5-85 Sectio N 506 – Structura L Steel
506.0 1 DESCRIPTION . This work shall consist of furnishing, erecting, and , when specified, coating fabricated metal structures and structural components. 506.02 MATERIALS . Materials shall meet the requirements of the following subsection s: Mortar, Type IV ................................ ................................ ................................ ......... 707.0 1(e) Powder Coating Systems ................................ ................................ ........................... 708.02 Structural Steel Coating Systems ................................ ................................ ............... 708.0 3 Grease Rustproofing Compound ................................ ................................ ................ 708.0 4 Structural Steel ................................ ................................ ................................ ........... 714.02 High -Strength Low -Alloy Structural Steel ................................ ................................ 714.03 Carbon Steel Bolts, Nuts , and Washers ................................ ................................ .....714.04 High -Strength Structural Bolts and Assemblies, 120 ksi ................................ ........... 714.05 High -Strength Structural Bolts and Assemblies, 150 ksi ................................ ........... 714.06 Anchor Bolts for Bearing Devices ................................ ................................ ............. 714.08 Welded Stud Shear Connectors ................................ ................................ ................. 714.10 Steel Tubing ................................ ................................ ................................ ............... 714.11 Direct Tension Indicators ................................ ................................ ........................... 714.12 Tension Control Assemblies ................................ ................................ ...................... 714.13 Galvanizing ................................ ................................ ................................ ................ 726.0 6 Metalizing ................................ ................................ ................................ .................. 726.0 7 Unless otherwise specified in the Contract, all steel shall be high -strength low -alloy structural steel conforming to the requirements of AASHTO M 270, Grade 345W (Grade 50W). All materials shall conform to the prescribed AASHTO or ASTM specifications and no substitutions will be allowed. 506.0 3 GENERA L FABRICATIO N REQUIREMENTS . Except as modified below, fabrication shall be performed in accordance with the applicable AASHTO design code, ANSI/AASHTO/AWS D1.5 (hereinafter designated as AWS D1.5 ), and interim specifications in effect on the date of Contract advertisement . Unless otherwise indicated in the Contract, the applicable AASHTO design code shall be the AASHTO LRFD Bridge Design Specifications .
5-86 Structural steel furnished under this section shall be fabricated in a plant having an AISC Certified Bridge
Fabricator – Advanced (ABR), or Intermediate (IBR) certification, and in a plant listed as a Category 1 fabricator on the Agency’s Pre-Qualified Fabricator List prior to Contract execution. Structural steel components such as bridge rail, bridge joints, bridge bearings, overhead sign structures , and compone nts for the repair of superstructures consisting of only cutting and drilling (no welding) which are fabricated under this section may be fabricated in a plant that does not have an ABR or IBR certification, provided that the fabrication plant has either a n AISC Certified Bridge Fabricator – Simple (SBR) certification or an AISC Bridge Component QMS certification, and is listed as a Category 2 fabricator on the Agency’s Pre-Qualified Fabricator List prior to Contract execution. Minor steel components, including, but not limited to, downspouts, scuppers, and pedestrian hand railings may be fabricated in a plant that does not have an AISC certification, provided that the fabrication plant is approved in writing by the Structural St eel Fabrication Engineer prior to Contract execution. All plants without certification shall have an organization, operation, and equipment capable of producing a product equal to a certified plant. These plants will be reviewed on a case -by-case basis. Structural steel that is to be painted or metalized under this section shall be coated in a plant having an AISC Sophisticated Paint Endorsement – Enclosed or SSPC -QP 3 – Enclosed Shop certification and which is listed as a Category 3 fabricator for the appl icable coating on the Agency’s Pre-Qualified Fabricator List prior to Contract execution. Structural steel that is to be galvanized or powder coated under this section shall also be coated in a plant listed as a Category 3 fabricator for the applicable coa ting on the Agency’s Pre-Qualified Fabricator List prior to Contract execution. The Agency’s Pre-Qualified Fabricator List can be found on the Agency ’s website. It is the responsibility of the fabricator to verify that they are on the list prior to bidding on work. It shall be known that being included on the list does not waive any certification requirements that are required for performing the intended work. Any fabricator who has been pre-qualified but does not perform any work for the Agency for a period of 5 years will be automatically removed from the list without notice. It is the fabricator’s responsibility to re -apply if they desire to be included on the list again . When certified fabrica tion or coating plants are required, the plant shall maintain certified status throughout the duration of the work under the Contract. The Agency reserves the right for the Structural Steel Fabrication Engineer to give written notification to any fabricator (regardless of certification level or status) restricting the types of items that they are approved to fabricate, up to and including restricting all structural steel fabrication for the Agency. Causes for such restrictions shall include concern s of quality, production, accountability, or any other cause that is deemed justifiable by the Agency.
5-87 The fabricator shall demonstrate full capability for fabricating materials meeting the requirements of the
Contract. Failure to meet Contract requireme nts will result in rejection of the material being fabricated and the termination of the ability to fabricate material for the Agency . Prior to performing any work under this section, the fabricator shall have received approval for all fabrication drawings , welding procedures , and any special Contract requirements and have notified the Agency’s Structural Steel Fabrication Engineer in writing at least 10 working days in advance of fabrication. The Contractor shall bear full responsibility and costs for all materials ordered, raw materials stockpiled, or for work performed prior to approval of the fabrication drawings or written authorization from the State Bridge Engineer. Except as noted in this subsection, all work shall be performed by the fabricator indi cated on the approved fabrication drawings, unless otherwise authorized in writing by the Structural Steel Fabrication Engineer. For coatings, if the fabricator intends to use a subcontractor, it shall be clearly outlined on the fabrication drawings to be submitted for review. At a minimum, the provided information shall include the subcontractor’s name and address; the name, phone number , and e -mail address of the quality control contact; and an acknowledgement of the Agency quality assurance inspection requirements which apply to the subcontractor. If the fabricator wishes to request the use of a subcontractor for material processing (e.g. cutting, drilling, bending, rolling, punc hing, machining, etc.), they shall include this information on the shop drawings that are submitted for review or they shall submit a set of the previously approved shop drawings to the Agency for review, with the requested changes and required information clearly marked and indicated (e.g. by making all additional notes red). At a minimum, the submittal shall include the subcontractor’s name and address; the name, phone number s and e -mail address of the quality control contact; an acknowledgement of the Agency quality assurance inspection requirements which apply to the subcontractor; and clear information on the extent and limits of work to be performed by the subcontractor. Requests will be evaluated on a case -by-case basis and may be rejected by the Agen cy for any reason. Use of a subcontractor does not relieve the fabricator of any responsibilities or quality control requirements specified by the Contract. All steel fabrication plants shall satisfy the following minimum requirements:
a.Reference Materials . The plant shall have a library containing the latest editions of the following publications:
1.AWS A5.1, AWS A5.5, AWS A5.17, AWS A5.18, AWS A5.20, AWS A5.23, AWS A5.28, AWS A5.29, AWS C2.18, AWS C2.23, AWS D1.1, AWS D1.2, AWS D1.3, AWS D1.4, and AWS D1.5
5-88 (2) AASHTO Standard Specifications for Transportation Materials and Methods of Sampling
and Testing, Part I and Part II
3.AISC Steel Construction Manual and Detailing for Steel Construction
4.Vermont Agency of Transportation Standard Specifications for Construction
5.AASHTO LRFD Bridge Design Specifi cations
6.AASHTO LRFD Bridge Construction Specifications
7.AREMA , when applicable
8.ASNT SNT-TC-1A
9.SSPC Steel Structures Painting Manua l, Volume 1 and Volume 2
10.AASHTO/NSBA G1.1 In addition to the above, access to the latest editions of any applicable ASTM standards is required.
b.Files . The fabricator shall maintain an organized file containing the following records:
1.Records of material purchased
2.Inventory of material in stock
3.Certification records of all material and welding supplies
c.Personnel . Fabrication personnel shall meet the following minimum requirements:
1.Inspectors . Quality control inspectors shall be onsite full-time during any hot work (e.g. burning, heating, welding, etc.), as well during as any operations that may affect the quality of the coating system.
a.Fabrication Inspectors . The fabricator’s representativ e responsible for fabrication inspection, testing and quality matters shall be qualified and certified in accordance with the provisions of AWS QC 1 .
5-89 b. Coating Inspectors . The fabricator’s coatings quality control manager shall possess
a minimum classification as a NACE Coating Inspector Level 2 – Certified, SSPC Bridge Coatings Inspector (BCI) Level 2, or SSPC Protective Coatings Inspector (PCI) Level 2. The coatings quality control inspector shall possess a minimum classification as a NA CE Coating Inspector Level 1 – Certified, SSPC Bridge Coatings Inspector (BCI) Level 1, or SSPC Protective Coatings Inspector (PCI) Level 1.
2.Welders . Welders shall be certified for each process and position of prequalified joints in the approved weld ing procedures, including tacking, in accordance with the requirements of AWS D1.5 for all structural bridge items and AWS D1.1 for items not covered in AWS D1.5.
d.Material Fabrication Facilities .
