550STRUCTURAL STEEL

New Hampshire Department of Transportation Standard Specifications – 2016 Description

1.1General. This work shall consist of furnishing, fabricating, painting if required, transporting, and erecting all structural steel,

bridge shoes, and other materials in accordance with these Specifications, the contract documents, and as shown on the plans. 1.1.1 References within this section are identified by a section number (e.g. 3.15.5 Setting Bearings), and references to sections of AASHTO LRFD Bridge Construction Specifications (current edition and interim specifications) are identified by the abbreviation AASHTO followed by the section number (e.g. AASHTO 11.3.1.7). Materials

2.1General. Materials for steel structures shall be as specified in the current edition and interim specifications of the AASHTO

LRFD Bridge Design Specifications, unless otherwise specified herein. 2.1.1 Materials shall conform to the AASHTO “ StandardS pecifications for Transportation Materials and Methods of Sampling and Testing”, in accordance with current editions and interim specifications, and as modified herein.

2.2Structural steel.

Steel shall be furnished according to the following specifications, or as otherwise specified on the plans. 2.2.1 General. 2.2.1.1 Structural steel shall meet the Standard Specifications for General Requirements for Rolled Structural Steel Bars, Plates, Shapes, and Sheet Piling, ASTM A 6. 2.2.1.2 Unless otherwise specified, structural carbon steel shall be furnished for all structural steel. Structural carbon steel shall conform to AASHTO M 270 (ASTM A 709), Grade 36. 2.2.2 High-strength, low-alloy (HSLA) structural steel shall conform to AASHTO M 270 (ASTM A 709) Grade 50 or Grade 50W (weathering), or HPS 50W, as shown on the plans. 2.2.3 Charpy V-notch impact requirements. All structural steel used in main load -carrying member components subject to tensile stress shall conform to the requirements for Zone 2 of AASHTO M 270 for the longitudinal Charpy V-notch impact tests. 2.2.3.1 These impact requirements are mandatory for members including but not necessarily limited to rolled beams, welded cover plates, webs and tension flanges of built-up girders, flange and web splice plates, longitudinal stiffener plates, cross frames and their connection plates on horizontally curved girders, and other members as shown on the plans.

2.3Paint.

2.3.1 Paint shall conform to NEPCOAT Qualified Products List A or B, unless supers eded by a Special Provision for Item 550.

2.4High Strength Bolts.

2.4.1 Blank. 2.4.2 Specifications. 2.4.2.1 Bolts. High strength bolts for structural steel joints including suitable nuts and plain hardened washers shall meet the requirements of ASTM A 325 as amended and modified herein. High strength bolts, nuts, and washers used with weathering steel shall be Type 3. 2.4.2.1.1 When high strength galvanized bolts are specified, they shall conform to ASTM B 695 Class 50 for mechanically-deposited galvanizing. Use galvanized fasteners where structural steel is painted. 2.4.2.1.2 The use of ASTM A 490 bolts will not be permitted without authorization by the Administrator, Bureau of Bridge Design. 2.4.2.2 Nuts. Nuts shall conform to ASTM A 563. 2.4.2.3 Washers. All washers shall be hardened steel and shall conform to ASTM F 436 and these specifications. 2.4.2.4 Direct Tension Indicators (DTI). All DTI’s shall conform to the requirements of ASTM F 959 Type 325, except that DTI's shall not exceed Rockwell hardness C35. The DTI supplier shall certify that testing has been performed on equipment required by ASTM F 959. 2.4.2.4.1 DTI's shall be furnished “ galvanized” (i.e. mechanically zinc coated) unless noted otherwise. For use with weathering steel, DTI’s shall be furnished as weathering steel or “ painted” (i.e. mechanically galvanized and epoxy coated or baked epoxy).

New Hampshire Department of Transportation Standard Specifications – 2016 2.4.2.4.2 DTI's which incorporate a self-indicating feature to signal sufficient bump compression are not permitted. 2.4.3 Manufacturing. 2.4.3.1 Dimensions. Bolt and nut dimensions shall conform to the dimensions given in Table 550-1 (see Fig. 1) and shall conform to the requirements for Heavy Hexagon Structural Bolts and for Heavy Semi -Finished Hexagon Nuts given in the following specifications: Bolts Heavy Hex Structural Bolts ANSI/ASME B18.2.1 Nuts Heavy Hex Nuts ANSI/ASME B18.2.2

Table 550-1 - Bolt and Nut Dimensions Nominal Bolt Heavy Hex Structural Bolts inches Heavy Hex Nuts inches Size, D Width Across Flats, F Height H Thread Length Width Across Flats W Height H 1/2 7/8 5/16 1 7/8 31/64 5/8 1-1/16 25/64 1-1/4 1-1/16 39/64 3/4 1-1/4 15/32 1-3/8 1-1/4 47/64 7/8 1-7/16 35/64 1-1/2 1-7/16 55/64 1 1-5/8 39/64 1-3/4 1-5/8 63/64 1-1/8 1-3/16 11/16 2 1-13/16 1-7/64 1-1/4 2 25/32 2 2 1-7/32 1-3/8 2-3/16 27/32 2-1/4 2-3/16 1-11/32 1-1/2 2-3/8 15/16 2-1/4 2-3/8 1-15/32

2.4.3.2 Threads. Threads for bolts and nuts shall conform to the following: External Internal Unified Coarse Thread Series, UNC ANSI/ASME B.1.1 2A 2B The 8-pitch thread series 8 UN shall be used on bolts larger than 1”. 2.4.3.3 Bolts. 2.4.3.3.1 Hardness. Hardness for bolt sizes 1/2 to 1” inclusive shall be as noted below:

New Hampshire Department of Transportation Standard Specifications – 2016 ASTM A325 Bolts Hardness Number Brinell Rockwell C Bolt Size Min. Max. Min. Max 1/2 to 1 in, incl. 253 319 25 34

2.4.3.3.2 Bolt markings. All bolts shall be identified with an “ A 325” marking on the top of the bolt head and also a symbol identifying the manufacturer (see Fig. 2). Type 3 bolts shall be identified by an underlined “ A 325”. 2.4.3.3.3 Bolt length. The required bolt length shall be determined by adding the value shown in Table 550-2 to the grip (i.e. the total thickness of all connected material, without washers). For each hardened flat washer that is used add 5/32”, and for each beveled washer add 5/16 ” The values of Table 550 -2 provide appropriate allowance for manufacturing tolerances, and also provide for full thread engagement (i.e. having the end of the bolt at least flush with the face of the nut) with an installed heavy hex nut. The length thus determined shall be adjusted to the next longer standard (1/4 in) length.

2.4.3.4 Nuts. 2.4.3.4.1 Plain nuts. Plain (ungalvanized) nuts shall be grade DH.

New Hampshire Department of Transportation Standard Specifications – 2016 2.4.3.4.2 Weathering nuts. Nuts used with ASTM A 325 Type 3 bolts shall be DH3. 2.4.3.4.3 Nut markings. Nuts shall be marked with the corresponding grade symbol DH3 on one face. G rade C nuts shall be marked on one face with three circumferential marks 120 degrees apart. Grade C3 nuts shall be marked the same as class grade C nuts along with the numeral 3. 2.4.3.4.4 Galvanized nuts. Nuts to be galvanized shall be grade DH. 2.4.3.4.5 Overtapping nuts to be galvanized. Nuts that are to be galvanized shall be tapped oversize the minimum amount required for proper assembly. The amount of overtap in the nut shall be such that the nut will assemble freely on the bolt in the coated condition and shall meet the overtapping requirements of ASTM A 563 and the required rotational-capacity test. 2.4.3.4.6 Lubrication. G alvanized nuts shall be lubricated with a lubricant containing a water soluble visible dye of a color that contrasts with the color of the galvanizing. 2.4.3.5 Washers. Type 3 washers shall be used with ASTM A 325 Type 3 bolts and shall be identified with the numeral 3 stamped on one face. 2.4.3.5.1 Circular hardened washers shall be flat and smooth and their nominal dimensions shall conform to the dimensions given in Table 550-3. Where necessary, washers may be clipped on one side to a point not closer than 7/8 of the bolt diameter from the center of the washer. Table 550-3 - Dimensions for Hardened Washers F436a

