711 - REINFORCING STEEL
700-51 (4) Reinforcing Bar Trusses. Place, support and secure bar trusses in proper position. Unless the bar
trusses are designed and fabricated with outstanding legs that are in contact with the forms, support them on metal supports and spacers. If the weight of th e trusses causes the supporting legs of trusses to indent into the forms, use bar supports as auxiliary support for the truss legs. (5) Mesh Reinforcement for Structures. Provide mesh reinforcement of the size and spacing shown in the Contract Documents. Lap the sheets of mesh as indicated in the Contract Documents. The method of placing the mesh and securing it in proper position must be approved by the Engineer. (6) Box Culvert Reinforcing. Use Grade 60 reinforcing steel for road culverts and reinforced concrete box bridges, unless otherwise noted in the Contract Documents.
7.Area Prepared for Patching (Existing Concrete Bridge Decks) or other Structure Repairs. If during the course of patching or repair, deteriorated existing reinforcing steel is encountered, and the Engineer requires it replaced, provide and place new reinfo rcing steel according to this specifica tion. This will be paid for as Reinforcing Steel (Rep air) (Set Price).
b.Epoxy-coated Reinforcement.
1.Perform all fabrication and jobsite handling of epoxy-coated reinforcing bars, dowel bars and tie bars for pavement according to ASTM D 3963/D 3963M, "Standard Specification for Fabrication and Jobsite Handling of Epoxy-Coated Reinforcing Steel Bars". For epoxy-co ated steel wire and welded wire fabric, follow ASTM A 884/A 884M, "Standard Specification for Epoxy-Coated Steel Wire and Welded Wire Fabric for Reinforcement". Consider the appendix to ASTM A 884/A 884M (that is identified as nonmandatory information) to be mandatory for this specification. Coating applicators and fabricat ors must comply with all aspects of above referenced documents.
2.Storage, Handling and Placement at the Jobsite. When handling coated steel reinforcement, avoid bundle- to-bundle or piece-to-piece abrasion. Do not drop or drag epoxy-coated reinforcement. Protect contact areas on equipment used for handling coat ed steel reinforcement. Use padded or non-metallic slings and padded straps when unloading. Off-load coated steel reinforcement as close as possible to its point of place ment, or within reach of the crane so that the material can be hoisted to the area of placement with minimum re-handling. Store coated steel off the ground on protective cribbing, with timbers placed between bundles if stacking is necessary. Space the supports sufficiently close to prevent sags in the bundles. Store coated and uncoated stee l reinforcement separately. Minimize long term storage. Due to the uncertainty of how long epoxy-coated steel will remain on the job site before incorporation in concrete, c over it with opaque material immediately on delivery, unless it is placed as soon as it arrives. For stacked material, drape the protective cover around the perimeter of the stack. Secure the covering adequately allowing for air circulation around the coated re inforcement to prevent condensation under the covering. Tie coated reinforcement with tie wire coated with epoxy, plastic, nylon or other non-conductive material that shall not damage or cut the coating. Use supports coated with, or made of, a dielectric material compatible with concrete. After placing, minimize walking on coated steel reinforc ement. Plan the placement of mobile equipment to avoid damage to the coated steel. If th e epoxy-coated reinforcing steel placed in a structure or on the roadway will not be incorporated in concrete within 30 days, cover the e poxy-coated reinforcing steel wi th opaque material until the concrete is placed. For all epoxy-coated steel reinforcement, except dowel bars and tie bars for pavement, use vibrators with heads of rubber or other resilient material for concrete consolidation. Do not use bare steel-headed vibrators. Rubber covers, securely fastened over steel heads will be acceptable.
3.Repair of Damaged Epoxy. If the extent of the damage to the epoxy coating, by any cause, is a maximum of 1% of the surface area in any 1 foot length, remove al l rust from damaged areas, and re pair according to patching material manufacturer’s instructions. Reject the damaged material if the extent of the coating damage exceeds 1% of the surface area of the coated steel reinforcement in any 1 foot length.
c.Splicing. If it is necessary to splice rein forcement at points other than those shown in the Contract Documents, before ordering the reinforcing steel, submit drawings showing the location of each splice to the Engineer for approval. Avoid splices at points of maximum stress. Where possible, stagger the splices, and design them to develop the strength of the bar without exceeding the allowable unit bond stress. Lap bars according to the details shown in the Contract Documents. Do not use lapped splices for bar sizes larger than No. 11 bar. Splicing of 711 - REINFORCING STEEL
700-52 reinforcing steel by welding is permit ted only when shown in the Contract Documents. Where the bar size exceeds
No. 11 bar, use welded splices or other positive connections with the approval of the Engineer. Make welds of direct butt splices, according to the Am erican Welding Society publication, AWS D1.4 “Structural Welding Code- Reinforcing Steel”. A welder certified by th e American Welding Soci ety is required.
d.Mechanical or Thermomechanical Splices. At locations shown in the Contract Documents, splice reinforcing bars, using a mechanical or thermomechanical splicing process, as specified herein using the designated type of splice. Provide splicing devices and systems prequalified as required in DIVISION 1600 .
