7-62 Section 707. Structural Steel Construction
707.01. Description This work consists of fabricating, furnishing, galvanizing, shop cleaning and coating, delivering, and erecting structural steel .
A.Definitions . The following definitions apply to this work: Main Member . Any member on the critical lo ad path that carries dead and live loads . The loss of capacity of this member would have a serious consequence on the structural integrity . Main members include, but are not limited to, rolled beams, plate girders, bent caps, end cross -frames and diaphragms and connecting plates, cross -frames and diaphragms and connecting plates of horizontally curved girder bridges, intermediate cross -frames and diaphragms and connecting plates in the negative moment region of continuous span and cantilevered span beams and girders, columns, arch ribs, link plates, tension ties, truss members, and modular expansion joints. Primary Components . The individual components of a main member including, but not limited to , webs, flanges, bearing stiffeners, splice plates, and cover plates . Secondary Member . Any member other than a main member, not designed to carry primary loads . Secondary members include, but are not limited t o, intermediate cross -frames and dia phragms for straight girders.
B.Plant Certification Requirements. American Iron and Steel Institute (AISC ) certification is required for the structural steel fabrication work listed below.
1.Certified Bridge Fabricator – Simple (SBR): Unspliced rolled beams, pin and hanger assemblies (excluding machining operations), diaphragms, cross-frames, lateral bracing, connection angles, and plates.
2.Certified Bridge Fabricator – Intermediate (IBR) : Spliced (field or shop) rolled beams that are straight or with a radius over 500 feet; built -up I-shaped plate girders with constant web depth (except for dapped ends) with or without splices (field or shop) that are straight or with a radius over 500 feet; built-up I-shaped plate girders with a variable web depth (haunched) that are straight or with a radius over 1,000 feet; trusses with a length of 200 feet or less that are entirely pre-assembled at the certified fabrication plant.
3.Certified Bridge Fabricator – Advanced (ABR) : Tub or trapezoidal box girders, closed box girders , non-preassembled trusses, trusses over MDOT Standard Specifications for Construction Section 707
7-63 200 feet in length, arches, cable-supported bridges, moveable
bridges, and bridges with a radius less than or equal to 500 feet.
4.Bridge Component Quality Management System Certification (CPT) : Bridge rails, stairs, walkways, bridge grid deck and sidewalks, drains, scuppers, expansion joint devices, bearings, ballast plates, mechanical movable bridge equipment , and other highway structures such as cameras, light standards, tower lighting units, dynamic message signs, bridge mounted signs, cantilever signs, truss signs, strain poles, and traffic signal mast arms.
5.Sophisticated Paint Endorsement (SPE): Painting steel surface areas greater than 500 square feet . Society of Protective Coatings (SSPC) QP 3, Certifica tion Standard for Shop Application of Complex Protective Systems, will also be accepted.
6.Fracture Critical Endorsement (FC): Required for the fabrication of steel bridge members designated fracture critical in the contract . The fabricator must also possess valid ABR or IBR certifications as defined above. Correct any findings that do not conform to AISC plant certification. Provide a copy of the certificate of conformance to the Engineer before beginning production. If requested, make all plant certi fication annual and make special , immediate audit findings and audit dates available to the Department for all fabrication plants performing w ork on the project.
C.Shop Cleaning and Coating . Shop clean and coat structural steel in accordance with section 716. 707.02. Materials Provide material in accordance with the following sections : Structural Steel ..................................................................................... 906 High Strength Steel Bolts, Nuts, and Washers ...................................... 906 Pins ....................................................................................................... 906 Shear Developers ................................................................................. 906 Miscellaneous Metals ............................................................................ 908 Elastomeric Bearings ............................................................................ 914 Non-Metallic Washers ........................................................................... 914 Provide b ushings with a nominal wall thickness of ¼ inch, selected from the Qualified Products List. Provide steel castings unless cast iron or other material is requir ed or approved by the Engineer in writing. MDOT Standard Specifications for Construction Section 707
7-64 Provide the Engineer with a Mill Test Report (MTR) from the manufacturer ’s
records that indicates the chemical composition and physical properties of the structural steel material . Provide an affidavit stating that the structural steel material meets the contract . If the MTR is unavailable, arrange f or chemical and physical property tests . Provide a certified copy of the test reports and affidavit to the Engineer at no additional cost to the Department. Identify each MTR and affidavit with the relevant p roject information ( structure number , control se ction, and project number) and specific member piece mark (as shown in the approved shop drawings) . Members designated to be fracture critical in the contract must be considered fracture critical regardless of the direction of stress . Steel material, inclu ding splice plates (excluding fill plates), for fracture critical members (FCM) must satisfy the material specifications stated on the plans and include supplemental requirements for toughness for FCM furnished to Zone 2. 707.03. Construction
A.Shop Drawings . Prepare shop drawings of fabrication details in accordance with subsection 104.02. Do not use contract plans instead of shop drawings . All weld procedure specification (WPS) numbers must be shown in the tail of each weld callout on the shop drawings . Submit all WPSs and supporting procedure qualification records with the shop drawings for the Department ’s review and approval. Do not start fabrication before the Engineer approves the shop drawings and WPS s. Provide the quality assurance inspector (QAI) with a hardcopy of the approved shop drawings and WPSs . Provide the Engineer with one complete set of pay weights for review and approval.
B.Shop Inspection . The Department will provide a QAI to perform shop inspection for structural steel, castings, and similar materials required to be accepted based on Fabrication Inspection in accordance with the contract . The fabricator must establish and maintain an effective quality control program in accordance with AISC and the contract . The Department ’s shop inspection is not a substitute for the fabricator ’s quality control program .
1.Fabrication Notification . Provide the Engineer with a fabrication start date at least 14 days before beginning fabrication. If the f abricator suspends work for a period in which the Department ’s QAI leaves the fabrication plant , provide the Engineer with a fabrication start date at least 14 days, or as approved by the Engineer, before restarting fabrication. MDOT Standard Specifications for Construction Section 707
7-65 2. Prefabrication Meeting . A prefabrication meeting will be held
between the Engineer and fa bricator before fabrication begins . The fabricator must provide the following representatives: plant manager and quality control manager , engineering and production personnel as appropriate, and if applicable, subcontractor representatives who are to perform operations including, but not limited to, coating, galvanizing, fabrication, and testing. The fabricator must review all aspects of the contract prior to the prefabrication meeting to avoid problems that may complicate or delay fabrication. The fabricator must provide the Engineer with the proposed fabrication schedule and delivery of completed material .
3.Inspection Facilities . Provide facilities for the inspection of material and workmanship at no additional cost to the Department and in accordance with subsection 809.03.A, except as follows:
a.Provide an office close to the fabrication facility with at least 120 square feet of floor space and shared by no more than one other QAI. The Engineer may approve sharing larger offices with additional QAI s.
b.Provide a parking space for the QAI next to the office.
c.Include a desk , chair , locker, plan rack, secure storage space for testing equipment, high-speed broadband internet service, and a telephone.
