410 Page 265PART E STRUCTURES
410.1DESCRIPTION
This work consists of furnishing, fabricating, and erecting structural steel and miscellaneous steel required for structures.
410.2MATERIALS
Materials will conform to the following sections: A.Steel: Steel will conform to Section 970. B.Bolts: Bolts will conform to Section 972. C.Paint: Paint will conform to Section 411. D.Stud Shear Connectors: Stud and shear connectors will conform to Section 970.
410.3CONSTRUCTION REQUIREMENTS
Structural steel fabricating plants will be an AISC Certified Bridge Fabricator with Simple (SBR), Intermediate (IBR), or Advanced (ABR) certifications. An SBR certification will be required to fabricate unspliced rolled sections. An IBR certification will be required to fabricate spliced rolled beam sections, built up I-shaped plate girders, and trusses up to 200’. An ABR certification will be required to fabricate tub or trapezoidal box girders, large trusses, arches, bascule bridges, cable supported bridges, moveable bridges, and bridges with complicated geometry like a tight curve radius. A Fracture Critical Endorsement (FCE) will be required to fabricate fracture critical members. A Certified Highway Component Manufacturer (CPT) certification will be required to fabricate bearings, highway sign structures, parts for bridges such as bridge traffic rail, cross frame diaphragms and expansion joints. Structural steel will be fabricated, erected, welded, and painted in accordance with these specifications. A.Shop Plans: Shop plans will be required for all structural steel and miscellaneous metal parts for structures. Shop plans for steel structures and structural steel components will give full detailed dimensions and sizes of component parts of the structures and details of all miscellaneous parts such as pins, nuts, bolts, drains, etc. Where specific orientation of plates is required, the direction of rolling of plates will be shown. Shop plans will identify the material type and grade for each piece of structural steel. Each drawing will be completely titled according to the contract plans, including structure number, project number, PCN, and county. Each drawing will pertain to only one structure. The Contractor is responsible for the shop drawings satisfying contract requirements, regardless of any review by the Engineer. Unless otherwise specified in the plans, the Contractor will submit shop plans in accordance with the following: 410 Page 266Prior to fabrication, the Contractor will submit shop plans to the Department for the Department’s opportunity for review. Any review by the Department of the shop plans is limited to general conformance with the contract plans and specifications only. The Contractor will send an email with the shop plans attached as a PDF to the Project Engineer and Office of Bridge Design. Upon request, the Project Engineer will provide the Contractor the appropriate email addresses. Within 14 calendar days of receiving the shop plans, the Office of Bridge Design will respond to the Contractor in one of the following ways: 1) No Exceptions Noted; 2) Returned for Revision; or 3) Not Required for Review. If the Department’s response states, “Returned for Revision”, the Contractor must make the revisions and resubmit the shop plans for review as specified above. The Contractor will not begin fabrication or construction of the work contained in the shop plans until the Department has confirmed, in writing, a completed review with a response of “No Exceptions Noted” or “Not Required for Review”. B.Inspection: 1.Notice of Beginning of Work: The Contractor will require the fabricator to give the Engineer a minimum 30 calendar day notice prior to beginning work in the shop, so inspection may be provided. Work will not be done in the shop prior to notification. 2.Facilities for Inspection: Facilities for the inspection of material and workmanship in the shop will be furnished. The inspector will be allowed free access to the work. 3.Rejections: The acceptance of any material or finished members by the inspector will not preclude the subsequent rejection if found defective by the Engineer. Rejected material and workmanship will be replaced or repaired. 4.Identification of Steel: The Contractor will require the fabricator to demonstrate, by a written procedure and by actual practice, a method of material application and traceability, visible at least through the "fit up" operation, of the main stress carrying elements of a shipping piece. The traceability method will be capable of verifying proper material application as it relates to: -Material specification designation. -Heat number if required. -Material test reports for special requirements where required. C.Welding and Welding Inspection: Shop and field welding and welding inspection of structural steel and steel railing will be done in accordance with the latest edition of the ANSI/AASHTO/AWS D1.5 or D1.1 whichever is applicable - Bridge Welding Code, (hereinafter referred to as the Code). Magnetic particle testing will be in accordance with the Code except that only the yoke (AC) method will be used. In addition to the Code requirements, magnetic particle testing is required for fillet welds attaching diaphragm stiffeners to girder flanges. When this detail is