1.Splice Types.
a.Thermomechanical splices are made using a pr ocess whereby molten filler metal is introduced into an annular space aro und the bars created by a high streng th steel sleeve of larger diameter than the bars. The Engineer will require operator prequalification.
b.For mechanical splices, use any mechanical device or system complying with the physical requirements in DIVISION 1600 .
2.Prequalification of Operators. Before commencing production splicing, operator qualification is required for all splicing systems. The individual that will perform the production splicing must prepare the test specimen. If more than one person will perform the splicing, make a separate set of specimens by each individual. For qualification, the Contractor’s operator must ma ke a set of 3 test splices of the predominant bar size and orientation in the project. The Engineer will obse rve the Contractor’s operator make the splices using manufacturer’s standard jigs, clamps, ignition devices and other required acces sories. Identify each operator by attaching their name to the test splice. Forward the test splices to the MRC (where they will be tension tested to destruction). The MRC will issue reports of the test s to the operator, Contractor and Field Engineer. If the splice is attached to one of th e bars in a fabricator’s shop and th e other end of the splice is performed in the field, or mechanical couplers are attached to bars for easy asse mbly in the field and the system is one identified as requiring operator prequalification, the fabri cator must prepare test specimens as outlined above and forward them to the MRC for testing before shipping material to the project. In lieu of observation by the Engineer, the fabricator must provide a nota rized certification of th e operator’s identity along with the specimens. The Engineer will waive the operator prequalification requirement if the operator provides a copy of a satisfactory KDOT test report, dated w ithin 2 years of the current date that was issued in conjunction with the operator’s qualification testing for the same splicing system on previous projects, as outlined in subsection 711.3d.(1)(a) or (b). Fabricators must provide a certified copy of such operator qualification to the Engineer along with the shipping documents.
3.Construction Requirements. Prepare the ends of bars for splicing in compliance with the splice manufacturer’s recommendations. The Engineer will visually examine mechanical or ther mal splices. Remove and replace all splices having visible defects. Do not encase any splice in concrete until approved by the Engineer. For those splicing systems requiring operator qualifica tion, make 1 tension test specimen splice to represent each lot of bars spliced in the field. Unless shown otherw ise in the Contract Documents, a lot consists of all bars in a days run for all splices. When possible, take test sp ecimens alternatively between the horizontal and vertical positions. Make specimens by the same operator and under the same conditions as the splices they represent. If the splicing systems require the entire splice be prepared in a fabricator’s shop for later assembly in the field, and unless the field assembly requ ires operator prequalification, each sh ipment to the project is considered a separate lot. One specimen is taken from each lot. For those projects requiring daily sampling, deliver the specimens to the MRC (where they will be tension tested to destruction) as soon as po ssible. The specimens must develop a minimum of 125% of the specified yield strength of the bar. To expedite testing for projects remote from the MRC, the Contractor may hire a private laboratory approved by the Engineer of Tests to perform the tests and issue reports. All costs of such testing and reports are borne by the Contractor. Provide 1 copy of all reports i ssued under such an arrangement to the Field Engineer, and forward 1 copy to the Engineer of Tests. If any single test specimen fails to meet the strength requirements, cut 2 production splices from the lot represented by the specimen and tension test them. If both re -tests meet strength requirements, all splices in the lot are accepted. If 1 or both re-tests fail to meet the require ments, all splices in the lot are rejected. All costs of removal and re-splicing are borne by the Contractor. 711 - REINFORCING STEEL
700-53 Protect any concrete forms which may be close to thermal bar splices from the heat generated by the splicing
operation by overlaying the affected surface of the form with fire protection sheeting, or by other means approved by the Engineer. 711.4 MEASUREMENT AND PAYMENT The Engineer will measure the reinforcing steel by the pound, based on the theoretical number of pounds shown in the Contract Documents or placed as ordered in writing by the Engineer. No allowance is made for the clips, wire or other fastening devices for holding the steel in place. The Engineer will verify the quantities of materials provided and placed based on the calculated weight of the reinfo rcing steel placed according to these specifications. Additions and deletions from plan quantity will be computed using TABLE 711-1 . TABLE 711-1: BAR SIZE WEIGHTS Bar Size (US Customary) Bar Size (SI) Weight (Pounds / Lin.Ft.) #3 or 3/8" 9 or 10* 0.376 #4 12 or 13 0.668 #5 15 or 16 1.043 #6 19 or 20 1.502 #7 22 2.044 #8 25 2.670 #9 29 or 30 3.400 #10 32 4.303 #11 35 or 36 5.313 #14 43 or 45 7.650 #18 55 or 57 13.600 *Consult with the State Bridge Of fice, to determine the correct conversion of the 10mm bars. No allowance is made for the weight of weld metal us ed in the fabrication of bar trusses. No separate compensation is allowed for the cost of making and providing splices and test splices. The Engineer will measure Reinforcing Steel (Repair) (Set Price) by the pound. The Engineer will not measure reinforcing steel damaged or broken through C ontractor’s negligence. The Engineer will not measure material in approved splices made for the Contractor’s convenience. Payment for "Reinforcing Steel" at th e contract unit price and "Reinforcing Steel (Repair) (Set Price)" at the contract set unit price is full co mpensation for the specified work. 712 - STRUCTURAL STEEL CONSTRUCTION