4.QAI Authority . The QAI has the authority to inspect the work at the fabrication facility in accordance with subsection 104. 01.E. If problems arise that the QAI cannot resolve, the Engineer will arrange a meeting with the QAI, Contractor, and fabri cator to resolve the issue.
5.Acceptance. Acceptance of structural steel material will be based on the two-part process described in MDOT’s Structural Fabrication Quality Man ual. The E ngineer may reject fabricated members at the project site that the QAI accepted at the shop because of damage or deficiencies . The Engineer will evaluate the damage or deficiencies on a case-by -case basis if the f abricator submits a nonconformance report (NCR) for the Engineer to revie w.
C.Fracture Critical Members. Fabrication procedures must follow the current AASHTO/AWS D1.5, Bridge Welding Code, as modified herein. All members (plates, bent plates, or rolled shapes) welded to fracture critical members must be considered fracture criti cal regardless of the direction of stress. All gusset plates, splice plates (excluding fill plates), and strengthening material (plates, bent plates, or rolled shapes) bolted to a fracture critical member must be considered fracture critical regardless of MDOT Standard Specifications for Construction Section 707
7-66 the direction of stress . This includes stiffener plates used as a connection
plate.
D.Furnishing and Fabricating
1.Direction of Rolling . Steel plates for main members and flange splice plates must be cut and fabricated so the primary direction of rolling is parallel to the direction of the main tensile and/or compressive stresses. Steel web splice plates, fillers, gusset plates not serving as chord splices, connection plates, and web stiffeners are not included in this rolling direction requirement.
2.Identificat ion. Identify all structural steel materials in accordance with ASTM A6/A6M . Transfer heat numbers to primary components removed from larger plates immediately after cutting. Use temporary markings that will remain integral with a component or member through fabrication until the final member is permanently identified using low -stress stamps or dot matrix. Do not s tamp link plates, pin plates, or pins . Stamp main members in the top flange cross -sectional area or on the top of the compression flange within 6 inches of the beam end before coating. Show the match -marking scheme on the shop drawings . Markings must be legible after completion of the final coating system. A low -stress die stamp is defined as a round bottom impression tool producing an indentation conforming to the dimensions shown in Table 707-1. Table 707- 1: Low-Stress Die Stamping Tool Dimensions (in ch) Character Size Minimum Tip Radius Nominal Impression Width for 0.010 Inch Depth 1⁄16 0.005 0.020 3⁄32 0.006 0.021 1⁄8 0.007 0.022 3⁄16 0.008 0.026 ⁄4 0.010 0.031 3⁄8 0.014 0.042 1⁄2 0.020 0.062
3.Workmanship . Fabricate bridge steel components in accordance with Clause 3 of A WS D1.5, except as modified herein. When flame cutting bridge member flange and web plates, flame cut both edges simultaneously to reduce warpage and distortion. MDOT Standard Specifications for Construction Section 707
7-67 Fabricate structural steel components in accordance with Clause 5 of
AWS D1.1 , Structural Welding Code– Steel (AWS D1.1), except as modified herein.
4.Lifting Methods . Lifting lugs may be used for beams and girders provided they are weld ed to the top of the top flange in areas subject to compression in the final structure. Lifting lugs may be used for other members provided they are welded in areas subject to compression in the final structure as approved by the Engineer . Lifting lugs must be designed by a Professional Engineer licensed in the State of Michigan. Submit lifting lug detail and design calculations to the Engineer for review and approval before fabricating. Perform VT and MT on the entire length of all fillet welds in accordance with subsection 707.03. D.11. Include a note on the shop drawings describing whether lifting lugs will lift one member or assemblies of two or more members. Remove lifting lugs immediately after erecting the member by cutting and grind ing the area to a smooth transition to a roughness not exceeding 125 micro -inches per inch root mean square (rms). After the lifting lugs are removed, perform VT, MT, and d ye PT on the entire base metal area in accordance with subsection 707.03. D.11 at all locations where welds were removed. Provide lifting devices with softeners to prevent damage. If using hooks for lifting, provide jaw and throat widths large enough to prevent damage. Provide spreader beams or multiple cranes for lifting plates and long, slender members to prevent overstress and distortion.
5.Distortion and Shrinkage . Control distortion and shrinkage in bridge fabrication in accordance with Clause 3 of AWS D1.5. Prepare a welding sequence and distortion control program in accordance with Clause 3 of AWS D1.5 before the start of welding on bridge member s. Control distort ion and shrinkage in non- bridge structural steel members in accordance with Clause 5 of AWS D1.1.
6.Straightening and Repair of Damaged Material . Submit a heat straightening plan to the Engineer for review and approval before the start of straightening. Straighten material without producing cracks or other damage. Straighten distorted members by carefully planned and supervised application of limited localized heat in conjunction with mechanical restraining forces . Do not heat material that meet s ASTM A709/A7 09M HPS70W and HPS100W above 1100°F or above 1 200°F for all other steels as determined by temperature-indicating crayons, liquids, or bimetal thermometers . Inspect the surface of the metal for MDOT Standard Specifications for Construction Section 707
7-68 damage after straightening. Perform VT and MT on the entire
heat-straightened area and on all weldments in or adjacent to the heat-straightened area as directed by the Engineer. Straighten flanges for bridge members with butt -welded connections before fitting flanges to the web. Remove distortion from welding or handl ing by applying heat over the full width of the flange and cool slowly . Do not force cooling. Complete straightening before performing VT and MT o f the welds . The Engineer may reject material with kinks or bends.
7.Dimensional Tolerances. The dimensions of bridge members must comply with the tolerances shown in Clause 3 of AWS D1.5, AISC 303, and the contract . The dimensions of other structural steel members must comply with the tolerances shown in Clause 5 of AWS D1.1, AISC 303, and the contract .
8.Cambering . For projects designed in accordance with the AASHTO LRFD Bridge Design Specifications , accomplish cambering, camber adjustment, and horizontal curvature of bridge members by heat or by cutting in accordance with the AASHTO LRFD Bridge Constr uction Specifications . For projects designed in accordance with AASHTO Standard Specifications for Highway Bridges , 17th edition, accomplish cambering, camber adjustment, and horizontal curvature by heat in accordance with Division II of AASHTO Standard Sp ecifications for Highway Bridges. When cover plates or stiffeners are to be attached to rolled beams/plate girders , the beams/girders must be heat -curved before the cover plates and stiffeners are attached. For projects designed in accordance with the AASHTO LRFD Bridge Design Specifications , accomplish cold or hot bending in accordance with the AASHTO LRFD Bridge Construction Specifications . For projects designed in accordance with AASHTO Standard Specifications for Highway Bridges , accomplish cold or hot bending in accordance with Division II of AASHTO Standard Specifications for Highway Bridges . Use temperature monitoring devices during the heating process to verify the temperature. The fabricator must m easure the camber of each bridge member in the shop with the QAI present .