present on the plans, magnetic particle testing will be in accordance with the following requirements: 100% of all such joints will be tested full length. The term “joint”, as used above, will be interpreted as 410 Page 267meaning the short fillet welds on each side of the stiffener connecting one end of the stiffener to either the top or bottom flange. Approved Welding Procedure Specifications (WPS) are required for all welding. WPS’s will be based upon Procedure Qualification Record (PQR) in accordance with the Code. The cost of the WPS and PQR will be incidental to the contract lump sum price for structural steel. Electroslag or Electrogas welding processes will not be used. Shear connectors will be welded and inspected in accordance with the requirements of Section 7 of the Code. Shear connectors will be end welded with automatically timed stud welding equipment. D.Welder Qualification : Welders, Welding Operators, and Tack Welders (hereafter the term Welder will refer to all three) will be qualified in accordance with the latest edition of the Code. Welders, except Tack Welders, will be qualified for an unlimited thickness groove weld in test Position 3G (vertical). If the project requires overhead welding, qualification in Position 4G (overhead) will also be required. Tack Welders will be qualified in accordance with the Code. Welder qualification will be performed under the supervision of an AWS Certified Welding Inspector (CWI) qualified and certified in accordance with the provisions of AWS QC1. In addition to these requirements, shop welders will be certified for the process and position that is to be used in fabrication. The fabricator will keep records of the process and position that all welders are qualified for. Inspectors performing nondestructive inspection, other than visual inspection will be qualified in accordance with the American Society for Nondestructive Testing (ASNT) “Recommended Practice No. SNTC-TC-1A, Level II.” Test results will be recorded on a code approved “Welder and Welding Operator Qualification Record,” signed by the inspector and submitted to the Department’s Bridge Construction Engineer (BCE). If approved, the BCE will issue a Welder Certification Card to the Welder. Welding will not be allowed without a valid Welder Certification Card. The BCE will accept a code approved form for review on which the test date is not more than one year old. If the test date is more than one year but not more than two years old, the BCE will also require evidence of continued employment as a Welder or Welding Operator. If the test date is more than two years old retesting will be required. Welder certification cards will remain valid indefinitely unless the Welder is not engaged in the processes of welding, for which he is qualified, for a period exceeding six months. If the Welder does not properly prepare the joint as shown on WPS or provide an acceptable weld, the Engineer may revoke the Welder Certification Card (WCC). To regain a WCC for SDDOT administered projects, the Welder must provide a satisfactory retest. E.Shop Assembling: 1.Cleaning Surfaces: Surfaces of metal in contact will be cleaned before assembling. When weathering steel is specified or used, all structural steel surfaces of the superstructure will be blast cleaned to a commercial finish in accordance with SSPC SP6 at the fabricator. Abrasives used for blast cleaning will be clean dry sand, steel shot, 410 Page 268mineral grit, or manufactured grit. Fins, tears, slivers, and burred or sharp edges will be removed by grinding and then reblasted to achieve the specified finish. 2.Bolted Connections: All fastener holes will be either punched or drilled. In all cases hereafter, drilling may be substituted for punching of full size holes, subdrilling may be substituted for subpunching, and holes may be drilled in assembly “from the solid” instead of being subpunched or subdrilled and reamed. Drilling in assembly will be done with the material in the same configuration required for reaming. Holes punched or drilled full size will be 1/16 inch larger than the nominal diameter of the fasteners. Subpunched holes for fastener diameters greater than 5/8 inch will be 3/16 inch smaller than the nominal diameter of the fasteners. For smaller fasteners, the holes will be subpunched to the fastener’s nominal diameter. Subpunched or subdrilled holes will be reamed to 1/16 inches larger than the nominal diameter of the fastener. Holes in carbon steel thicker than 3/4 inch or alloy steel thicker than 5/8 inch will be drilled or subdrilled and reamed. Punching or subpunching will not be permitted. Where reaming is not required, holes in carbon steel up to 3/4 inch thick or in alloy steel up to 5/8 inch thick may be punched to their final specified size. Holes for main truss or arch connections, field connections of skewed portals, splices or rigidly framed end connections of main beams or girders and rigid frames carrying design loads will be subpunched and reamed with members assembled in the shop. For beams and girders, this assembly may be made in the web-horizontal position, except horizontally curved members will be assembled with the web-vertical, unless web-horizontal assembly is approved by the Engineer. The assembly, including the