700-54 Section 712
STRUCTURAL STEEL CONSTRUCTION 712.1 DESCRIPTION Fabricate and erect the structural steel as designated in the Contract Documents. See SECTION 705 for fabrication of structural steel. Provide and place the castings designa ted in the Contract Documents. B I D I T E M S U N I T S Structural Steel (*)(**)(***) Pound Structural Steel (Merchant Quality) Pound Welded Stud Shear Connectors Each *Type **Grade ***Use 712.2 MATERIALS Provide materials that comply w ith the applicable requirements. Structural Steel Fabr ication and Painti ng ............................................................... DIVISION 700 Cast St eel ............................................................................................................... DIVISION 1600 Structural Steel ...................................................................................................... DIVISION 1600 Steel Fast eners ....................................................................................................... DIVISION 1600 Welded Stud Shear Connectors ............................................................................. DIVISION 1600 Bearings or Pads .................................................................................................... DIVISION 1700 712.3 CONSTRUCTION REQUIREMENTS
a.Erecting Structural Steel.
1.General. Erect the fabricated structure as detaile d in the Contract Documents. Provide all falsework, tools, machinery and appliances, including drift pins and erection bolts required to complete the work. After the structure is erected, remove all falsework, appliances and other obstructions or debris resulting from erection. Provide the Engineer with safe means (such as scaf folding, safety lines, snoopers or hoist buckets) to inspect any portion of the structure during the erection operations.
2.Handling Structural Steel. Use protective devices or softeners to safeguard plate edges, when loading, transporting, unloading, storing and erec ting structural steel. Store the struct ural steel above ground on platforms, skids or other supports. Keep the structural steel properly drained, clean and free of dirt, grease and other foreign matter. Protect the structural steel from corrosion. Store girders and beams upright with sufficient support to prevent warping or change in design camber.
3.Erection Plans. Provide the En gineer with detailed plans for the erection of the structure, including calculations, shop details, camber diagrams, list of field bolts and a copy of shipping statements showing a list of parts and their weights. Provide erectio n plans, sealed by a licensed Professi onal Engineer, for span lengths greater than 125 feet.
4.Falsework. Comply with DIVISION 700 .
5.Bearings and Anchorage. Do not place masonry bearing plates upon bridge seat bearing areas which are improperly finished, deformed or irregular and not unt il the elevations have been verified. Set bearing plates level in exact position and have a full and even bearing upon the masonry. Unless otherwise shown in the Contract Documents, place bearing plates on mats or pads. Set the anchor bolts according to SECTION 842-DRILLING AND GROUTING and preferably, if construction conditions permit, by first setting the bearing devices and superstructure and then drilling the holes or using preformed holes for the anchor bolts. When drillin g anchor bolts use a pacometer to avoid drilling in the existing reinforcing steel. When required, cast anchor bolts in place accordi ng to the Contract Documents. Vary the location of the anchor bolts in relation to the slotted hole s in the expansion shoes with the prevailing temperature. 712 - STRUCTURAL STEEL CONSTRUCTION
700-55 Adjust the nuts on anchor bolts at the expansion ends of spans to permit the free movement of the span, and either
provide lock nuts or burr the threads of the anchor bolts.
6.Straightening Bent Ma terial. Do not put bent or twisted members in place until all defects are corrected. The Engineer, (based on recommendations from the State Bridge Office) will reject damaged members. Straighten plates or other sh apes by approved methods that will not produce fract ure or other injury to the metal (i.e. yield strength, ductility, toughn ess). Do not heat the metal without ap proval of the Engineer. Submit the heat straightening procedure to the Engineer for approval. When permitted, perform the heat straightening procedure complying with AASHTO/AWS D1.5 (edition referenced in subsection 705.2e. ) "Bridge Welding Code" and the latest versions of AASHTO’s "Standard Specificatio ns for Highway Bridges"; AASHTO’s "LRFD Bridge Construction Specifications"; and the FHWA report, "Heat-Straightening Repairs of Damaged Steel Bridges". Following the straightening of a bend or buckle, the surface of the metal will be inspected by the Engineer for evidence of fracture, using the dye penetrant or magnetic particle inspection method.