1.All fabrication shall be performed in an enclosed pe rmanent structure, unless otherwise approved by the Structural Steel Fabrication Engineer . To meet minimum requirements, a plant shall have the following facilities:
a.Dry storage for manual electrodes and fluxes
b.Ovens with proper temperature ranges for drying electrodes and fluxes
c.Calibrated tools, gauges, tapes, and instruments
d.Suitable preheating equipment and means for measuring preheat temperatures
e.DC and AC manual shielded metal arc welding equipment capable of an out put of at least 500 amps
f.Mechanically guided burning equipment
g.Machine shop facilities sufficient to perform the work specified
h.Facilities and equipment for applying shop paint to perform the work specified
i.Blast cleaning equipment suitable for preparing a surface meeting the requirements of Subsection 506.14
j.Suitable storage for materials and finished products
5-90 (2) A plant engaged in fabrication of plate girders, rolled beams, and other main member
compo nents requiring continuous welds over 2 feet in length shall also have the following equipment:
a.Automatic arc equipment
b.Semiautomatic arc equipment
c.Stud-welding equipment capable of installing a 7/8 -inch diameter stud, when applicable
d.Equipment suitable for heat curving or heat cambering
e.Hydraulic jacking equipment suitable for aligning and positioning structural components
3.Adequate office facilities and equipment for the Agency’s quality assurance inspector shall be separate from the quality control facilities and shall include the following items:
a.A standard office desk with drawers, locks, and keys
b.Adjustable office chair
c.Telephone
d.Plan rack and file cabinet with lock and keys
e.The following tools shall be available for the inspector ’s use:
1.Weld gauges
2.Micrometer
3.Dry and wet film paint gauge
4.10-foot steel measuring tape
5.100-foot steel measuring tape
5-91 6. 6-foot straightedge
7.Temperature and marking crayons
8.Ambient air thermometer
9.2-foot level
10.2-foot carpenter’s square The Structural Steel Fabrication Engineer reserves the right to reject inadequate office facilities and require suitable alternatives.
e.Testing Equipment . When code requirements necessitate nondestructive testing for quality control or quality assurance, the fabricator shall have available the necessary nondestructive testing equipment for material or weld inspection (such as magnetic particle, radiograph, ultrasonic, or dye penetrant) or employ an outside inspection firm to fulfill the necessary nondestructive test requirements of the code. Nondestructive tests shall be performed in accordance with the applicable code in effect on the date of Contract adve rtisement . 506.0 4 DRAWING S AND PROCEDURES .
a.General Requirements . As soon as practical after Contract execution, the fabricator shall prepare fabrication draw ings in accordance with the requirements of Subsection 105.06 . Drawings, details, and welding procedures shall be submitted as a complete package for each structure. The Agency will review fabrication draw ings, details, and procedures for their compliance with the Contract. The Agency will refer to the requirements of AASHTO/NSBA G1.1 , Section 4 and use them as the basis for the review of structural steel fabrication draw ings. The Agency assumes no responsi bility for dimensions and other information calculated by the fabricator. The fabricator is responsible for the fit of all components. If errors occur that cause problems during erection, the Contractor is responsible for making acceptable corrections. The Agency is responsible for all principal dimensions and material properties contained in the Contract. The fabricator and Contractor are responsible for bringing to the Agency’s attention any errors or discrepancies they discover.
5-92 The fabricator is responsible for dimensioning members and ordering material to compensate for
weld shrinkage, distortion, elastic deformation, sweep, slope, machining, waste from cutting, and other incidentals that are affected by the fabrication process.
b.Details . Details not shown on the Plans that are necessary for completing the fabrication draw ings shall be developed by the fabricator. The fabrication draw ings shall provide a material list on each sheet for tabulating the number of pieces, piece marks, description, dimensions, type of material, and weight of each piece. When the Contract item pay unit is on a per pound basis, the weight of each piece shall be extended and summarized for each sheet as specified in Subsection 506.2 2. Weight extensions (extended weights) shall be submitted to the Agency upon completion of fabrication. All welds shown on the fabrication draw ings shall identify, by symbol, the applicable proced ures and appropriate nondestructive testing requirements. A separate symbol shall be used to identify each approved welding procedure.
c.Welding Procedures . Detailed welding procedures shall be prepared in accordance with the provisions of the applicable AWS , ANSI , and AASHTO code revisions and submitted in accordance with the following:
1.All procedures shall be prequalified. Procedure qualification test records shall be submitted along with each procedure. Heat input values during welding shall be shown for each procedure (except for SMAW procedures). All weld procedure sheets shall identi fy the project name, number, structure, and procedure qualification record or fillet weld soundness test.
2.Procedure qualification test records and welding procedure specifications shall be presented in a format similar to example forms as shown in AWS D1.5 and AWS D1.1 as applicable.
3.Details of welded joints shall conform to the standard joint details per AWS D1.5 (or AWS D1.1 as applicable) unless otherwise approved by the Structural Steel Fabrication Engineer.
d.Revisions . Adjacent to or incorpo rated with the title box of each sheet shall be a revision record box including provision for the date of revision, symbol of revision number, revision made by, and description of each revision. As changes or revisions are made to previously approved sheet s, the appropriate information shall be recorded, a revision number symbol placed adjacent to the appropriate detail, and the sheet resubmitted for approval. It is the fabricator’s responsibility to transfer all as noted corrections to the originals. Revis ions of welding procedures shall also be resubmitted as they occur.
5-93 (e) Approval of Procedures . All weld procedures, heat corrective procedures, coatings procedures,
and any other procedures that are required to be submitted for approval, and are being used in production, shall bear a n Agency approved or approved as noted stamp. 506.0 5 QUALIT Y ACCEPTANCE . Quality acceptance is inspection of fabrication by the Agency or the Agency’s representative ( quality assurance inspector), to verify compliance with these specifications. Acceptance of materials, test results, or completed fabricated items by the quality assurance inspector or Structural Steel Fabrication Engineer does not relieve the fabricator of any responsibility to meet Contract requirements and specifications. The Contractor shall r efer to the Agency’s Quality Assurance Manual for Metal Fabrication for more information.
a.Scope of Work . Inspection will include the examination of materials, processes, quality of work, reports, and test results; the performance of tests specified; the evaluation of reports and tests; the approval, disapproval, or rejection of materials, pro cesses, quality of work, reports, and test results; or other work specified or directed by the Engineer.
b.Control of Work . The quality assurance inspector is a representative of the Engineer and will perform all the duties assigned and delegated to the Engineer in Section 105 as they pertain to the Contract except for measuring quantities of materials and payment thereof. The inspector will witness, interpret, and accept or reject all testing. Inspection of the work will conform to the requirements of the applicable AWS , ANSI , and AASHTO codes and specifications referenced in the Contract.
c.Tools and Equipment . Quality assurance inspectors are expected to furnish their own personal safety equipment. They may make use of any tools the fabricator is required to make available , however, the fabricator is responsible for verifying that the equipment is properly cali brated and in working order. 506.0 6 QUALIT Y CONTROL .
a.General Requirements . Quality control is the inspection, testing, and management of quality matters necessary for producing a product that conforms to the requirements of the Contract. The fabricator is responsible for quality control . The fabricator is responsible for performing all n ondestructive tests required by the Contract and any nondestructive tests necessary to determine the extent of metallurgical defects discovered in the base metal.
5-94 (b) Qualifications of Inspectors . Inspectors shall meet the requirements of Subsection 506.03(c) .
c.Nondestructive Testing . The fabricator shall notify the Agency sufficiently in advance of any scheduled nondestructive testing so that all tests can be witnessed by an Agency quality assurance inspector. Nondestructive tests shall be performed in accordance with the requirements of AWS D1.5 . Personnel performing and interpreting nondestructive tests (radiographic (RT) , magnetic particle (MT) , ultrasonic (UT), and dye penetrant (PT)) shall be NDT certified for Level II qualification in accordance with ASNT SNT-TC-1A.
d.Ultrasonic Testing . Ultrasonic testing will not be permitted as a substitute for radiographic testing . However, ultrasonic testing may be used by the fabricator to determine the ex tent of discontinuities, laminations, and inclusions discovered in any weld or base metal.
e.Testing of Overhead Traffic Sign Structures, Mast Arms, and Strain Poles . Nondestructive testing of overhead traffic sign structures, mast arms, and strain poles shall be in accordance with the AASHTO Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals as well as the following:
1.Fillet Welds . If any fillet welds examined require a welded repair, an additional 10% of the original lot shall be examined using MT. If any welds in the second 10% require a welded repair, all welds in that production lot shall be tested using MT.
2.Partial Joint Pen etration (PJP) Welds . If any PJP welds examined require a welded repair, all remaining PJP welds in that production lot shall be tested using MT. For the purposes of this subsection, a production lot shall be defined as a day’s production on any given pro ject. 506.0 7 MATERIA L IDENTIFICATION .
a.Material Traceability . The origin of each piece of material to be incorporated in a product shall be clearly identified at all times during the fabrication of the product. If fabrication operations could obliterate the identity, the fabricator may use a lo w stress die stamp pla ced in an area not exposed on the finished structure. The die stamp character size shall be a minimum of 1/8 inch and a maximum of 1/4 inch. Nonmetallic materials shall be identified to the satisfaction of the Engineer.
5-95 When requested, the Contractor shall furnish an affidavit certifying that throughout the fabrication
operation identification of the steel has been maintained in accordance with this specification. When a steel stamp identification is used at a tension joi nt transition, the impression shall be placed on the thicker of the members. 506.0 8 BASE META L REQUIREMENTS . When backing bars, extension bars, and runoff plates are part of a welding process, the material used shall be of the same chemistry as the base metal. Discontinuities, laminations, inclusions, or other anomalies discovered in the base metal during the manufacturing process shall be individually evaluated. The Agency may require nondestructive testing to determine the extent of the defect. Repair procedures or replacement will be approved on an individual case basis. Rolled beams shall be ordered from the mill without camber, unless pre -approved in writing by the State Bridge Engineer. Main members are defined as compression members, tension members, and members subject to reversals of stress, including stringers, girders, cover plates, rigid frames, floor beams, gusset plates, and curved girder cross frames. Other members may be indicated in the Contract as main members. Material for main members shall be ordered and prepared so that the direction of rolling is parallel to the stress in the member, in accordance with the requirements of AASHTO LRFD Bridge Construction Specifications, Section 11.4.3.1 . Charpy V -notch (CVN) testing shall be performed as required in Subsection 714.01 . Members identified as fracture critical shall be subject to additional base metal requirements as specified in Subsection 506.11 . 506.0 9 PREPARATIO N OF BASE METAL . Material flame cuts by any thermal cutting process shall be made with an approved mechanically -guided torch. The fabricator shall use preheating, post -heating, or control of the cutting process to ensure that flame -cut edges of main members of structural steel are not flame -hardened. Flame -cut edges that will not be included in a permanent weld shall have a Rockwell hardness value not greater than C30. When p ieces are to be bent during fabrication , bending shall be performed in accordance with the requirements of AWS D1.5 and the applicable design code as defined in Subsection 506.03 .
5-96 Cold bending of main members will not be permitted without written approval of the Agency. This
approval may limit the radius of curvature and require nondestructive testing to verify that no internal distress or separation has occurred. Expenses incurred in performing any such nondestructive test examination shall be the responsibility of the fabricator. 506.1 0 WELDING .
a.General Requirements . All design details, quality of work, procedures, and inspection of welding shall conform to the requirements of the AWS D1.5 . For welding items other than those covered in AWS D1. 5, the Contractor shall adhere to AWS D1.1 , AWS D1.2 , AWS D1.3 , or AWS D1.4 as applicable. Welding will not be permitted without approved welding procedures and fabrication draw ings meeting the requirements of Subsection 506.04 . Welding and inspection of shear connectors shall conform to the requirements of Section 508 . Stitch welds are not permitted , however, the skip -and-fill technique may be used when applicable to prevent distortion. Prior to performing any corrective weld rep airs to base metal, the fabricator shall do the following:
1.Submit the proposed repair procedure to the Agency’s Structural Steel Fabrication Engineer in writing. Corrective procedures for radiographed butt welds may be included in the welding procedure .
