the member from one of the milled ends or scribed lines.
D.Progressive Chord Assembly Progressive Chord Assembly shall consist of assembling contiguous chord members in the manner specified for Full Chord Assembly in
602.13 C and in the num ber and length specified for Progressive Truss
or Girder Assembly in 602.13.B. 602.14 440 E. Special Complete Structure Assembly Special Complete Structure Assembly shall consist of assembling the entire structure, including the floor system . (This procedure is ordinarily needed only for complicated structures such as those having curved girders or extreme skew in combination with severe grade or camber.)
F.Check Assemblies with Numerically Contr olled (N/C) Drilled Field Connections Fabricate a check assembly for each major structural type of each project, unless otherwise shown on the Plans or specified in the Special Provisions . The check assembly shall consist of at least three contiguous shop sections or, for a truss, all members in at least three contiguous panels but not less than the number of panels associated with three contiguous chord lengths (i.e., length between field splices). Base check assemblies on the proposed order of erection, joints in bearings, special complex p oints (such as portals of skewed trusses), and similar considerations . Use geometric angles (giving theoretically zero secondary stresses under dead load conditions after erection) or cambered angles (giving theoretically zero secondary stresses under no load conditions) as shown on the Plans or specified in the Special Provisions. For each major structural type to be fabricated, fabricate the check assemblies first. The Department does not require any matchmaking or shop assemblies other than the check assemblies. If the check assembly fails to demonstrate that the required accuracy is being obtained, the Engineer may require the fabrication of additional check assemblies at no cost to the Department.
602.14 Drifting of Holes
Only drift holes during assembling to the extent that it brings the parts into position but does not enlarge the holes or distort the metal.
602.15 Match-Marking
Match-mark connecting parts preassembled in the shop to ensure proper fit in the field. Provide a diagram showing such match -marks to the Engineer. 602.16 441 602.16 Bolts and Bolted Connections The requirements of this Subsection do not pertain to the use of high strength bolts. For bolted connections fabricated with high strength bolts, comply with 602.17.
A.General Use unfinished, turned, or ribbed bolts conforming to ASTM A307 for Grade A bolts for Low -Carbon Steel Ex ternally and Internally Threaded Standard Fasteners. Only use bolted connections as shown on the Plans or specified in the Special Provisions. Use bolts with single self -locking nuts or double nuts unless otherwise shown on the Plans or specified in the Special Provisions. Use beveled washers where bearing faces have a slope of more than 1:20 with respect to a plane normal to the bolt axis.
B.Unfinished Bolts Furnish unfinished bolts unless other types are specified.
C.Turned Bolts Furnish turned bolts having a body surface that meets the ANSI roughness rating value of 125. Furnish hex headed bolts and nuts of the nominal size specified or the next larger nominal size. The thread diameter shall be equal to the body of the bolt or the nominal diameter of the bolt specified. Carefully ream holes for turned bolts with bolts furnished to provide for a light driving fit. Keep bolt threads entirely outside of the holes. Provide a washer under the nut.
D.Ribbed Bolts The body of ribbed bolts shall be of an approved form with continuous longitudinal ribs. The diameter of the body measured on a circle through the points of the ribs shall be 5/64 inch greater than the nominal diameter specified for t he bolts. Furnish ribbed bolts with round heads conforming to ANSI B 18.5 unless otherwise specified. Furnish hexagonal nuts that are either recessed or have a washer of suitable thickness. Ribbed bolts shall have a driving fit when installed in the hole s. The hardness of the ribs shall be such that the ribs do not compress, deform, or allow the bolts to turn in the holes 602.17 442 during tightening. If the bolt twists before drawing tight, ream the hole and provide an oversized replacement bolt.
602.17 Connecti ons Using High Strength Bolts
A.General All high strength bolts, or equivalent fasteners, tightened to a high tension shall be coated with permitted coatings in accordance with ASTM F3125 fo r their respective grade. Use the bolts in holes conforming to 602.06, 602.07, and 602.08. All Grade A325 and A490 bolts, except Type 3 bolts used in weathering steel, shall be coated. Permitted coatings for Grade A325 and Grade A490 bolts are listed in ASTM F3125, Annex A1.
B.Bolts, Nuts, and Washers The Department will pre -test bolts, nuts, an d washers in accordance with
908.04 Bolts used with w eathering steel shall be ASTM F 3125 Grade
A325 Type 3, and all bolts, nuts and washers shall have the same weathering characteristics as the structural steel. Galvanized nut s shall be grade DH. Supply the Materials and Tests Division with samples of bolts, nuts, and washers used on the Project for purposes of testing (provide three per shipping lot). Where the outer face of the bolted parts has a slope greater than 1:20 with respect to a plane normal to the bolt axis, use a hardened beveled washer to compensate for the lack of parallelism. Use hardened beveled washers for American Standard Beams and Channels. The washers shall be square or rectangular, shall conform to the requirements of AASHTO M 293 (ASTM F436) and ASTM F3125 Grade A490, and shall taper in thickness. Where necessary, wash ers may be clipped on one side from the center of the washer to a point not closer than 7/8 times the bolt diameter. Hardened washers are not required for connections using ASTM F3125 Grade A325 and A490 bolts except as follows:
1.Use hardened washers un der the turned element when tensioning is to be performed by the calibrated w rench method. 602.17 443 2. Regardless of the tensioning method, use hardened washers under both the head and the nut when ASTM F3125 Grade A490 bolts are to be installed in material having a specified yield point less than 40 kips per square inch . However, use of DTI’s may replace a hardened washer provided a standard hole is used.
3.Where ASTM F3125 Grade A325 bolts of any d iameter or ASTM F3215 Grade A 490 bolts equal to or less than 1 in ch in diameter are to be installed in oversize or short -slotted holes in an outer ply, use a hardened washer con forming to AASHTO M 293 (ASTM F 436).
4.Where ASTM F3125 Grade A490 bolts over 1 in ch in diameter are to be installed in an oversized or short -slotted hole in an outer ply, use a hardened washer conforming to AASHTO M 293 (ASTM F436).
5.Where ASTM F3125 Grade A490 bolts over 1 inch in diameter are to be installed in an oversized or short -slotted hole in an outer ply, use hardened washers conforming to AASHTO M 293 (ASTM F436) except with 5/16 in ch minimum thickness under both the head and the nut instead of standard thickness hardened washers. Using multiple hardened washers with a combined thickness equal to or greater than 5/16 in ch does not satisfy this requirement.