camber, alignment, and accuracy, of subpunched holes and mill- to-bear joints will be approved by the Engineer before reaming is commenced. Holes may be punched or drilled to their final specified size for field connections of secondary items including lateral bracing for girders, truss chords, and arch ribs; hanger supports for laterals and utilities; portal and sway bracing; and cross frames or diaphragms that do not require reamed holes. All holes for end field connections of floor beams will be subpunched or subdrilled to a hardened steel template, and corresponding holes in the members to which they connect will be reamed with the members assembled. Stringer connections to floor beams may have holes punched or drilled to their final specified size. Reaming templates will have hardened steel bushings and reference lines inscribed to locate the template on the members. Computer-numerically-controlled (CNC) equipment may be used to produce full sized holes in components otherwise requiring reamed, subsized holes, subject to the Engineer’s approval and the demonstrated accuracy of the CNC system. Accuracy must be verified by periodic check assemblies of components, and the Contractor’s quality control plan for the system must be acceptable to the Engineer. Errors detected by check assemblies will require additional assemblies to define the extent of problems and subsequent CNC work may be restricted or prohibited until system corrections are accepted by the Engineer. 410 Page 269a.Punched Holes: The diameter of the die will not exceed the diameter of the punch by more than 1/16 inch. Holes will be cleanly cut, without torn or ragged edges. b.Accuracy of Unreamed Holes: All subdrilled or subpunched holes will be so accurate that after steel is assembled and before reaming, a cylindrical pin 1/8 inch smaller in diameter than the punched hole may be inserted perpendicular to the face of the member, without drifting, through at least 75% of the holes in the connection or the pieces will be rejected. Holes punched or drilled to their final specified size without assembly will be so accurate that fasteners may be installed without reaming or additional drilling. c.Reamed or Drilled Holes: Reaming and drilling will be perpendicular to the faying (contact) surface of the connection. Drilling will be done with twist drills and reaming with fluted or adjustable reamers. Where practical, reaming will be directed by mechanical means, and done after all the components are assembled and firmly secured. Unless otherwise approved by the Engineer, assembled parts will be taken apart for removal of cutting oil, shavings, and burrs caused by drilling and reaming. d.Accuracy of Reamed and Drilled Holes: Where full size holes are reamed, drilled from the solid, or made by CNC equipment, 85% of the holes in any group will show no offset greater than 1/32 inch between adjacent thicknesses of metal. The Contractor will be responsible for the accuracy of all holes, regardless of tolerance in dimensions of rolled sections or fabricated members. If the required accuracy cannot be obtained otherwise, holes will be drilled with the members assembled. e.Assembly: Only the girder or beam sections involved in the reaming of a particular connection must be assembled at any one time. The sections involved, including all splice plates and filler plates, will be assembled and firmly drawn together with bolts before reaming. A 1/8 inch or greater difference in plate thickness or member depths across a bolted splice will be rectified with shims included during reaming, match marked and shipped with the member. The cost for additional shim plates required due to no fault of the Department will be borne by the Contractor. f.Disassembly : After disassembly, all burrs and shavings produced by the reaming operation will be removed. F.Painting Structures: Painting structures will be in accordance with Section 411. New structural steel will have all paint, including the finish coats of paint applied in the shop prior to shipment unless otherwise specified in the plans. G.Transportation, Handling, Storage, and Erection: Structural steel will be loaded, transported, unloaded, and stored without damaging the material. Material will be stored on skids above the ground, so the materials can be kept clean and drained. Girders and beams will be placed upright and shored. Long members, such as columns and chords, will be supported on skids properly spaced to prevent deflection. High strength bolts will be stored so they will be kept free from rust or foreign material. 410 Page 270Girders will not be placed until the supporting concrete, including grout used to construct bearing pads, has met the time and strength requirements of Section 460.3 O. Forming operations for the deck will not begin until all of the girders in a continuous unit have been erected and adjusted and required erection elevations taken. 1.Falsework: The falsework will conform to the requirements of Section 423. 