Circular Washers Square Beveled Washers for American Standard Beams and Channels Bolt D Nominal Outside Nominal Diameter Thickness

Minimum Side

Mean Slope or Taper in Diameter of Hole Min Max Dimension Thickness Thickness 1/2 1-1/16 17/32 0.097 0.177 1-3/4 5/16 1:6 5/8 1-5/16 21/32 0.122 0.177 1-3/4 5/16 1:6 3/4 1-15/32 13/16 0.122 0.177 1-3/4 5/16 1:6 7/8 1-3/4 15/16 0.136 0.177 1-3/4 5/16 1:6 1 2 1-1/8 0.136 0.177 1-3/4 5/16 1:6 1-1/8 2-1/4 1-1/4 0.136 0.177 2-1/4 5/16 1:6 1-1/4 2-1/2 1-3/8 0.136 0.177 2-1/4 5/16 1:6 1-3/8 2-3/4 1-1/2 0.136 0.177 2-1/4 5/16 1:6 1-1/2 3 1-5/8 0.136 0.177 2-1/4 5/16 1:6 1-3/4 3-3/8 1-7/8 0.178b 0.28b 2 3-3/4 2-1/8 0.178b 0.28b Over 2 to 4 incl. 2D-1/2 D+1/8 0.24c 0.34c a Dimensions in inches. (Tolerances as noted in Table 550-2, ASTM F 436.) b 3/16” nominal. c 1/4” nominal. 2.4.4 Testing. 2.4.4.1 Testing Bolts. 2.4.4.1.1 Proof load test. Proof load tension tests of full size bolts are required in accordance with Method 1, Length Measurement, of ASTM F 606. The minimum frequency of tests shall be as specified in ASTM A 325 paragraph 9.2.4. 2.4.4.1.2 Wedge test. Wedge tension tests, ASTM F 606 paragraph 3.5, on full size bolts are required in accordance with ASTM A 325 paragraph 10.1.1 (If bolts are to be galvanized, tests shall be performed after galvanizing.) The minimum frequency of tests shall be as specified in ASTM A 325. 2.4.4.1.3 If galvanized bolts are supplied, the thickness of the zinc coating shall be measured. Measurements shall be taken on the wrench flats or top of bolt head. New Hampshire Department of Transportation Standard Specifications – 2016 2.4.4.2 Testing Nuts. 2.4.4.2.1 Proof load test. Proof load tension tests are required for nuts in accordance with paragraph 4.2 of ASTM F 606. The minimum frequen cy of tests shall be as specified in ASTM A 563 or ASTM A 194 paragraph 7.1.2.1. If nuts are to be galvanized, tests shall be performed after galvanizing, overtapping and lubricating. 2.4.4.2.2 If galvanized nuts are supplied, the thickness of the zinc coating shall be measured. Measurements shall be taken on the wrench flats. 2.4.4.3 Testing Galvanized Washers. 2.4.4.3.1 If galvanized washers are supplied, hardness testing shall be performed after galvanizing. (Coating shall be removed prior to taking hardness measurements.) 2.4.4.3.2 If galvanized washers are supplied, the thickness of the zinc coating shall be measured. 2.4.4.4 Rotational-capacity test for fastener assemblies. Rotational-capacity tests are required and shall be performed on all black or galvanized (after galvanizing) bolt, nut and washer assemblies by the manufacturer or distributor prior to shipping. Washers are required as part of the test. The following shall apply: 2.4.4.4.1 Except as modified herein, the rotational-capacity test shall be performed in accordance with the requirements of ASTM A 325. 2.4.4.4.2 Each combination of bolt production lot, nut lot, and washer lot shall be tested as an assembly. 2.4.4.4.3 A rotational-capacity lot number shall be assigned to each combination of lots tested. 2.4.4.4.4 The minimum frequency of testing shall be two assemblies per rotational-capacity lot. 2.4.4.4.5 The bolt, nut and washer assembly sha ll be assembled in a Skidmore-Wilhelm Calibrator or an acceptable equivalent device. For short bolts which are too short to be assembled in the Skidmore-Wilhelm Calibrator, see section 2.4.4.4.9. 2.4.4.4.6 The minimum rotation, from a snug tight condition (10% of the specified proof load), shall be: 240 deg. (2/3 turn) for bolt lengths < 4D 360 deg. (l turn) for bolt lengths > 4D and < 8D 480 deg. (1-1/3 turn) for bolt lengths > 8D Notes:

2.4.4.4.7 The tension reached at the above rotation shall be equal to or greater than 1.15 times the required minimum bolt installation tension. Assemblies which do not meet this tension fail the test. The minimum bolt installation tension and the required tension for the turn test are shown below:

2.4.4.4.8 After the required minimum bolt installation tension listed above has been exceeded, one reading of tension and torque shall be taken and recorded. The torque value shall conform to the following: Torque ≤ 0.25 PD where, Torque = measured torque, foot-pounds P = measured bolt tension, pounds D = bolt diameter, feet 2.4.4.4.9 Bolts that are too short to test in a Skidmore -Wilhelm Calibrator may be tested in a steel joint. The tension requirement of section 2.4.4.4.7 need not apply. The maximum torque requirement of section 2.4.4.4.8 shall be computed using a value of P equal to the turn test tension shown in the table in section 2.4.4.4.7. Bolt Diameter (Inches) 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 Min. Req’d. Bolt Installation Tension (kips) 12 19 28 39 51 56 71 85 103 Req’d Turn Test Tension

New Hampshire Department of Transportation Standard Specifications – 2016 2.4.4.5 Reporting. 2.4.4.5.1 Results. The results of all tests (including zinc coating thickness) required herein and in the appropriate AASHTO specifications shall be recorded on the appropriate document. 2.4.4.5.2 Location. The location where tests are performed and date of tests shall be reported on the appropriate document. 2.4.4.6 Witnessing. The tests need not be witnessed by an inspection agency; however, the manufacturer or distributor that performs the tests shall certify that the results recorded are accurate. 2.4.5 Documentation. 2.4.5.1 Mill Test Reports. 2.4.5.1.1 Mill test reports shall be furnished for all mill steel used in the manufacture of the bolts, nuts, or washers. 2.4.5.1.2 Mill test reports shall indicate the place where the material was melted and manufactured. 2.4.5.2 Manufacturer Certified Test Reports - (MCTR). 2.4.5.2.1 The manufacturer of the bolts, nuts, and washers shall furnish test reports (MCTR) for the item furnished. 2.4.5.2.2 Each MCTR shall show the relevant information required in accordance with 2.4.4.5. 2.4.5.2.3 The manufacturer performing the rotational-capacity test shall include on the MCTR:

specifications.

2.4.5.3 Distributor Certified Test Reports - (DCTR). 2.4.5.3.1 The DCTR shall include MCTR above for the various bolt assembly components. 2.4.5.3.2 The rotational-capacity test may be performed by a distributor (in lieu of a manufacturer) and reported on the DCTR. 2.4.5.3.3 The DCTR shall show the results of the tests required in 2.4.4.4. 2.4.5.3.4 The DCTR shall also show the pertinent information required in 2.4.4.5.2. 2.4.5.3.5 The DCTR shall show the rotational-capacity lot number as required in 2.4.4.4.3. 2.4.5.3.6 The DCTR shall certify that the MCTR are in conformance to this specification and the appropriate AASHTO specifications. 2.4.6 Shipping. 2.4.6.1 Bolts, nuts, and washers from each rotational-capacity lot shall be shipped in the same container. If there is only one production lot number for each size of nut and washer, the nuts and washers may be shipped in separate containers. Each container shall be permanently marked with the rotational -capacity lot number such that identification will be possible at any stage prior to installation. 2.4.6.2 The appropriate mill test reports, MCTR or DCTR shall be supplied to the State with two copies of each.