6.Where ASTM F3125, Grade A325 bolts of any d iameter or ASTM F3125 Grade A490 bolts equal to or less than 1 in ch in diameter are to be installed in a long slotted hole in an outer ply, use a plate washer or continuous bar o f at least 5/16 in ch thickness with standard holes. The washers or bars shall have a size sufficient to completely cover the slot after installation and shall be of structural grade material but need not be hardened except as foll ows. When ASTM F3125 Gra de A490 bolts over 1 inch in diameter are to be used in long slotted holes in external plies, use a single hardened washer conf orming to AASHTO M 293 (ASTM F 436), but with 5/16 inch minimum thickness, instead of washers or bars of structural grade material. Using multiple hardened washers with combined thickness equal to or greater than 5/16 in ch does not satisfy this requirement. 602.17 444 7. Alternate design fasteners conforming to Article 11.3.2.6 , with a geometry that provides a bearing circle on the head or nut with a diameter equal to or greater than the diameter of hardened washers conforming to AASHTO M 293 (ASTM F 436), satisfy the requirements for washers specified herein and may be used without washers.
C.Bolted Parts Limit the maximum slope of surfaces of bo lted parts in contact with the bolt head and nut to 1:20 with respect to a plane normal to the bolt axis. Ensure that bolted parts fit solidly together when assembled and are not separated by gaskets or any other interposed compressible material. Ensure that, when assembled, all joint surfaces, including those adjacent to the bolt head, nuts, or washers, are free of loose scale, burrs, dirt, and other foreign material that would prevent solid seating of the parts. Paint is permitted unconditionally in bea ring type connections. Unless otherwise shown on the Plans, all contact surfaces of bolted parts shall be Class B as described in the AASHTO Bridge Specifications identified in the Plans .
D.Installation Comply with the following when installing high strengt h bolts in the field or shop:
1.Install b olts to the minimum tensions specified in Table 602.17-1 and in accordance with the AASHTO LRFD Bridge Construction Specifications identified on the Plans. During installation, take particular care to achieve the snug tight condition as defined in Article 11.5.6.4. 602.17 445 Table 602.17 -1: Minimum Bolt Tension (1) Bolt Diameter (inches) Bolt Tension (pounds) (Grade A325) Grade A490 Bolts ½ 12,000 15,000 5/8 19,000 24,000 ¾ 28,000 35,000 7/8 39,000 49,000 1 51,000 64,000 1-1/8 64,000 80,000 1-1/4 81,000 102,000 1-3/8 97,000 121,000 1-1/2 118,000 148,000
1.Equal to 70% of the specified minimum tensile strength of bolts.
2.Perform t he rotational capacity test described in 602.17.E.1 and
602.17 E.2 on each rotational capacity lot before starting bolt
installation. Provide h ardened steel washers as part of the test.
3.Install bolt, nut, and washer combinations of the same rotational capacity lot together.
4.Un-galvanized bolts shall be “oily” to the touch when delivered and installed.
5.Clean and re -lubricate w eathered or rusted bolts or nuts not satisfying the requiremen ts of paragraph D.2 above prior to installation. Test re-cleaned or re -lubricated bolt, nut, and washer assemblies in accordance with paragraph D.2 above prior to installation.
6.Direct Tension Indicators (DTIs)
a.Use Direct Tension Indicators (DTIs) for each bolt. Do not use DTIs on weathering steel , and therefore all bolts shall be installed by either turn -of-nut tightening or calibrated wrench tightening in accordance with the construction specifications of the AASH TO Bridge Specifications 602.17 446 identified on the Plans. The load indicator average gap shall be 0.005 in ch. After the joint has been properly pinned, tighten the joint to approximately half the specified tension to ensure firm contact of all plies, and then tighten the joint by systematically progressing from the center most rigid part to the free edges. Re -tightening may be necessary to restore tension if gaps increase from original measurements.
b.Maintain a tension calibrator, such as a Skidmore Wilhelm, on the Project during all bolting operations. The Engineer will check the bolt tension versus the average gap of the DTI daily to ensure correct tension.
c.Supply the Materials and Tests Division with samp les of bolts, nuts, and washers used on the project for purposes of testing (provide three per shipping lot).
d.Ship bolts, nuts, and washers in sealed containers, labeled with the supplier’s name and lot identification. Ensure that the containers can protect the bolts from moisture and other contaminants until they are opened at the site. Damaged containers are cause for rejection.
e.Verify the DTI’s performance as specified in 602.17.E.3 .
f.Install DTIs by one of the fo llowing three methods unless otherwise approved by the Engineer.
1.Place the DTI under the bolt head and turn the nut to tighten. The protrusions on the DTI shall face the underside of the bolt head. Place the hardened flat washer under the nut and reduce the gap in the DTI to 0.005 inch.
2.Place the DTI under the nut and turn the nut to tighten. Place the hardened flat washer between the nut and the DTI. The protrusions on the DTI shall face the underside of the hardened flat washer and nut and the gap in the DTI reduced to 0.005 in ch. This method is suggested when it is too difficult to see the bolt head for inspection, or when the wrench operator wants to the see the gap. 602.17 447 (3) Place the DTI under the bolt head and turn the bolt head to tighten. Place the hardened flat washer between the bolt head and the DTI. The protrusions on the DTI shall face the under side of the hardened flat washer and bolt head and the gap in the DTI reduced to 0.005 in ch. This method is suggested when it is too difficult to see the nut for inspection, or when the wrench operator wants to the see the gap.
E.Inspection In the presence of the Engineer, conduct the following tests to certify materials in accordance with 908.04 and prior to in stallation:
1.Rotational Capacity Test s on Long Bolts in Tension Calibrator
a.Equipment Required
1.Calibrated bolt tension measuring device of size required for bolts to be tested. Mark off a vertical line and lines 1/3 of a turn (120 degrees); and 2/3 of a turn (240 degrees), from vertical in a clockwise direction on the face plate of the calibrator.
2.Calibrated torque wrench.
3.Spacers and/or washers with hole size no larger than 1/16 inch greater than bolt to be te sted.
4.Steel section to mount bolt calibrator. Flange of girder or cross frame accessible from the ground is satisfactory.
b.Procedure
1.Install nut on bolt and measure stick -out of bolt when three to five full threads of the bolt are located between the bearing face of the nut and the bolt head. Measure the bolt length, the distance from the end of the threaded shank to the underside of the bolt head. 602.17 448 2. Install the bolt into the tension calibrator and install the required number of shim plates and/or washer (one washer under the nut must always be used) to produce the thread stick -out measured in Step 1.
3.Tighten bolt using a hand wrench to the snug tensions specified in Table 602.17 -2, -0 kips, +2 kips. Table 602.17 -2: Snug Tension Bolt Diameter (inches) Grade A325 Snug Tension (kips) Grade A490 Snug Tension (kips) ½ 1 1 5/8 2 2 ¾ 3 4 7/8 4 5 1 5 6 1-1/8 6 8 1-1/4 8 10 1-3/8 10 12 1-1/2 12 15
4.Match mark the nut to the vertical stripe on the face plate of the bolt calibrator.