2.Bearings and Anchorages: Bridge bearings will be set level, in exact position, and must have full and even bearing on the concrete. Elastomeric bearing pads will set directly on the concrete. Cast iron, steel, or rolled steel bearings will be bedded on the concrete with a single thickness sheet of preformed fabric bearing pad. Anchor bolts and anchor rods may be set in the concrete or the concrete blocked out and the bolts set later with grout. When holes are blocked out, they will be approximately four inches in diameter to allow for horizontal adjustment of the bolts or rods. Grout will be injected into the bottom of a clean, dry hole with a grout pump. Grout will be placed from the bottom up to eliminate air pockets and voids. Location of anchors and setting of rockers or rollers will take into account any variation from the mean temperature at time of setting and anticipated lengthening of bottom chord or bottom flange due to dead load after setting. At mean temperature, or the temperature indicated in the plans, and under dead load, the rockers and rollers will set vertical and the anchor bolts at expansion bearings will be centered in their slots. Full and free movement of the superstructure at the movable bearings must not be restricted by improper setting or adjustment of bearings or anchor bolts/rods and nuts. Bridge bearings will not be placed on masonry bearing areas, which are irregular or improperly formed. Grout used to set anchor bolts and anchor rods and construct bearing pads will conform to the requirements of Section 460.2 . 3.Straightening Bent Material and Cambering: The straightening of plates, angles, other shapes, and built-up members will be done by methods that will not produce fracture or other injury. Distorted members will be straightened by mechanical means or by the carefully planned and supervised application of a limited amount of localized heat. Heat straightening of ASTM A514/A517 steel members will be done only under rigidly controlled procedures. The maximum temperature of the ASTM A514/A517 steel will not exceed 1125°F, nor will the temperature exceed 950°F within 6 inches of weld metal. Heat will not be applied directly on weld metal. In all other steels, the temperature of the heated area will not exceed 1150°F. Temperature will be controlled by indicating-crayons, liquids, or infrared thermometers. Parts to be heat straightened will be free of stress and external forces, except stress resulting from mechanical means used with the application of heat. 410 Page 271Following the straightening of a bend or buckle, the surface of the metal will be inspected for evidence of fracture. Correction of errors in camber in welded beams and girders of ASTM A514/A517 material will be done only under rigidly controlled procedures. 4.Field Assembly: The parts will be accurately assembled and match-marks will be followed. The material will be handled so parts will not be bent, broken, or damaged. Hammering which injures or distorts the members will not be done. Bearing surfaces and surfaces to be in permanent contact will be cleaned before the members are assembled. Unless erected by the cantilever method, truss spans will be erected on blocking to give the trusses proper camber. The blocking will be left in place until the tension chord splices are fully bolted and all other truss connections pinned and bolted. Permanent bolts in splices of butt joints of compression members and permanent bolts in railings will not be tightened until the span has been swung. Splices and field connections will be faired up with a sufficient number of fit-up-bolts or erection pins to maintain dimensions and plumbness of the structure and allow free entry of the bolts used in the final connection. Girder erection data given in the plans will be utilized to establish proper girder profile, prior to final tightening to the bolts in the splices. Drifting during assembly to bring the parts into position will not enlarge holes or distort the metal. 5.High-Strength Bolts: Will conform to Section 972 and the following: a.Unless otherwise specified, high-strength bolts will be new ASTM F3125 Grade A325. The high-strength bolts will be Type 1 for painted steel structures and Type 3 for weathering steel bridges. b.Unless otherwise specified, high-strength bolts require tightening using direct tension indicators. The average load indicator gap will be reduced to 0.005 inches while tightening. The appropriate 0.005 inch feeler gauge will be supplied. c.Fasteners will be protected from accumulating dirt prior to installation. d.High strength fasteners will be subjected to a rotational-capacity test in accordance with SD 507. e.A Skidmore-Wilhelm Calibrator, or other acceptable bolt tension indicating device, may be furnished by the Department at each job site during bolt installation. The Contractor will notify the Department a minimum of 7 calendar days prior to installing bolts. 