2.5Anchor rods.

Anchor rods for bridge shoes shall be fabricated from deformed billet -steel concrete- reinforcement bars conforming to AASHTO M 31, (ASTM A 615 ), Grade 60. As an alternative, anchor rods shall conform to ASTM A449 or F1554 (Grade 55)material (all-thread for diameters up to 1 1/2” and swedged for diameters over 1 1/2” ). 2.5.1 The details of the anchor rods shall be as shown on the plans. Threads shall be cut or rolled into the specified length of the bar which has been turned to a uniformly circular cross -sectional area of the specified diameter. Anchor rod threads shall be unified coarse thread series, UNC-2A as specified in ANSI/ASME B1.1. Bars shall be furnished as follows:

New Hampshire Department of Transportation Standard Specifications – 2016 Specified Thread Diameter Reinforcing Bar Size 1” No. 9 1-1/4” No. 11 1-1/2” No. 14 2.5.2 Nuts. Nuts shall be hex nuts with mechanical properties conforming to ASTM A 307. Threads for nuts shall be unified coarse thread series, UNC-2B as specified in ANSI/ASME B1.1. 2.5.3 Washers. Washers shall be circular washers of commercial quality, unless otherwise specified. 2.5.4 Galvanizing. Anchor rods, nuts, and w ashers shall be galvanized after fabrication and conform to AASHTO M 232 (ASTM A 153). 2.5.5 Tightening anchor rods. See 3.15.5.6.

2.6Preformed Fabric Bearing Pads.

2.6.1 Type 1. Preformed fabric bearing pads shall meet the requirements of AASHTO LRFD Bridge Construction Specifications, Section 18.10 “ Fabric-reinforced Elastomeric Bedding and Masonry Plates” and –the most current version of MIL- C-882. Pads used to set bridge bearing masonry plates on concrete masonry (see 3.15.5) shall be single sheets approximately 1/8” thick. 2.6.1.1 The preformed fabric pads shall be composed of multiple layers of 8 oz/sy cotton or cotton -polyester 50-50 blend duck impregnated and bound with high -quality natural rubber or of equivalent and equally suitable materials compressed into resilient pads of uniform thickness and vulcanized. The number of plies shall be such as to produce the specified thickness after compression vulcanizing. The finished pads shall withstand compression loads perpendicular to the plane of the laminations of not less than 10,000 psi without detrimental reduction in thickness or extrusion. 2.6.1.2 The thread filling count of the duck shall be 40 ± 2 th reads per 1” and the warp count shall be 50 ± 1 threads per 1”. The pad shall meet the requirements of the load deflection and permanent set compression tests. 2.6.2 Type 2. Preformed fabric bearing pads with a polytetrafluorethylene (PTFE) surface for use in expansion bearing assemblies shall consist of the following two components:

confining substrate. The substrate shall limit flow (elongation) of the confined PTFE to less than 4% under load of 2000 psi for 15 minutes at 78 °F for a 2 by 3” test sample, per ASTM D261, Deformation Under Load. 2.6.3 Acceptance. Bearing pads shall be accepted based upon receipt of a Certificate of Compliance stating that the products comply with the requirements of 2.6.1 or 2.6.2, as applicable, including test results performed by an independent testing laboratory.

2.7Stainless steel plate.

2.7.1 Stainless steel for use in expansion bearing assemblies shall be 16 gage and conform to ASTM A 240 Type 304 with a #8 mirror finish on the side in contact with the PTFE surface.

2.8Steel tubing.

2.8.1 Steel tubing shall conform to the requirements of ASTM A 500, Grade B.

2.9Galvanizing.

When galvanizing is shown on the plans or specified, it shall meet the requirements of AASHTO M 111 (ASTM A 123) for fabricated steel products, and AASHTO M 232 (ASTM A 153) for hardware items other than high strength bolts (such as anchor rods, nuts and washers). 2.9.1 Galvanizing Touch-up and repairs. 2.9.1.1 The total repair area shall be less than 0.25% of the area of an individual member, or the member shall b e rejected and regalvanized. [The repair area definition is comparable to Rust Grade 7 in ASTM D610, Standard Test Method for Evaluating Degree of Rusting on Painted Steel Surfaces.] 2.9.1.2 Repair damaged galvanizing and bare steel surfaces in accordance with ASTM A780, Standard Practice for Repair of Damaged Hot Dipped Galvanized Coatings, Annex A2. Thoroughly clean damaged areas to produce a clean, bare and dry bright metal surface with a roughened profile and feather into the edges of adjacent undamaged galvanizing. Use a power sanding disk per SSPC-SP3. For bolts use a thorough hand wire brushing and SP1 cleaning as a minimum.

New Hampshire Department of Transportation Standard Specifications – 2016 2.9.1.3 Apply an approved organic zinc -rich repair paint containing 92 percent (min.) zinc by weight in the dry film, according to the manufacturer’s recommendations, in two to four coats to a thickness equivalent to the surrounding galvanizing. Silver paint, brite paint, or aluminum paint is not acceptable. 2.9.1.4 The repair to the galvanizing may be a liquid and brushed o n or an aerosol and sprayed, whichever is appropriate to achieve an aesthetic finish and as long as the coats, cure, and minimum thickness of the original system are achieved. The Contractor shall provide a dry film thickness gage and check the thickness of the repair areas. Touch -ups shall be such that the repair is not noticeably visible from a distance of six feet.

2.10PTFE surfaces for bearings.

PTFE for use in expansion bearing assemblies shall be 100 percent virgin (unfilled) polytetraflourethyle ne polymer conforming to AASHTO LRFD Bridge Design Specifications, Section 14.7.2 “ PTFE Sliding Surfaces ” and AASHTO, LRFD Bridge Construction Specifications, Section 18.8.2 “ Materials” and Section 18.8.3 “ Fabrication Requirements”. Construction Requirements

3.1General.

3.1.1 Specifications. 3.1.1.1 Fabrication, painting, transportation and erection of steel structures shall conform to the latest edition and interim Specifications of the AASHTO LRFD Bridge Construction Specifications unless otherwise specified herein. 3.1.1.2 Welded fabrication shall conform to the AASHTO Welding Specifications, namely, the latest edition of the AASHTO/AWS D1.5 “ Bridge Welding Code” and all Interim Revisions published by AASHTO as of the bid opening date, unless otherwise specified herein. 3.1.2 Guidelines. 3.1.2.1 The latest edition of the following AASHTO/NSBA Steel Bridge Collaboration documents shall provide procedural guidance to the work unless directed otherwise in the governing specifications or by the Department :

3.1.3 Approval. Prior to performing any work under Section 550, the fabricator must have received approval for all shop fabrication drawings, welding procedures, and any special Contract requirements. The fabricator shall bear full responsibility and costs for all materials ordered or work performed prior to approval of the shop fabrication drawings or written authorization to proceed from the Engineer. 3.1.4 Quality of workmanship and finish. The workmanship and finish shall be first class and equal to the best practice in modern bridge shops. Shearing, flame cutting, bolting, and welding shall be neatly and accurately done, and all portions of the work exposed to view shall be neatly finished. 3.1.5 Main members. The main members of steel structures are defined to include but not be limited to rolled beams, girder flange and web plates, truss components, arches, floor beams, stringers, bridge shoes, cross frames carrying direct live loads, cover plates, bearing stiffeners, longitudinal stiffeners, transverse stiffeners, splice pla tes, cross frames on horizontally curved bridges, and end connecting or gusset plates for any of these members. The Contract plans may also designate other members as main members.