9.Fit of Stiffeners . Remove and correct stiffeners showing evidence of compressive stress, such as waviness along the stiffener length, after fitting is completed but before welding. Stiffeners must be fabricated MDOT Standard Specifications for Construction Section 707
7-69 with a tight fit in accordance with AWS D1.5 unless otherwise stated in
the contract .
10.Shop Welding
a.General Bridge Welding . Weld bridge main members and secondary members in accordance with AWS D1.5 as modified herein. When necessary, use a butt joint for primary components (flanges and webs for flexural members and plates for axial members) of main members using CJP groove welds prior to welding the primary components together to form the member . Use the automatic SAW process in the flat (1F or 1G) or horizontal (2F) welding positions to make the following welded connections as specified in the contract:
a.Flange-to -flange and web-to -web butt joint;
b.Flange-to -web corner or T -joint;
c.Plate-to -plate corner or T -joint for built -up axial members;
d.Cover-plate lap joint; and
e.Stiffener and connection plate T-joint to web. Use the SMAW process , handheld SAW process, flux -cored arc welding (F CAW), or GMAW process to make the following welded connections as specified in the contract:
a.Stiffener and connection plate T -joint to flanges;
b.Internal stiffener and connection plate T -joint (built -up box, trapezoidal , or 3-sided members);
c.Intermediate cr oss frames for horizontally curved girders; and
d.Other welding applications if the limited access, isolated locations, or short weld lengths render the use of automatic or semi -automatic welding equipment impractical as determined by the Engineer. Use E7018 electrodes for the SMAW process unless the contract requires use of a different electrode specification and classification . Do not weld using e lectroslag or electrogas processes . Do not use GMAW on FCM. MDOT Standard Specifications for Construction Section 707 7-70 Remove weld metal splatter on adjacent base metal using a procedure approved by the Engineer before blast cleaning and coating the steel. Maintain areas where welding is taking place at an ambient temperature of 40°F for at least 1 hour before the start of welding and during the entire welding operation. Provide a minimum 5⁄16-inch fillet weld for the following connections unless a larger weld size is specified in the contract :
a.Flange-to -web T -joint;
b.Plate-to -plate T -joint for built -up axial members; and
c.Cover-plate lap joint. Determine the mini mum fillet weld size for all other bridge welding in accordance with Table 707-2, unless a larger weld size is specified in the contract. Table 707- 2: Minimum Fillet Weld Size Base Metal Thickness of Thicker Part Joined, T (inch ) Minimum Size of Fillet Weld (in ch) T ≤ ¾ ¼ ¾ < T ≤ 1 ½ 5⁄16 1 ½ < T ≤ 2 ¼ 3⁄8 2 ¼ < T ≤ 6 ½ T > 6 5⁄8 Determine the minimum partial joint penetration (PJP) groove weld size for all bridge welding in accordance with Table 707-3 unless a larger weld size is specified in the contract . Table 707- 3: Minimum Effective Weld Size for PJP Groove Weld Base Metal Thickness of Thicker Part Joined, T (in ch) Minimum Effective Weld Size(a) (inch) T ≤ ¾ ¼ ¾ < T ≤ 1 ½ 5⁄16 1 ½ < T ≤ 2 ¼ 3⁄8 2 ¼ < T ≤ 6 ½ T > 6 5⁄8
a.The effective throat need not exceed the thickness of the thinner part. MDOT Standard Specifications for Construction Section 707 7-71
b.General Structural Steel Welding . Perform structural steel welding in accordance with AWS D1.1 as modified herein. The following structures and members are required to be welded in accordance with AWS D1.1: Highway structures including, but not limited to, light standard, tower lighting unit , dynamic message sign, bridge-mounted sign, cantilever sign, truss sign, strain pole, traffic signal mast arm, and other highway structures specified in the contract; Bridge railing; Stairs and walkway s; Bridge deck grids; Sidewalk grids; Bridge expansion joint s (except modular expansion joints) ; and Mechanical moveable bridge equipment . Use E7018 electrodes for the SMAW process unless the contract requires the use of a different electrode specification and classification . Do not use electroslag or electrogas welding processes . Remove weld metal splatter on adjacent base metal using a procedure approved by the Engineer before blast cleaning and coatin g the steel. Determine the minimum fillet weld size for structural steel welding in accordance with AWS D1.1 unless a larger weld size is specified in the contract . Determine the minimum PJP groove weld size for structural steel w elding in accordance with AWS D1.1 unless a larger weld size is specified in the contract .
c.Welder Endorsements. Welding personnel , such as welders, welding operators, and tack welders , must be qualified in accordance with AWS D1.5 for bridge welding and AWS D1.1 for structural steel welding . Additional performance testing is required in accordance with MDOT ’s Welder Qualification Program under the supervision of the QAI . Welder performance endorsements from other agencies will not be accepted. The period of effectiveness for shop welding personnel endorsed through MDOT ’s Welder Qual ification Program is 3 years unless welding personnel are not engaged in a welding process for at MDOT Standard Specifications for Construction Section 707
7-72 least 6 months or a specific reason exists to question the welder ’s
ability . The Engineer may require a confirming performance test during the progress of the work.
11.Nondestructive Testing of Bridge Welds . NDT of bridge welds is required in accordance with AWS D1.5 except as modified herein. The fabricator must provide labor, equipment, and materials for testing as specified in the contract . The Engineer may review the NDT equipment, materials, an d procedures . Do not begin NDT before QAI is present. Personnel certified as Level II in accordance wit h the ASNT Recommended Practice No. SNT -TC-1A must perform NDT as required by the contract . VT of the entire length of all welds must be performed by a CWI . Perform UT of the entire length of all plug and slot welds in main members.
a.Scope of Examination of Groove Welds . Conduct r adiographic testing (RT) of CJP groove welds in butt joints of main members . Use UT methods for examining CJP groove welds in corner and T-joints of main members . RT or UT frequency of CJP groove welds in main members must be performed in conformance with AWS D1.5 except as specified below: 100% of each flexural member flange butt joint subject to tension or compression; 100% of each axial member joint subject to tension or reversal of stress; Vertical web joints must be tested for one-third of the web depth beginning at the point of maximum tension but not less than 12 inches . In addition, test 25% of the remainder of the web depth beginning at the point of maximum compressi on but not less than 12 inches. 25% of each axial member joint subject to compression; 25% of each joint subject to shear such as web to flange joints in flexural member s; and If unacceptable discontinuities are found in any of the above partial examinations , test the remainder of the weld and test 100% of similar welds. Place RT film on each side of the joint on the planar side of the plate. Film may need to be double loaded on thicker side of joint to improve density readings . Correctly p osition the pack on the transition side of the plate and use tapered edge blocks . If MDOT Standard Specifications for Construction Section 707
7-73 substandard images result from film placement on the planar side,
move the film to the transition side and retest . Use extension blocks to extend RT film at least 1 inch beyond the edges of the joint being RT . Submit UT procedures for CJP groove weld corner joints and other weld joints with backup bars to the QAI for review prior to performing NDT. Perform RT or UT on all CJP groove welds and provide final reports to the QAI before assembling and welding t o fabricate members . Perform PT of both ends of all CJP and PJP groove welds in the main members listed in subsection 707.01.A or specified in the contract in accordance with ASTM E165/E165M. Perform MT at least 12 inches in every 10 feet of each PJP groove weld connecting primary components of main members or connecting a secondary component to a main member . Perform MT in accordance with ASTM E709 with dry powder using the yoke method. Make required identification marks on CJP groove welds in butt joints with paint . Do not stamp identification marks.