7.Assembling the Structural Steel. Use drift pins fo r all main member fit-up. Main members are defined as all girders and beams, cross-frames on curved girders or as specified in the Contr act Documents. Assemble the parts as shown in the Contract Documents and erection diagrams, utilizing the matchmarks. Before the members are assembled, clean bearing surfaces and surfa ces to be in permanent contact. Care fully handle the material so that no parts are bent, broken or otherwise damaged. Hammering th at will injure or distort the members is prohibited. Misfitting may require revision of erection details and shop drawings by the Contractor with approval of the Engineer.
8.Erecting Weathering Steel. Erect the fabricated weathering steel according to this subsection, with these additions: Unless shown otherwise in the Cont ract Documents, protect the expos ed surfaces of th e substructure concrete from staining caused by the w eathering steel. Cover the surface of piers and front faces of the abutments with polyethylene sheeting or other material approved by the Engineer before erecting the weathering steel. Maintain the protection until the bridge deck is completed. After the bridge is completed, but before acceptance, sandblast the piers and front face of the abutment to a uniform appearance by removing all laitance, staining, any visible form lines, etc.
b.Bolted Field Connections.
1.General. During field erection, follow the blocking diagram shown in the shop drawings. When designated, a “no-load ” condition for blocking or la ydown indicates the pieces were drilled/punched from solid plates laid on their sides without the deadload deflection included. Reproduce this geometry during erection by the use of falsework or cranes to “float” adjacent pieces together to facilitate proper fit-up. Drift Pins: Use drift pins (cylindrical body pins with tapered ends) to facilitate driving and to line up the open holes in a connection. Use hardened steel drift pins with a minimum yield strength of 50 ksi and with the same nominal diameter as that of the open hole into which they are driven. Drive drift pins only to line up the holes. Do not deform the material. Erection Bolts: Use A325 bolts the same size as the permanent bolts. Uniquely identify the erection bolts from the permanent bolts. Once erecti on bolts are no longer required, remove and replace with permanent bolts. Erection bolts may only be reused as such. Fitting-Up: Accurately align all connections by drivin g drift pins in all corners and ¼ of the remaining holes in each plate in a well distributed pattern to align or “fair-up” the holes. Light drifting is pe rmitted to affect this fairing-up of the holes. Heavy drifting which would deform the material is prohibited. Before removing any drift pins from structures being connected, or moving th e connected members, fully ti ghten the bolts in a minimum of ¼ of the holes in the splices and fi eld connections. For structures carryi ng workers and equipment, fully tighten the bolts in ¾ of the holes. Use high-strength erection bo lts in combination with drift pins to hold the material together during fit-up. Use pilot and driving nuts in driving pins (pin connections). Drive the pins so that the members take full bearing on them. Screw pin nuts up tight and burr the threads at the face of the nut with a pointed tool. Immediately report to the Engineer any error in shop work that prevents the proper assembling and fitting up of parts. Reaming, chipping or cutting is prohibite d without approval from the Engineer. Submit correction method for approval by the Engineer. Make the approved correction in the presence of the Engineer.
2.Field Bolting with non-high-strength bolts. If non-high-strength bolts are specified for miscellaneous connections, use unfinished or machined bolts in bolted co nnections. Provide unfinished or machined bolts that have hexagonal heads and nuts and are of such length that they shall extend entirely through the nut a maximum of ¼ inch beyond the nut. 712 - STRUCTURAL STEEL CONSTRUCTION
700-56 The diameter of the unfinished bolt may not be more than 1/16 inch smaller than the di ameter of the hole.
The threads of machined bolts must be entirely outside the grip. Th e grip is the area from the finished head of the bolt to the finished nut. Use approved nut locks or flat washers ¼ inch thick under nuts, with the threads burred. Ream the holes for machined bolts. The hole diameters may not be more than 1/32 inch greater than the diameter of the finished bolt. In bo lted connections, draw the bolts up tight and burr the threads at the face of the nut with a pointed tool.