2.Receive written authorization from the Agency to proceed. Repair procedures detailed in an approved welding procedure may be authorized by the Agency’s quality assurance inspector. The fabricator will be permitted a maximum of two repairs on any given weld ed joint. Should nondestructive test inspection indicate weld rejection after two repairs, the Agency may reject the entire weld and require its removal.
b.Welding Processes . Shielded metal arc welding (SMAW) conforming to the requirements of AWS D1.5, Section 1 shall be deemed prequalified. Submerged arc welding (SAW), flux core arc welding (FCAW), and gas metal arc welding (GMAW) shall be subject to qualification testing as described in AWS D1.5 prior to approval. Other processes may be approved, on a project -by- project basis, provided procedure qualification results meet the specified acceptance criter ia.
5-97 Submerged arc welding (SAW) shall be used for all principal welds, as follows:
1.The fully automatic process shall be used for attaching cover plates, flange to web welds, and attaching connection or stiffener plates to girder webs.
2.The semiautomatic process may be used when joint length, position, or physical location restricts the use of the automatic process. The manual shielded metal arc welding process shall be limited to attaching connection plates to rolled beams, welding bearing a ssemblies, repairs, tack welding, joints under 24 inches in length, minor attachments, and other applications where the use of an automatic process is impractical. When prior authorization has been granted, the GMAW and FCAW processes will be limited to indoor shop welding of bridge rail, expansion joints, cross frames, bearing devices, scuppers, sign fixtures, light fixtures, and low -stressed members or components. Gas metal arc welding -short circuit arc (GMAW -S) will not be permitted. Any gas shielded process subject to wind velocities in excess of 5 mph shall be protected using draft barriers.
c.Shop Welding . The fabricator shall maintain a file of the qualifications of all welders, welding operators, and tackers qualified in accordance with the requirements of AWS D1.5 . Requalification may be requi red in accordance with the requirements of AWS D1.5 . The requirements of AWS D1.1 shall be adhered to for welding of items not covered in AWS D1.5 . Groove welds shall be started and terminated with extension bars or runoff plates. Fillet welds shall be performed in the flat or horizontal position unless restricted by member size or physical position.
d.Field Welding . Welding performed in the field shall be done by welders or welding operators who are on the Agency’s Pre-Qualified Welder List . The requirements for field welding are contained in the Agency’s Field Welding Manual and shall be adhered to. This manual may be obtained from the Agency’s website. Welding performed in the field is subject to all of the requirements of Subsection 506.10 . The SMAW process is the only process approved for field welding.
5-98 All welds used to attach miscellaneous construction fixtures to any portion of the bridge structure
shall be approved in writing by the Engineer. Welding to tension members or tension com ponents of members will not be allowed. Welding of miscellaneous construction fixtures such as form supports, screed supports, and reinforcing steel chairs to any portion of the bridge structure will not be permitted without approved draw ings and welding procedures. Any increase in material thic kness made necessary by reduced allowable stresses resulting from such welding shall be at the Contractor’s expense. Approval for any welding requiring an increase in material thickness shall be obtained before the affected structural steel is fabricated. Shear connectors shall be installed in accordance with the requirements of Section 508 .
e.Process and Procedure Qualification .
1.General Requirements . Welding processes and procedures requiring qualification shall be qualified in accordance with the requirements of AWS D1.5 . Welding and testing of samples shall be witnessed by the Agency, or the Agency’s quality assurance inspector , or an authorized re presentative of a testing agency that is AWS certified in accordance with the provisions of AWS QC 1 .
2.Acceptance Requirements . The basis for acceptance shall conform to the requirements of AWS D1.5 . The requirements of AWS D1.1 shall be adhered to for items not covered in AWS D1.5 . 506.1 1 FRACTUR E CRITICA L MEMBERS . The Agency will identify in the Contract the members or member components that are categorized as fracture critical. Material for members or member components identified as fracture critical shall be furnished and fabricated in conformance with the requir ements of AWS D1.5 for fracture critical components. Welding performed on fracture critical members or components, and testing, shall be witnessed by an Agency representative. Qualification acceptance for any welding procedure shall be based on the results of mechanical tests and chemical analysis of deposit ed weld metal. Procedure requirements and basis of acceptance shall meet the requirements in AWS D1.5 for fracture critical components .
5-99 506.1 2 Assembly .
a.Camber . Beams and girders shall be fabricated to the camber indicated on the approved fabrication draw ings.
b.Curved Girders . Welded curved girders with a radius of less than 750 feet shall be fabricated by cutting the flange plates to the required curvature. Each plate shall be flame cut simultaneously on both edges to reduce unbalanced shrinkage stresses. The flange plate lengths between shop splices shall not be less than 20 feet. Web plates shall be aligned to the center of the flange plates. If the final curvature is not as specified after the flanges have been welded to the web, the girder shall be corrected by application of heat in accordance with an approved procedure.
c.Heat Curving and Cambering . The final horizontal curvature and vertical ca mber shall be measured only after the member has cooled. The member shall be supported in a manner that will ensure accurate measurements for sweep and camber. The web shall be in a vertical position for measuring curvature and in a horizontal position for measuring camber. Heating shall be performed in such a manner that the temperature of the steel does not exceed 1,150°F. Any member heated to a temperature of more than 1,200°F shall be rejected. Artificial cooling will not be permitted until a member h as cooled to 600°F. Under no conditions will water be permitted for cooling. Dry a ir may be used subject to the approval of the quality assurance inspector.
d.Finish . All sharp corners, and edges that are marred, cut, or roughened in handling shall be rounded to a minimum 1/16 -inch radius by grinding.
e.Connections and Bolting . The materials and fabrication procedures shall comply with the provisions of Subsection 506.1 8.
f.Bearing Connections . Field bearing connections shall not be permitted. Conne ctions in bearing may require different tolerances of fit. Terms used to define the fit of connections are as follows:
1.Tight Fit . Tight fit means that 50% of the projected bearing area shall be in contact within 0.02 inch with a permissible variation of 1/16 inch for the remaining 50% of projected area.
2.Grind to Bear . Grind to bear means that 75% of the projected area shall be in contact within 0.01 inc h with a permissible variation of 1/32 inch for the remaining projected area.
3.Mill to Bear . Mill to bear means that 100% of the projected bearing area shall be in full contact. 5-100 (g) Intermediate Stiffeners . The ends of intermediate stiffeners shall fit closely to the flanges with a maximum allowable gap of 1/16 inch.
h.Straightening Material . Straightening or repair of any member or component will be subject to written approval by the Agency. Procedures will be required describing in detail the distor tion to be corrected and all procedures for heating, cooling, verifying final dimensions, and nondestructive tests. 506.1 3 TOLERANCES . Rolled steel plates, shapes, and bars shall be supplied to the permissible tolerances specified in ASTM A6 . The camber and sweep of fabricated rolled members shall be subject to the same dimensional tolerances specified for welded members in AWS D1.5 . The metal bearing surface of any masonry bearing plate shall be flat, with a maximum permissible variation of 0.04 inch from a plane determined by any three of its corners. The fabricator is responsible for straightening to specification tolerances any weldme nts that may have been distorted through stress relieving during the galvanizing process. 506.1 4 SURFAC E PREPARATION . All materials shall be blast -cleaned to the specified grade as defined by the SSPC Painting Manual and supplemented by reference to SSPC -VIS 1 . Further preparation shall conform to the following:
a.Surfaces to Remain Uncoated . Surfaces shall be blast -cleaned at least equivalent to SSPC -SP 10. This work may be performed either before or after fabrication. The final surface appearance after fabrication shall be clean and free from any contaminants or blemishes so as to allow the metal to weather uniformly .
b.Surfaces to be Coated . Prior to application of any coating, all material to be coated shall be cleaned and prepared in accordance with the appropriate Contract specifications. 506.1 5 MARKING , STORING , AND SHIPPING .
a.Marking . Each member shall be identified with an erection mark corresponding with the member identification mark on the approved fabrication draw ings. Identification marks may be painted on members that will receive field coats of paint. Identification marks on unpainted steel shall be impressed into the member with a low -stress stamp in a non -stressed or low -stressed area of the member. The fabricator shall identify to the Contractor the procedure used for ma rking material. 5-101 (b) Storing . Material at the fabricator’s plant shall be stored above ground on platforms, skids, or other suitable supports. It shall be kept clean, properly drained, and protected from unwanted corrosion. Free circulation of air shall b e provided around all surfaces. Girders and beams shall be stored in the upright position, supported at their ends or points of bearing. Long members (e.g. columns and chords) shall be supported at sufficient points to prevent damage from deflection. Speci al care shall be taken for unpainted steel to ensure that it can weather uniformly. In addition to the requirements specified above, material or raw material stockpile storage shall be subject to any other storage criteria deemed necessary by the Engineer in accordance with the requirements of Subsection 106.09 .
c.Shipping . Beams and girders shall be transported in the upright position. If the member’s size or shape prohibits shipment in the upright position, the fabricator shall submit a proposed method and details of shipment to the Agency for approval. The fabricator shal l not ship any material, either to the project or to another manufacturer or subcontractor, without the Agency’s approval. The Agency’s quality assurance inspector will place a seal of approval on all material (or on the bill of lading) that ha s been accep ted for shipment and will accept the loading, positioning, and anchorage of all material being shipped. If the quality assurance inspector is not available, the Structural Steel Fabrication Engineer shall be contacted for approval to ship. 506.1 6 FIELD HANDLIN G AND STORING . The Contractor is responsible for providing equipment that is adequate to safely lift and plac e, without damage, all material furnished. Permanent distortion caused by handling or storage will be cause for rejection. The edges of nicks or bumps caused by handling shall be carefully ground to a 1/16 -inch radius. The storage requirements in Subsection 506.1 5 shall be applicable for all materials stored in the field. 506.1 7 ERECTION .
a.Methods and Equipment . Cranes, lifting devices, and other equipment for all structural steel erection shall be of adequate design and capacity to safely erect, align, and secure all members and components in their final positions without damage. The Contractor is solely responsible for the methods and equipment employed for the erection of the structural steel. However, the Contractor shall lift and erect curved girders so that the we b of the girder is maintained vertical within a 10° vertical tolerance. 5-102 The Contractor shall submit construction draw ings in accordance with the requirements of Subsection 105.06 for the methods and sequence of structural steel erection, the temporary br acing, and the equipment to be used for the erection. The Agency will use the requirements specified in AASHTO/NSBA S10.1, Appendi x B and AASHTO/NSBA S10.1, Appendix C, as the basis for review of erection plans. The erection plan shall include the necessary computations to indicate the magnitude of stress in the segments during erection and to demonstrate that all of the erection equipment has adequate capacity for the work to be performed. The erection plan shall contain provisions for all stages of construction, including offloading, temporary storage conditions, and temporary stoppages. The Contractor shall include additional information in the erection plan for curved girders as indicated in AASHTO LRFD Bridge Construction Specifications, Section 11.8.2 . The structural steel may be used for support of equipment prior to placement of the deck only with the written permission of the Engineer. The proposed use of structural steel for support of equipment shall be detailed in the erection plan. Submittal of the erection plan is for documentation purposes only and shall in no way be construed as approval of the proposed method of erection. Unless otherwise directed by the Engineer, the Contractor shall follow the erection plan as submitted .
b.Assembly .