b.Scope of Examination of Fillet Welds . Perform MT of fillet welds joining primary components of main members and secondary components welded to main members in accordance with AWS D1.5 except as modified herein. Perform MT in accordance with ASTM E709 with dry powder using the yoke method. Perform MT at least 12 inches in every 10 feet of each fillet weld for the following joints: Web to flange of girders, floor beams, stringers; Plate to plate for built -up axial members; End diaphragm connection plates to web or flange; Diaphragm sealing plate or gussets to web or flange in box members; Cross-frame and diaphragm assemblies on curved bridges; Sole plate to flange; and Intermediate stiffeners and connection plates to web. MDOT Standard Specifications for Construction Section 707
7-74 Perform MT of the entire length of each stiffener or connection
plate fillet weld connecting to the tension flange of main members . Locate the MT randomly in members to produce results typical for each fillet weld size . If test results show unacceptable defects, test the full length of the weld or 5 feet on each side of the tested length, whichever is less.
c.Weld Condition . Clean paint, scale, grease, slag, and other deleterious material from welded edges and surfaces . Grind flange, web, and pin plate CJP groove welds flush on aligned side and merge smoothly on transition side. Finish surfaces to a roughness rating of 125 micro -inches per inch rms or less. Remove loose mill scale adequately away from the weld joint to allow UT using the required scanning patterns and testing angles.
d.Defective Welds. Repair and replace welds with rejectable defects documented by the fabricator or Department personnel, regardless of the NDT method and regardless of conflicts in test results from other NDT methods . Submit an NCR for the Engineer ’s approval before beginning repairs. Repair or remove and replace welds in accordance with AWS D1.5. Perform NDT on repaired or r eplaced welds, including at least 3 inches on all sides of the repair, using the methods and frequencies stated in the contract. Remove and replace the entire weld if a second repair attempt results in a defective weld. The Engineer may reject the entire member if it is determined that the weld defects are excessive, proposed weld repairs are excessive, or the same defect undergoes weld repair more than twice.
12.Nondestructive Testing of Structural Steel Welds. NDT of structural steel welds is required in accordance with AWS D1.1 except as modified herein. The fabricator must provide labor, equipment, and materials for testing as specified in the contract . The Engineer may review the NDT equipment, materials, an d procedures . Do not begin NDT before the QAI is present. Personnel certified as Level II in accordance with the ASNT Recommended Practice No. SNT -TC-1A must perform all NDT tests . VT must be performed by a CWI on the entire length of all welds. Perform PT on both ends of all CJP a nd PJP groove welds in the structures and members listed in subsection 707.03.D.10.b in accordance with ASTM E165/E165M. MDOT Standard Specifications for Construction Section 707
7-75 Perform MT on at least 12 inches in every 10 feet of each PJP groove
weld and fillet weld in the structures and members listed in subsection 707.03.D.10.b, except that MT is not required for walk platform welds used on dynamic message signs, end cap welds, and other welds determined by the Engineer. Perform MT in accordance with ASTM E709 with dry powder using the yoke method. Perform UT of the entire length of all CJP groove, plug, and slot welds in the structures and members listed in subsection 707.03.D.10.b.
13.Splices and Connections
a.Shop Splices . Bridge member web, flange, and cover plates may be shop splice provided the girder is great er than 50 feet long, but cover plates may only contain one splice. Built-up axial member plates may be shop spliced provided the axial member is greater than 50 feet long. Obtain the Engineer ’s approval for the location of shop splices. Separate bridge member web, flange, and cover plate splices by at least 1 foot and separate these splices from stiffener and connection plate welds by at least 1 foot.
b.Holes for High Strength Bolts . Punch or drill all holes . Hole punching is limited to material thickness no greater than 3⁄4 inch for carbon steel , 5⁄8 inch for high- strength (low-alloy structural steel ), and 1⁄2 inch for high-strength (low -alloy, quenched, and tempered structural steel) . When punching full -size holes, provide a die with a diameter that does not exceed the diameter of the punch by more than 1⁄16 inch. When required, subpunch or subdrill holes 3⁄16 inch smaller than required and ream or drill to full size after assembling. For subpunching, provide a die wi th a diameter that does not exceed the diameter of the punch by more than 3⁄32 inch. Drilling holes full size is allowed while working on the splice if all material is assembled since it will be used in the final splice assembly . When drilling assembled splices, predrilling one plate full size for use as a template is acceptable. Drilling holes full size with computer numerically controlled (CNC) equipment is allowed. Verify the accuracy of CNC -drilled full -size holes during assembly with all plates installed. Match -mark all joints that have been reamed or drilled with the parts assembled . Partially assemble joints with plates attached (after faying surfaces are cured) so erecting crews do not MDOT Standard Specifications for Construction Section 707
7-76 misplace, interchange, or reverse joint parts . Match -mark in one
location using dot matrix or low-stress die stamping. Show match -marking schemes on the shop drawings and obtain the Engineer ’s approval for mark locations. Bridge main member bolt hole diameters must not exceed 1⁄16 inch larger than the nominal bol t diameter specified in the contract in all plies of bolted joints . Secondary member bolt hole diameter must not exceed the following: 3⁄16 inch larger than 5⁄8 inch through 7⁄8 inch nominal bolt diameter; 1⁄4 inch larger than 1 inch nominal bolt diameter ; and 5⁄16 inch larger than 11⁄8 inch and greater nominal bolt diameters . Clean cut bolt holes without torn, ragged, burred, or crimped edges . Do not w eld to fill , butter, or repair misplaced drilled or punched holes.