3.Field Bolting with High-Strength Steel Bolts and Washers. No reaming, cutting and chipping is allowed for girder flange and web splices. The slope of surfaces of bolted parts in contact with the bolt head and nut is a maximum of 1:20 with respect to a plane normal to the bolt axis. Do not separate bolted steel parts by gaskets. Steel parts must fit solidly together after the bolts are tightened. St andard holes have a diameter nominally 1/16 inch in excess of the nominal bolt diameter. Use a hardened washer under the turned elements (head or nut) for all installations. Where shown on approved shop drawings, oversized, short-slotted and long-slotted holes may be used with high strength bolts ⅝ inch in diameter and larger in connections assembled as shown in TABLE 712-1 . TABLE 712-1: OVERSIZED HOLES Bolt diameter, d (inch) Excess of nominal bolt diameter (inch) d ≤ ⅞ 3/16 d = 1 ¼ d ≥ 1 ⅛ 5/16 Oversized holes may be used in only one of the connected part s of either a friction or bearing connection at an individual faying surface. Install hardened washers (o f a sufficient size to completely cover the hole, after installation) over the oversized holes in an outer ply.* Short-slotted holes shall be nominally equal to a standard hole width, and have a length that does not exceed the oversize diameter provisions for oversize holes by more than 1/16 inch. Short-slotted holes may be used in only one of the connected parts of either a friction or bearing connection at an individual faying surface. The slots may be used without regard to direction of loading in friction connections, but must be normal to the direction of the load in bearing connections. In stall hardened washers over short-slotted holes in the outer plies that have a size sufficient to completely cover the slots after installation.* Long-slotted holes shall be nominally equal to a stan dard hole width and have a length more than allowed for short-slotted holes, but not more than 2 ½ times the nominal bolt diameter. Long-slotted holes may be used in only one of the connected parts of either a friction or bearing connection at an individual faying surface. The slots may be used without regard to direction of loading in friction connections, but must be normal to the direction of the load in bearing connections. Where long-slotted holes are used on an outer ply, provide a plate washer or continuous bar a minimum of 5/16 inch thickness with standard holes. This washer or bar shall be of structural grade material, but need not be hardened. Provide washers or bars that have a size sufficient to completely cover the slots after installation. If hardened washers are required by th e Contract Documents, place th e hardened washers over the outer surface of the plate washer or bar.* *When ASTM A490 bolts over 1 inch in diameter are used in slotted or oversized holes in external plies, use a single hardened washer comply ing with ASTM F436, except with 5/16 inch minimum thickness, in lieu of the standard washer. When assembled, all joint surfaces, in cluding those adjacent to the bolt head s, nuts or washers, shall be free of scale, burrs, dirt and other foreign material that would prevent solid seating of the parts. Tight mill scale may be accepted.
4.Bolting Operation. See FIGURE 712-1. The Bolting Operation shall require Calibration, Installation and Inspection Verification. Provide the Engineer applicable test results and certifications for bolt and DTI lots being used on the project: Rotational-Capacity Test (Bo lt, Nut and Hardened Washer) & ASTM F 606 Annex A1 Compression Load Test (DTI). Calibration. Calibration ( FIGURE 712-1 ) is the process of determining the correct tightening procedures so that consistency and accuracy are obtained. This procedure is only applicable to calibrating the turn of fasteners using DTI’s. This is only used on girder splices and diaphragm connections or as noted in the Contract Documents. The calibration procedure is as follows: 712 - STRUCTURAL STEEL CONSTRUCTION
700-57 Using plies with equivalent grip of the connection and correct bolt hole diameter, snug-tighten the
fasteners such that all plates are in uniform contact; Place appropriate marks on the bolt, nu t and plate so that the amount of nut rotation relative to the bolt can be verified; Hold the static element and rotate the turned element one ha lf a turn. Record the number of gaps that refuse the 0.005 inch gage; If this rotation causes all of the gaps to refuse the feeler gage, move to another bolt and rotate the turned element ⅓ of a turn and record the number of gaps that refuse the feeler gage; Continue rotating the turned element until all the gaps refuse the 0.005 inch gage. Record the rotation. This is the target rotation for the bolting op eration for this bolt length and diameter; Repeat this procedure for every bolt length and diameter on the project. FIGURE 712-1 Installation . To achieve uniform results, install bolts af ter performing calibration tightening procedures. Tighten threaded bolts by methods described below. If required because of bolt entering and wrench operation clearances, tightening may be accomplished by turnin g the bolt while the nut is prevented from rotating. Use impact wrenches of adequate capacity and su fficiently supplied with air to perform the required tightening of each bolt in approximately 10 seconds. ASTM 325 Rotational-Capacity Test (Bolt, Nut and Hardened Washer) ASTM F 606 Annex A1 Compression Load Test (DTI) 712 - STRUCTURAL STEEL CONSTRUCTION
700-58 Indicate in the shop drawings where washers are required. Only use ha rdened washers. Use an additional