1.Parts shall be accurately assembled as shown on the Plans, fabrication draw ings, or erection drawings, following match marks when provided. Material shall be carefully handled so that no members or pieces will be bent, broken, or damaged. Hammering that wi ll injure or deform members will not be permitted. Bearing surfaces and contact surfaces shall be clean.
2.Drift pins shall be used to align and center the connections of main and secondary members. Only light drifting will be permitted. Any member subj ected to drifting that results in distortion of the member or elongation of the holes will be rejected. Cylindrical erection pins, the same size as the hole, shall be used at least in the extreme corners of all main member connections. 5-103 Main members shall be match marked by the fabricator and should fit together easily. Main members shall not be reamed larger than the hole size indicated on the approved fabrication draw ings without written authorization from the Project Manager . Secondary members ma y be subjected to limited field reaming with the written approval of the Engineer. Assembled parts that have been approved for field drilling or reaming shall be disassembled to remove any burrs, shavings, oils, or lubricants. Pins used for hinged connections and bearings shall be inserted with care and aligned so the members take full and even bearing. Nuts shall be adequately tightened and locked in position either by upsetting the threads or tack welding the nut to the bolt.
3.Errors in shop fa brication that prevent proper assembly shall be reported immediately to the Engineer. The Engineer shall approve any corrective action prior to it occurring. 506.1 8 BOLTIN G AND CONNECTIONS .
a.General Requirements . Connections shall be made with high -strength bolts conforming to the requirements of Subsection 714.05 unless otherwise specified. Bolts and nuts shall be furnished by the same supplier. Bolts, nuts, and washers shall be packaged and shipped so they are kept dry. When not in transit, bolts, nuts, and washers shall be stored indoors under dry, ventilated conditions. All bolts and nuts shall be adequately and uniformly lubricated. Bolts and nuts not properly lubricated shall be cleaned and re -lubricated prior to installation in accordance with applicable specifications. Bolt holes are specified as 1/16 inch larger in diameter than the bolt. Bolt holes shall be fabricated to the requ irements of the AASHTO LRFD Bridge Construction Specifications , Section 11.4.8 , except that holes shall not be punched full -size unless otherwise permitted in the Contract or approved by the Structural Steel Fabrication Engineer.
b.Bolted Parts . Bolted parts shall fit solidly together when assembled and shall not be separated by gaskets or other interposed compressible material. All joint contact surfaces and areas adjacent to bolt holes shall be free of scale, burrs, dirt, and other foreign mater ial that may prevent solid seating of the parts. 5-104 Unless otherwise specified in the Contract , faying surfaces of bolted connections shall have a Class B slip coefficient value of not less than 0.50 as specified by AASHTO. Splices and field connections of main members shall have all holes filled with high -strength bolts or cylindrical drift pins, with bolts snug -tightened before external support systems are removed. Cylindrical drift pins shall be used in the extreme corners of all main member connection s to ensure alignment and shall remain until all bolts in the connection have been fully tightened.
c.Installation . Bolted connections shall be assembled with a hardened washer under the turned element. Hardened steel washers shall be used under both the head and the nut when bolts are used for the following connections:
1.Oversized holes (fabricated as per the Contract)
2.Replacing existing bolts or rivets
3.Oversized and irregular hole conditions caused from field drilling or reaming (reaming shall not be allowed unless approved in writing by the Engineer)
4.Connections between new and existing steel members Where an outer face of the bolted parts has a slope of 1:20 (V:H) or steeper with respect to a plane normal to the bolt axis, a smooth beveled washer shall be used to compensate for the lack of parallelism. Bolts installed with the stem oriented vertically shall have the heads up. Bolts installed with the stem oriented horizontally s hall have the head towards the weather unless clearance restrictions dictate otherwise. Normally the nut will be the turned element . However, if the position of bolt entering or wrench operation clearances prohibit this procedure , the bolt may be the turned element. Tightening of a bolt group s hall progress systematically from the most rigid part of the joint to its free edges. Previously tightened bolts shall be re -tightened until all bolts in the connection are tightened to the minimum required tension. 5-105 Recalibration of the tightening wren ch may be required any time there appears to be a significant change in the bolt tightening conditions. All bolts in a connection shall first be brought to a snug tight condition. Snug tight is defined as initial tension sufficient to bring all the plies o f the connection into firm contact while the drift pins remain in the connection. Snugging shall progress systematically, beginning at the most rigid part of the connection and progressing to the free edges until the connection is fully compacted. All high -strength bolts shall be tightened to the specified tension as soon after installation as feasibly possible. Under no circumstances shall bolts be left untightened for more than 5 days after installation unless specific requirements to do so are indicated in the Contract or directed by the Engineer. Bolts left in place beyond five days without specific requirements in the Contract or as directed by the Engineer shall be removed and replaced with new bolts at the Contractor’s expense. Bolts shall be tightened to develop a tension not less than 5% more than the minimum bolt tension specified in Table 506.1 8A. Unless otherwise indicated on the Plans, ASTM F3125 Grade A325 hex head bolts shall be used.
d.Bolt Tensioning Methods . Bolts shall be tensioned by the Contractor in the presence of the Engineer using one of the following methods:
1.Tension Control Assembly Method . A tension control assembly consists of a tension control bolt with a spline end and a suitable nut and washer. This method shall be employed when installing button -headed or dome -headed high -strength bolts. This method shall only be used when required by the Contract. All bolts shall be tightened by the application of torque to the nut and counter -torque to the spline end of the bolt using an approved spline drive installation tool. A random sample of not less than three tension control assemblies of each diameter, length, grade, and type to be used in the work shall be checked a minimum of once each working day in a device capable of indicating bolt tension. The test shall be performed to verify that the spline twist -off develops a tension at least 5% greater than the minimum bolt tension specified in Table 506.1 8A. Additional verification of the tension con trol assemblies shall be performed as directed by the Engineer. Separate checks will be required for each diameter fastener with hardened washers placed under the nut or bolt head as they will be used in the structure. Variations in the number or location of washers will require separate checks. 5-106 (2) Direct Tension Indicator Method . Direct tension indicators (DTIs) are compressible washers capable of indicating that a spe cified minimum bolt tension has been attained. DTIs installed with high strength bolts to indicate bolt tension shall be subjected to field verification testing prior to installation and the installation requirements specified in this subsection . DTIs inst alled with high -strength bolts to indicate bolt tension shall be placed under the head of the bolt with the protrusions facing the head of the bolt, and the nut shall be turned, with a hardened washer underneath it, to tension the fastener. Additional hard ened washers shall be provided if required by the DTI manufacturer for their specific product. If for reasons of wrench operations clearance it is necessary to place the DTI under the turned element, the DTI shall be oriented so that the protrusions face o utward from the work, and a hardened washer shall be placed between the DTI and the turned element. Placement of the DTI under the turned element will only be allowed when approved by the Engineer. The bolt, DTI, hardened washer, and nut assembly used in t he verification testing device and installed in the work shall be such that at least three and preferably not more than five threads are in the grip. The grip is defined as the distance between the bearing face of the nut and the bolt head. The Contractor shall supply 5 -mil tapered feeler gauges, a calibrated bolt tension - measuring device and equipment necessary to perform field verification testing and inspection of tensioned bolts. The feeler gauges, fasteners, and impact and manual wrenches shall be the same as that to be used in the work. The Contractor shall obtain the services of a qualified technical advisor employed by the DTI manufacturer to make at least one site visit to assist the Contractor and to ensure the proper installation and use of DTIs. This requirement may be waived by the Engineer if the Contractor can demonstrate to the Agency ’s satisfaction successful use of DTIs on previous projects for the Agency. Verification testing shall be performed in a calibrated bolt tension measuring device, such as a Skidmore -Wilhelm Calibrator, with a special flat insert (supplied by the Contractor) replacing the normal bolt head -holding insert. The special insert allows the DTI to be located on the flat front face of the tension measuring device for ease of observation and improved access for measuring the DTI gap during testing. The Contractor shall supply hardened steel spacers as needed for testing longer bolts in the bolt tension measuring device. Stacked washer s will not be permitted as a substitute for hardened steel spacers. 5-107 The purpose of verification testing is to validate the DTI assembly’s ability to indicate installation tension above the minimum. The verification tension specified in Table 506.1 8A is 5% higher than the minimum required installation tension in Table 506.1 8A. The increase provides confidence that the installation tension can be achieved for the lot. Three verification tests are required to be performed on random samples of each combin ation of fastener rotational -capacity lot, DTI lot and DTI position (under the nut or bolt head) used on the project. All three tests must pass for the DTI and assembly combination to be approved. Testing shall be performed at the project site by the Contr actor and witnessed by the Engineer. When testing for the normal DTI position, the nut shall be turned from the rear of the tension measuring device, with the bolt head against the DTI restrained from turning with another wrench. When testing with the DTI under the turned element, the turned element shall be placed on the flat front face of the tension measuring device and the unturned element will be in the rear held by another wrench.
a.Verification Test . The verification test shall be conducted as follo ws:
1.Tension the fastener to the verification tension load specified in Table 506.1 8A for the grade and size of fastener. If an impact wrench is used, tension to a load two -thirds below the required load and use a manual wrench to attain the required tension.
2.Determine and record the number of entries of a 5 -mil feeler gauge in the spaces between the protrusions. When using galvanized or epoxy coated DTIs under the turned element, there shall be at least one entry of the feeler gauge. The DTI lot will be rejected if the number of entries is less than the value in column 2 of Table 506 .18B. If coated DTIs are used under the turned element, the DTI lot will be rejected if there are no entries.