14.Assembly . Field connections of bridge main members for trusses, arches, continuous beams, plate girders, bents, towers, and rigid frames must be preassembled in the shop prior to erection to verify the geometry of the completed structure or unit and to verify and prepare field splices . Before reaming, obt ain the Engineer ’s approval of each assembly, including camber, alignment, accuracy of holes, and fit of milled joints . Maintain a gap no greater than ⅜ inch between girder ends at bolted field splices. Provide a camber diagram to the Engineer that show s the camber at each panel point of each truss, arch rib, continuous beam line, plate girder, or rigid frame. Show the camber measured in assembly on the camber diagram if shop assembly is according to the methods described in subsection 707.03.D.14.a or 707. 03.D.14.d. For other shop assembly methods, show calculated camber on the camber diagram. Use bolts for assembly of the same diameter as bolts required for erection. Use pins for assembly of the same diameter as the hole and in sufficient number to ensure accuracy. Do not allow drifting performed during assembl y of field connections to enlarge holes or distort steel . Ream under -size holes to admit bolts . Do not m ove assemblies or disassemble a joint before drilling and MDOT Standard Specifications for Construction Section 707
7-77 reaming is complete and before providing the QAI with the opportunity
to inspect the holes and markings. If temporary fitting aids are proposed to be tack welded to the member, submit a plan for the Engineer to r eview . Do not tack weld fitting aids to the flange. For structures up to 150 feet in length, assemble using the method described in subsection 707.03.D.14.a. For structures 150 feet in length and greater, assemble using the method described in subsection 707.03.D.14.b.
a.Full Beam, Girder, Arch Rib, or Truss Assembly . Assemble members of each continuous beam line, girder line, arch rib, truss, bent, tower , or rigid frame for structures up to 150 feet in length at one time.
b.Progressive Beam, Girder, Arch Rib, or Truss Assembly . Assemble three contiguous longitudinal sections of truss panel, arch section, or longitudinal member accurately adjusted for line and camber . Successive a ssembl ies must consist of at least one carry-over longitudinal segment of the previ ous assembly, repositioned for accurate alignment (i.e. , providing the advancing assembly the proper relative rotation and horizontal and vertical position), plus one or more longitudinal segments at the advancing end.
c.Progressive Chord Assembly . When required in the contract, follow method described in subsection 707.03.D.14.b, except locate the holes in the truss connections to provide the final desired geometry . Vertical and diagonal truss panel members have connections to each truss chord made separately, based on calculated deflections, so top and bottom chords cannot be placed in a concurrent shop assembly . This assembly process requires that the truss members, when erected in a supported condition, must be forced to fit the end conditions . This condi tion introduces an initial reverse secondary stress that theoretically disappears when the structure carries its own weight and members become straight.
d.Special Complete Structure Assembly . When required in the contract, simultaneously shop- assemble all structural steel, including the diaphragms, cross -frames, integral steel substructure, and floor components . Miscellaneous components are not included unless specified in the contract. MDOT Standard Specifications for Construction Section 707
7-78 15. Pins and Link Plates. The contract drawings show the nominal
diameter of pins . The fabricator must establish the exact diameter of the pin, show it on the shop drawings within +0 inch and −1⁄32 inch of the nominal diameter and then fabricate the pin to within ±0.005 inch. Provide stainless steel hanger pins . Finish the surface to less than 16 micro -inches per inch rms on the bearing surface and less than 125 micro -inches per inch rms on the ends. Finish the surface on link plates to less than 125 micro -inches per inch rms on cut edges and bored holes. Orient the longitudinal axis of the link plates and pins in the direction of rolling or forging of plates or bars. Do not w eld on pins or link plates . Finish pin holes smooth, straight, at right angles to the axis of the member, and parallel to each other. Do not exceed 1⁄32-inch variation from the required distance from outside to outside of adjacent pin holes in tension members or from inside to inside of adjacent pin holes in compression members . Bore built-up members after welding. Drill or bore link plates in a jig or in assembled pairs. Drill or bore the pin hole in the web 1⁄32 inch ±0.005 inch larger than the pin diameter.
16.Bushings for Pins and Link Plates . Prime the inside of the holes in the link plate with an organic zinc -rich primer before installing bushings . Install bushings before the primer dries . Install bushings with an interference fit of at least 0.001 inch. Provide a clearance from 0.005 to 0.015 inch between the inside diameter of the bushing and the finished dia meter of the stainless steel pin.
17.Bearings and Bearing Surfaces. The fabricator may build up sole plates 3 inches thick or greater by welding together 1½ -inch-thick or greater plates. Bevel plate edges ¼ inch and weld with a continuous PJP groove weld along the full perimeter using the SMAW process . Plane the top and bottom surfaces of column and pedestal base plates and cap plates or flatten by pressing if the plates are less t han 4 inches thick . Face member parts, contacting column and pedestal base plates , and cap plates to fit. Verify sole plates on beams and plate girders fully contact flanges within 1⁄32 inch for at least 75 % of the projected area of the flange and sole plate . Provide structural weld s around sole plates for joints not specified to be welded to seal the joint from moisture intrusion as MDOT Standard Specifications for Construction Section 707
7-79 directed by the Engineer at no additional cost . Satisfy flatness
tolerances for sole plates and masonry plates by plan ing, heat straightening , pressing, or a combination of these methods . If planing is required on welded pedestals, complete the welding prior to planing. Planing surfaces bearing on elastomeric bearing pads is not required. Verify planed or bored bearing surfaces meet the following roughness rating values:
a.Bridge rockers, 250 micro -inches per inch rms; and
b.Pin holes and sliding bearings, 125 micro -inches per inch rms .
18.Finished Members. Provide finished members true to the line shown on the plans and free of twists, bends, and open joints. Break or condition the corners of exposed steel edges and thermally cut edges by grinding or other methods approved by the Engineer before shop cleaning and coating. Repair damage caused by handling and shipping to the Engineer ’s satisfaction.
19.Correction of Errors or Defects . Obtain the Engineer ’s approval for the proposed method of correcting errors or defects in fabricated material prior to beginning the corrective work. Perform repairs in a timely manner unless the Engineer approves delaying the work until later fabrication stages. Obtain written approval from the Engineer before beginning corrective work paid by the Department . Maintain an accurate record of the labor, equipment, and m aterials and present an itemized bill for the Engineer ’s review and approval . Correlate records daily with those kept by the QAI .
20.Galvanizing Structural Steel . Hot-dip galvanize position dowels , anchor bolts , nuts, and washers in accordance with AASHTO M232 . Remove excess hot -dip galvanizing on threaded portions by centrifuging or air blasting upon withdrawal . Do not f lame-chas e. Galvanize portions of bearings not welded to the structure and other structural steel requiring galvanizing in accordance with section 716.