hardened washer with all ASTM A 490 bolts under the elem ent not turned, if the material against which it bears has a specified minimum yield point less than 40 ksi. Where an outer face of the bolt part has a slope greater than 1:20 with respect to a plane normal to the bolt axis, use a beveled washer to compensate for the slope. Use the turn-of-nut method to provide the required bolt tension for all bolted connections. Install bolts in a minimum of ¼ of the connection holes and bring them to a "snug tight" condition. Snug tight is defined as the condition that exists when the plies of the splice are in firm uniform contact. A few impact s of an impact wrench or the full effort of a man using an ordinary spud wrench should attain this condition. Perform snug tightening systematically from the center of the sp lice to the free edges, and then re-tight en the bolts in a similar systematic manner until all bolts are snug tight and all splice plates are fully compacted. The connection is then ready for final tightening. For proper installation bring all bolts to “snug tight” in the same manner as in the calibration. Only use a Direct Tension Indicator (DTI) for girder splices and diaphragm connections, or as noted in the Contract Documents. Install the DTI’s by one of the following methods: Place a DTI under the bolt head and turn nut to tight en. This method is preferred whenever possible. Face the protrusions on the DTI to the underside of the bolt head. Place a hard ened flat washer under the nut; Place a DTI under the nut and turn the nut to tighten . Place a hardened washer between the nut and the DTI. Place the DTI against the plates w ith the protrusions facing the washer; Place a DTI under the nut and turn the bolt. F ace the protrusion on the DTI to the nut. Place a hardened flat washer under the bolt head; or Place a DTI under the bolt head and turn the bolt head to tighten. This method is suggested when the nut can not be turned. Place hardened flat wa sher between bolt head and the DTI. Face the protrusions on the DTI to the unders ide of the flat washer and bolt he ad. Place a hardened flat washer under the nut. On connections specifying the use of DTI’s, use the turn-of-nut method and tighten all bolts in the connection as determined from the "Target Rotation" in FIGURE 712-1 . During the tightening operation, there must be no rotation of the part not turned by the wrench. Perform tightening systematically from the most rigid part of the joint to its free edges. Place ap propriate marks on the bolt, nut and pl ate so that the amount of nut rotation relative to the bolt can be verified. Use the turn specified in TABLE 712-2 for all connections other than girder splices and diaphragm connections. TABLE 712-2 - NUT ROTATION (*) FROM SNUG TI GHT CONDITION Bolt Length (as measured from underside of head to extreme end of point) Disposition of Outer Faces of Bolted Parts Both faces normal to bolt axis One face normal to bolt axis and other face sloped not more than 1:20 (bevel washer not used) Both faces sloped not more than 1:20 from normal bolt axis (bevel washer not used) Up to and including 4 diameters 1/2 turn 1/2 turn 2/3 turn Over 4 diameters, but not exceeding 8 diameters 1/2 turn 2/3 turn 5/6 turn Over 8 diameters, but not exceeding 12 diameters 2/3 turn 5/6 turn 1 turn Over 12 diameters The method of tightening bolts over 12 diameters in length is as shown on the shop details and approved by the Engineer *Nut rotation is relative to the bolt, regardless of the element (nut or bolt) being turned. For bolts installed by ½ turn and less, the tolerance is ± 30°; for bolts installed by ⅔ turn and more, the tolerance is ± 45°. Lubricate all galvanized nuts with a lubricant containing a visible dye so a visual check can be made for the lubricant at the time of field installation. Black bolts must be "oily" to the touch when installed. Clean and re-lubricate weathered or rusted bolts before installation. Stor e bolts in closed containers, at all times when not in use. 712 - STRUCTURAL STEEL CONSTRUCTION
700-59 Do not reuse ASTM A 490 and A 325 bolts, or any bolt that has been fully tightened.
Inspection Verification. Inspection verification confirms end results of the bolting operation; the inspection provides acceptance or rejection of the finished connection. See FIGURE 712-2 . Commencing with each day’s bolting operation, the E ngineer will inspect each bo lt until the Contractor’s procedures for that day are confirmed. After the day’s pr ocedures are confirmed, a mini mum of 20% of all the bolts in all splices will be checked with a f eeler gauge. This check should be randomly distributed over all the plates within the splice. Visually compare the number of thr eads extending past the face of the nut for uniform appearance. Record the number of refusals using the 0.005 inch gage. (Note: some DTI suppliers provide both 0.005 inch and 0.015 inch gages. Use only the 0.005 inch gage). If the number of refusals is less than 3, tighten until there are a minimum of 3 refusals. If this occurred with the proper rotation, all the pl ies were not in proper snug-tight condition. If the number of refusals with the 0.005 inch gage is great er than or equal to 3, but less than th e number of protrusions, accept the bolt. If all the gaps refuse the 0.005 inch gage, the actual rotation must be compared with the target rotation: If the element has been turned more than 45° beyond the target rotation, reject the bolt. If the element has been turned less than 45° beyond the target rotation, accept the bolt. If the feeler gage is refused by all gaps and the bolt, nut and plate have not been marked, the bolt will be rejected. 712 - STRUCTURAL STEEL CONSTRUCTION
700-60 FIGURE 712-2 – Direct Tensio n Indicator Verification
Bolt Size DTI Spaces Minimum Installation Refusals A 325 A 490 A 325 A 490 5/8 4 5 2 3 3/4 5 6 3 3 7/8 5 6 3 3 1 6 7 3 4 1-1/8 6 7 3 4 1-1/4 7 8 4 4 1-3/8 7 8 4 4
c.Welded Field Connections. Perform field welding and gas cutting of structural steel according to the applicable requirements of SECTION 705 . The company/individual performing non-destructive testing of field welds shall be separate and independent of the company/individual that performed the field welding. The company/individual performing non-destructive testing of field welds shall be separate and independent of the company/individual that performed the field welding. 712 - STRUCTURAL STEEL CONSTRUCTION
700-61 Fill erection holes in the girder webs with button head or hex head bolts equipped with regular hex nuts.