3.2Fabricator qualification.

Structural steel for bridges furnished under Section 550 shall be fabricated in a plant/shop that has established proof of its competency and responsibility by being registered and certified in accordance with the American Institute of Steel Construction, Inc. (AISC) Quality Certification Program. 3.2.1 AISC Category - Major Steel Bridges (CBR). AISC Category CBR Certification is required for the fabrication of bridge structures incorporating welded plate girders, trusses, arches, welded floor beams , rolled beams with cover plates, rolled beams wi th bolted field splices, horizontally curved rolled beams, cross frames for curved bridges, and pot bearings. The fabrication of fracture critical members requires an AISC Fracture Critical Endorsement. New Hampshire Department of Transportation Standard Specifications – 2016 3.2.2 AISC Category - Simple Steel Bridges (SBR). AISC Category SBR or CBR certification is required for the fabrication of simple straight unspliced rolled beam bridges, structural members for bridge repair or rehabilitation work, br idge shoes, high mast poles, overhead sign support structures, modular and finger-type expansion joints, and pedestrian truss bridges. 3.2.3 AISC Category - Bridge and Highway Metal Component Manufacturers (CPT). AISC Category SBR or CPT certification is required for the fabrication of strip seal and compression seal expansion joints, drains, scuppers, bridge rail, bridge approach rail, grid decks, non-structural items, and ancillary members requiring minimal welding and fabrication. 3.2.4 Shop Painting Qualification. Fabricators supplying painted or metallized products shal l be certified with the AISC Certification Standard for Shop Application of Complex Protective Coating Systems (SPE) [formerly, Sophisticated Paint Endorsement P1 (enclosed shop)], or The Society for Protective Coatings (SSPC) QP3 program. For duplex coating and metallizing see the requirements in Section 708 Appendix A, B, and C.

3.3Shop Fabrication Drawings.

3.3.1 The fabricator shall furnish shop fabrication drawings of all details of fabrication of all structural metals required under the Contract, for approval in accordance with 105.02. The shop fabrication drawings shall show details, dimensions, size and grade of materials, match marking diagrams for field connections, procedures, and other information necessary for the complet e fabrication and erection of the work. 3.3.2 Shop fabrication drawings shal l meet the requirements of AASHTO 11.2.1. All shop fabrication drawings shall be neatly and accurately drawn. All shop fabrication drawings shall show both the detailer’s and checker’s initials as an indication that the details have been checked for accuracy. 3.3.3 The shop fabrication drawings shall be furnished sufficiently in advance of fabrication to allow for review, resubmission, and approval by the Engineer. 3.3.4 The shop fabrication drawings shall be furnished as a complete set for each structure. They may be furnished according to a sequence in partial sets if approved in advance by the Engineer. 3.3.5 The fabricator shall submit three sets of the shop drawings to the Engineer for approval. After receiving approval, the fabricator shall supply the Engineer with six distribution sets of revised working drawings. If a design consultant is involved in the project, four approval sets and seven distribution sets of working drawings shall be supplied. 3.3.6 Fabrication shall not begin until written a pproval of the submitted shop fabrication drawings has been received from the Engineer. 3.3.7 Deviation from the approved shop fabrication drawings will not be permitted without the written order or consent of the Engineer. 3.3.8 Detailed welding procedure specifications shall be considered an integral part of shop fabrication drawings and shall be submitted for approval along with the shop fabrication drawings. The shop fabrication drawings and welding procedures sha ll clearly indicate the welding procedure corresponding to each weld shown. 3.3.9 The fabricator shall expressly understand that the Engineer’s review of shop fabrication drawings submitted by the fabricator covers requirements for strength and arrangement of component parts, and the Engineer a ssumes no responsibility for errors in dimensions. 3.3.10 Originals. Original shop fabrication drawings, corrected ‘as -built’, shall be delivered to the Department before final payment will be made.

3.4Material Identification.

3.4.1 The identification of steels during fabrication shall be according to AASHTO 11.4.1, except that steel stamping shall not be used for material identification. 3.4.2 Mill Test Reports. 3.4.2.1 Two copies of certified heat number identified mill test reports showing physical tes t results and chemical analysis for all main and secondary structural members shall be furnished to the Engineer. Mill test reports shall be traceable to th e piece mark and identified by the State project name, project number, and bridge number. 3.4.2.2 Any material not properly identified shall not be incorporated in the work. 3.4.2.3 Receipt of acceptable mill test reports by the Inspector is required before fabricated material may be released for shipment. Receipt of acceptable mill test reports by the Engineer is a prerequisite for payment for any fabricated material. 3.4.3 Substitutions. Materials other than those shown on shop fabrication drawings reviewed by the Engineer may be used under the following provisions:

New Hampshire Department of Transportation Standard Specifications – 2016

3.4.4 Die Stamping. 3.4.4.1 Die stampings hall not be permitted on main members for radiographic testing, welder identification, heat number transfer or quality assurance acceptance. Girder piece marks may be made with low stress stamps on the web at mid -depth at the end of the girder and on splice plates outside the bolt pattern, or as approved. 3.4.4.2 When die stamping is permitted, low stress dies (i.e. dies manufactured to produce impressions that are rounded at the bottom of the impression rather than sharp edged) shall be used and shall con form to the following requirements: Nominal Character Size inches Minimum Character Face Radius inches 1/8 0.007 3/16 0.008 1/4 0.01

3.5Preparation of Base Metals.

3.5.1 Thermal cutting of structural steel shall conform to the requirements of the AASHTO Welding Specifications. Thermal cutting of main members shall be done only when the steel in the area of the cut is above 40 ° F and in a surface- dry condition except when using plasma arc. 3.5.2 All thermal cut surfaces shall be produced using a mechanically guided torch, unless otherwise approved. Thermal cut surfaces produced by manually guided torch, when allowed, shall be made with a suitable guiding device and be smoothed by grinding. 3.5.3 Reentrant corners. Reentrant corners shall be formed to a radius of not less than 1”. On main material a 2” minimum radius shall be provided whenever possible. All reentrant corner edges shall be ground to a 1/16” radius. 3.5.4 Thermal cutting of high strength steel, 50 ksi min. yield strength. The fabricator shall take steps to ensure that the thermal cut edges of main material subject to tensile stresses are not hardened by the cutting process. This may be achieved by preheating, post heating or control of the burning process. Flame cu t edges of webs which are incorporated into final submerged arc web-to-flange fillet welds need not be tested for hardness. 3.5.4.1 Thermal cut edges found to have a Rockwell Hardness Value of C30 or greater will be considered unacceptable. A portable Rockwell Hardness Tester will be employed by the fabricator and witnessed by the Inspector to determine conformance with these requirements. Unacceptably hard surfaces shall be removed by grinding, machining, or approved heat treating procedures. 3.5.4.2 All Rockwell Hardness testing shall be performed on the thermal cut edge at the mid -thickness location of the plate. Testing shall be performed randomly along the length of each plate. 3.5.5 Weld repairs. Approved weld repairs of notches and gouges in thermal cut plate edges shall be performed in accordance with the requirements of the AASHTO Welding Specifications and 3.6.9. 3.5.6 Facing of bearing surfaces. The surface finish of bearings shall meet the surface roughness requirements of AASHTO 11.4.6. 3.5.6.1 Sliding bearings with a surface roughness greater than ANSI 60 shall be machined or ground or machined and ground so that the lay of the cut does not restrict movement in the longitudinal direction. This includes the rotating portion of the top of rockers and rocker sockets in sole plates. 3.5.7 Flange plates. All flange plates shall be furnished with either thermal cut edges or Universal Mill plates. When thermal cutting flange plates, both edges shall be cut simultaneously to minimize distortion. 3.5.8 Web plates. Web plates of built up girders shall be thermal cut to produce the required camber. 3.5.9 Splice plates and gusset plates. Flange and web splice plates shall be furnished with thermal cut edges, although web splice plates 5/8” or less in thickness may be made of sheared plates. 3.5.10 Stiffeners and connection plates. Stiffeners and connection plates welded transverse to girder webs and flanges may be furnished with sheared edges provided their thickness does not exceed 5/8 ”. Universal Mill plate may be used provided its thickness does not exceed 1”. All other stiffener and connection plates shall be furnished with thermal cut edges. New Hampshire Department of Transportation Standard Specifications – 2016 3.5.11 Bending of Plates. 3.5.11.1 Bending of steel plates and bars shall meet the requirements of AA SHTO 11.4.3.3, as modified herein, and shall be performed in a manner such that no cracking occurs. Before bending, the corners of the plate shall be rounded to a radius of 1/16” throughout the portion of the plate at which the bending is to occur . After bending is complete, all surfaces of the bent area shall be magnetic particle inspected. 3.5.11.2 Plates of Primary Members. Plates of primary members may be cold-bent, or hot-bent as approved. Cold-bending shall be performed gradually in a slow, contro lled, uniform manner with roller equipment built for the purpose and adequate for the task, and by facilities experienced in the work and approved by the Department. Bending by piston -driven “ cold-gagging” is not permitted. 3.5.11.2.1 Hot-bending of primary members shall use heating methods and equipment as described in 550.3.10. Hot - bending is required for bend radii of 2 ft. or less. The area to be bent shall be heated for the full width of the plate and for a distance of at least six times the thickness of the plate. No bending force shall be applied until this area is heated to a temperature between 900° and 1,150° F. 3.5.11.3 Plates of Secondary Members. Plates of secondary members, e.g. cross frame gusset plates on a skewed bridge, may be cold-bent or hot-bent. 3.5.11.4 Rolled Beams and Fabricated Members. Rolled beams, welded girders, and fabricated primary members shall use heating methods for cambering, sweep, and straightening according to 550.3.10.