6.Connections Using High Strength Bolts: Girder splices and other structural joints utilizing high strength bolts in friction-type connections will use direct tension indicators. a.Direct tension indicator protrusions will bear against a hardened surface. The direct tension indicators will be capable of indicating the required bolt tension when the measured gap between the direct tension indicator and the surface against which the protrusions bear is reduced to that specified. The direct tension indicator will be 410 Page 272specifically marked to identify the type of bolt for which it is to be used. Direct tension indicators will be new and unused. b.Bolt lengths will be determined as shown in the following: Table 1 Bolt Length Bolt Size, InchesAdd to Grip*1 to Determine Bolt Length, Inches 5/8 7/8 3/4 1 7/8 1 1/8 1 1 1/4 *1Grip is thickness of material to be connected, exclusive of washers. For each flat washer, add 1/8 inch to the grip. For each bevel washer, add 5/16 inch to the grip. For each direct tension indicator, add 3/16 inch to the grip. Irregular lengths will be adjusted to the next longer 1/4 inch increment. c.Bolted parts will fit solidly together when assembled and will not be separated by gaskets or other interposed compressible material. When assembled, all joint surfaces, including those adjacent to the bolt heads, nuts or washers will be free of scale, burrs, dirt, other foreign material, and defects that would prevent solid seating of parts. Tight mill scale does not apply. In girder splices, bolted splices and other friction-type connections, all contact surfaces will be free of oil, paint, lacquer, and other coatings, except as specified in Section 411.3 B.3. When weathering steel is specified or used, all faying surfaces of connections will be blast cleaned to a near-white finish in accordance with SSPC SP10 immediately prior to assembling connections in the field. d.All fasteners will have a hardened washer under the element turned in tightening. For installations utilizing Grade A490 bolts where the steel work comprising the grip has a specified yield strength less than 40 ksi, special requirements for hardened washers will be noted in the plans. When the outer face of the bolted parts has a slope of more than 1:20 with respect to a plane normal to the bolt axis, a smooth hardened beveled washer will be used to compensate for the lack of parallelism. In the normal installation, the direct tension indicator will be placed on the bolt with the protrusions bearing against the underside of the bolt head. For this type installation, the nut is the turned element and the hardened washer will be placed between the steelwork and the nut. If required, due to bolt entering and wrench operation clearances, it will be permissible to use the bolt head as the turned element. In this type of installation, a hardened 410 Page 273washer will be placed under the bolt head and the direct tension indicator placed on the bolt with its protrusions bearing against the hardened washer. In those installations, where inspection of the bolt head is too difficult, it will be permissible to place the direct tension indicator at the nut end. The direct tension indicator will be placed on the bolt with protrusions facing toward the nut. A hardened washer is then placed on the bolt against the protrusions and the nut is installed. With this type of installation, the nut is the turned element. The surface contacting the protrusions of a direct tension indicator will not turn during the tightening operation. For those type installations where the direct tension indicator is used adjacent to a hardened round washer, some slight movement of the hardened round washer is acceptable. On bolt installations where beveled washers are used or galvanized bolts are specified or slotted or oversize holes are used, special requirements for hardened round washers and direct tension indicators must be observed, as provided in the contract. e.All bolts in a joint will be tightened to reduce the gap between the washer face of the bolt head and the face of the direct tension indicator. If the direct tension indicator is installed nearest to the turned element, between the face of the direct tension indicator and the hardened round washer, the average gap will conform to that specified in Section 410.3 G.5.b . When the average gap is equal to or less than that specified in Section 410.3 G.5.b , the minimum required fastener tension will be assumed satisfied, unless the Engineer determines additional verification is required. A sufficient number of bolts will first be placed in the joint and “snugged” to ensure that all faying surfaces are in firm contact, prior to tightening. Snug tight is defined as the tightness attained by a few impacts of an impact wrench or the full effort of a man using an ordinary wrench. Bolts will be placed in any remaining holes and snugged tight as erection bolts or pins are removed. All bolts in the joint will then be tightened progressing systematically from the center most rigid part of the joint to its free edges. When tightening, the element not turned will be held with a hand wrench to prevent rotation. The gap between the bolt head and the face of the direct tension indicator is reduced while tensioning due to the bolt clamping force, which flattens the washer protrusions. When tightening, complete closure of the gap around the circumference should be avoided to prevent over tightening the bolt. The gap may not be uniform around the circumference of the direct tension indicator as the wrench may pull the bolt off center in the hole, resulting in non-uniform compression of the protrusions. When non-uniform gap exists, the average gap criteria is satisfied if the gap measured at several points around the circumference shows 50% of the measurements to be equal to or less than the value specified in Section 410.3 G.5.b . If there is no gap at only one point on the circumference, the bolt is properly tightened, and no further tightening will be attempted. 