277 SECTION 616
616.01 Description
The work consists of fabricating, furnishing, delivering and erecting structural steel. If structural steel is included in the contract as a “Lump Sum” item, verify the estimated weight of structural steel before submitting a proposal. The contract unit price for “Lump Sum” s tructural steel will only be revised if contract revisions are issued or authorized. No revisions will be made to the contract unit price of structural steel if the actual weight of the required structural steel varies from the estimated plan weight.
616.02 Equipment
Reserved.
616.03 Materials
Item Section Structural Steel and Related Materials 834 Three Coat Organic Zinc Rich Paint System 852.02 Use welded stud shear connectors meeting the requirements of AASHTO LRFD Bridge Construction Specifications , Section 11.3.3 and AASHTO/AWS D1.5 Bridge Welding Code, Clause 7. The Department does not require performance of the Charpy V -Notch test on structural steel used in the following locations: • Bearings ; • Bearing stiffeners; • Transverse web stiffeners; • Ice noses ; • Cross frames; • Gusset plates • Diaphragms ; • Transverse connection plates; • Deck drains; and • Barrier expansion plates .
616.04 Construction Requirements
A.Work Drawings. Submit work drawings for the fabrication and erection of steel. Show dimensions and sizes of materials for fabrication, bolt lists for field erection, a match-marking diagram, and a complete field erection plan. The Engineer’s review applies only to the requirements for strength, details and arrangements of parts and details. 278 B. Shop Inspection. Ensure shop inspection personnel are qualified as specified in the latest AASHTO/AWS D 1.5 Bridge Welding Code. The D epartment will not accept welded plate girders without a Department shop inspection. Provide the Engineer at least three weeks notice before beginning fabrication. Furnish facilities for the inspection, allow the Inspector access to all areas, and furnish the inspector at least two 4 inch by 18 inch samples of each grade and brand of structural steel.
C.Fabrication.
1.General. Fabricate as specified in the latest AASHTO/AWS D 1.5 Bridge Welding Code except as modified by this Specification. For structures that carry railroad traffic, fabricate the structural steel as specified by AREMA Specifications.
2.Structural Steel. Position shear connectors on splice plates to clear the bolt holes. The Engineer will allow shop-welded connections of diaphragm angles to gusset plates in place of the bolted connections. On the shop drawings, indicate which connection method will be used. Do not attach any devices that are not shown on the Plans to the structural steel members during the fabrication and construction process without written permission from the Department’s Bridge Engineer.
3.Blast Cleaning of Weathering Steel. After fabrication for weathering applications, blast clean the exterior faces of outside beams or girders, including stiffeners, flanges, and other steel readily exposed to view as specified in the Steel Structures Painting Council Surface Preparation Specification “No. 6 Commercial Blast Cleaning”, (SSPC -SP 6). Do not use a corrosion inhibitor.
4.Painting.
a.General. Shop apply the paint system to all structural steel surfaces except, intermediate and finish coats on splice and filler plates may be field applied. Spray apply coatings according to the manufacturer's instructions. Apply the coating with a brush on surfaces i naccessible to spray.
1.Submittals. Submit the manufacturer’s written recommendations for equipment, spray pressures, shelf life, pot life, cure time and top coat window. Apply coatings in a uniform, even coat and work into all corners and crevices. Submit quality control records that incl ude the following for each coating layer: - Date and Time of Application; - Ambient Air Temperature; 279 - Humidity; - Dew Point; - Surface Profile Measurements; and - DFT Readings.
2.Application. Apply each coating layer so its Dry Film Thickness (DFT) is in accordance with the manufacturer’s instructions when measured according to SSPC PA -2. Re-blast, clean, and recoat any surfaces that have a coating thickness outside of the manufacturer's specified range.
3.Mixing and Thinning Paint. Thoroughly mix all paint system components so the pigment is completely in suspension and the consistency is uniform. Strain the zinc primer over a sieve having openings no larger than a No. 50 sieve and continuously agitate until application is completed. Thinners may be us ed if they are part of the paint manufacturer’s instructions. Follow the manufacturer’s instructions regarding the quantity and type of thinner used.
b.Shop Painting.