21.Handling and Storing Materials . Store structural steel material on platforms, skids, or other supports above high-water elevations . Maintain materials free of dirt, oil, or other contami nants and protect from corrosion . Pad structural steel members in storage at points of contact . Pitch trough sections to provide drainage. Support long members at frequent intervals to prevent deflection. Handle, store, MDOT Standard Specifications for Construction Section 707
7-80 and brace members in the erected position to avoid distortion, unless
otherwise authorized by the Engineer. Protect fasteners from dirt and moisture on the project . Remove only the number of fasteners required to be installed and tightened during a work ing shift. Lubricant must not be removed from fasteners . Visible corrosion or contamination is a cause for rejection of the fasteners. Handle fabricated structural steel members and primary components of main members with clamps or plate hooks that do not leave nicks, gouges , or depressions . Repair damage to main members using methods approved by the Engineer . Repair damage consistent with the delivery of structural steel in accordance with ASTM A6/A6M and AWS D1.5 . Do not use chains or chokers for handling structural steel, unless placing a protective shield (softener) between the chain or choker and the structural steel . Minimize handling stresses on beams and girders during transportation, storage, and erection. Use a one-point pickup so overhang does not exceed the values specified in Table 707-4 . Do not exceed the distances specified in Table 707- 4 between hooks for a two-point pickup. Table 707- 4: Rigging Requirements Beam Size 30-inch WF 33-inch WF 36-inch WF Plate Girders Overhang for one-point or 2-point pickup, m aximum 37 feet 40 feet 42 feet 50 feet Distance between hooks for 2-point pickup, m aximum 74 feet 80 feet 85 feet 100 feet WF = wide flange
22.Shipping . Provide the Department with copies of the bill of lading as directed by the Engineer . Show the weights of individual members on the statements . Mark weights on the member if greater than 6 tons. Load, transport, and unload structural members using trucks or railcars, without stressing, deforming, or otherwise d amaging members . Place a protective shield between the chain or chain binder and main members during shipping, to prevent gouging the flange edges or damaging the coating. Pack bolts, nuts, and washers of each size separately . Store and ship pins, small parts, and packages of bolts, washers, and nuts in clean, moisture -proof boxes, crates, kegs, or barrels . Limit the gross weight of each package to 300 pounds . Provide a list and description of contents on the outside of each shipping container. MDOT Standard Specifications for Construction Section 707
7-81 E. Erection
1.Methods and Equipment . Before beginning work, obtain the Engineer ’s approval for proposed equipment and erection methods . Do not use material intended for the finished structure for erection or temporary purposes , unless otherwise shown on the plans or approved by the Engineer. The Engineer ’s approval does not relieve the Contractor of the responsibility for the safety of the method or equipment.
2.Bearing s. Position column bases, truss and girder pedestals, shoes, and bearing plates with a full, uniform bearing on the substructure concrete. Adjust bearing plate and masonry plate locations and rocker positions to compensate for temperature at the time of er ection.
3.Falsework. Build and remove falsework in accordance with subsection 706.03.C and subsection 706.03.O.
4.Assembling . Assemble parts according to the plans and approved shop drawings . Do not damag e structural steel during erection. Clean rust, loose mill scale, dirt, oil or grease, and other deleterious material from bearing surfaces and surfaces in permanent contact before assembly. At the time of erection, coat machine-finished surfaces with a high-performance synthetic polymer lubricant approved by the Engineer . Lubricate pedestal and rocker -to-sole plate surfaces and sliding metal -on-metal bearing surfaces. Align all parts in field splices and connections before inserting connection bolts . The Engineer may direct filling at least 10 % of each splice connection with temporary bolts to bring the plies of steel tight before installing permanent bolts . Install permanent bolts in remaining splice locations and tighten to a snug-tight condition per subsection 707.03.E.6.c . Remove temporary bolts and replace with permanent bolts and tighten to a snug-tight condition. Tighten all permanent bolts using the turn- of-nut (TON) method per subsection 707.03.E.6.d. Bolts used in bottom flange field splices must be positioned with the head on the bottom side of the bottom flange and the nut on the top side of the bottom flange. Likewise, bolts in the fascia member must be positioned with the head on the outside (fascia) of the structure and the nut on the interior side of the structure. If field -splicing girders in the air, install one-third of the bolts, evenly distributed over the connecting members , and snug tighten before releasing lifting devices. MDOT Standard Specifications for Construction Section 707
7-82 Tighten bolts in spans of continuous girders using the TON tightening
method in accordance with subsection 707.0 3.E.6.d before casting deck concrete.
5.Misfits . Correct and replace misfits, errors, and damage at no additional cost to the Department . Obtain the Engineer ’s approval of correcti ve actions prior to beginning repairs . Do not f orce structural steel members into place. The Engineer must witness all repairs .
6.High -Strength Bolted Connections . A high- strength bolt assembly consists of one high-strength bolt, one heavy hex nut, one hardened circular washer, and one lock washer where required. Provide a high-strength bolt assembly for each hole in the connection of structural joints . Provide 5% more assemblies of each bolt diameter and length than required. Use the same lot combinations of high-strength bolt assemblies for f ield assembly of structural joints as those tested and approved by the Engineer. Install a hardened circular washer under the end of the high -strength bolt assembly (head or nut) rotated during tightening. Additionally, install hardened circular washers to cover oversized holes where required in the outer plies of the structural joint .
a.Connected Plies. All connected plies within the grip of the bolt and any materials that are used under the bolt head or nut must be steel . Compressible m aterials must not be placed within the grip of the bolt . Faying surfaces and surfaces adjacent to the bolt head and nut must be free of mill scale, burrs, dirt, and other foreign material. All bolt holes in the plies must be aligned to allow insertion of t he bolt without undue damage to the threads. The s lope of the outer ply surfaces in contact with the bolt head and nut must be equal to or less than 1:20 with respect to a plane that is perpendicular to the bolt axis . Use beveled square or rectangular was hers to compensate for slopes greater than 1:20. If the beveled washer is not hardened, install a hardened circular washer between the beveled washer and end of the high-strength bolt assembly ( head or nut) being rotated.
b.Pre-Installation Bolt Tension Veri fication . Pre-installation verification is required for high-strength bolt assemblies to verify the TON pretensioning method results in the required minimum bolt tension. Use a tension calibrator that is calibrated annually to verify the following: MDOT Standard Specifications for Construction Section 707 7-83 Suitabi lity of the lubricated high-strength bolt assembly; and Procedure and proper use of the TON pretensioning method. A representative sample of not less than three high-strength bolt assemblies of each combination of diameter, length, grade, and lot to be use d in the work must be verified at the site of installation in a tension calibrator to verify that the TON pretensioning method develops a pretension that is equal to or greater than that specified in Table 707- 5. Perform periodic verification of high-strength bolt assemblies using a tension calibrator if directed by the Engineer. Tighten bolts using the TON pretensioning method in accordance with subsection 707.03. E.6.d . If required because of bolt entering and wrench operation clearances, tighten by t urning the bolt while preventing the nut from rotating. Table 707- 5 Minimum Pre -Installation Bolt Tension Verification(a) Nominal Bolt Diameter, d b (inch) ASTM F3125/F3125M Grade A325 (lb) ½ 12,700 ⅝ 20,200 ¾ 29,900 ⅞ 41,300 1 54,100 1⅛ 68,100 1¼ 86,500 1⅜ 103,100 1½ 125,500
a.Equal to 1.05 times 70% of specified minimum tensile strength of bolt rounded up to nearest hundred.