5.Using the calibrated manual torque wrench, tighten the bolt to at least the tension specified in Table 602.17-3, and record the torque required to reach the tension and the value of the bolt tension. Measure t orque with the nut in motion. 602.17 449 Table 602.17 -3: Minimum Installation Tension Bolt Diameter (inches) Grade A325 Tension (kips) Grade A490 Tension (kips) ½ 12 15 5/8 19 24 ¾ 28 35 7/8 39 49 1 51 64 1-1/8 64 80 1-1/4 81 102 1-3/8 97 121 1-1/2 118 148
6.Further tighten the bolt to the rotation specified in Table 602.17 -4. Measure t he rotation from the initial marking in Step 4. Record the bolt tension. Assemblies that fail prior to this rotation either by stripping or fracture fail the test. Table 602. 17-4: Rotation from Snug Condition Bolt Length (measured in Step 1) Grade A325 Required Rotation Grade A490 Required Rotation Up to and including 4 diameters 2/3 2/3 Over 4 diameters, but not exceeding 8 diameters 1 5/6 Over 8 diameters to 12 diameters 1-1/6 1
7.The bolt tension measured in Step 6 after the required rotation must equal or exceed the values specified in Table 601.17 -5. Assemblies that do not meet this tension have failed the test. 602.17 450 Table 602.17 -5: Turn Test Tension Bolt Diameter (inches) Grade A325 Tension (kips) Grade A490 Tension (kips) ½ 14 17 5/8 22 28 ¾ 32 40 7/8 45 56 1 59 74 1-1/8 74 92 1-1/4 94 117 1-3/8 112 139 1-1/2 136 170
8.Loosen and remove the nut and examine the threads on the nut and bolt. No signs of thread shear failure, stripping, or torsional failure of the bolt should be evident. Assemblies that have evidence of stripping have failed the test.
9.Ensure that the torque measured in Step 5 does not exceed the maximum torque calculated as follows: Tmax = 0.25 (P x 1,000 )(D 12) Where: Tmax = maximum torque expressed in foot - pounds P = bolt tension measured in Step 5 expressed in kips D = bolt diameter expressed in inches Assemblies with torque values exceeding this calculated value have failed the test. 602.17 451 2. Rotational Capacity Test s on Bolts too Short to fit Tension Calibrator
a.Equipment Required
1.Calibrated torque wrench and a spud wrench or equivalent.
2.Spacers and/or was hers with hole size no larger than 1/16 inch greater than bolt to be tested.
3.Steel section with normal size hole to install bolt. Any available splice hole can be used with a plate thickness that will provide the number of threads under the nut required in Step 1 below. Mark off a vertical line and lines 1/3 of a turn (120 degrees ); ½ of a turn (180 degrees); and 2/3 of a turn (240 degrees), from vertical in a clockwise direction on the plate.
b.Procedure
1.Install nut on bolt and measure stick -out of bolt when three to five full threads of the bolt are located between the bearing face of the nut and the bolt head. Measure the bolt length, the distance from the end of the threaded shank to the underside of the bolt head.
2.Install the bolt into the hol e and install the required number of shim plates and/or washer (one washer under the nut must always be used) to produce the thread stick -out measured in Step 1.
3.Use a hand wrench to tighten the bolt to a snug condition. The snug condition is the norma l effort applied to a 12 -inch long wrench. The applied torque should not exceed 20% of the torque determined in Step 5.
4.Match mark the nut to the vertical stripe on the plate.
5.Tighten the bolt by turning the nut using the torque wrench to the rotation specified in Table 602.17 -6. Use a second wrench to prevent rotation of the bolt 602.17 452 head during tightening. Record the torque required to reach this rotation. Measure t orque with t he nut in motion. Table 602.17 -6 Bolt Length (measured in Step 1) Required Rotation (All Grades) Up to and including 4 diameters 1/3 Over 4 diameters, but not exceeding 8 diameters ½ The measured torque should not exceed the values specified in Table 602.17 -7. Assemblies that exceed the listed torques have failed the test. Table 602.17 -7 Bolt Diameter (inches) Grade A325 Torque (ft-lbs) Grade A490 Torque (ft-lbs) ½ 150 180 5/8 290 370 ¾ 500 630 7/8 820 1,020 1 1,230 1,540 1-1/8 1,730 2,160 1-1/4 2,450 3,050 1-3/8 3,210 3,980 1-1/2 4,250 5,310
6.Tighten the bolt further to the rotation specified in Table 602.17 -8. The rotation is measured from the initial marking in Step 4. Assemblies that fail prior to this rotation either by stripping or fracture have failed the test. 602.17 453 Table 602.17 -8 Bolt Length (measured in Step 1) Additional Required Rotation Grade A325 Additional Required Rotation Grade A490 Up to and including 4 diameters 1/3 ¼ Over 4 diameters, but not exceeding 8 diameters ½ 1/3
7.Loosen and remove the nut and examine the thread on the nut and bolt. No signs of thread shear failure, stripping, or torsional failure of the bolt should be evident. Assemblies that have evidence of stripping have failed the test.
3.Verification and Installation of High Strength Bolts with Direct Tension Indicators (DTIs)
a.Verification of DTI Performance . If installing DTIs with high strength bolts to indicate bolt tension, perform the verification testing described below, and install the DTIs in accordance with the method specified below. Unless otherwise approved by the Engineer, install the DTIs under the head of the bolt and turn the nut to tighten the fastener. Follow the manufacturer’s recommendations to properly orient the DTI and additional washers, if any, required for the correct use of the DTI. In the presence of the Engineer, perform v erification testing in a calibrated bolt tension measuring device. Use a special flat insert in place of the normal bolt head holding insert. Perform three verification tests for each combination of fas tener rotational -capacity lot, DTI lot , and DTI position relative to the turned element (bolt head or nut) to be used on the project. Tighten the fastener by turning the element not against the DTI. Do not allow t he element (bolt head or nut) against the DTI to rotate. The purpose of the verification testing is to ensure that the fastener will be at or above the desired installation tension when half or more of the spaces in the DTI have a gap of less 602.17 454 than 0.005 in ch and that the fastener will not underg o excessive plastic deformation at the minimum gap allowed on the Project. Conduct the verification test as follows:
1.Install the bolt, nut, and DTI assembly in a manner so that at least three and preferably not more than five threads are located betwe en the bearing face of the nut and the bolt head.
2.Tighten t he fastener first to the load equal to that specified in Tables 602.17 -9 and 602.17 -10 under Verification Tension for the grade and diameter of fastener. If an impact wrench is used, it is ac ceptable to tighten to a load slightly below that required and then use a manual wrench to attain the required tension.
3.Determine and record the number of refusals of a 0.005-inch tapered feeler gage in the spaces between the protrusions. The number of spaces between protrusions is listed below in Tables 602.17 -9 and
602.17 10. The number of refusals shall not exceed
the number listed under Maximum Verification Refusals in Tables 602.17-9 and 602.17 -10 below for the grade and diameter of bolt for un -coated DTIs. The maximum number of refusals for coated DTIs (galvanized, painted or epoxy coated) used under the turned element shall not exceed the number of spaces on the DTI less o ne. The DTI lot is rejected if the number of refusals exceeds the values in the applicable table or, for coated DTIs , if the gage is refused in all spaces.