1.Surface Preparation. Remove oil and grease from surfaces to be painted before blast cleaning. Remove the oil or grease by solvent cleaning according to SSPC SP -1. Blast clean surfaces to be painted to a near white finish according to SSPC SP -
10.Produce a surface profile depth that is consistent with the paint manufacturer's recommendations. Remove blast residue from the steel surfaces before painting. Keep the steel dry. Apply prime to surfaces within 24 hours after blasting and cleaning.
2.Paint System Application. The paint system is composed of 3 layers; primer, inter mediate coat, and finish coat. Mask contact or faying surfaces of bolted field splices of the main members, shear connectors, and the upper surface of the top flanges during the intermediate and finish coat application. Do not apply subsequent layers of the paint system until the Engineer has approved the previous application.
3.Handling, Shipping, and Erection. If the coating system is damaged prior to shipment, repair the damaged coating using the same process that was used to apply the coating initially. Load the steel for shipment after the Engineer has approved the finish coat. 280 If damage to the coating system occurs during transport or erection, repair damaged areas as specified in Section 616.04 C.4.c, “Field Application” .
c.Field Application.
1.General. Do not allow paint or paint materials to come in contact with surfaces not intended to be painted. Provide a means to protect traffic from spattering of paint or paint materials. Prevent deleterious material from adhering to freshly painted surfaces.
2.Surface Preparation. Remove areas of damaged coating down to bare metal. Remove all rust and loose paint. Feather edges of cleaned repair areas to ensure a bond of new paint to old paint and to provide a smooth finish.
3.Paint System Application. Apply paint only when environmental conditions, such as temperature, humidity, and dew point, are within the manufacturer's recommended range.
D.Shop Welding. Perform shop welding as specified in the latest AASHTO/AWS D1.5 Bridge Welding Code. Do not use the electroslag and electrogas welding processes for welding bridge members. Perform flange-to-web welds and shop welded splices in flanges or webs using the automatic submerged arc and welding process.
1.Built -up Plate Girders. Cut web plates of built up beams and girders to the prescribed camber with allowance for shrinkage due to cutting and welding. Make shop butt welds in the flange plates before final fitting and welding into the girders.
2.Nondestructive Testing. Perform nondestructive testing (NDT) on welds as specified in AASHTO/AWS D 1.5 Bridge Welding Code and the following: − Perform the NDT under the observation of the Engineer. Testers sha ll be certified by the American Society for Nondestructive Testing (ASNT) at Level II or higher and shall have at least two years of experience at that level. − Submit a written report of all NDT to the Engineer along with material certification documenting compliance of the welds with contract requirements.
a.Radiographic and Ultrasonic Inspection. Test groove welds in main members of built up girder structures by radiographic or ultrasonic inspection as follows: − Completely inspect tension splices and splices subject to reversals of stress; − Test 1/6 of the web depth beginning at the point or points of maximum tension and 25 percent of the remainder of the web depth on girder and beam web splices; and − Test all compr ession flange splices. Test welds after grinding and retest repaired welds.
b.Magnetic Particle Inspection. Use the magnetic particle inspection method to test longitudinal beam or girder web butt splices and fillet welds in main members, including the end connections, as follows: − Test at random locations in the members so as to be typical for each size of weld and type of joint; − Test 1 foot of every 10 foot length of weld; and − Test 1 foot of each weld less than 10 feet in length. If defects are found in a test area, repair the full length of the weld or 5 feet on either side of the test length, whichever is less. Retest the repaired area plus at least 2 inches on each side of the repaired area.
E.Handling, Marking, Shipping, and St oring Materials. Mark each member with an erection mark for identification, and furnish an erection diagram showing the erection marks. Pack bolts of one length and diameter, and loose nuts and washers of each size separately. Ship pins, small parts, smal l packages of bolts, washers, and nuts in suitable containers with a list and description of the material plainly marked on the outside of each container. Load, transport, unload, and store structural material without stressing, deforming, or damaging the structural members and so the metal is kept clean. Handle long steel members by placing saddles at approximately the quarter points and during storing and shipping placing blocking at intervals that prevent sag and distortion. Store, ship and handle rolled beams and built-up plate girders in a vertical position. Keep stored materials properly drained. Store steel above ground on platforms, skids or other supports. Support girders, beams, and long members such as columns and chords to prevent damage from deflection. Handle girder sections with beam clamps or other approved devices and do not use wire rope slings. Keep AASHTO M 270 Grade 50W steel clean and free of materials that may affect the metal’s natural oxidation. Place match marks for G rade 50W steel on the top flange and remove the match marks as soon as they are no longer necessary. Provide temporary protection during concrete operations and all operations that can affect uniform natural oxidation.