410 Page 274Impact wrenches will be of adequate capacity to perform the required tightening of each bolt in approximately 10 seconds. Grade A490 bolts will be tightened with an electric or hydraulic wrench. The Contractor will check the gap on all bolts to assure that the completed joint meets the requirements of this specification. A metal feeler gauge capable of probing between adjacent protrusions of the direct tension indicator will be supplied by the Contractor. The Contractor will supply the Engineer with an identical gauge for inspection. After all bolts in a joint have been tightened, the Contractor will return to the first bolts tightened to assure that they have not loosened. Lost tension may be restored by tightening so that the gap is slightly less than originally measured. f.In order to determine acceptability of direct tension indicators the Engineer will: 1)Sample and test the direct tension indicators in accordance with SD 503. The cost for the bolts and direct tension indicators used for field verification will be incidental to the cost for the structural steel. 2)Have full opportunity to witness installation of bolted connections and will periodically observe the installation and tightening operation to ensure that proper procedures are being adhered to. 3)Determine that all bolts have been tightened upon completion of a bolted joint. A minimum of 20%, but not less than four bolts in each joint, will be inspected with a metal feeler gauge. If all gaps checked are within the allowable distance described, the joint will be accepted as properly tightened. If gaps checked are in excess of that specified, the Contractor will reinspect and retighten each bolt in the joint, as required, and resubmit the joint for inspection. The metal feeler gauge will be used as a “no go” inspection tool by inserting the tapered nose of the gauge into the openings between protrusions. If the gauge does not reach the shaft of the bolt, but a gap is evident, the installation is acceptable. g.The turn-of-nut method for bolt tightening may be used when specified in the plans. When the turn-of-nut installation method is specified, hardened washers are not required except as specified in Section 410.3 G.6.d. A sufficient number of bolts will first be placed in the joint and snugged to insure that all faying surfaces are in firm contact, prior to tightening. Snug tight is defined as the tightness attained by a few impacts of an impact wrench or the full effort of a man using an ordinary wrench. Bolts will be placed in any remaining holes and snugged tight as erection bolts or pins are removed. All bolts in the joint will then be tightened the amount shown in Table 2 progressing systematically from the center most rigid part of the joint to its free edges. When tightening, the element not turned will be held with a hand wrench to prevent rotation. 410 Page 275Table 2 Nut Rotation from Snugged Condition*1,*2 Geometry of Outer Faces of Bolted Parts Bolt Length Measured from Underside of Head to End of BoltBoth Faces Normal to Bolt AxisOne Face Normal to Bolt Axis and Other Face Sloped Not More Than 1:20, Bevel Washer Not UsedBoth Faces Sloped Not More Than 1:20 From Normal to Bolt Axis, Bevel Washers Not Used Up to and including 4 diameters1/3 turn 1/2 turn 2/3 turn Over 4 diameters but not exceeding 8 diameters1/2 turn 2/3 turn 5/6 turn Over 8 diameters but not exceeding 12 diameters*32/3 turn 5/6 turn 1 turn *1Nut rotation is relative to bolt, regardless of the element (nut or bolt) being turned. For bolts installed by 1/2 turn and less, the tolerance is plus or minus 30 degrees; for bolts installed by 2/3 turn and more, the tolerance is plus or minus 45 degrees. *2Applicable only to connections in which all material within grip of the bolt is steel. *3No research work has been performed by the Research Council Riveted and Bolted Structural Joints to establish the turn-of-nut procedure when bolt lengths exceed 12 diameters. Therefore, the required rotation must be determined by actual tests in a suitable tension device simulating the actual conditions. 7.Pin Connections: Pilot and driving nuts will be used in driving pins. They will be furnished by the Contractor without charge to the Department. Pins will be driven so the members will take full bearing on them. Pin nuts will be screwed up tight and the threads burred at the face of the nut with a pointed tool. 8.Misfits: When approved by the Department’s Bridge Construction Engineer, the correction of minor misfits involving harmless amounts of reaming or grinding will be considered a legitimate part of the erection. Any error in the shop fabrication or deformation resulting from handling and transportation which prevents the proper assembling and fitting of parts by the moderate use of drift pins or by a moderate amount of reaming or grinding will be reported immediately to the Engineer. The Engineer’s approval of the method of correction will be obtained. The correction will be made in the Engineer’s presence. The Contractor will be responsible for all misfits, errors, and injuries and will make the necessary corrections and replacements.