c.Snug -Tight Joints . All high -strength bolt assemblies must be installed with the washer positioned as required in subsection 707.03.E.6. Install bolts in all holes and compact the joint by tightening bolts s ystematically from the most rigid part of the joint to the free edges . The snug-tight condition is the tightness that is attained with a few impacts of an impact w rench or the full effort of a person using an ordinary spud wrench to bring the connected plies into firm contact . More than one cycle through the bolt pattern is required to achieve the snug-tight joint . The Engineer will not consider re-snugging previous ly tightened bolts loosened by the tightening of adjacent bolts as reuse. MDOT Standard Specifications for Construction Section 707
7-84 d. Turn -of-Nut (TON) Pretensioning . All high -strength bolt
assemblies must first be installed in accordance with subsection 707.03. E.6.c before performing the TON method. Perform the TON pretensioning method by systematically tightening bolts from the most rigid part of the joint to the free edges by rotating the nut relative to the bolt head as specified in Table 707-6 . High-strength bolt assemblies can be tightened by rotating either t he bolt head or nut. Mark each bolt , nut, and outer ply to reference the rotation required for tightening. Prevent the part (head or nut) not turned from rotating relative to the part (head or nut) that is being turned during the tightening operation. If impact wrenches are being used to perform the TON pretensioning method, then provide wrenches sufficient to tighten each bolt in approximately 10 seconds. Do not r euse high-strength bolt assemblies that have been tensioned beyond a snug-tight condition. Table 707- 6 Nut Rotation from Snug Tight Condition(a): Disposition of Outer Faces of Bolted Parts Bolt Length(b) Both Faces Normal to Bolt Axis One Face Normal to Bolt Axis, Other Face Sloped(c) Both Faces Sloped(c) Not more than 4db 120° –0°/+30° 180° –0°/+30° 240° –0°/+45° More than 4d b but not more than 8d b 180° –0°/+ 30° 240° –0°/+45° 300° –0°/+45° More than 8db but not more than 12d b 240° –0°/+45° 300° –0°/+45° 360° –0°/+45° More than 12d b The required nut rotation must be determined by actual testing in a suitable tension calibrator that simulates the conditions of steel in firm contact.
a.Nut rotation is relative to bolt regardless of the element (nut or bolt) being turned.
b.Nominal bolt length is m easured from underside of head to end of bolt, where (d b) denotes the bolt diameter.
c.Sloped face not more than 1:20 . Bevel ed washer prohi bited .
e.Inspection . The Engineer will determine if bolts meet the requirements for bolt tension. Provide the Engineer with the opportunity to witness the pre -installation bolt tension verification, snug-tight installation procedures, and TON pretensioning installation procedures .
7.Field Welding
a.General Bridge Welding . Perform bridge welding of bridge members in accordance with AWS D1.5, except as modified herein. These specifications apply for field welding to rolled and built-up flexural and axial main members and secondary members. MDOT Standard Specifications for Construction Section 707
7-85 Perform bridge field welding using the SMAW process with E7018
electrodes unless the contract requires use of a different electrode specification and classification. Do not use GMAW or other gas shielded processes . The Engineer may approve SAW an d FCAW for field welding. Do not field weld unless otherwise shown on the plans or approved by the Engineer . Field welding requires MDOT Form 0395 AASHTO/AWS D1.5 - Field Welding Plan to be completed and submitted for review and approval by the Engineer prior to welding . Do not start field welding before the Engineer approv es the WPS . Remov e weld metal splatter on adjacent base metal before blast cleaning and coating the steel using a procedure approved by the Engineer. Determine the minimum fillet weld size for bridge welding in accordance with Table 707-2 , unless a larger weld size is specified in the contract . Determine the minimum PJP groove weld size for all bridge welding in accordance with Table 707-3 , unless a larger weld size is specified in the contract.
b.General Structural Steel Welding . Perform structural steel welding in accor dance with AWS D1.1, except as modified herein. These specifications apply to field welding to structures and members listed in subsection 707.03.D.10.b. Perform field welding using the SMAW process with E7018 electrodes unless the contract requires use of a different electrode specification and classification. Do not use GMAW or other gas shielded processes . The Engineer may approve SAW and FCAW for field welding. Do not field weld unless otherwise shown on the plans or approved by the Engineer . Field welding requires MDOT Form 0394 AWS D1.1 Field Welding Plan to be completed and submitted for review and approval by the Engineer prior to welding . Do not starting field welding before the Engineer approv es the WPS . Remove weld metal splatter and arc strikes on adjacent base metal before blast cleaning and coating the steel using a procedure approved by the Engineer. Determine the minimum fillet weld size for structural steel welding in accordance with AWS D1.1 , unless a larger weld size is specified in the contract . Determine the minimum PJP groove weld size for structural steel welding in accordance with AWS D1.1 unless a larger weld size is specified in the contract . MDOT Standard Specifications for Construction Section 707
7-86 c. Welder Endorsements . Weld ing personnel , including welders,
welding operators, and tack welders , must be qualified in accordance with AWS D1.5 for bridge welding and AWS D1.1 for structural steel welding. Additional performance testing is required in accordance with the current MDOT ’s Welder Qualification Program under the supervision of the QAI . Welding performance endorsements from other agencies will not be accepted. The period of effectiveness for field welding personnel endorsed through MDOT ’s Welder Qualification Program is 2 years unless welding per sonnel are not engaged in a welding process for at least 6 months or a reason exists to question the welder ’s ability . The Engineer may require a confirming performance test during the progress of the work . Welding personnel must have their welding endorsements (AWS and MDOT) and MDOT -approved welding plan available at all times . Failure to produce the welding endorsements and plans while welding on a n MDOT project will result in welding privileges being removed from the project until acceptable information is provided to the Engineer . The Department considers welding personnel who are qualified on high-strength steel (low -alloy structural steel) to also be qualified to weld carbon steel.
d.Welding Requirements . Prepare base metal for welding in accordance with Clause 3 of AWS D1.5 for bridge welding or Clause 5 of AWS D1.1 for structural steel welding. Surfaces and edges to be welded must be smooth, uniform, and free from fins, tears, cracks, and other disco ntinuities . Surfaces to be welded and surfaces adjacent to a weld must also be free from loose or thick scale, slag, rust, moisture, grease, and other foreign material that would prevent proper welding . Grind joints before field welding to remove pitting and irregularities . The parts to be joined by fillet welds must be brought into as close contact as practicable; however, when the joints specified in the contract must have a tight fit or mill to bear , joint root openings in accordance with Clause 3 of AW S D1.5 for bridge welding or Clause 5 of AWS D1.1 for structural steel welding are required. If the joint root opening exceeds 1⁄16 inch, which is not allowed for joints specified to have a tight fit or mill to bear , increase the fillet weld leg equal to t he joint root opening. Do not weld if the joint root opening exceeds 3⁄16 inch. Transition weld profiles by grinding stop-start areas or other irregularities. MDOT Standard Specifications for Construction Section 707
7-87 Do not f ield weld when the ambient air temperature falls below
40°F or during periods of precipitation such as rain, snow, or fog that leaves condensation on the steel , unless heating and enclosing the area, as approved by the Engineer. Store and use filler metal for bridge welding and structural steel welding in accordance with AWS D1.5 and A WS D1.1, respectively . Dry all electrodes in an oven at a temperature of at least 500°F for at least 2 hours before use unless the electrodes are from a hermetically sealed container . Store the electrodes in a hot box at a temperature of at least 250°F aft er drying . Use electrodes within 2 hours of exposure to the atmosphere or redry as described above. Do not r edry electrodes more than once. Do not use electrodes that have been wet. Preheat s urfaces for welding 3 inches in every direction from the weld. Before welding, preheat surfaces to at least 250°F for base metal no greater than 1½ inches thick . For base metals from 1½ to 2½ inches thick, preheat to at least 300°F . If welding on plates greater than 2½ inches thick, preheat to at least 400°F.