F.Falsework, Methods, and Equipment. Submit falsework plans to the Engineer. If changes in an existing structure are necessary for maintaining traffic, submit plans to the Engineer for review.
G.Assembling Steel. Do not assemble steel on structure until previously placed concrete is at l east 14 days old or has reached 70 percent design strength Before assembly, clean bearing surfaces and surfaces that will be in permanent contact. 282 Assemble parts using the match marks. Bring splice points in beam or girder spans to proper elevation and support them in position before the fasteners are tightened.
1.Bolts. Make permanent field connections using 7/8 inch diameter ASTM F3125 Grade A325 high-strength bolts. Make the diameter of the bolt holes 1/16 inch greater than the diameter of the bolts used. Use bolts for transmitting shear that are threaded to a length that a maximum of one thread is within the grip of the metal. Use bolts that are long enough to extend entirely through the nuts but not more than 1/4 inch beyond the face of the nut. Place one lock washer under the nut of each bolt connecting handrails. Install a hardened washer over slotted holes. When using galvanized nuts, use nuts with a visible lubricant on the threads. When using black bolts and nuts, use bolts and nuts that are oily to the touch when delivered and installed. If bolts and nuts lose lubrication, clean and lubricate the bolts and nuts before installation. Test recleaned or relubricated bolt, nut and washer assemblies as specified in
2.Bolt Connections. Tighten high strength steel bolts using the following requirements:
a.Bolt-Nut-Washer Assembly Testing. Perform the rotational -capacity test specified in Section 834.03 A.2, “Rotational Capacity Testing of Assemblies” on each rotational -capacity lot before starting bolt installation. A Skidmore-Wilhelm Calibrator tension measuring device will be provided by the Engineer at each project site during erection. Use hardened steel washers for tests. If using the calibrated wrench method, perform the test each day that bolts are installed. If using other methods, perform the tests on each production lot. The Engineer will verify the installation test procedures. Use direct tension indicators when testing bolts that are too short for the Skidmore- Wilhelm Calibrator. Calibrate the direct tension indicators in the Skidmore-Wilhelm Calibrator using longer bolts.
b.Installation Preparation and Tension Requirements. Ensure bolted parts fit firmly together when assembled. Descale contact surfaces, including washers that carry more than normal tight mill scale. Contact surfaces shall be free of defects that would pr event solid seating of the parts. Install bolts with nuts on the interior side of the web and on the top side of the flange. Install bolts with a hardened washer under the bolt head or nut, whichever is turned in tightening. Use a flat washer when the abutment surface adjacent to the bolt head or nut does not have a slope of more than 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of more than 1:20 with respect 283 to a plane normal to the bolt axis, u se a smooth beveled washer to compensate for the lack of parallelism. Tighten all fasteners to the minimum bolt tension values shown in Table 616 -01 “Required Fastener Tension” on completion of the joint. Table 616 -01 Required Fastener Tension Bolt Size (Inches) Minimum Bolt Tension1 (Pounds) 1/2 12,000 5/8 19,000 3/4 28,000 7/8 39,000 1 51,000 1-1/8 56,000 1-1/4 71,000 1-3/8 85,000 1-1/2 103,000 1 Equal to 70 percent of specified minimum tensile strength of bolts as specified in ASTM Specifications for tests of full size ASTM F3125 Grade A 325 bolts with UNC threads loaded in axial tension.
c.Installation Methods. Do not use high strength bolts that were previously tightened to requirements of Table 616-01. Replace the assembly with a new bolt and nut. Replace the assembly at no additional cost to the Department.