410.4METHOD OF MEASUREMENT
Field measurement of structural steel will not be made. Adjustment in the contract price will not be made if the weight furnished is more or less than the estimated weight. The weights of rolled shapes, slabs, and plates will be computed on the basis of their nominal weights and dimensions. The weight will be computed on the following basis: 410 Page 276Unit weights of material in pounds per cubic foot: Cast Iron................................................................................................................... 445.0 Copper Sheet ............................................................................................................ 558.0 Lead Sheet ............................................................................................................... 707.0 Steel: cast, copper bearing, silicone, nickel, or stainless .......................................... 490.0 Wrought Iron............................................................................................................. 487.0 Zinc........................................................................................................................... 450.0 Bronze or Copper-Alloy Bearing Plates .................................................................... 490.0 The quantities of the various other pay items, which constitute the completed and accepted structure, will be measured for payment according to the plans and specifications.
410.5BASIS OF PAYMENT
Structural steel will be paid for at the contract lump sum price unless otherwise specified in the plans. Payment will be full compensation for furnishing, fabricating, delivery, erecting ready for use, for the required non-destructive weld testing by radiographing, magnetic particle, ultrasonic inspection, or other specified alternate test procedures. Payment will also include painting of the structural steel, unless a separate bridge painting bid item is included in the contract. The cost of the required shear studs, bolts, nuts, washers, and direct tension indicators will be incidental to the cost of the structural steel. If changes in the work, which vary the weight of steel to be furnished, are ordered the payment will be adjusted as follows: The value per pound of the increase or decrease in the weight of structural steel involved in the change will be determined by dividing the contract lump sum amount by the estimate of weight shown on the plans. The overall contract payment will be the contract amount plus or minus the value of the steel involved in the change. The accepted quantities will be paid for at contract unit price. 411 Page 277411 SHOP PAINTING
411.1DESCRIPTION
This work consists of shop cleaning metal surfaces and shop application of the specified coating system.
411.2MATERIALS
Coatings, including primer, intermediate (if used), finish, and field repair coats will all be from the same manufacturer and will be one of the systems from the Department’s Approved Product List for shop paint (new construction).
411.3CONSTRUCTION REQUIREMENTS
A.General: The coatings will be applied in accordance with the manufacturer's recommendations. A written copy of the manufacturer’s recommendations, including product data sheet, will be furnished to the Department prior to painting. The recommendations will indicate the recommended minimum and maximum dry film thickness (DFT) for each coating layer of the system, mixing and thinning directions, recommended spray nozzles and pressures, minimum drying time, maximum time to recoat, cure time based on application temperature, maximum coating application temperature, and the recommended procedures for coating galvanized bearings, bolts, nuts, and washers. Coatings will be shipped from the manufacturer with a date stamp to indicate expiration. Coatings outside of the expiration window will not be used. Whenever the manufacturer’s recommendations are more stringent than the provisions of this section, the manufacturer’s recommendations will apply. Coatings will not be applied when the surface temperature is below 40F or above 90F, when the air is misty, when the humidity exceeds 85%, when the surface temperature is less than 5F above the dew point, or when conditions are otherwise unsatisfactory. Coatings will not be applied when the metal is hot enough to cause the paint to blister or produce a porous paint film. Coatings will not be applied on damp or frosted surfaces. Coatings applied under cover in damp or cold weather will remain under cover until dry or until weather conditions are suitable. Coatings will be applied in a uniform, even coat and will be worked into all corners and crevices. Coatings will be applied with approved equipment. On surfaces which are otherwise inaccessible the coating may be applied with sheepskin daubers. Coatings that do not meet the requirements of this section will be removed. The metal will be reblasted, cleaned, and recoated at no expense to the Department. During coating application, scaffolding or other safe devices will be provided to permit inspection of the steel. The Contractor will provide protective devices as necessary to prevent damage to the work and to other property or persons from all cleaning and painting operations.