4.After the number of refusals is recorded at the verification load, further tighten the fastener until the 0.005-inch feeler gage is refused at all the spaces and a visible gap exists in at least one space.
5.Record the load at this condition and remove the fastener from the tension measuring device. 602.17 455 6. Ensure that t he nut can be reassembled by h and for the complete thread length of the bolt excluding thread run-out. If the nut cannot be assembled for this thread length, the DTI lot is rejected unless the load recorded is less than 95% of the average load measured in the rotational capacity test of the fastener lot as specified in 908.04.C.3.g . If the bolt is too short to be tested in the calibration device , test the DTI on a long bolt in a calibrator to determine the number of refusals at the Verification Tensio n listed in Tables 602.17 -9 and 602.17 -10 below. The number of refusals shall not exceed the values listed under Maximum Verification Refusals. Then test another DTI from the same lot with the short bolt in a convenient hole in the work. Tighten t he fastener assembly until the 0.005 -inch feeler gage is refused in all spaces and a visible gap exists in at least one space. Disassemble t he fastener. Ensure that the nut can be reassembled by hand for the complete thread length of the bolt excluding thread run-out. Reject the DTI lot if the nut cannot be assembled to this thread length.
b.Installation. Install fasteners using DTIs in two stages. Prevent rotation of t he fastener element during each stage of the installation.
1.First, snug the connection with bolts installed in all the holes of the connection. Then, tighten the bolts sufficiently to bring all the plies of the connection into firm contact. Ensure that t he number of spaces in which a 0.005 in ch-feeler gage is ref used in the DTI after snug does not exceed those listed under Maximum Verification Refusals in Tables 602.17 -9 and 602.17 -10 for the grade and diameter of bolt . If the numbers exceed the values in the table, remove the fastener, install another DTI , and re-snug the fastener.
2.Further tighten t he connection until the number of refusals of the 0.005 -inch feeler gage is equal to or greater than the number listed under Minimum Installation Refusal s in Tables 602.17 -9 and
602.17 10 for the grade and diameter of bolt. If the
fastener is tightened so that no visible gap in any space 602.17 456 remains, remove the bolt and DTI, and replace with a new properly tightened fastener and DTI. Table 602.17-9: DTI Requirements for Grade A325 Bolts Bolt Diameter (inches) Verification Tension (kips) Maximum Verification Refusals DTI Spaces Minimum Installation Refusals ½ 13 1 4 2 5/8 20 1 4 2 ¾ 29 2 5 3 7/8 41 2 5 3 1 54 2 6 3 1-1/8 67 2 6 3 1-1/4 85 3 7 4 1-3/8 102 3 7 4 1-1/2 124 3 8 4 Table 602.17-10: DTI Requirements for Grade A490 Bolts Bolt Diameter (inches) Verification Tension (kips) Maximum Verification Refusals DTI Spaces Minimum Installation Refusals ½ 16 2 5 3 5/8 25 2 5 3 ¾ 37 2 6 3 7/8 51 2 6 3 1 67 3 7 4 1-1/8 84 3 7 4 1-1/4 107 3 8 4 1-3/8 127 3 8 4 1-1/2 155 4 9 5 602.17 457 c. Equipment Required
1.Calibrated bolt tension measuring device with a special flat insert in place of normal bolt head holding insert. Special insert required to allow access to measure DTI gap.
2.Tapered leaf thickness (feeler) gage 0.005 in ch. Same gage as to be used to inspect the bolts after installation.
3.Bolts, nuts, and standard washers to be used in the work with the DTIs.
4.Impact and manual wrench to tighten bolts. Equipment should be the same as to be used in the work.
d.Verification Test Procedure . Conduct three tests for each rotational -capacity lot and position of DTI.
1.Install bolt, nut, DTI, and standard washer (if used) into bolt tension measuring device. Assembly should match that to be u sed in the work.
2.Snug the bolt to no more than 50% of the required installation tension using the equipment that will be used in the work. Use another wrench on the bolt head to prevent rotation of the head against the DTI if the DTI is to be used unde r the unturned element.
3.Further tighten the bolt to tension specified in Table
602.17 11 (which is 1.05 times the required
installation tension of the bolt). Use another wrench on the bolt head to prevent rotation of the head against the DTI if the DTI is to be used under the unturned element. If an impact wrench is used, tighten to a load slightly below the required load and use a manual wrench to attain the required tension. The load indicating needle of the bolt calibrator cannot be read accurately when an impact wrench is used. 602.17 458 Table 602.17 -11 Bolt Diameter (inches) Bolt Tension (kips) Grade A325 Bolts Grade A490 Bolts ½ 13 16 5/8 20 25 ¾ 29 37 7/8 41 51 1 54 67 1-1/8 67 84 1-1/4 85 107 1-3/8 102 127 1-1/2 124 155
4.Determine and record the number of spaces between the protrusion s on the DTI that a 0.005 -inch thickness gage is refused. The total number of spaces in the various sizes and grade of DTIs is listed in Table
602.17 12.
Table 602.17 -12 Bolt Diameter (inches) Number of Sp aces Grade A325 Bolts Grade A490 Bolts ½ 4 N/A 5/8 4 N/A ¾ 5 6 7/8 5 6 1 6 7 1-1/8 6 7 1-1/4 7 8 1-3/8 7 8 1-1/2 8 N/A 602.17 459 5. The number of spaces that the 0.005 -inch thickness gage is refused should not exceed the number specified in Table 602.17 -13. If the number of spaces exceeds the number in the table, the DTI fails the verification test. Table 602.17 -13: Verification Criteria (1) Number of Spaces in Washer Maximum Number of Spaces Gage is Refused 4 1 5 2 6 2 7 3 8 3
1.If the test is a coated DTI under the turned element, the maximum number of spaces the gage is refused is the number of spaces on the washer minus one.
6.Further tighten t he bolt to the smallest gap to be allowed in the work. Normally, this smallest gap is defined as the gap at all the spaces less than 0.005 in ch and not all gaps completely closed. Ensure that t he 0.005-inch gage is refused at all spaces, but a visible gap exists in at least one space. The bolts in this test and in the actual installation should not be installed to a no visible gap condition. The load in the bolt becomes indeterminate when no gap exists. Failure of the bolt due to over -tightening may occur if the bolt is tightened beyond complete crushing of the DTI.
7.Remove the bolt from the calibrator and turn the nut on the threads of the bolt by hand. The nut should be able to be turned on the complete length of the threads, excluding the thread run -out. If the nut is unable to go the full thread length, the load required for the minimum gap in Step 6 is too large. The test must be repeated with a larger minimum gap, for example, one space that will accept a 0.005 -inch feeler gage to 602.18 460 establish the smallest gap allowed in the work for the fastener rotational -capacity lot allowed in the work.
8.Bolts from rotational -capacity lots that are too short to fit in the tension measuring device shall be tested by tightening to the minimum gap in Step 6 and checked in accordance with Step 7. The DTI used with the short bolt should be checked in accordance with Steps 1 through 5 using a longer bolt in the tension measuring device.