1.Turn -of-Nut Tightening. Snug tighten all bolts in the joint with a few impacts of an impact wrench or the full effort of a worker using an ordinary spud wrench. Ensure the parts of the joint are in full contact with each other. Match mark the nuts and protruding bolt ends before final tensioning so that the actual rotation can be determined. Perform final tensioning by the applicable nut rotation specified in Table 616-02 with tightening progressing systematically from the rigid part of the joint to its free edges. During this operation, do not allow rotation of the part not turned by the wrench. For bolts installed by 1/2 turn or less, rotate within a tolerance of plus or minus 30 degrees. For bolts installed by 2/3 turn or more, rotate within a tolerance of plus or minus 45 degrees. Table 616-02 “Nut Rotation from Snug Ti ght Condition Disposition of Outer Faces of Bolted Parts” applies only to connections in which all material within the grip of the bolt is steel. 284 Table 616-02 Nut Rotation from Snug Tight Condition Disposition of Outer Faces of Bolted Parts Bolt Length (underside of head to end of bolt) Both faces normal to bolt axis One face normal to both axis and other sloped not more than 1:20 (beveled washer not used) Both faces sloped not more than 1:20 from normal to the bolt axis (beveled washers not used) 4 Diameters and smaller 1/3 turn 1/2 turn 2/3 turn Over 4 thru 8 Diameters 1/2 turn 2/3 turn 5/6 turn Over 8 thru 12 Diameters1 2/3 turn 5/6 turn 1 turn 1 For bolt lengths exceeding 12 diameters, determine the required rotation by actual test in a suitable tension measuring device which simulates conditions of solidly fitted steel.
2.Calibrated Wrench Tightening. Set calibrated wrenches to the minimum tensions required in Table 616-03 “Required Fastener Tension – Calibrated Wrench Tightening”. Table 616 -03 Required Fastener Tension – Calibrated Wrench Tightening Bolt Size (Inches) Minimum Bolt Tension (Pounds) 1/2 12,600 5/8 19,950 3/4 29,400 7/8 40,950 1 53,550 1-1/8 58,800 1-1/4 74,550 1-3/8 89,250 1-1/2 108,150 Calibration: Calibrate wrenches using the Skidmore-Wilhelm Calibrator. Calibrate by tightening three typical bolts of each diameter, length and grade from the bolts being installed. Use a hardened washer from the washers being used in the work under the el ement turned in tightening. Recalibration: Recalibrate wrenches when there is significant difference in the surface condition of the bolts, threads, nuts, or washers. Verification: Verify that the wrench adjustment selected by the calibration does not pr oduce a nut or bolt head rotation from snug tight greater than that permitted in Table 616-02 during actual installation in the assembled steelwork. 285 If manual torque wrenches are used, measure torque when turning nuts in the tightening direction. Installation: Install and tighten bolts in all holes of the connection to a snug tight condition. Use hardened washers under the element turned. Following the initial tightening operation, further tighten the connection using the calibrated wrench. Tighten systematically from the most rigid part of the joint to its free edges. Recheck: Recheck previously tightened bolts to ensure they have not relaxed as a result of the subsequent tightening of adjacent bolts. Keep rechecking bolts until all bolts are tightened to the specified minimum required tension.
3.Direct Tension Indicator (DT I) Tightening. Use DTI’s that indicate the minimum tensions specified in Table 616-01. Follow the manufacturer’s installation procedure for installation of bolts in the calibration device and in all connections. Properly install flat hardened washers when using DTI with bolts installed in oversize or slotted holes and when using the DTI under the turned element.
a.Calibration Testing of DTI. Assemble a minimum of 3 DTI test assemblies for each length, diameter, and grade of fastener. Perform the rotational -capacity test specified in Section
834.03 A.2, “Rotational Capacity Testing of Assemblies” on each rotational -
capacity lot before starting bolt installation. The test assemblies shall be identical to the assem blies required in the connection. Test the assemblies in a calibration device capable of indicating bolt tension.
b.Installation. Install bolts in all holes of the connection and tighten to achieve partial compression of the DTI protrusions. Tighten all fasteners, progressing systematically from the most rigid part of the connection to the free edges in a manner that will minimize relaxation of previously tightened fasteners. Proper tensioning of the bolts may require more than a single cycle of systematic partial tightening before final tightening to deform the DTI protrusions to the specified gap.