3.Further tension the fastener, as needed, until the number of entries is within the range in column 3 of Table 506.1 8B. 5-108 4. Verify that the pretension achieved is at least that specified for the verification tension load in Table 506.18A . If the actual pretension developed in the fastener is less than the verification tension load specified in Table 506.18A , the causes shall be determined and resolved before the fasteners are used in the work. Cleaning, lubrication, and retesting new fasteners is permitt ed for this step provided that all fastener assemblies are treated in the same manner. If the bolts are too short to be tested in the tension measuring device, the verification test for the DTI shall be conducted on longer bolt s supplied by the Contractor. The longer bolts shall be new, meet the requirements of Subsection 714.05 , and be of the same type as the DTI being tested. Three verification tests are required as specified above. Bolts and DTIs used in verification tests sh all be marked and shall not be reused in the work. TABLE 506.18A – BOLT TENSION VALUES FOR ASTM F3125 BOLTS Nominal Bolt Diameter (in.) Minimum Bolt Tension (kips) 1 Verification Tension (kips) 2 Grade A325 Grade A490 Grade A325 Grade A490 1/2 12 15 13 16 5/8 19 24 20 25 3/4 28 35 29 37 7/8 39 49 41 51 1 51 64 54 67 1-1/8 64 80 67 84 1-1/4 81 102 85 107 1-3/8 97 121 102 127 1-1/2 118 148 124 155 1 Equal to 70% of the specified minimum tensile strength of bolts. 2 Verification tension is 1.05 times the minimum bolt tension. 5-109 b. Installation . Installation of fasteners using DTIs shall be conducted in two steps as follows:
1.Step 1 . All of the bolts in a connection shall be installed to a snug -tight condition. Snugging shall progress systematically beginning at the most rigid part of the connection and progressing to the free edges until the connection is fully compacted. At the snu g-tight condition all of the DTIs shall be inspected with the feeler gauge to verify that they meet the number listed in column 2 of Table 506.1 8B. If the number of entries is less than the values specified in Table 506.1 8B, the fastener shall be removed and another DTI installed, followed by re - snugging of the fastener. This is required because a fastener ’s tension may have relaxed during the snugging of adjacent fasteners. A compressed DTI does not rebound if the fastener tension is reduced. If a DTI which has fewer entries were left in place, it would give a false indication of bolt tension.
2.Step 2 . The bolts in the connection shall then be further tensioned to the point that the number of entries for a 5 -mil feeler gauge meets the number listed in column 3 of Table 506.1 8B. Tightening shall progress systematically beginning at the most rigid part o f the connection and progressing to the free edges. Drift pins shall be removed during this process , with the exception that drift pins in the extreme corners of main member connections shall remain in place until all other bolts are fully tensioned. Sever al cycles may be required. The Contractor shall use the minimum amount of force necessary to achieve the number of entries listed in column 3 of Table 506.1 8B. If DTIs are consistently being tensioned to a point where there are zero entries of the feeler gauge, the amount of force applied to the bolt shall be reduced. 5-110 TABLE 506.1 8B – NUMBER OF DTI ENTRIES FOR ASTM F3125 BOLTS Number of Spaces Between DTI Protrusions Verification - Required Number of DTI Entries 1, 2 Installation - Required Number of DTI Entries 1, 3 4 2 – 4 0 – 1 5 3 – 5 0 – 2 6 3 – 6 0 – 2 7 4 – 7 0 – 3 8 4 – 8 0 – 3 9 5 – 9 0 – 4 1 An entry occurs when a 5 -mil tapered feeler gauge fits into the space between DTI protrusions and touches the bolt shank. 2 For coated DTIs under the turned element, at least one entry is required. 3 For coated DTIs under the turned element, 0 – 1 entries are required .
e.Acceptance of Bolt Tensioning . The installation and tightening of bolted connections shall be observed to determine if the tightening procedure is working properly and the correct tension has been achieved The Contractor shall pr ovide a tension measuring device, such as a Skidmore -Wilhelm Calibrator, which has been calibrated within the last year and is accompanied by a certificate verifying its date of calibration. Before the installation of fasteners in the work, the Engineer sh all check the marking, surface condition, and storage of bolts, nuts, and washers and the faying (contact) surfaces of joints for compliance with the Contract requirements. Bolt tension for fasteners with DTIs shall be verified using 5 -mil tapered feeler g auges provided and operated by the Contractor. 5-111 All bolts installed using DTIs shall be inspected after snug tightening and again after full tensioning, with 100% of the bolts inspected visually and 10% of the bolts in any connection (but not less than two) inspected by feeler gauge. If the installation of inspected bolts is accepted, then the connection shall be accepted as properly tensioned. If any bolt in a connection does not pass inspection, then all (100%) of the bolts in that connection shall be inspected with the feeler gauge. Any bolt which does not pass inspection as described herein shall be further tensioned if required. If the Engineer suspects that the Contractor is using an excessive amount of force on fasteners with DTIs, the Engineer ma y require a sample of no less than three fasteners to be removed from the work in one or more locations for further inspection. All costs for further inspection, including replacement fasteners, shall be at no additional cost to the Agency. Further inspect ion shall be performed as follows for each sample of fasteners:
1.Step 1 . Each fastener shall be checked to verify that the nut can be turned by hand for the full length of the threads, excluding thread runout. If this is successful for all fasteners, the fasteners represented by the sample will be accepted and new fastener assemblies and DTIs shall be installed in the work where the sample fasteners were removed. If the nut cannot be turned down the full length of the threads by hand on all fasteners, proceed to Step 2.
2.Step 2 . Each fastener shall be installed in a calibrated bolt tension measuring device and tensioned to the verification tension load in Table 506.18A . The bolt tension measuring device shall be supplied with short bolt plates and bushings as needed for testing shorter bolts and hardened steel spacers as needed for testing longer bolts. Stacked washers will not be permitted as a substitute for hardened st eel spacers, with the exception that additional flat washers may be used in combination with hardened steel spacers if necessary to achieve the appropriate grip length. The complete fastener assembly that was removed from the work, excluding the DTI, shall be installed in the calibrated bolt tension measuring device with a grip length equal to or greater than the grip length when installed in the work. If this is successful for all fasteners, the fasteners represented by the sample will be accepted and new fastener assemblies and DTIs shall be installed in the work where the sample fasteners were removed. If all fasteners cannot be tensioned to the verification tension load in Table 506.18A , the Contract or shall replace all fasteners in the work represented by the sample as determined by the Engineer. 5-112 Bolts installed using tension control assemblies shall be visually inspected for consistent twist -off and thread stick -out. Undamaged fasteners may only be reinstalled with the approval of the Engineer . Galvanized bolts, ASTM F3125 Grade A490 bolts, tension control assemblies, and DTIs shall not be re installed . An additional required inspection step is to check the bolt thread stick -out on the nut side after installation to the final specified g ap to look for inconsistency of pattern. Any stick -outs greater than the other bolts shall be investigated and discarded (e.g. if necking down of the bolt has occurred or the wrong length bolt was used). The end of the properly installed bolt shall be at l east flush with the nut. The Engineer shall be provided with safe access in accordance with the requirements of Section 105 to conduct all inspection deemed necessary during and after the installation of the bolts. If the Engineer determines that the acces s provided is unsafe, work will be ordered to halt until such time that the access is made safe. Any delays incurred by the unsafe access will not be cause for a monetary, material, or delay claim. 506.19 RIVET REMOVAL . When the Plans specify existing rivets to be removed, they shall be removed without damaging the base metal. The rivets identified for removal shall have the rivet head ground flush with the base metal and the shaft drilled for removal. If necessary, the rivet head on the opposite side shall be removed in the same manner. The use of pneumatic rivet breakers and punching of rivet shanks will not be allowed, unless approved in writing by the Engineer. Flame cutting, performed by a certified welder on the Agency’s Pre-Qualified Welder List , will be allowed if approved by the Engineer. Each worker performing rivet removal work shall successfully demonstrate the process on scrap metal to the satisfaction of the Engineer prior to each worker performing any rivet removal work on the bridge. If it is necessary to pierce the shaft of rivets with a torch, the outer surface of the rivet shank shall remain intact during this process. Absolutely no gouging or other damage to the structural steel will be permitted on an y member that will remain in service after the rivet is removed. If the rivet removal process causes any damage to structural steel, the damaged member shall be repaired or replaced in a manner satisfactory to the Engineer at the Contractor ’s expense. If a ny gouging or other damage to structural steel occurs, the rivet removal work shall stop immediately, and the Engineer shall be notified. At the discretion of the Engineer, the Contractor may be required to obtain the services of a professional engineer to assess the structural capacity of the damaged member prior to restoring traffic. All costs associated with assessing damage caused by this removal process will be at the Contractor’s expense. 5-113 Where rivets are specified to be replaced, they shall be replaced with high -strength bolts meeting the requirements of Subsection 506.18 unless otherwise specified in the Contract. Rivets shall be replaced one at a time, unless otherwise specified in the P lans or approved by the Project Manager . Use of temporary bolts to replace a rivet will only be allowed with written approval from the Engineer, and provided that temporary bolts meet the requirements of Subsection 506.18 . 506.20 STRAIGHTENIN G BENT MATERIAL . Damaged, bent, or misaligned structural steel may only be straightened or corrected by procedures approved by the Agency. The method of repair proposed by the Contractor shall be submitt ed as construction draw ings for approval in accordance with the requirements of Subsection 105.06 . No corrective work shall be performed without Agency approval. Heating limitations and procedures shall conform to the requirements of Subsection 506.12 . Members or parts to be heat straightened shall be free of stress from external forces other than those necessary and used in conjunction with the application of heat. Following straightening, the surface of the metal shall be free of any evidence of distor tion or fracture. Required nondestructive tests shall be performed by NDT Level II or NDT Level III personnel at the Contractor’s expense. 506.2 1 FIELD CLEANING . When assembly of the fabricated structural components is complete, any rust, scale, dirt, grease, or other foreign material shall be removed from the metal components. The cost of such necessary cleaning will not be paid for directly but will be considere d incidental to the Section 506 items in the Contract. 506.2 2 STEEL SURFACE S AND COATINGS . All welding and anticipated hot work shall be completed prior to applying any coatings on a given item unless approved in writing by the Structural Steel Fabricati on Engineer.
a.Uncoated Steel . Care shall be taken to keep chemicals and oils from contacting the exposed surfaces of unpainted steel during storage, erection, and construction of the deck.
1.Staining of Masonry . The Contractor shall protect all concrete and masonry from staining due to oxide formation on the steel .