602.18 Plate Cut Edges
A.Edge Planing Remove to a depth of ¼ inch all sheared edges of plates that are thicker than 5/8 inch and carry calculated stress. Fillet re -entrant corners to a minimum radius of ¾ inch before cutting.
B.Visual Inspection and Repair of Plate Cut Edges Visually inspect an d repair plate cut edges in accordance with Article 3.2.3 of the AASHTO/AWS Bridge Welding Code , D1.5, current edition.
602.19 Welds
Perform all welding in accordance with the AASHTO/AWS Bridge Welding Code, D1.5, current edition. Where con flicts occur, these Specifications shall govern. All welders shall be qualified in accordance with the AASHTO/AWS D1.5, Bridge Welding Code , current edition. Welders shall be certified for each weld process and position which they will be using. Grind all full penetration welds in webs and flanges flush with the base metal. The following are revisions to the AASHTO/AWS Bridge Welding Code :
1.Add the following sentence to Article 6.1.1.1: After fabrication, Quality Control (QC) shall mark each piece (girde rs, beams, diaphragms, X -frames, bearings, etc.) with the 602.19 461 fabricator’s logo and the CWI Number of the QC Inspector accepting the piece. These stamps will signify that Quality Control (QC) has inspected the piece and that it meets the requirements of the p lans and specifications.
2.Delete Article 6.1.3.1(3).
3.Delete Article 6.1.3.2.
4.Delete the last sentence in Article 6.1.3.4 and substitute the following: Only individuals certified for NDT Level II may perform nondestructive testing.
5.Delete 6.1.3.4 (1) and 6.1.3.4(2) .
6.Delete the period at the end of Article 6.6.1 and add the following: and access to all records necessary to verify conformance to plans and specifications.
7.Delete Article 6.7.1 and substitute the following: Complete joint penetration groove welds in main members, as identified in the contract documents shall be QC tested by nondestructive testing. Radiographic and ultrasonic testing shall both be performed in accordance with the requirements of Section 6.7.1.2:
8.Delete 6.7.1.2(2d) and substitute the following : Longitudinal butt joints in beam or girder webs shall be 100% QC tested by nondestructive testing.
9.Add the following Article 6.17.5: Each Ultrasonic Unit shall be certified for general operational performance at a minimum time interval of 12 months with a method approved by the instrument manufacturer. 602.20 462 602.20 Facing of Bearing Surfaces Finish bearing and base plates and other bearing surfaces that will come in contact with each other or with concre te according to the ANSI surface roughness requirements defined in ANSI B46.1, Surface Roughness, Waviness and Lay, Part I , as specified in Table 602.20 -1. Table 602. 20-1: Surface Roughness Bearing Surface ANSI Roughness Value Steel Slabs 2000 Heavy plates in contact in shoes to be welded 1000 Milled ends of compression members, milled or round ends of stiffeners and fillers 500 Bridge rollers and rockers 250 Pins and pin holes 125 Sliding bearings 125
602.21 Abutting Joints
Face and bring abutting joints to an even bearing in compression members and girder flanges, and in tension members where so shown on the Plans and show working drawings. Where joints are not faced, the opening shall n ot exceed ¼ inch.
602.22 End Connection Angles
Build floor -beams, stringers, and girders having end connection angles to the exact length shown on the Plans, as measured between the heels of the connection angles, with a permissible tolerance of plus 0 inch to minus 1/16 inch. Where continuity is requ ired, face end connections. The thickness of the connection angles shall not be less than 3/8 inch or less than that shown on the detail drawings, after facing.
602.23 Lacing Bars
Neatly round the ends of lacing bars unless another form is required. 602.24 463 602.24 Fabrication of Members Unless otherwise shown on the Plans, cut and fabricate steel plates for main members and splice plates for flang es and main tension members, not secondary members, so that the primary direction of rolling is parallel to the direction of the main tensile and/or compressive stresses. Ensure that fabricated members are true to line and free from twists, bends and open joints.
602.25 Web Plates
In built-up girders having no cover plates and that will not be encased in concrete, the top edge of the web plate shall not extend above the backs of the flange angles and shall not be more than 1/8 inch below at any point. Chip portions of the plate, projecting beyond the angles, flush with the backs of the angles. Web plates of girders having cover plates may be ½ inch less in width than the distance back to back of flange angles. Before painting, use silicone caulk to seal the top of splices of webs in girders without cover plates. At web splices, the clearance between the ends of the web plates shall not exceed 3/8 inch. The clearance at the top and bottom ends of the web splice plates shall not exceed ¾ inch.
602.26 Bent Plates
Furnish un -welded, cold bent, load carrying, rolled steel plates conforming to the following:
1.Take material from the stock plates so that the bend line will be at right angles to the dire ction of rolling, except that cold -bent ribs for orthotropic deck bridges may be bent in the direction of rolling if approved by the Engineer.
2.Before bending, round the corners of the plate to a radius of 1/16 inch throughout the portion of the plate where bending is to occur.
3.Cold bend so that no cracking of the plate occurs. Use the m inimum bend radii, shown in Table 602.26 -1, measured to the concave face of the metal . 602.27 464 Table 602.26-1: Minimum Cold -Bending Radii Thickness (inches) (1,2) Minimum Bending Radii (by Steel Grade) 36 50 50W HPS70W 100 100W t < ¾ 1.5t 1.5t 1.5t 1.5t 1.75t 1.75t ¾ < t < 1 1.5t 1.5t 1.5t 1.5t 2.25t 2.25t 1 < t < 2 1.5t 2.0t 2.0t 2.5t 4.5t 4.5t t > 2 2.0t 2.5t 2.5t 3.0t 5.5t 5.5t
1.t = plate thickness
2.Low alloy steel in thickness over ½ inch may require hot bending for small radii. Allow for spring -back of ASTM A 709 Grade 100 or 100W steels equal to about 3 times that for structural carbon steel. For break press forming, use a lower die span of at least 16 times the plate thickness. Multiple hits are advisable. If a radius shorter than the minimum specified for cold bending is essential, hot bend the plates at a temperature not greater than 1200 F, except for ASTM A 709 Grade HPS70W steels. If A STM A709 Grade HPS70W steel plates to be bent are heated to a temperature greater than 1100 F, re-quench and temper according to the producing mill ’s standard practice. Hot bent plates shall conform to requirement ( 1) above.
602.27 Fit of Stiffeners
Fabricate (by milling, grinding, or welding, as shown on the Plans or otherwise specified) end -bearing stiffeners of girders and stiffeners intended as supports for concentrated loads to provide full bearing on the flanges to which they transmit load or from which they receive load. Stiffeners not intended to support concentrated loads shall, unless shown or specified otherwise, fit sufficiently tight to exclude water after being painted. Fillers under stiffeners shall fit within ¼ inch at each end.