Use only one type of bolt head. Place the heads of the bolts on the outs ide faces of the webs. Erection bolts or other methods approved by the Engineer may be used for closing erection holes in other parts of the structure. All permanent field welded connections of structural steel, except splices in steel piles, shall be made by welders who have qualified in accordance with the requirements of SECTION 713 .
d.Welded Stud Shear Connectors. Welded Stud Sh ear Connectors may be applied during shop fabrication or in the field. If field applied, refer to subsection 705.2d.(12) .
e.Field Painting. Prepare the structural steel surfaces and field paint the prepared surfaces according to
Division 700
712.4 MEASUREMENT AND PAYMENT The Engineer will measure structural steel by the pound. The measured quantity for payment of structural steel is the quantity shown in the Contract Documents. If the Contract Documents are altered for changes in design, or if disagreement exists between the Contractor and the Engin eer as to the accuracy of th e quantities in the Contract Documents, either party has the right to request a nd cause the quantities involved to be measured. Use TABLE 712-3 to compute the weights. TABLE 712-3: CONVERSION UNIT WEIGHTS Type Unit Weight (Lb. per Cu. In.) Structural Steel 0.2833 Bronze 0.315 Cast Iron 0.26 The Engineer will not measure fasteners including erection bolts, button head bolts used for filling erection bolt holes, high-strength bolts for permanent connections, temporary laterals or similar items. The Engineer will not measure weld metal deposited in fillets, or otherwise outsi de the lines and surfaces of the connected parts; but no deductions are made from the computed quantities of such work to allow for material that is removed by beveling or other cutting, and subsequently replaced with weld metal. The Engineer will measure each welded stud shear connector either applied during fabrication or in the field. Payment for "Structural Steel", "Structural Steel (Mer chant Quality)" and "Welded Stud Shear Connectors" at the contract unit prices is full compensation for the specified work. The Engineer will pay for structural steel according to TABLE 712-4 . TABLE 712-4: PAYMENT FOR STRUCTURAL STEEL % Payment of the Contract Quantity Milestone 90 All structural steel is completely fabricated, in place, inspected and ready to weld or bolt according to the Contract Documents. 95 All structural steel is welded or bolted according to the Contract Documents.* 100 All structural steel is painte d according to the Contract Documents, when in the contract. *If painting of structural steel is not required, pay 100%. 713 - QUALIFICATION OF FIELD WELDERS
700-62 Section 713
QUALIFICATION OF FIELD WELDERS 713.1 DESCRIPTION To field weld structural steel on KDOT projects, become qualified for each welding process by passing tests witnessed by the Regional Materi als Engineer or a designated represen tative, according to this specification and the latest version AASHTO/AWS D1.5 “Bridge Welding Code” (except as modified by this section). Perform testing using portable equipment at an outdoor location selected by the Regional Materials Engineer. 713.2 TEST SPECIMENS Supply test plates and backing bars. Present mill test reports for each heat used in the test plates and backing bars before the test begins.
a.Base Metal for Test Specimens. Qualification established with any of the steels listed shall be considered as qualification to weld or tack weld any of the other steels listed except qualification to weld or tack weld steel with a minimum yield strength of 90 ksi or greater shall be established with steel meeting the same specification as steel for the project. Use the following base metals for tests: AASHTO M 270 or ASTM A 709. Other steels may be approved by the Regional Materials Engineer.