4.Alternate Design Fasteners (ADF). Use alternate design fasteners (ADF) that meet the specifications in Section 834.03, “Bolts, Nuts, and Washers”. Follow the manufacturer’s installation procedure for installation of bolts in the calibration device and in all connections.
a.Verification Testing of ADF. Assemble a minimum of 3 ADF test assemblies for each length, diameter, and grade of fastener to be used in the work. If required in the actual connection, include flat- hardened washers in the test ass embly arranged as in the actual connections to be tensioned. Test the samples at the job site in a device capable of indicating bolt tension. Only use ADF represented by samples that develop a tension required by Table 616-01. 286 (b) Installation. When ADF are used, install bolts in all holes of the connection and initially tighten them sufficiently to bring all plies of the joint into firm contact but without yielding or fracturing the control or indicator element of the ADF. Then, further tighten all ADFs, progressing systematically from the most rigid part of the connection to the free edges in a manner that will minimize relaxation of previously tightened ADFs. Ensure proper tensioning of the bolts by systematically partially tensioning them until final twist -off of the control or indicator element of individual ADFs during the final tightening cycle. Use more than a single cycle of systematic partial tightening. If twist- off occurs on an individual ADF prior to the final tightening cycle, replace the fastener with a new one.
3.Welded Stud Sheer Connectors. Install welded stud sheer connectors in the field after the structural steel has been erected and the deck forms are in place, but before the installing reinforcing steel. Use automatically timed stud welding equipment to weld sheer connectors. Perform production testing as specified in Clause 7.7, “Production Control”, of the AASHTO/AWS D1.5 Bridge Welding Code. In addition to the stud bend test specified in Clause 7.7, perfor m stud bend tests at the following times: − At the start of each work day; − When welding has been interrupted for one hour or more; − When changing grounds; − When changing weld settings; and − When changing cable loop due to arc blow. Do not weld more than 500 studs without performing a bend test. Bent studs that show no signs of failure may be left in the bent position.
H.Straightening Steel Members. If members are bent, they must be replaced or returned to fabricator for repair. Do not straighten bends in main structural members in the field. Straighten bent members without producing embrittlement, fracture, or damage. Straighten all material cold. Do not use members that cannot be straightened. The Engineer may authorize heating mild steel and structural grade steel. Do not allow the temperature of the heated area to exceed 1,200°F (a dull red) as controlled by temperature indicating crayons, liquids, or bimetal thermometers.
I.Rust Stains. When Weathering Steel is used protect substructure units with r einforced polyethylene or similar material. Leave the protection material in place to prevent staining until the superstructure is completed. Use a concrete rust stain remover to remove all rust stains on the substructure units. Flush all areas receiving applications of rust stain remover with water. 287 616.05 METHOD OF MEASUREMENT The Engineer will measure as specified in Section 109.01, “Measurement of Quantities” and as follows:
A.Measurement by Weight. Measurement by weight will be by the Pound. The quantity paid for will be the total weight, determined as specified. If the structural steel is measured by weight, furnish two copies of calculated weights and dimensions. The Engineer will measure and pay for all castings and miscellaneous metal parts as Structural Steel. The Engineer will use Table 616- 04 to determine the weight of structural steel components. Table 616 -04 Material Type Lbs/CF Aluminum, Cast or Wrought 173.0 Brass 534.0 Bronze, Cast 536.0 Bronze, Wrought 555.0 Copper, Sheet 558.0 Iron, Cast 445.0 Iron, Malleable 470.0 Lead, Sheet and Plate 707.0 Steel 490.0 Zinc, Sheet 450.0
1.Structural Steel and Wrought Metals. The Engineer will not measure or pay for the weight of permanent bolts 6 inches or less in length. The Engineer will not make deductions for cuts, copes, bevels, or open holes; and will not make allowance for mill overruns.
2.Structural Plates. The plan quantity structural plates will be used for m easurement and payment. The Department will not make allowance for planed or sheared edges. The Engineer will compute the weight of irregular shape on the basis of the dimensions of the smallest rectangular plate from which it can be cut. When plates are machine finished, the Engineer will consider the dimension of the plates the maximum machine finished dimension plus 1/8 inch for each finished surface.