2.Cleaning of Steel . After all concrete has been placed, the outside surface of the fascia beams and bottom surface of their lower flanges shall be cleaned of all foreign material to a uniform appearance. The Engineer may require the exposed surfaces to be blast cleaned to meet SSPC -SP 10 . The use of acids for cleaning is prohibited.
b.Galvanized Steel . All steel surfaces to be galvanized shall be coated in accordance with Subsectio n 726.0 6 and the following: 5-114 (1) Certifications as described in ASTM A123 , Section 10 for the completed products shall be furnished to the quality assurance inspector (or the Structural Steel Fabrication Engineer, if there is no quality assurance inspector assigned to the project) prior to shipment from the galvanizer ’s plant. Certifications shall include a report of all test results and measurements.
2.Repai rs to coating shall conform to Subsection 726.0 6 and shall be brush applied unless approved otherwise by the Engineer. Products containing aluminum shall not be used.
3.Surfaces to be painted or powder coated after galvanizing shall not be water quenched or treated with chromate conversion coatings.
c.Metalized Steel . All steel surfaces to be metalized as specified on the Plans shall be metalized and seal coated in accordance with Subsection 726.0 7.
d.Powder Coated Steel . When the Plans specify powder coated steel, the work shall be performed in accordance with the requirements of this subsection.
1.Materials . All products specified to be powder coated shall receive two coats of exterior grade powder meeting the requirements of Subsecti on 708.02 .
2.Submittals . The fabricator shall submit a complete package, in accordance with Subsection 105.0 6 for construction drawings, which includes the following information. The submittals shall be made sufficiently in advance of coating work to allow for review, resubmittals, and approval.
a.Surface Preparation Plan . The surface preparation plan shall incl ude the specified methods of surface preparation and types of equipment to be used. The plan shall identify the solvents proposed for solvent cleaning.
b.Abrasives . The fabricator shall submit the type of abrasives to be used for abrasive blast cleaning.
c.Coating System Information . The fabricator shall submit the latest version of the product manufacturer’s recommendations for coating thickness, curing, and product data sheets for each and every coating product.
d.Powder Coating Plan . The powder coat ing plan shall include the pre -bake time and temperature, the thickness of each coat to be applied, and the curing time and temperature for each coat, and shall be in accordance with the manufacturer’s recommendations. 5-115 (3) Quality Control (QC) Inspection s. The fabricator shall perform first line, in progress QC inspections. The personnel performing any QC tests shall be trained in coatings inspection and the use of the testing instruments. Documentation of training shall be provided upon request. Reports for all quality control testing and observations shall be completed and provided to the QA inspector on a daily basis unless otherwise authorized by the Structural Steel Fabrication Engineer. Fabricator QC inspections shall include, but are not limited t o, the following:
a.Surface preparation and surface profile (solvent cleaning, abrasive blast cleaning, etc.).
b.Pre-bake time and temperature
c.Coating application (materials verification, dry film thickness).
d.Records of fabricator QC inspections sh all document any applicable product batch numbers.
e.Coating cure time and temperatures
4.Surface Preparation . All steel surfaces to be powder coated shall be prepared in accordance with the manufacturer’s recommendations. At a minimum, the steel surfa ce shall be prepared by SSPC -SP 1 followed by SSPC -SP 7. When powder coating is to be applied over galvanizing, the galvanized surface shall be prepared by SSPC -SP 1 , followed by SSPC -SP 16 , and in accordance with ASTM D7803 . Surface grinding in accordance with SSPC -SP 11 and ASTM D7803 will be permitted in areas where SSPC -SP 16 is not achievable or practical.
5.Surface Profile . A uniform surface profile of 1.5 mils to 3.5 mils for bare steel and 1 mil to 2 mils for galvan ized steel shall be produced. If the profile requirements of the coating manufacturer are more restrictive, the fabricator shall advise the Structural Steel Fabrication Engineer and comply with the more restrictive requirements. The surface profile produc ed by the fabricator’s surface preparation procedures shall be determined by replica tape and spring micrometer and in accordance with SSPC -PA 17 . Areas having unacceptable measurements shall be further tested to determine the limits of the deficient area. The replica tape shall be attached to the daily report. 5-116 When unacceptable profiles are produced, work shall be suspended. The fabricator shall make the necessary adjustments to ensure that the correct surface profile is achieved on all surfaces. The f abricator shall not resume work until the new profile is verified by the QA observations and they confirm that the profile is acceptable.
6.Coating Application . Coatings should be applied as soon as possible after blast cleaning but shall be applied within 8 hours of the completion of blast cleaning.
7.Coating Thickness . The dry film thickness of each coat shall be measured in accordance with SSPC -PA 2 and shall be within the manufacturer’s recommended thickness range. The minimum total DFT of the powder coating shall not be less than 5.0 mils.
e.Painted Steel . When the Plans specify shop painted structural steel, the work shall be performed in accordance with the requirements of this subsection .
1.Materials . The fabricator shall provide a three coat paint system meeting the requirements of Subsection 708.03 . Shop applied systems may have isolated areas where the coatings were damaged during shipping or erection and will have areas around faying surfaces that may need field applied prime r, intermediate, and top coatings. Thus, any coating system that is used in the shop shall be acceptable for the field conditions that are expected to be encountered. When the plans specify paint to be applied over galvanizing, a galvanized coating applie d in accordance with Subsection 506.22(b) shall be used in place of the prime coat of the three coat system. The first coat of paint applied over the galvanizing (intermediate coat) shall be recommended for application over galvanizing by the manufacturer. Any and all galvanizing repair products used prior to painting shall be compatible with the intermediate coat.
2.Submittals . The fabricator shall submit a complete package, in accordance with Subsection 105.0 6 for construction draw ings, which includes the following information. The submittals shall be made sufficiently in advance of coating work to allow for review, resubmitta ls, and approval.
a.Surface Preparation and Painting Plan . The surface preparation and painting plan shall include the specified methods of surface preparation and types of equipment to be used for removal of rust, mill scale, or foreign matter. 5-117 The plan shall identify the solvents proposed for solvent cleaning, together with the solven t safety data sheet s (SDS). If any detergents, additives, or inhibitors are incorporated into the water used for any coating work operations, the plan shall include the names of the materials and their SDS. The plan shall also include the methods of coat ing application, including any required stripe coats, and all equipment to be used. The plan shall also identify all applicable QC/QA hold points . Specific inspection items throughout these specifications are designated as hold points . These hold points are for the QA inspector to perform inspections. QA inspections will be performed only after a proper QC inspection by the fabricator. Permission to proceed beyond a hold point without a QA inspection will be granted solely at the discretion of the Structural Steel Fabrication Engineer, and only on a case -by-case basis. If re -work is necessary, as determined by a QA inspection, it shall be accomplished and a new hold point for the re -work shall be observed as defined above.
b.Abrasives . The fab ricator shall submit the type of abrasives to be used for abrasive blast cleaning and their SDS. For expendable abrasives, the Contractor shall provide certification from the abrasive supplier that the abrasive meets the requirements of SSPC -AB 1 . For stee l grit abrasives, the certification shall indicate that the abrasive meets the requirements of SSPC -AB 3 .
c.Coating System Information . The fabricator shall submit the latest version of the product manufacturer’s application and thinning instructions, SDS , and product data sheets for each and every coating, thinner, sealer, and grease rustproofing compound. Specific attention shall be drawn to storage temperatures and the temperatures of the material, surface, and ambient air at the time of application. Recommended minimum ambient weather conditions during curing shall also be included A letter or written instructions from the coating manufacturer shall be provided indicating the length of time that each coat must be protected from cold or inclement weather (e.g. exposure to rain) during the drying/curing period. 5-118 When the Agency accepts the submittals, the fabricator will receive written notification. The fabricator shall not construe Agency acceptance of the submittals to imply approval of any parti cular method or sequence for conducting the work, or for addressing health and safety concerns. Acceptance of the submittals does not relieve the fabricator from the responsibility to conduct the work according to the requirements of federal, state , or loc al regulations, this specification, or to adequately protect the health and safety of all workers involved in the project and any members of the public who may be affected by the project. The fabricator remains solely responsible for the adequacy and compl eteness of the programs and work practices, and adherence to them.
3.Quality Control (QC) Inspections . The fabricator shall perform first line, in progress QC inspections. The personnel performing any QC tests shall be trained in coatings inspection and the use of the testing instruments. Documentation of training shall be provided upon request. Painters shall perform wet film thickness measurements, with the quality control inspector conducting random spot checks of the wet film. Reports for all quality control testing and observations shall be completed and provided to the QA inspector on a daily basis.
a.Fabricator QC inspections shall include, but are not limited to, the following:
1.Ambient conditions.
2.Compressed air cleanliness.
3.Surface preparation and surface profile (solvent cleaning, abrasive blast cleaning, etc.).
4.Coating application (materials verification, mixing, thinning, induction/ sweat -in time, and wet/dry film thickness).
5.Recoat times and cleanliness between coat s.
6.Coating continuity and coverage (freedom from runs, sags, overspray, dry spray, pinholes, shadow -through, skips, misses, etc.).
7.Records of fabricator QC inspections shall document any applicable product batch numbers. 5-119 b. The following equipmen t shall be provided by the fabricator as necessary to perform QC inspections:
1.Psychrometer or comparable equipment for the measurement of dew point and relative humidity, together with all necessary tables or psychrometric charts.
2.Surface temperature digital spot thermometer. 3 SSPC -VIS 1 and SSPC -VIS 3 , as applicable.
4.Commercially available putty knife of a minimum thickness of 40 mils and a width between 1 and 3 inches.
5.Replica tape and spring micrometer.
6.Wet film thickness gauge.
7.Blotte r paper for compressed air cleanliness checks.
8.Type 2 electronic dry film thickness gauge per SSPC -PA 2.
9.Calibration standards for dry film thickness gauge.
10.Light meter for measuring light intensity during surface preparation, painting, and inspe ction activities.
11.Printed copies of all applicable ASTM and SSPC standards used for the work.
12.SSPC Manual of Good Painting Practice, Volume 1 . The instruments shall be calibrated within 12 months of the date of project usage or according to the equipment manufacturer’s recommendations and the fabricator’s QC Program if they require a shorter duration.
4.Quality Assurance (QA) Observations . The QA inspector will conduct QA observations of any or all phases of the work. The presence or activity o f QA inspector observations in no way relieves the fabricator of the responsibility to provide all necessary daily QC inspections and to comply with all requirements of this specification. The Structural Steel Fabrication Engineer has the right to reject any work that was performed without adequate provision for QA observations. 5-120 (5) Inspection Access and Lighting . The fabricator shall provide artificial lighting in areas where natural light is inadequate, to allow proper cleaning, inspection, and paintin g. Illumination for inspection shall be at least 30 foot -candles.