b.Shielded Metal Arc Weld ing (SMAW) Restrictions. A welder qualified for SMAW using EXX18 electrodes shall be qualified to weld with all SMAW electrodes allowed by AASHTO /AWS D1.5 except welders required to use an electrode classifi cation of E100XX-X or higher to join metals with a minimum specified yield strength of 90 ksi or greater shall be tested using E10018-X or E11018-X electrodes as necessary to match the yield strength of the base metal to be used in the work. 713.3 PREPARATION OF SPECIMENS Use test plates as shown in AASHTO/AWS D1.5, Figure 5.17 and free from rust, grease, paint and dirt. Test in the vertical and in the overhead positions. Securely tack or clamp the plates in pos ition. Then, weld and prepare as follows: The weld reinforcing shall be sufficient to obtain full cross-sectional area and in no case shall it be greater than ⅛ inch; Deposit all vertical welds from the bottom to the top; Use hand chipping and hand brushing to clean between weld passes. Power chippers or grinders are prohibited during the test. Do not modify root or intermediate weld contours by chipping, grinding, cutting, or other means before depositing subseque nt weld passes. Perform weld cleaning without moving the test plates out of position during the test; Cut out the side bend specimens (see D1.5, Figure 5.17) with a saw. Smoothly cut the edges of the specimens with a grinding wheel or file. If the welder elects to have the test weld radiographically examined, do not make saw cuts; and Unless radiography is used, carefully remove the weld reinforcement and backing by grinding or machining so that the weld shall be flush with the parent metal. Perform all grinding or machine marks perpendicular to the weld. Emery cloth or a file finish is recommended. When radiography is used, leave a 3 inch minimum width backing bar in place. 713.4 TESTING OF SPECIMENS
a.General. All testing shall be by or in the presence of the Regional Materials Engineer or a designated representative. With the exception of fracture critical welder tes ting, testing may be by mechanical means or by radiography at the welder’s option. All radiography will be at the welder’s expense. If all specimens meet the test requirements, the welder will be qualified and an identifica tion card will be issued. A card will be issued yearly unless either subsection 713.5a. applies, or the welder fails to m eet the reporting requirements of subsection 713.6 . 713 - QUALIFICATION OF FIELD WELDERS
700-63 b. Test Procedure for Mechanical Testing. Each test specimen shall be subj ected to a side bend test by
bending around a 1 ½ inch diameter pin in a test jig. A specimen whose surface contains undercut or discontinuities exceeding the following dimensions will be considered to have failed the test. ⅛ inch measured in any direction on the surface. ⅜ inch for the sum of the greatest dimensions of all discontinuities exceeding 1/32 inch, but less than or equal to ⅛ inch. ¼ inch for the maximum corner crack, except: When that corner crack results from a visible slag inclusion or other fusion type discontinuity, the ⅛ inch maximum shall apply. Specimens with corner cracks ex ceeding ¼ inch with no evidence of slag inclusions or other fusion type discontinuities shall be disregarded, and a replacement test specimen from the original welding shall be tested.
c.Procedures for Radi ographic Qualification. Ground the weld reinforcement flush with the surface of the test plate. Follow radiographic procedures and techniques that are in compliance with the latest edition of AASHTO/AWS D1.5.
d.Retesting. If any specimen fails to pass the above test requirements, the test may be repeated. The welder shall prepare 2 sets of specimens for retest for each position that failed. If both sets of specimens meet the requirements, the welder will be qualified. If either of th e sets of specimens submitted for retest fails to meet the requirements, the welder will not be permitted to take qualification tests for a minimum of 6 months unless evidence of further training is provided. 713.5 REQUALIFICATION
a.General. With the exception of fracture critical field welding, the welder’s qualification here-in specified shall be considered as remaining in effect indefinitely unless:
1.The welder has not welded steel for use on a KDOT project for a period of 1 year.
2.The welder has not welded for a period exceeding 6 months in a given process of welding for which the welder was qualified. The requalification test need be made only in the ⅜ inch thickness.
3.The welder has been suspended while welding on a KDOT project due to one of the following: Poor workmanship. Unsatisfactory appearance of the weld. Undercutting. Slugging. Using electrodes that have not been properly dried or stored. Poor cable connection. Excessive inclusions determined by radiographic inspection.
b.Test Required for Re-Qualification. When the quality of welder’s wo rk becomes unsatisfactory, as defined above, the welder will be suspended and will remain suspended until permitted to re-qualify by the Regional Materials Engineer. Prepare and test all specimens required for re-qualifi cation tests in the presence of the Regional Materials Engineer or a designated representative. 713.6 EVIDENCE OF WELDING ON KDOT PROJECTS Regional Materials Engineers will maintain a record on each field welder who is qualified by their office to weld on KDOT projects. Annually submit to the qualifying Regional Materials Engineer a list of KDOT project numbers on which field welding was performed during the past 12 months. 713.7 QUALIFICATION FOR FILLET WELDING ONLY Some KDOT projects require only fillet welds to attach stiffe ners or bearings in the field. In this case, and with the approval of the Regional Mate rials Engineer, qualification for fillet welding will be done on a job by job 713 - QUALIFICATION OF FIELD WELDERS
700-64 basis by testing in the vertical and overhead fillet weld positions according to AASHTO/AWS D1.5 Section
5.26.3.1. See D1.5, Figure 5.21 for the test. No welder’s card will be issued to fillet welders. The approval by the Regional Materials Engineer to accept this type of qualifica tion will be based on the stru cture type, location of work within structure, and the overall complexity of work. 713.8 QUALIFICATION FOR FRACTURE CRITICAL WELDING Perform fracture critical welder qualification according to AASHTO/AWS D1.5, Section 12. 713.9 REGIONAL MATERIAL’S LABS Kansas City Regional Materials Lab P.O. Box 860462 Shawnee Mission, KS 66286-0462 Phone: 913-441-0346 Wichita Regional Materials Lab: 3200 E. 45 th St. N. Wichita, KS 67220 Phone: 316-744-0421
Source: Kansas Standard Specifications for State Road and Bridge Construction, 2015 Edition. Pages 382–395 of 978.