e.Nondestruc tive Testing of Bridge Welds. NDT of bridge welds is required in accordance with AWS D1.5, except as modified herein. Provide labor, equipment, and materials for testing as specified in the cont ract. The Engineer will review the NDT equipment, materials, and procedures and will verify that the NDT , including VT, has been performed in accordance with the contract . Do not perform NDT before the Engineer is present . Provide the Engineer with NDT personnel certifications prior to starting the inspec tions . The Engineer must witness NDT. PT, MT, UT, and RT tests must be performed by personnel certified as Level II in accordance with the ASNT Recommended Practice No. SNT -TC-1A . VT must be performed by a CWI on the entire length of all welds . Clean weld s and base metal, as required, before performing NDT. PT both ends of all CJP and PJP groove welds in accordance with ASTM E165 /E165M . MT the entire length of all fillet welds in accordance with AWS D1.5, except as modified herein. Perform MT in conforman ce with ASTM E709 with dry powder using the yoke method. UT the entire length of all CJP groove, plug, and slot welds. Repair cracked welds or welds that the Engineer determines are unacceptable. Perform NDT of the base metal after the removal of MDOT Standard Specifications for Construction Section 707
7-88 weld met al or portions of the base metal as directed by the
Engineer . Repair welds in accordance with AWS D1.5. Perform NDT of repaired welds before the Engineer ’s acceptance. Repair and perform NDT of welds at no additional cost to the Department.
f.Nondestructive Testing of Structural Steel Welds. NDT of structural steel welds is required as specified in 707.03.E.7.e, except all references to AWS D1.5 are to be replaced with AWS D1.1.
g.Welding Falsework, Form Support , and Accessor ies. Do not weld falsework, form support s, or accessories to structural steel.
h.Shear Developers. Stud application qualification requirements, production control, and inspection requirements must be in accordance with Clause 7 of AWS D1.5. Steel studs must be welded with autom atically timed stud-welding equipment. At the time of welding, the studs and base metal to which the studs are to be welded must be free of rust, mill scale, paint, galvanizing, moisture, oil, and other deleterious matter that would adversely affect the welding operation. Repair studs without a full 360-degree fillet weld by adding a 5⁄16-inch fillet weld using the SMAW process to replace missing welds . Repair of welds must be performed by a welder endorsed in accordance with subsection 707.03.E.7.c. 707.04. Measurement and Payment Pay Item Pay Unit Structural Steel, Rolled Shape, Furn and Fab ........................................ Pound Structural Steel, Rolled Shape, Erect ..................................................... Pound Structural Steel, Plate, Furn and Fab ...................................................... Pound Structural Steel, Plate, Erect ................................................................... Pound Structural Steel, Mixed, Furn and Fab .................................................... Pound Structural Steel, Mixed, Erect ................................................................. Pound Bearing, Elastomeric, __ inch ........................................................ Square Inch Shear Developers (Structure Identification) ..................................... Lump Sum Bushing ..................................................................................................... Each
A.Structural Steel . The Engineer will measure structural steel by the calculated weight of metal in the finished structure, excluding filler metal in welding, as shown on the working drawings . The Engineer will calculate the weight using the rules and assumptions specified in this subsection. Unless otherwise required, the following metal weights apply:
1.Steel — 0.2833 pound per cubic inch; MDOT Standard Specifications for Construction Section 707
7-89 2. Cast iron — 0.26 pound per c ubic inch;
3.Bronze — 0.315 pound per cubic inch; and
4.Lead — 0.411 pound per cubic inch. The Engineer will calculate the weights of rolled shapes and plates incorporated in the finished work on the basis of nominal weights and dimensions, as shown on the approved shop drawings, deducting for copes, cuts, and holes, except those for high- strength bolts. The Engineer will include the total calculated weight of bolts, nuts, and washers in the finished work in the weight of structural steel. The Engineer will cal culate the weight of castings from the dimensions shown on the approved shop drawings with an addition of 10% for fillets and overrun. The Engineer will not make allowance for galvanizing, optional splices, lifting lugs, shop coating, or excess bolts in the calculated weight. The Engineer will not include the weight of lifting lugs in the calculated weight for structural steel . The unit prices for structural steel pay items include the cost of providing, welding, and removing the lugs.
B.Welding. The Depart ment will not pay for shop or field welding and subsequent NDT of Structural Steel, Furn and Fab and Structural Steel, Erect pay items. All costs associated with shop or field welder endorsement to MDOT ’s Welder Qualification Program testing including, but not limited to, providing the specimen test plates, completing performance testing, and submittal of qualification specimen will be at the Contractor ’s expense. The Department will perform testing (cut, machine, test, and report out ) of specimens at no cost to the Contractor for the first test; however, the Contractor is responsible for the cost of performing retesting if the first test specimen fail s a specific test .
C.Plant Certification . The Department will not allow additional compensation for costs incurred in the certification of structural steel plants or claims by the Contractor for delays and inconvenience attributed to certification requirements.
D.General . The unit prices for Structural Steel, Erect pay items include the cost of installing and removing temporary bolts as directed by the Engineer . The unit prices for Structural Steel, Erect pay items include the cost of field drilling. The unit prices for Structural Steel, Furn and Fab pay items include the cost of shop cleaning and coating the steel. MDOT Standard Specifications for Construction Section 707
7-90 The Engineer will measure Bearing, Elastomeric of the size required, by
area, with no deductions for holes . The unit price for Bearing, Elastomeric includes the cost of steel laminates bonded to the elastomeric bearing. The Engineer will measure Shear Developers as a unit for each structure . The unit price for Shear Developers includes the cost of providing studs, cleaning the surface by grinding, and welding studs to the girder flanges. The unit price for Bushing includes the cost of priming the inside holes in the link plate and providing and installing the bushing. The cost of supplying, installing, and removing temporary bolts at field-splice connections when this work is required by subsection 707.03.D is included in the unit price for relevant pay items.
Source: Michigan Standard Specifications for Construction, 2020 Edition. Pages 426–454 of 1,146.