6.Surface Preparation and Painting Equipment . All cleaning and painting equipment shall include gauges capable of accurately measuring fluid and air pressures and shall have valves capabl e of regulating the flow of air, water, or paint as recommended by the equipment manufacturer. The equipment shall be maintained in proper working order. Hand tools, power tools, abrasive blast cleaning equipment, brushes, rollers, and spray equipment sha ll be of suitable size and capacity to perform the work required. All power tools shall be equipped with vacuums and high efficiency particulate air (HEPA) filtration. Appropriate filters, traps, and dryers shall be provided for the compressed air used for abrasive blast cleaning and conventional spray application. Paint pots shall be equipped with air operated continuous agitation devices unless prohibited by the coating manufacturer. The air discharge from power tools and air motors shall be directed away from steel surfaces . If this is not possible a filtering device shall be appropriately placed.
7.Ambient Conditions . Surfaces to be painted after cleaning shall remain free of moisture and other contaminants. The fabricator shall control operations to ensure that dust, dirt, or moisture does not come in contact with surfaces cleaned or painted that day. The following ambient conditions shall be met:
a.The surface and ambient temperatures shall be at least 5°F above the dew point during final surface preparation operations.
b.The surface and ambient temperatures shall be a minimum of 40°F, at least 5°F above dew poin t, and the maximum relative humidity shall be less than or equal to 85% during the application and cure/dry time of each coat of the paint system. If the manufacturer’s published literature is more restrictive it shall be followed for specific temperature, dew point, and humidity conditions during the application cure/dry of each coat. The cure/dry time shall be measured as the time following application when the ambient conditions are within the ranges above. 5-121 The fabricator shall monitor and documen t temperature, dew point, and relative humidity at the beginning of each work day and every 4 hours during surface preparation and coating application, in the specific areas where the work is being performed. The frequency of monitoring shall increase if w eather conditions are changing. If the weather conditions are forecast to be borderline relative to the limits established by the manufacturer, monitoring shall continue at a minimum of 4 hour intervals throughout the curing/drying period. The Structural S teel Fabrication Engineer has the right to reject any work that was performed under unfavorable weather conditions. Rejected work shall be removed, re -cleaned, and repainted at the fabricator’s expense.
8.Compressed Air Cleanliness . Prior to using compre ssed air for abrasive blast cleaning, blowing down the surfaces, and painting with conventional spray, the fabricator shall verify that the compressed air is free of moisture and oil contamination in accordance with the requirements of ASTM D4285 . The test s shall be conducted at least one time each shift for each compressor system in operation. If air contamination is evident, the fabricator shall change filters, clean traps, add moisture separators or filters, or make other adjustments as necessary to achi eve clean, dry air. The fabricator shall also examine the work performed since the last acceptable test for evidence of defects or contamination caused by the compressed air. Affected work shall be repaired at the fabricator’s expense.
9.Surface Preparat ion and Profile (Hold Point) .
a.Surface Preparation . All bare steel surfaces to be painted shall be prepared by dry abrasive blast cleaning to meet the requirements of SSPC -SP 10 . When the Plans specify paint to be applied over galvanizing, the galvanized surface shall be prepared prior to applying the intermediate coat. The galvanized surface shall be prepared by SSPC -SP 1 followed by SSPC -SP 16 , and in accordance with ASTM D 6386 . Surface grinding in accordance with SSPC -SP 11 and ASTM D6386 will be permitted in areas where SSPC -SP 16 is not achievable or practica l.
b.Abrasives . Abrasive blast cleaning shall be performed using either expendable abrasives (other than silica sand), or recyclable steel grit abrasives. Expendable abrasives shall be used one time and disposed of. The fabricator shall verify that recycl ed abrasives are free of oil contamination by conducting oil content tests in accordance with SSPC -AB 2 on a daily basis. 5-122 c. Surface Profile . The abrasives used for blast cleaning shall have a gradation such that the abrasive will produce a uniform surf ace profile of 1.5 mils to 3.5 mils for bare steel and 1 mil to 2 mils for galvanized steel. If the profile requirements of the coating manufacturer are more restrictive, the fabricator shall advise the Structural Steel Fabrication Engineer and comply with the more restrictive requirements. For recycled abrasives, an appropriate operating mix shall be maintained in order to control the profile within these limits. The surface profile produced by the fabricator’s surface preparation procedures shall be dete rmined by replica tape and spring micrometer and in accordance with SSPC -PA 17 . Areas having unacceptable measurements shall be further tested to determine the limits of the deficient area. The replica tape shall be attached to the daily report. When unac ceptable profiles are produced, work shall be suspended. The fabricator shall make the necessary adjustments to ensure that the correct surface profile is achieved on all surfaces. The fabricator shall not resume work until the new profile is verified by t he QA observations and they confirm that the profile is acceptable.
d.Surface Condition Prior To Painting . Prepared surfaces shall meet the specified degrees of cleaning immediately prior to painting and shall be painted before rusting appears on the surface. If rust appears or bare steel remains unpainted for more than 8 hours, the affected area shall be pre pared again at the expense of the fabricator. All surface preparation cleaning residue on steel surfaces shall be removed prior to painting. The quality of surface preparation and cleaning of surface dust and debris shall be accepted by the QA inspector prior to painting. The Structural Steel Fabrication Engineer has the right to reject any work that was performed without adequate provision for QA observations to accept the degree of cleaning. Rejected coating work shall be removed and replaced at the fa bricator’s expense.
10.General Paint Requirements . Paint storage, mixing, and application shall be accomplished according to these specifications and as specified in the paint manufacturer’s written instructions and product data sheets for the paint syst em used. In the event of a conflict between these specifications and the coating manufacturer’s instructions and data sheets, the fabricator shall advise the Structural Steel Fabrication Engineer and comply with the most restrictive requirements. 5-123 a. Paint Storage and Mixing . All paint shall be stored according to the manufacturer’s published instructions, including handling, minimum and maximum temperatures, and warming as required prior to mixing. All coatings shall be supplied in sealed containers beari ng the manufacturer’s name, product designation, batch number, and mixing/thinning instructions. Leaking containers shall not be used. The paint shall be stored in a secure fireproof location. Mixing shall be performed according to the manufacturer’s inst ructions. Thinning shall be performed using thinner provided by the manufacturer, and only to the extent allowed by the manufacturer’s written instructions. In no case shall thinning be permitted that would cause the coating to exceed the local volatile or ganic compound emission restrictions. For multiple component paints, only complete kits shall be mixed and used. Partial mixing is not allowed. The ingredients in the containers of paint shall be thoroughly mixed by mechanical power mixers according to th e manufacturer’s instructions, in the original containers before use or mixing with other containers of paint. The paint shall be mixed in a manner that will break up all lumps, completely disperse pigment, and result in a uniform composition. Paint shall be carefully examined after mixing for uniformity and to verify that no unmixed pigment remains on the bottom of the container. Excessive skinning or partial hardening due to improper or prolonged storage will be cause for rejection of the paint, even th ough it may have been previously inspected and accepted. Manufacturer recommended induction/sweat -in times and temperature of mixed coatings shall be observed. Multiple component coatings shall be discarded after the expiration of the pot life. Single com ponent paint shall not remain in spray pots, paint buckets, etc. overnight and shall be stored in a covered container and remixed before use.
b.Paint Application . Painting shall be performed in a neat and skilled manner. Each coat of paint shall be applied as a continuous film of uniform thickness free of defects including, but not limited to, runs, sags, overspray, dry spray, pinholes, voids, skips, misses, and shadow -through. Defects such as runs and sags shall be brushed out immediately during application. 5-124 Unless prohibited by the coating manufacturer’s written instructions, paint may be applied by spray methods, rollers, or brushes. If applied with conventional or airless spray methods, paint shall be applied in a uniform layer with overlapping at the edges of the spray pattern. The painters shall monitor the wet film thickness of each coat during application. The wet film thickness shall be calculated based on the specified dry film thickness using th e solids by volume of the material and the amount of thinner added. When brushes or rollers are used to apply the coating, additional applications may be required to achieve the specified thickness per layer.
c.Re-Coating and Film Continuity (Hold Point for Each Coat) . Paint shall be considered dry for re -coating according to the re -coat time/temperature/humidity criteria provided in the manufacturer’s instructions , and when an additional coat can be applied without the development of film irregularities such as lifting, wrinkling, or loss of adhesion of the under coat.
d.Stripe Coats . Unless indicated otherwise in the Contract, the Contractor shall apply an additional stripe coat to edges, crevices, welds, and similar surface irregularities for the pri me coat and intermediate coat. The stripe coat shall be applied by brush or roller, as per the manufacturer’s recommendations, such that the coating is thoroughly worked into or on the irregular surfaces . The stripe coat shall extend onto the surrounding s teel a minimum of 1 inch in all directions. The purpose of the stripe coat is to build additional thickness and to ensure complete coverage of these areas. The stripe coat shall not be applied as part of the application of the full coat. The stripe coat shall be applied and dried separately according to the manufacturer’s recommended drying times. Also, the color of the stripe coat shall contrast with the colors used for the full coats immediately preceding and succeeding the stripe coat.
e.Coating Sequ ence. For locations painted under this specification, coatings shall be applied as follows:
1.Prime Coat . The full prime coat shall be applied first to protect the steel. Once the full prime coat has dried, the prime stripe coat shall be applied.
2.Intermediate Coat . After the prime stripe coat has dried, an intermediate stripe coat shall be applied and allowed to dry, followed by the full intermediate coat. 5-125 3. Top Coat . After the full intermediate coat has dried, the full top coat shall be applied.
11.Coating Thickness . The dry film thicknesses of the full coats shall be as follows, as measured in accordance with SSPC -PA 2 . If the manufacturer’s upper or lower thickness limit is more restrictive, it shall be followed instead.
a.Prime Coat . The prime coat of organic zinc -rich primer shall be between 3.5 mils and 5.0 mils dry film thickness.
b.Intermediate Coat . The intermediate coat of epoxy or urethane shall be between 3.0 mils and 6.0 mils dry film thickness.
c.Top Coat . The top coat of aliphatic urethane shall be between 2.5 mils and 4.0 mils dry film thickness. The top coat color shall be according to Contract .
12.Amine Blush . Amine blush is a residue that can form on newly applied epoxy coating films under certain conditions . Amine blush often appears as a yellowish milky or blotchy residue on the coating surface and is a deterrent to the adhesion of subsequently applied coating layers. If amine blush is detected, the Contractor shall provide the Engineer with written procedu res from the coating manufacturer for complete removal prior to the application of additional coating layers.