3.6Shop Welding.

3.6.1 Welding Procedures. 3.6.1.1 The fabricator shall submit welding procedure specifications to the Administrator, Bureau of Bridge Design and receive written approval of the procedures prior to the start of fabrication. 3.6.1.2 All welding shall conform to the approved welding procedure specifications. 3.6.1.3 Welding procedures shall be provided to the welders and welding operators and shall be posted on welding machines for use during production. 3.6.1.4 Welding Procedure Specifications. Form N -2 of Annex N of the AASHTO Welding Specifications shall be required for use in both qualified and prequalified written welding procedure specifications. 3.6.2 Qualification of Welders and Welding Operators. 3.6.2.1 Welding shall be performed by only prequalified welders, welding operators, and tackers; and shall be qualified by the applicable tests as described in the AASHTO Welding Specifications. 3.6.2.2 Welder and welding operator qualification tests shall be the responsibility of the fab ricator. However, the qualification tests shall be witnessed and approved by an independent, qualified testing/inspection agen cy. 3.6.2.3 The fabricator shall maintain a file of the welder and welding operator qualification test records and make this file available for examination to the Administrator, Bureau of Bridge Design, upon request. Welder qualification test records shall be Form III-4 of Annex III of the AASHTO Welding Specifications or equal. 3.6.2.4 For each project, the fabricating shop shall submit a letter of compliance to the Engineer listing by name all welders and welding operators employed on the fabrication of material for the project. The letter shall certify that these welders or welding operators have been prequalified and that they have been continuously engaged in the welding process for which they are qualified with no lapses in such employment in excess of 6 months since being prequalified. 3.6.3 Welding Processes. 3.6.3.1 Main members. Welding of main load -carrying members and attachments (3.1.5) shall be performed using only submerged arc (SAW) and shielded metal arc processes (SMAW). 3.6.3.2 Submerged arc welding. All principal welds on main members shall be made with the submerged arc process, including all welding of butt splices, flange-to-web welds, connection or stiffener plates to webs, and attaching cover plates. 3.6.3.3 Shielded Metal Arc Welding. 3.6.3.3.1 The use of the manual shielded metal-arc process shall be limited to welding connection plates to rolled beams, welding bridge shoes, repairs, tack welding, joints under 2 ft. in length, minor detail attachments, and other limited weldin g applications where the use of submerged arc welding equipment is impractical because of limited access or the isolated location and short length of welds involved. Shielded metal arc welding may be used for submerged arc weld repairs.

New Hampshire Department of Transportation Standard Specifications – 2016 3.6.3.3.2 Only low hydrogen electrodes will be allowed. Proper electrode storage must be strictly adhered to according to the AASHTO Welding Specifications. 3.6.3.4 Flux cored arc welding. The flux cored arc welding process (FCAW) may be used for members which are not main load-carrying members, such as bridge shoes, cross frames, diaphragms, steel bridge rail, steel light poles, scuppers, expansion joints, and approved secondary material, unless directed otherwise. 3.6.3.5 Gas metal arc welding. The gas metal arc welding process (GMAW) may be used for welding the products listed in 3.6.3.4, unless directed otherwise. 3.6.3.6 Electroslag (ESW) and electrogas (EGW) welding processes are not permitted. 3.6.3.7 Calibration. The fabricator shall periodically calibrate the amperage and voltage meters on welding machines, or, alternatively, verify meter readings by the use of a tong ammeter and volt meter external to the welding machine at regular intervals, or as requested by the Inspector. 3.6.3.8 Arc strikes. Arc strikes outside the area of permanent welds are prohibited on any base metal. Arc strikes are to be ground smooth, and on main member material the area shall be checked for soundness by magnetic particle testing at all locations. 3.6.4 Welding AASHTO M 270 Grade 50 W (weathering) steel. 3.6.4.1 Deposited weld metal. When AASHTO M 270 Grade 50 W is specified, deposited weld metal shall have the atmospheric corrosion resistance and coloring characteristics that match that of the base metal. 3.6.4.2 Minimum heat input. The minimum heat input during welding of M 270Grade 50W steel shall be determined by the procedure qualification test parameters. 3.6.5 Preheat and interpass temperature. Preheating is required for all welding when the temperature of the base metal is below the minimum specified in the AASHTO Welding Specifications (see Table 550 -4). The base metal shall be preheated in such manner that the parts on which the weld metal is being deposited are above the specified minimum temperature for a distance equal to the thickness of the part being welded but not less than 3 ” in all directions from the point of welding. In joints involving combinations of base metals, preheat shall be as specified for the higher strength metal being welded. Temperatures above th e minimum specified may be required for highly restrained welds. Preheat temperatures shall be monitored at the locations specified above. Table 550-4 - Minimum Preheat and Interpass Temperature* Thickness of thickest part at point of welding M 270 Gr 36 M 270 Gr 50 M 270 Gr 50W °F To 3/4 in 50 Over 3/4 to 1-1/2” 70 Over 1-1/2 to 2-1/2 in 150 Over 2-1/2” 225