602.28 Eyebars
Pin holes may be flame cut at least 2 inches smaller in diameter than the finished pin diameter. Securely fasten together, in the order that they will be 602.29 465 placed on the pin, all eyebars that are to be placed side by side in the structure and bore at both e nds while so clamped. Pack and match -mark eyebars for shipment and erection. Stamp all identifying marks with steel stencils on the edge of one head of each member after fabrication is completed to be visible when the bars are nested in place on the stru cture. Ensure that the eyebars are straight and free from twists with pin holes accurately located on the centerline of the bar. The inclination of any bar to the plane of the truss shall not exceed 1/16 inch to a foot. Simultaneously cut the edges of ey ebars that lie between the transverse centerline of their pin holes with two mechanically operated torches abreast of each other, guided by a substantial template, to prevent distortion of the plates.
602.29 Annealing and Stress Relievin g
Machine, finish bore, and straighten structural members, indicated in the Contract to be annealed or normalized, after heat treatment. Normalize and anneal (full annealing) according to ASTM A919. Maintain uniform temperatures throughout the furnace during the heating and cooling so that the temperature difference between any two points on the member does not exceed 100 F at any one time. Do not anneal or normalize members of ASTM A709 Grade 100W steels. Stress relieve these g rades only with the Engineer’s approval. Maintain a record of each furnace charge, identifying the pieces in the charge and listing the temperatures and schedule used. Provide proper instruments, including recording pyrometers, for determining at any time the temperatures of members in the furnace. The records of the treatment operation shall be available to and meet the approval of the Engineer. The holding temperature for stress relieving ASTM A709 Grade HPS70W and 100W steels shall not exceed 1100 °F. Stress relieve members, such as bridge shoes, pedestals, or other parts that are built up by welding sections of plate together, according to Section 4.4 of AASHTO/AWS Bridge Welding Code D1.5 when required by the Contract.
602.30 Pins and Rollers
Accurately fabricate pins and rollers to the dimensions shown on the Plans and working drawings and to be straight, smooth, and free from flaws. Forge and anneal pins and rollers more than 9 inches in diameter. Pins and rollers 602.31 466 9 inches or less in diameter may be either forged and annealed or cold - finished carbon steel shafting. In pins larger than 9 inches in diameter, bore a hole not less than 2 inches in diameter full length along the axis after the forging has been allowed to cool to a temperature below the critical range, under suitable conditions to prevent damage by too rapid cooling, and before being annealed.
602.31 Boring Pin Holes
Bore pin holes true to the specified diameter, smooth and straight, at right angles with the axis of the member and parallel with each other unless otherwise required. Produce the final surface using a finishing cut. The distance outside -to-outside of end holes in tension members and inside - to-inside of end holes in compression mem bers shall not vary from that specified more than 1/32 inch.
602.32 Pin Clearances
The diameter of the pin hole shall not exceed that of the pin by more than 1/50 inch for pins 5 inches or less in diameter or by 1/32 inch for larger pins.
602.33 Threads for Bolts and Pins
Provide threads on all bolts and pins for structural steel construction that conform to the Unified Standard Series UNC -ANSI B 1.1, Class 2A for external threads and Class 2B for internal threads; but when pin ends have a diameter of 1 -3/8 inches or more, provide 6 threads to the inch.
602.34 Pilot and Driving Nuts
Provide two pilot nuts and two driving nuts for each size of pin, unless otherwise specified.
602.35 Identification of Steels During Fabrication
A.Identification by Contractor Provide the Engineer with complete certified mill test reports showing chemical analysis and physical tests for each heat of steel for all members 602.36 467 unless excepted by the Engineer . Properly identify for the Engineer each piece of steel to be fabricated. Identify in the shop drawings each piece that is to be made of steel other than ASTM A709 Grade 36 steel. Ensure that pieces made of different grades of steel are not given the same assembling or erecting mark, even if they are of identical dimensions and d etail. Use a system of assembly -marking of individual pieces made of steel other than ASTM A709 Grade 36 steel and of issuing cutting instructions to the shop (generally by cross -referencing the assembly marks shown on the shop drawings with the correspond ing item covered on the mill purchase order) that will maintain identity of the mill test report number. The Contractor may furnish material from stock that can be identified by heat number and mill test report. Mark any excess material placed in stock for later use with the mill test report number and with its AASHTO M 160 (ASTM A6) specification identification color code, if any, when separated from the full -size piece furnished by the supplier.
B.Certification of Identification Upon request, furnish an aff idavit certifying that throughout the fabrication, the identification of steel was maintained in accordance with this Specification.
602.36 Weighing of Members
If it is specified that any part of the material is to be pai d for by actual weight, weigh the finished work in the presence of the Engineer, if practicable. In such case, supply satisfactory scales and perform all work involved in handling and weighing the various parts.
602.37 Full Size Tests
When the Contract requires full size tests of fabricated structural members or eyebars, the Plans or Specifications will state the number and nature of the tests, the results to be attained, and the measurements of str ength, deformation or other performance parameters that are to be made. Provide suitable facilities, material, supervision, and labor necessary for making and recording the tests. The Department will pay for the testing of members in 602.38 468 accordance with the Contract as specified in 602.50. Include the cost of testing, including equipment, handling, supervision, labor, and incidentals for making the tests, in the Contract price for the fabrication or fabrication and erection of stru ctural steel, whichever is the applicable item in the Contract, unless otherwise specified.
602.38 Marking and Shipping
Paint or mark each member with an erection mark for identification. Provide an erection d iagram that identifies the erection marks. Permanently stencil heat numbers on the main material so they will be identifiable in the field. Ensure that the steel fabricator submits three sketches identifying these heat numbers on 8 -1/2 by 11 -inch sheets to the Inspecting Agency and to the Engineer (see example shown in Figure 602.38 -1). 602.38 469 Figure 602.38 -1: Example Diagrams showing Heat Numbers In addition to the heat number shown, the fabricator shall identify all high strength steels regardless of where i t is used. Provide as many copies of material orders, shipping statements, and erection diagrams as the Engineer may direct. Identify the weights of the individual members on the statements. Mark members weighing more than 3 tons with their weights. Loa d structural members on trucks or cars so that they may be transported and unloaded at their destination without being excessively stressed, deformed, or otherwise damaged. 602.39 470 Separately pack bolts of one length and diameter and loose nuts or washers of each size. Ship pins, small parts, and packages of bolts, washers, and nuts in boxes, crates, kegs, or barrels. Ensure that the gross weight of each package does not exceed 300 pounds. Plainly mark the outside of each shipping container with a list and descr iption of the contained material. CONSTRUCTION REQUIREMENTS – ERECTION – REMOVAL
602.39 Erection
Provide the falsework and all tools, machinery, and appliances, including drift-pins and fitting -up bolts, necessary for the expeditious performance of the work. Erect the metalwork, remove the temporary construction, and do all work necessary to complete the structure as required by the Contract . Shear Stud Connectors After erecting the beams , attach the shear stud connectors in compliance with OSHA standards. Install the studs in the locations shown on the Plans. Install and test shear studs in accordance with the latest version of AASHTO/AWS D1.5, Chapter 7 Stud Welding. Clean the surface receiving the studs by shot blasting or grinding to a bright metal surface immediately before welding. Weld studs using automatically timed stud welding equipment only. At the beginning of each day or shift , each individual welder/operator and equipment must complete the Production Control/Pre -production Testing described in paragraph 7.7.1 of AASHTO/AWS D1.5. Only allow individuals , who repeatedly demonstrate satisfactory installation , to install the shear studs. The Contractor is responsible for the q uality of all welds. The Department will inspect and randomly test the welds before any reinforcing steel is placed.