3.Structural Shapes and Bars. The plan quantity will be used for measurement and payment of structur al shapes and bars. The Engineer will compute the weight of each structural shape with mitered ends on the basis of the section and overall length measured parallel to the axis of the shape. 288 For identical structural shapes with mitered ends that are less than 5 feet long, the Engineer will consider ends multiple cut. The Engineer will compute their total weight as the weight of the shortest parent section from which they can be cut, provided the length of the parent section is not more than 30 feet.
4.Pins and Rollers. The Engineer will consider the parent section for forged segmental rollers square in section, and of the same length, width, and thickness as the finished roller. The Engineer will compute the weight of hot-rolled bar steel pins and rollers on the basis of the length shown on the Plans and on the basis of a diameter 1/4 inch greater than that of the finished pin or roller. The plan quantity will be used for measur ement and payment of cold finished bar steel pins and rollers.
5.Bolts and Tie Rods. The Engineer will compute the weight of bolts over 6 inches long and tie rods including necessary nuts and washers used for connecting structural steel parts from the nominal weights as given by the American Institute of Steel Construction.
6.Castings. The Engineer will compute the weight of each casting from the net dimensions shown on the approved shop drawings, with an addition of 10 percent to compensate for fillet s and overruns. Where machine-finished surfaces are required, the Engineer will make an allowance of 1/8 inch in thickness for each surface so finished. If cored holes are shown on the Plans, the Engineer will make a deduction for the full size of the core.
7.Pipe. The plan quantity of pipe will be used for measurement and payment.
B.Lump Sum Basis. When the quantity of structural steel is included in the plans as a “Lump Sum”, the “Lump Sum” includes all required structural steel. If changes are made to the contract that increase or decrease the weight of the material required, the Engineer will determine the weight of additional material using Table 616-04.
616.06 Basis of Payment
Pay Item Pay Unit Structural Steel Pound Structural Steel Lump Sum Structural Steel M270 – Grade 36 Pound For changes to structural steel quantities as specified in Section 616.05 B, “Lump Sum Basis”, the Engineer will make payment for the changed quantity as follows: − If changes are made to the contract that increase the quantity of structural steel, payment for additional structural steel will be made at a contract unit price per pound. 289 The contract unit price will be obtained by dividing the lump sum contract unit pri ce by the estimated quantity of structural steel included in the plans. − If changes are made to the contract that reduce the weight of material required, the contract unit price for the lump sum item will be reduced proportionally to the reduction in material weight. Such payment is full compensation for furnishing all materials, connection devices, swedge bolt, equipment, labor, and incidentals to complete the work as specified. Section 622 290 SECTION 622 PILING
622.01 Description
This work consists of furnishing and driving piles.
622.02 Equipment
Reserved.
622.03 Materials
Item Section Portland Cement Concrete 802 Reinforcing Steel, Dowel Bars, and Tie Bars 836 Steel Piling H -Piling and Special Sections 840.01 A Shells for Steel -Encased Concrete Piling 840.01 B Timber Piling 840.02 Steel Sheet Piling 840.03 A Corrugated Steel Sheet Piling 840.03 B Paints, Oils, and Thinners 852 Three Coat Organic Zinc Rich Paint System 852.02 Galvanizing 854
622.04 Construction Requirements
A.Pile Formulas. Pile formulas will be included in the plans. The Engineer will apply the formulas when computing the bearing value by pile penetration for all piles. The Engineer will not make penetration measurements to determine pile bearing values immediately after inserting fresh cushioning material over the head of the pile or when pile heads are damaged by burring, corrugating, or crushing. If water jets are used with the driving, the Engineer will determine the bearing value by the formulas from the results of driving after the jets have been withdrawn. The Engineer will make a reduction in the rated energy of an open top diesel hammer if the hammer does not maintain the minimum measured stroke. This reduction will be based on the percentage of the reduced stroke.
B.Pile Driving.
1.General. Give at least 24 hours advance notice of any pile driving operations. Drive piling in the presence of the Engineer.
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 312–324 of 550.