*A minimum preheat temperature of 150 ° F [max. 400° F ] will be required for all field welding, irrespective of existing temperatures. 3.6.6 Weather Conditions. 3.6.6.1 Welding shall not be performed when surfaces to be welded are wet from condensation, rain, snow or ice, when rain or snow is falling on the surfaces to be welded, or during periods of high wind unless the welder and the work are properly protected. Welding shall not be permitted when the ambient temperature is below 32°F. (The ambient temperature does not mean the ambient environmental temperature but the temperature in the immediate vicinity of the weld.) 3.6.6.2 Shop areas for automatic and semiautomatic welding shall be kept at a temperature not lower than 40 ° F for at least one hour before work begins and at all times when work is being performed. 3.6.7 Tack Welds. 3.6.7.1 The provisions of the AASHTO Welding Specifications shall govern the use of tack welds. New Hampshire Department of Transportation Standard Specifications – 2016 3.6.7.2 Temporary welds that are not incorporated into the final weld are not permitted, except as shown on the shop fabrication drawings and approved. All the quality requirements of final welds shall apply to such temporary welds including preheat. Temporary welds shall be removed by grinding smooth and flush, the area inspected by dye penetrant testing, and tested for hardness as required. 3.6.7.3 Tack welds shall be thoroughly cleaned before final welding. 3.6.7.4 Tack welds shall be sufficiently small to ensure that they do not produce objectionable changes in the appearance of the weld surface or result in a decrease in penetration. Tack welds larger than permitted shall be reduced by grinding befor e final welding is begun. 3.6.7.5 Unless otherwise approved, tack welds shall be made by E7018 electrodes. 3.6.7.6 Tack welds that contain cracks shall be removed and rewelded before placing final welds. 3.6.7.7 Preheat is required for tack welds which are remelted and incorporated into any final weld made by a process other than submerged arc. 3.6.8 Weld Terminations. 3.6.8.1 Run-on and run- off extension plates . Welds shall be terminated (started and stopped) at the end of a joint in a manner that will ensure sound welds. Whenever possible, this shall be done by the use of weld tabs (run-on and run-off extension plates) placed in a manner that will duplicate the joint detail being welded. Weld tabs shall be of sufficient length in the d irection of the weld that potential crater cracks do not extend into the edge of the member, but not less than 2”. 3.6.8.2 Weld tab installation. Weld tabs shall be installed in a manner that will prevent cracks from forming in the area where the weld tab is joined to the member. The preferred method is by tack welding inside the joint where the tack welds will be consumed in producing the final weld. 3.6.8.3 Weld tab removal. Weld tabs shall be removed upon completion and cooling of the weld. The ends of the welds shall be made smooth and flush with the edges of the abutting parts. The edges of flanges and webs at the ends of gro ove-weld butt in tension joints shall be inspected by dye penetrant testing or magnetic particle testing. 3.6.8.4 Fillet weld terminations. All fillet welds must have full throat and no unfilled craters at the beginning and end of the weld. Fillet weld terminations shall have a smooth, rounded profile free of sharp irregularities. Grinding required to correct irregular profiles shall be done with a burr grinder. 3.6.9 Repairs. 3.6.9.1 Weld repairs shall be performed in accordance with the requirements of the AASHTO Welding Specifications. 3.6.9.2 Approval. Prior to performing any corrective weld repairs, the Fabricator shall submit a proposed repair procedure to the Department and receive approval. Prior approval does not have to be obtained in writing, unless required by the Engineer. However, a written record shall be made of all repair work performed and locations. 3.6.9.3 Multiple repairs. The maximum number of repairs to unacceptable defects in main member welds shall be three; i.e. the number of times a weld may be opened, repaired, and resubmitted for nondestructive testing, unless otherwise approved by the Administrator, Bureau of Bridge Design. 3.6.9.4 Structural members shall not be accepted for placement in the structure until all repairs have been made and accepted. 3.6.9.5 Preheat. All weld repairs shall be performed with a minimum preheat and interpass temperature of 150° F. 3.6.9.6 Air carbon-arc gouging. Air carbon-arc gouging shall be followed by thorough grinding, that is, grinding to all- over bright metal. 3.6.9.7 Testing. All weld repairs in tension areas shall be inspected for soundness by dye penetrant testing and shall be retested by the method originally used. The repair of a repair (i.e. successive repairs in a given location) at a main member groove- weld location in tension shall be inspected for soundness by radiographic, ultrasonic and dye penetrant testing after waiting for an interval of 72 hours. All groove-weld repairs shall be ground smooth and flush prior to testing. 3.6.10 Stud welding. Studs shop welded to pier nose angles, scuppers and expansion joints as required on the plans shall meet the requirements of 547, Shear Connectors and AASHTO Welding Specifications, Chapter 7.

3.7Shop Inspection.

3.7.1 Quality assurance inspection. The Department will inspect the fabrication of structural steel on bridge projects which involve main load-carrying members, including welded girders and rolled beams. This quality assurance inspection will include the examination of materials, welding, nondestructive testing, work procedures, painting, and the final fabricated product.

New Hampshire Department of Transportation Standard Specifications – 2016 3.7.1.1 Fabrication shall only be done in the presence of an authorized inspector representing the Department. The Department’s authorized quality assurance inspector is herein referred to as the Inspector. 3.7.1.2 The Engineer may waive shop inspection for secondary structural components and make a complete inspection at a later stage in the construction sequence. 3.7.2 Notice. The fabricator shall give a mple notice (two weeks minimum) of the beginning of work so that arrangements can be made for inspection. No materials shall be fabricated before the Engineer has been so notified. 3.7.3 Authority. The Inspector shall have the authority to reject any mat erial or workmanship that does not meet the requirements of the Contract documents. In case of dispute, the Contractor may appeal to the Engineer, whose decision shall be final. 3.7.3.1 Inspection at the shop is intended as a means of facilitating the wor k and avoiding errors, and it is expressly understood that it will not relieve the fabricator from any responsibility in regard to imperfect material or workmanship and the necessity for replacing the same. 3.7.4 Acceptance. The Inspector shall affix the acceptance stamp of his company to the structural steel when it is ready for shipment and has been properly loaded. This acceptance mark shall be made by paint or ink stamp placed near the erection mar k of the piece. Boxed or bundled material may be stamped on durable tags. 3.7.4.1 Receipt of acceptable mill test reports by the Inspector and the completion of all inspections are prerequisite for fabricated material being approved and released for shipment. 3.7.4.2 The fabricator shall present the Inspecto r with a copy of the shipping invoice to be stamped for verification of inspection and approval of steel items prior to shipment. 3.7.4.3 The Inspector’s acceptance implies that at the time of shipment from the shop, it was the opinion of the Inspector that the structural steel was fabricated from accepted materials by approved processes, painted and loaded for shipment in accordance with the Contract requirements. The Inspector’s stamp of approval for shipment does not imply that the structural material w ill not be rejected by the State if subsequently found to be defective. 3.7.5 Facilities. The fabricator shall furnish facilities for the quality assurance (QA) inspection of materials and workmanship in the shop. The facilities for inspection shall incl ude office accommodations separate from fabricator personnel and convenient to the work equipped with adequate and working lighting, electrical outlets, heating, ventilation and if neces sary air conditioning, a desk and chair, a metal file cabinet, plan rack, and a telephone available for the exclusive use of the Inspector. The fabricator shall provide and permit the QA inspector access to and use of a fax machine, and broadband email connection. 3.7.6 Cooperation. 3.7.6.1 The fabricator shall fully cooperate with the Inspector in the inspection of the work in progress. This shall include the storage of members completed during the Inspector’s absence, in such a manner, that he can completely and safely inspect the finished work. 3.7.6.2 The fabricator shall allow the Inspector unrestricted access to the necessary parts of the shop during working hours. Work done while the Inspector has been refused access shall be automatically rejected. 3.7.6.3 The fabricator shall furnish the Inspector with as many copies of mill orders as may be requested. 3.7.7 Testing. The fabricator shall perform nondestructive testing required by the Contract, the specifications, and as detailed in 3.8. 3.7.7.1 Nondestructive testing shall only be done in the presence of the Inspector. 3.7.7.2 The fabricator shall notify the Inspector 48 hours in advance if nondestructive testing is to be performed at times other than regular daylight hours of the regular workweek. 3.7.7.3 The fabricator shall comply with all requests of the Inspect or to correct deficiencies in materials and workmanship as provided in the Contract documents.

3.8Nondestructive Testing of Welds.