602.40 Handling and Storing Materials
Place material to be stored on the Project on skids above the ground. Keep material clean and properly drained. Place girders and beams upright and shore. Support long members, such as columns and chords, on skids placed near enough together to prevent damage due to deflection. If the Contract is for erection only, check the material received against the shipping lists and report promptly in writing any shortage or damage 602.41 471 discovered. The Contractor is responsible for the loss of and damage to any material in its care.
602.41 Temporary Supports
Design, construct, and maintain temporary supports for steel beam erection to support the loads to which they will be subjected. Submit construction drawings for temporary supports and working drawings for changes in any existing structure necessary for safely maintaining traffic, in accordance with
105.02 All drawings shall be stamped by a Professional Engineer licensed
in the State o f Tennessee.
602.42 Method and Equipment
All contractors and subcontractors directly engaged in the erection or removal of structural steel, precast prestressed or mild steel reinforced concrete bridge beams or girders over active highway traffic lanes, on any route, railroad or any stream deemed navigable to commercial or pleasure water craft, shall submit an erection or removal plan prepared and stamped by a Professional Engineer licensed in the State of Tennessee. Include the following in these plans: the sequences of erection or removal, the generalized location of all pick points, and the plan to adequately stabilize the structure throughout the erection or removal process. Submit this plan to the Engineer at least 30 days before starting ere ction or removal. At each stopping point in the erection or removal sequence, have a competent contractor’s representative inspect the beams to ensure adequate stability. Do not begin any erection or removal work without the Engineer’s approval. The Engineer’s approval does not relieve the Contractor of the responsibility for the safety of its method or equipment or from carrying out the work in accordance with the Plans and Specifications.
602.43 Straightening Bent Material and Cambering
A.Straightening B ent Material Straighten plates, angles, other shapes, and built -up members, when permitted by the Engineer, using methods that will not produce fracture or other damage. Straighten distorted members by mechanical means or, if approved by the Engineer, by the careful planned and supervised application of a limited amount of localized heat, except that heat straightening of ASTM A709 Grade 100W or ASTM A517 steel members shall be done only under rigidly controlled procedures, each 602.44 472 application subject to the approval of the Engineer. Ensure that the maximum temperature of the ASTM A709 Grade 100W and the HPS70W steels does not exceed 1100 °F. Do not apply heat directly on weld metal. In all other steels, do not allow the temperature of the heated area to ex ceed 1200 F as determined by temperature indicating crayons, liquids, bimetal thermometers, or infrared thermometers (conductor or non-conductor). Keep parts to be heat straightened substantially free of stress and from external forces, except stresses re sulting from mechanical means used in conjunction with the application of heat. Following the straightening of a bend or buckle, carefully inspect the surface of the metal for evidence of fracture. Fractured material will be rejected.
B.Cambering Correct er rors in camber in welded beams and girders of ASTM A709 Grade HPS70W and 100W material under rigidly controlled procedures, with each application subject to the Engineer’s approval.
602.44 Misfits
Assume responsibility for all misfits, errors, and damage, and make the necessary corrections and replacements. The Engineer will allow the correction of minor misfits using small amounts of reaming, cutting, and chipping. However, immediately report any error in the shop fabric ation or deformation resulting from handling and transportation that prevents the proper assembling and fitting up of parts by moderate use of drift pins or by a moderate amount of reaming and slight chipping or cutting. Obtain the Engineer’s approval of the proposed method of correction. Perform the correction in the Engineer’s presence.
602.45 Assembling
Accurately assemble parts as shown on the working drawings and follow all match-marks. Carefully handle the mat erial so that no parts will be bent, broken, or otherwise damaged. Do not perform any hammering that will damage or distort the members. Clean bearing surfaces and surfaces to be in permanent contact before assembling the members. Unless erected by the cantilever method, erect truss spans on blocking that is placed to give the trusses proper camber. Leave the blocking in place until the tension chord 602.46 473 splices are fully connected with permanent fasteners and all other truss connections pinned and erection bolted. Do not permanently fasten splices of butt joints of compression members and railing until the span has been swung. For splices and field connections, fill one -half of the holes with erection bolts and cylindrical erection pins (half erection bol ts and half pins) before placing permanent fasteners. Use fitting -up bolts that are of the same nominal diameter as the permanent fasteners and cylindrical erection pins that are 1/32 inch larger.
602.46 Pin Connections
Furnish p ilot and driving nuts for use in driving pins at no cost to the Department. Drive pins so that the members fully bear on the pins. Screw pin nuts tight and burr the threads at the face of the nut with a pointed tool.
602.47 Setting Shoes and Bearings
Do not place shoes and bearing plates on bridge seat bearing areas that are improperly finished, deformed, or irregular. Set shoes and bearing plates level in exact position and to have full and even bearing. Unless otherwise specified, the Contractor may use any of the following methods to set shoes and bearing plates:
1.A preformed fabric pad composed of multiple layers of 8 -ounce duck impregnated and bound with high quality natural rubber or of equivalent and equally suitable materials compressed into r esilient pads of uniform thickness. The number of plies shall be such as to produce a thickness of 1/8 inch after compression and vulcanizing. The finished pads shall withstand compression loads perpendicular to the plane of the laminations of not less t han 10,000 pounds per square inch without detrimental reduction in thickness or extension.
2.Elastomeric Bearing Pads.
3.Grouted Bearing Plate. Do not place any load on them until the grout has set for at least 96 hours. Take adequate provisions to keep the grout well moistened during this period. The grout shall consist of one part Portland cement to one part mortar sand. Unless otherwise shown on the Plans or conditionally approved by the Engineer, cast anchor bolts into the masonry. If the Engineer approves the 602.48 474 drilling of holes for setting anchor bolts, set the bolts accurately, and completely fill the holes with grout meeting the requirements of 921.09. The location of the anchor bolts in relation to the slotted holes in the expansion shoes shall correspond with the temperature at the time of erection. Adjust the nuts on anchor bolts at the expansion ends of spans to allow the free movement of the span.