13.Repair of Damage to New Coating System . The Contractor shall repair all damage to the newly installed coating system, at no cost to the Agenc y. If the damage extends to the substrate, the damaged areas shall be prepared to meet SSPC -SP 3. The surrounding coating at each repair location shall be feathered for a minimum distance of 1-1/2 inches to achieve a smooth transition between the prepare d areas and the existing coating. If the bare steel is exposed, all coats shall be applied to the prepared area. If only the intermediate and finish coats are damaged, the intermediate and finish coats shall be applied. If only the finish coat is damaged, the finish coat shall be applied. All hold points and specifications are applicable to the repair of damaged areas and areas concealed by containment. 5-126 (f) Field Connections .
1.Waiver of Certifications . For applications of shop painting and field assembly, the Contractor may request that the Engineer waive the requirements for NACE certification and SSPC -QP 1 certification for the necessary field painting of the bolted connection areas. Requests will be reviewed on a case -by-case basis and will only be considered on projects with limited amounts of required field painting such as diaphragm and cross frame connections. If the Engineer grants the request, all other requirements for certifications, inspecti ons, quality control, supplying inspection equipment, hold points, etc. will remain in effect.
2.Surface Cleaning for Hardware . The requirements of this part shall apply when the Contract requires installation of bolts that are to be painted. This work shall occur after bolt tensioning has been completed. All exposed oils, lubricants, and wax on the bolts, nuts, washers, and surrounding surfaces to be painted shall be completely removed by solvent cleaning. This also includes any foreign material that ha s come out of the DTIs during the tensioning process. Light hand wire brushing or scrubbing with bristle brushes is allowed. Use of power tools is not allowed. For galvanized hardware, the Contractor shall remove the colored lubricant from the nuts. The g alvanizer may be able to provide information to the Contractor on the most effective solvent cleaner to remove the colored lubricant (common examples include methyl -ethyl - ketone (MEK), foaming glass cleaners containing ammonia, and foaming alkaline -type household cleaners). It is not necessary to remove 100% of the dye, and it is acceptable for some staining to remain after cleaning. A white cloth wipe test with no color transfer can be used to confirm that all lubricant and non -absorbed dye has been remove d, leaving only the residual stain on the surface. The final cleanliness shall be acceptable to the Engineer.
g.Grease Coating . When the Plans specify that any steel surfaces are to be grease coated, all work shall be performed in accordance with Subsect ion 708.0 4. Grease rustproofing compound shall be uniformly applied in a single coat by brush or spray at an approximate rate of 20 square feet per gallon to the steel as specified. This shall occur after all concrete form work has been removed, and after the final coat of paint, including repairs, has fully cured. A fully cured condition has occurred when a thumbnail driven into the coating surface does not leave an impression and when a thumb firmly pushed against the surface and twisted does not disturb the coating. Surfaces adjacent to areas being grease coated shall be protected against over -spray. Non -metallic and stainless steel surfaces shall not be coated. 5-127 506.2 3 METHO D OF MEASUREMENT .
a.Bids on a Pound Basis . The quantity of Structural Steel, or other material being paid for under this item, to be measured for payment will be the number of pounds used in the complete and accepted work. The weight of the material to be measured for payment under this item will be computed based on the approved fabrication draw ings, as follows:
1.Weight determined by the volume of material will be computed based on the densities specified in Table 506.2 3A. TABLE 506.2 3A – MATERIAL DENSITIES Material Density (lbs/ft3) Aluminum, Alloy 173 Bronze, Cast 536 Copper, Alloy 536 Copper, Sheet 558 Iron, Cast 445 Iron, Wrought 487 Lead, Sheet 707 Steel – Rolled, Cast, Copper Bearing, Silicon, Nickel, or Stainless 490 For any material not listed in Table 506.2 3A, the material will be paid for by actual weight as measured on a certified scale.
2.The weight of rolled structural shapes will be computed based on their nominal weight per foot as shown on the Plans or, if not shown on the Plans, by the weights shown in the AISC Steel Construction Manual . The weight of rolled shapes will be b ased on the overall net length shown on the approved fabrication draw ings, with no allowance for milling, finishing, or overrun, and with no deduction for cuts, clips, copes, or open holes.
3.The weight of plates will be based on the net finished dimensions shown on the approved fabrication draw ings, with no allowance for milling, finishing, tolerance, or overrun, and with no deductions for copes, clips, and open holes. The weights of beveled p lates or curved surface plates will be based on the finished maximum thickness shown on the approved fabrication draw ings. 5-128 For gusset plates, scupper components, slotted plates, and similar minor fixtures the net finished dimensions will be the minimum re ctangular dimensions from which the parts are cut, except when it is practical to cut the parts in multiples from pieces of larger dimensions, in which case the weight will be based on the dimensions of the larger pieces, making necessary allowance for the material lost in cutting. The net finished dimensions of flange plates will be the nominal width and the finished length measured along the centerline of the flange without deduction for width transitions, bevels, or chamfers. The net finished dimensions of the webs of all girders and of the webs of rigid frame legs will be the actual area of the web as detailed on the approved fabrication draw ings.
4.All welding shall be considered as incidental work to the fabrication, and no measurement will be made for the weight of weld metal used.
5.The weight of permanent shop and field bolts, nuts, direct tension indicators, and washers incorporated into the structure and temporary erection bolts, nuts, and washers shall be incidental to the Structural Ste el item and no measurement will be made for weight of the bolts, nuts, direct tension indicators, and washers.
b.Bids on Lump Sum Basis . The quantity of Structural Steel, or other material being paid under this item, to be measured for payment will be on a lump sum basis in the complete and accepted work .
c.Bids on an Each Basis . The quantity of Rivet Replacement to be measured for payment will be the number of existing rivets replaced with high strength bolts in the complete and accepted work. Rivets measured for replacement will be made in only the locations specified in the Contract and in any other locations identified for replacement by the Engineer. Unless otherwise specified in the Contract, rivet removal and installation of new fasteners associ ated with structural steel repairs will not be measured for payment as Rivet Replacement. 506.2 4 BASIS OF PAYMENT . The accepted quantity of Structural Steel will be paid for at the Contract unit price per pound or at the Contract lump sum price for the items specified in the Contract. Payment will be full compensation for furnishing, detailing, handling, transporting, and placing the materials specified, including nondestructive testing of welds; for preparing the surface of new steel to be paint ed, galvanized, metalized, or to remain unpainted; for necessary field cleaning; and for painting, metalizing, sealing, galvanizing, or grease coating of surfaces, unless otherwise paid for. Payment will also be full compensation for furnishing and impleme nting the erection plan, nondestructive testing , quality control activities, and for furnishing all labor, tools, equipment, and incidentals necessary to complete the work. 5-129 The Engineer may authorize partial payments in the following manner:
a.The fir st payment of 15% of the estimated quantity may be paid when the fabrication draw ings are approved for fabrication.
b.The second payment of 60 % of the estimated quantity may be paid when the steel has been entirely completed and accepted in accordance wi th the approved fabrication draw ings, stored in a location and man ner accepted by the Structural Steel Fabrication Engineer, and all applicable material certifications have been approved.
c.The third payment of 15 % of the estimated quantity may be paid when the steel has been erected, falsework removed, and painting of connections and touch -up completed where required.
d.The final payment of 10% of the estimated quantity may be paid a fter completion and acceptance of all work under this section , including extended weights being received and checked . The accepted quantity of Rivet Replacement will be paid for at the Contract unit price for each. Payment will be full compensation for per forming the work specified and for furnishing all labor, tools, equipment, and incidentals necessary to complete the work. Payment will be made under: Pay Item Pay Unit 506.50 00 Structural Steel, Rolled Beam ................................ ................................ ...Pound 506.55 00 Structural Steel, Plate Girder ................................ ................................ ....Pound 506.56 00 Structural Steel, Curved Plate Girder ................................ ........................ Pound 506.57 00 Structural Steel, Truss ................................ ................................ ............... Pound 506.60 00 Structural Steel ................................ ................................ .......................... Pound 506.75 00 Structural Steel ................................ ................................ .......................... Lump Sum 506.8500 Rivet Replacement ................................ ................................ .................... Each 5-130 SECTIO N 507 – REINFORCIN G STEEL 507.0 1 DESCRIPTION . This work shall consist of furnishing and placing bar reinforcement of the level specified, dowels, wire, welded wire reinforcement (WWR), and mechanical bar connectors. Levels and associated types of reinforcing steel are specified as follows:
a.Level I (Limited Corrosion Resistance) . Level I reinforcing includes plain, low -alloy, and epoxy - coated reinforcing steel.
b.Level II (Improved Corrosion Resistance) . Level II reinforcing includes dual -coated, continuously -galvanized , low -carbon chromium, and hot-dipped galvanized reinforcing steel.
c.Level III (Exceptional Corrosion Resistance) . Level III reinforcing includes solid stainless reinforcing steel. The location, level, and when specified, type of reinforcing shall be as indicated on the Plans. Reinforcing supplied shall meet the requirements of the level specified or any higher level. Only one type of reinforcing steel shall be used for each level for the Contract work, unless permitted in writing by the Engineer. 507.0 2 MATERIALS . Materials shall meet the requirements of the following subsection s: Mortar, Type IV ................................ ................................ ................................ ......... 707.0 1(e) Bar Reinforcement ................................ ................................ ................................ .....713.01 Mechanical Splices for Bar Reinforcement ................................ ............................... 713.02 Welded Wire Reinforcement ................................ ................................ ..................... 713.0 3 507.0 3 FABRICATIO N AND SHIPMENT . Bar reinforcement shall be deformed bar cold bent to the shapes required. Bar reinforcement shall be fabricated, bundled, tagged, marked, and shipped in accordance with the CRSI Manual of Standard Practice . The fabricator shall maintain records that will provide traceability of identifying heat numbe rs for all material being fabricated for Agency projects or Contract orders referencing materials covered under this section . 507.0 4 PROTECTIO N OF MATERIAL . Reinforcing steel shall be protected from damage at all times by storing it on blocking, racks, or platforms. When multiple levels of reinforcing steel are used on a project, they shall be stored separately, including during transport in order that there is no direct contact between the bars. When placed in the work, the reinforc ing steel shall be free from dirt, detrimental scale, paint, oil, previously placed concrete, or other foreign substances.
Source: Vermont Standard Specifications for Construction, 2024 Edition. Pages 499–543 of 1,380.