3.8.1 Responsibility. The fabricator is responsible for providing nondestructive testing of welds, including equipment, supplies, and technicians. Nondestructive testing shall be performed as required by the AASHTO Welding Specifications. 3.8.2 Personnel qualification. Personnel performing and interpreting nondestructive tests (i.e. magnetic particle, dye penetrant, radiographic, and ultrasonic) shall be certified Level II individuals qualified in accordance with the American So ciety for Nondestructive Testing Recommended Practice No. SNT -TC-1A, or equivalent, as required by the AASHT O Welding Specifications. New Hampshire Department of Transportation Standard Specifications – 2016 3.8.3 Witness. Nondestructive testing shall be performed in the presence of the Inspector, unless permitted otherwise. The fabricator shall advise the Inspector of nondestructive testing schedules. The Inspector shall be given 48 hours advance notice of any nondestructive testing that is to be performed at times other than regular daylight hours of the regular work week. Radiographic test films shall be made available to the Inspector in a timely manner for review. 3.8.4 Reports. Nondestructive test reports shall be identified as to structure member and location of weld or welds and shall also list all the defective welds, the number of times defective welds were corrected, and the amount of additional inspectio n required. All radiographs shall become the property of the Department and shall be turned over to the Department on completion of the fabrication, or when otherwise requested by the Inspector. 3.8.4.1 Forms. Nondestructive testing shall be reported on forms from the A ppendices of the AASHTO Welding Specifications, or equal. Use Annex F Form F4 for ultrasonic testing, Annex N Form N6 for radiographic testing, and Form N7 for magnetic particle testing. 3.8.5 Zone of stress reversal. For the purpose of determining nondestructive testing requirements in beams and girders, the zone of stress reversal shall b e assumed to extend 10 ft. each side of the field splice location (or secondarily, the dead load point of contra flexure), unless otherwise detailed on the Contract plans. 3.8.6 Visual inspection. All welds shall be visually inspected. 3.8.7 Magnetic Particle Testing. 3.8.7.1 Magnetic particle testing shall be performed on welds as described in the AASHTO Welding Specifications, including web-to-flange, bearing stiffene r-to-web, cover plate to flange, bridge shoes, and cross frame welds and connection plate- to-web welds on horizontally curved girders. 3.8.7.2 When magnetic particle testing is used, the procedure and technique shall be in accordance with the dry powder magnetic particle examination of welds using the yoke method or prod method in accordance with ASTM E 709. 3.8.7.3 Yoke Method. The yoke method shall be performed in conformance with ASTM E709 using half -wave rectified direct current (DC) or alternating cur rent (AC). DC electromagnetic yokes and shall have a lifting force of at least 50 lb. at the maximum pole spacing that will be used over four inches. 3.8.7.4 Prod Method. When the prod method is performed on AASHTO M 270 Gr 50 or Gr 50W steel or other steels with minimum specified yield strength of 50 ksi or greater, aluminum prods shall be used on the test equipment. Copper prods shall not be used on such steels. Arcing shall be minimized by following the proper testing procedures. 3.8.8 Radiographic t esting. Radiographic testing shall be performed on groove welded butt joints in main members. Radiographic testing shall be performed in accordance with the requirements of the AASHTO Welding Specifications. 3.8.8.1 All identification marks required on butt welds for radiographic purposes shall be made with paint. Steel die stamping shall not be permitted. 3.8.8.2 Edge blocks shall be used when radiographing butt welds greater than 1/2 ” thickness. The edge blocks shall have a length sufficient to extend beyond each side of the weld centerline for a minimum distance equal to the weld thickness, but not less than 2”, and shall have a thickness equal to or greater than the thickness of the weld. The minimum width of the edge blocks shall be equal to half the weld thickness, but not less than 1” The edge blocks shall be centered on the weld against the plate being radiographed, allowing not more than 1/16” gap for the minimum specified length of edge blocks. Edge blocks shall not be tack welded. Edge blocks shall be made of radiographically clean steel and the surface shall have a finish of 125 micro -inches (ANSI 3 µm) or smoother. 3.8.9 Ultrasonic testing. Ultrasonic testing shall not be used as a substitute for radiographic testing. Ultrasonic testing may be used by the fabricator to determine the extent of discontinuities, laminations and inclusions discovered in any base metal. 3.8.10 Dye penetrant testing. Dye penetrant testing shall be used to inspect transverse fillet welds (3.9.3.2), ends of groove weld butt splices (3.6.8), weld repairs (3.6.9), arc strikes (3.6.3.8), and may be used to supply additional information at the discretion of the Inspector. Dye penetrant testing shall only be performed when the steel is between the temperatures of 40 to 110 °F. After dye penetrant testing is completed and approved, discoloration shall be removed from the steel with suitable solven ts.

3.9Assembly of Shop Welded Connections.

3.9.1 Plate girder assembly. Flange and web plates for welded girders shall be completely shop welded separately before assembly as shown on the plans. 3.9.2 Butt splice welds. All butt splice groove welds shall be made flush and smooth by grinding in the longitudinal direction of the girder.

New Hampshire Department of Transportation Standard Specifications – 2016 3.9.3 Assembly of Vertical Stiffeners. 3.9.3.1 Intermediate stiffeners, bearing stiffeners, and connection plates shall be snipped at the corners and welded to the web and flanges as specified on the Contract plans. The fillet welds connecting the stiffener or connection plate to the web shall be started at the end of the stiffener that is adjacent to the tension flange and progress toward the compression flange. Th e fillet welds shall extend to within 1/2” of all snipped corners and shall not be wrapped around the end of the plate in the snipped corner. Care shall be taken to prevent the stiffener welds from intersecting the continuous flange to web welds. The maximum possible clearance between intersecting welds is desired. All fillet welds must have full throat and no unfilled craters at the beginning and end of the weld. Localized undercut of the stiffener at the point where the welding machine is started or stopped shall not require repair unless severe in the opinion of the Inspector. 3.9.3.2 Undercut. When fillet weld toe undercut is less than 1/32” deep and transverse to the primary stress, the undercut may be corrected by grinding to a smooth profile not to exceed 1/32” deep. Repair by grinding shall be inspected by dye penetrant testing. 3.9.3.3 Before welding, there shall be no g ap between the web and the intermediate stiffeners, bearing stiffeners, or connection plates in excess of 3/32”. 3.9.3.4 Intermediate stiffeners and connection plates may be cut 3/16 ” short and then assembled with the stiffener tight against the tension flange and the weld size at the compression flange increased to include the gap. Stiffeners shall not be driven in place with sufficient force to distort the flange, web or stiffener. Stiffeners which show evidence of being under compressive stress, such as waviness along the length of the stiffener after fitting is completed, shall be removed and corrected prior to final welding. 3.9.3.5 Tack welds shall be so placed that weld passes do not start or stop on the tack weld. 3.9.4 Bearings. Sole plates of be ams and girders shall have full contact with the flanges, and the bearing surface shall be smooth and true and shall be truly perpendicular to the web of the member. Curved sole plates shall make full -line bearing with masonry plates, which line, unless otherwise shown on the plans, shall be at right angles to the web of the member. 3.9.4.1 Sole plates. The sole plate-to-flange fillet welds which are on opposite sides of a common plane of contact shall not be wrapped but terminated 1/4” short of the common corner. 3.9.5 Longitudinal stiffener plates shall be continuous and shall be butt spliced, if required, with full penetration groove welds, and 100% inspected by radiographic testing before being welded to the web. 3.9.6 Cross frames. Cross frame welds which are on opposite sides of a common plane of contact shall not be wrapped but terminated 1/4” short of the common corner.

3.10Heat Curving, Cambering, and Straightening.