602.48 Painting
Unless otherwise shown on the Plans or specified in the Contract, perform shop and field painting in accordance with the 603. Pay special attention to 603.06. Grease rollers, when no t painted, with hard grease that will readily adhere to the metal in cold and hot weather. Paint the ends of rollers with the same kind and type of paint as the rest of the structure. COMPENSATION
602.49 Method of Measurement
The Department will measure metal in a structure by the unit, lump sum, when the item is designated “Steel Structures” and by the pound when the item is designated “Structural Steel.” The Department will calculate weight for Structural Steel on the following bases:
A.Unit Weights (pound per cubic foot) The Department will use the material unit weights specified in Table
602.49 1.
602.49 475 Table 602.49 -1: Material Unit Weights Materials Unit Weight (pound per cubic foot) Aluminum, cast or wrought 173.0 Bronze 536.0 Copper-Alloy 536.0 Copper-Sheet 558.0 Iron, cast 445.0 Iron, malleable 470.0 Iron, wrought 487.0 Lead, sheet 707.0 Steel, rolled, cast, copper bearing, silicon, nickel and stainless 490.0 Zinc 450.0
B.Shapes and Plates The Department will compute the weight of rolled shapes, and of plates up to and including 36 inches in width, on the basis of their nominal weights and dimensions, as shown on the Plans, deducting for cuts, and open holes. The Department will compute weights of plates wider than 36 inches on the basis of their dimensions as shown on the Plans, deducting for cuts and holes. To this will be added one -half of the “Permissible Variation in Thickness and Weight,” as tabulated in ASTM A6, General Requirements for Delivery of Rolled Steel Plates, Shapes and Bars for Structural Use.
C.Castings The Department will compute the weight of castings from the dimensions shown on the approved shop drawings, deducting for open holes. To this weight will be added 5% allowance for fillets and overrun. Scale weights may be substituted for computed weights of castings or of small complex parts for which accurate computations of weight would be difficult. 602.49 476 D. High Strength Bolts The Department will include the weight of heads, nuts, single washers, and threaded stick -through of all high tensile strength shop bolts on the basis of the weights shown in Table 602.49 -2. Table 602.49 -2: Weight of High Strength Bolts Diameter of Bolt (inches) Weight per 100 Bolts (pounds) ½ 19.7 5/8 31.7 ¾ 52.4 7/8 80.4 1 116.7 1-1/8 165.1 1-1/4 212.0 1-3/8 280.0 1-1/2 340.0
E.Welds The Department will base the weight of shop and field fillet welds on the weights shown in Table 602.49 -3. Table 602.49 -3: Weight of Shop and Field Fillet Welds Size of Weld (inches) Pounds per Linear Foot ¼ 0.20 5/16 0.25 3/8 0.35 ½ 0.55 5/8 0.80 ¾ 1.10 7/8 1.50 1 2.00 602.50 477 F. Shear Connectors The Department will compute weights of shapes for shear connectors on the basis of their nominal weights per foot as shown on the approved shop drawings. The Department will compute weights of spirals for shear connectors on the basis of the weights per foot as shown on the approved shop drawings. The weight of stud bar shear connectors will be based on Table 602.49 -4. Table 602.49 -4: Weight of S tud Bars Diameter of Shank (inches) Weight per inch of Shank (pounds) Weight of Head (pounds) ¾ 0.125 0.174 7/8 0.170 0.210 1 0.223 0.250
G.Miscellaneous The Department will not include the weight of temporary erection bolts, shop and field paint, boxes, crates, and other containers used for shipping, and materials used for supporting members during transportation and erection.
H.Other Items The Department will measure quantities of other Contract items that enter into the completed and accepted structure for payment in the manner prescribed for the items involved.
602.50 Basis of Payment
The Department will pay for accepted quantities on a unit price per pound or on a lump sum basis, as required by the Contract and as follows: 602.50 478 A. Structural Steel – Per Pound Under Contracts containing an item for Structural Steel, all metal parts, other than metal reinforcement for concrete and metal piling, such as anchor bolts and nuts, shoes, rockers, rollers, bearing and slab plates, pins and nuts, e xpansion dams, weld metal, bolts embedded in concrete, and cradles and brackets, will be considered as structural steel, unless otherwise specified. The Department will pay for accepted quantities of structural steel at the contract unit price per pound f or Structural Steel.
B.Steel Structures – Lump Sum When the bid schedule calls for a lump sum price for Steel Structures, the Department will pay for the item at the contract lump sum price, complete in place and accepted. The Department will not pay for mat erials used in standard tests, unless otherwise indicated on the Plans or in the Special Provisions. The Department will pay for full size fabricated structural members or eye - bars that are tested in accordance with the Specifications, when such tests are indicated on the Plans or in the Special Provisions, at the same rate as for comparable members in the structure. The Department will not pay for members that fail to meet Contract requirements and members that are rejected as the result of tests. The cost of drilling anchor bolt holes is incidental to other pay items. The estimate of the weight for steel structures shown on the Plans is approximate only, and no guarantee is made that it is the correct weight to be furnished. The Department will not adjus t the contract price if the weight furnished is more or less than the estimated weight. If the Engineer directs changes in the work that modify the weight of steel to be furnished, the Department will adjust the lump sum payment as follows:
1.The Departme nt will determine the value per pound of the increase or decrease in the weight of structural steel involved in the change by dividing the contract lump sum amount by the weight of steel in the original structure(s).
2.To determine the adjusted contract lump sum payment, the Department will take the contract lump sum amount, plus or minus 602.50 479 the value of the steel involved in the change. The Department will not allow any additional compensation for such change. 603.01 480 SECTION 603 – PAINTING
603.01 Description ................................ ................................ ................... 480
603.02 Materials ................................ ................................ ...................... 481
603.03 Reserved ................................ ................................ ....................... 482
603.04 Clearing and Removing Obstructions ................................ .......... 482
603.05 Preparing Surfaces ................................ ................................ ....... 482
603.06 Schedule of Painting ................................ ................................ .... 483
603.07 Weather Conditions ................................ ................................ ...... 485
603.08 Storing Paint ................................ ................................ ................. 486
603.09 Mixing Paint ................................ ................................ ................. 486
603.10 Applying Paint ................................ ................................ ............. 486
603.11 Shop Painting ................................ ................................ ............... 489
603.12 Field Painting ................................ ................................ ............... 490
603.13 Repainting Existing Steel Structures ................................ ............ 491
603.14 Protection of Traffic ................................ ................................ ..... 495
603.15 Protection of Structures and Surfaces ................................ .......... 495
603.16 Final Cleanup ................................ ................................ ............... 495
603.17 Method of Measurement ................................ .............................. 496
603.18 Basis of Payment ................................ ................................ .......... 496
DESCRIPTION
603.01 Description
A.General This work consists of surface preparation, paint application, furnishing protection from paint spat ter and disfigurement, and final cleanup. The type, color, and number of paint coats shall be as specified in 603.06 and as shown on the Plans. Each coat, for all systems, shall have a contrasting tint to aid in even application and inspection.
Source: Tennessee Standard Specifications for Road and Bridge Construction, 2021 Edition. Pages 436–488 of 1,072.