3.10.1 Straightening rolled or bent material, cambering, and heat curving rolled beams and welded girders shall conform to the requirements of AASHTO 11.4.7 and 11.4.12.2, respectively. 3.10.2 Temperature. 3.10.2.1 When heating is permitted, the maximum allowable temperature of the steel shall be 1,200 ° F (a dull red) for AASHTO M 270(ASTM A 709) steels with a specified minimum yield point equal to or less than 50 ksi, e.g. Gr 36, 50, and 50W. When the application of heat to AASHTO M 270 Grade 70W and 100Wsteels is permitted by the Engineer, the temperature shall not exceed 1,050 °F nor shall the temperature exceed 900 °F at weld metal or within 6” of weld metal, nor shall the heat be applied directly to weld metal. 3.10.2.2 Heating temperatures shall be controlled with temperature indicating crayons. The fabricator shall provide temperature indicating crayons manufactured for 600º, 1,000º, 1,100º and 1,250 ° F. Heat measurements shall be made after the heating flame has been removed from the steel. 3.10.3 Artificial cooling. Quenching with water or water and air will not be permitted. Cooling with dry compressed air will be permitted after the steel has cooled to 600 °F. 3.10.4 Destructive heating. Any heating procedure which causes a portion of the steel to be heated to a temperature greater than 1,250 °F shall be considered destructive heating. Destructive heating shall automatically cause the rejection of the steel. Steel rejected for destructive heating shall be investigated for reacceptance, repair, or replacement by tests ordered by the Depar tment. 3.10.5 Damage. Any method of handling, supporting, or loading that causes the member to distort permanently (yield without the application of heat) will result in rejection of the member. All nondestructive tests to evaluate damage and any corrective work ordered by the Department to compensate for overstressing shall be performed by the fabricator. New Hampshire Department of Transportation Standard Specifications – 2016 3.10.6 Sequence of operations for heat curving. Members shall be heat curved prior to performing the following work, unless otherwise approved by the Department.

3.10.7 Heating patterns. 3.10.7.1 Heating patterns shall be marked on the flange surfaces prior to heating. 3.10.7.2 Heating shall be conducted to bring the steel within the planned pattern to a temperature between 900º and 1,150 ° F as rapidly as possible without overheating the steel. 3.10.7.3 The heating torches shall be manipulated to guard against general and surface overheating. When heating thick plates, it may be necessary to occasionally interrupt heating for periods of less than one minute to allow the heat to soak i nto the flange and avoid surface overheating. 3.10.8 Verification of camber and sweep. After fabrication of rolled beams and welded girders is complete, the fabricator shall measure the camber in the unloaded position (with the web horizontal) and, if applicable, the sweep (with the web vertical) at the 1/4 points as a minimum. The fabricator shall furnish a report to the Department listing the camber and sweep measurements and certify that they are within specified tolerances.

3.11Connections Using High Strength Bolts.

3.11.1 General. 3.11.1.1 Structural joints shall be assembled using ASTM A 325 high strength bolts tightened to a high tension. 3.11.1.2 Bolts, nuts, washers and direct tension indicators (DTIs) shall conform to the requirements of 2.4. 3.11.1.3 Standard holes (1/16” larger than diameter of bolt) shall be used in high strength bolted connections. Proposed use of oversize or slotted holes shall be subject to approval by the Administrator, Bureau of Bridge Design. (See Table 550-5) 3.11.1.4 The assembly of structural joints with high strength bolts shall conform to the requirements of AASHTO 11.5.6. Installation and tightening of high strength bolts sha ll be in accordance with AASHTO 11.5.6.4. Of particular importance is obtaining the snug tight condition (as defined in 3.11.6.4.2) before final tightening. 3.11.1.5 All bolted connections are classified as slip critical, unless noted otherwise on the pla ns. 3.11.1.6 Bolts shall be tightened to the required pretension by the direct tension indicator (DTI) method according to the procedures and requirements of 3.11.6.7. At the written request of the Contractor and with approval of the Engineer, bolts may be tensioned to the required tension by the turn -of-nut method according to 3.11.6.4 or the calibrated- wrench method, provided the procedures required in 3.11.6.5 are carefully and thoroughly followed. 3.11.1.7 An approved tension calibrator (i.e. tension m easuring device) shall be required at each job site during bolt installation. Periodic testing (at least once each working day) shall be performed to assure compliance with the installation test procedures required herein. Bolts that are too short for the tension calibrator may be tested using direct tension indicators (DTIs). The DTIs must be calibrated in the tension calibrator using longer bolts. 3.11.1.8 The rotational-capacity test described in 2.4 shall be perf ormed on each rotational -capacity lot prior to the start of bolt installation. 3.11.1.9 Bolt, nut and washer combinations as installed shall be taken from the same rotational -capacity lot. Table 550-5 - Nominal Hole Dimensions Hole Dimensions, inches Standard (Dia.) Oversize (Dia.) Short Slot (Width x Length) Long Slot (Width x Length) 1/2 9/16 5/8 9/16 x 11/l6 9/16 x 1-1/4 5/8 11/16 13/16 11/16 x 7/8 11/16 x 1-9/16 3/4 l3/16 15/16 13/16 x 1 13/16 x 1-7/8 7/8 15/16 1-1/16 15/16 x 1-1/8 15/16 x 2-3/16 1 1-1/16 1-1/4 1-1/16 x 1-5/16 1-1/16 x 2-1/2 >1-1/8 d + 1/16 d+ 5/16 (d +1/16) x (d+ 3/8) (d+ 1/16) x (2.5 x d)

New Hampshire Department of Transportation Standard Specifications – 2016 3.11.1.10 The Contractor shall supply a sufficient number of extra bolts, nuts, washers and DTIs for testing as may be required and described herein. 3.11.1.11 Direct Tension Indicators shall conform to ASTM F 959, AASHTO 11.5.6.4.7. 3.11.1.12 Spline end (twist-off) bolts and lock-pin and collar fasteners shall not be used. 3.11.2 Bolt Holes. 3.11.2.1 Holes for high strength bolts shall conform to the requirements of AASHTO 11.4.8. 3.11.2.2 Primary members. All holes in components of main members shall be subpunched and reamed, subdrilled and reamed, or drilled from the solid. 3.11.2.3 Secondary members. Holes in secondary members, including cross frames, diaphragms, and lateral bracing, may be punched full size when the thickness of the steel does not exceed the limits specified in AASHTO 11.4.8.1.1 [namely, 3/4” thick for structural carbon steel and 5/8” for high-strength steel]. 3.11.2.4 Lateral bracing. Oversize holes (see Table 550-5) may be used for lateral bracing with the following provisions:

3.11.2.5 Field reaming. The field reaming of bolt holes is not permitted without approval of the Administrator, Bureau of Bridge Design, and shall conform to the requirements of 3.15.7. 3.11.2.6 Welded restoration of material with misplaced holes. The restoration by welding of material with misplaced holes shall be approved by the Engineer and shall be performed in accordance with 3.6.9 and the AASHTO Welding Specifications (section 3.7.7). Soundness of the restored base metal shall be verified by radiographic testing. For main members in tension , the weld repair shall be postheated at 200°F for one hour per 1” of plate thickness, and weld soundness shall be verified by ultrasonic or radiographic testing. 3.11.3 Preassembly of bolted connections. Preassembly shall conform to the requirements of AASHTO 11.5.3. 3.11.4 Match-marking. Connecting parts assembled in the shop for the purpose of reaming or drilling holes in field connections shall be match-marked. A diagram showing the match marks shall be furnished to the Engineer, unless the connecting parts are shipped attached to the piece. 3.11.5 Bolted Parts. 3.11.5.1 All material within the grip of th e bolt shall be steel. There shall be no compressible material such as gaskets or insulation within the grip. Bolted steel parts shall fit solidly together after the bolts are tightened. The slope of the s urfaces of parts in contact with the bolt head or nut shall not exceed 1:20 with respect to a plane normal to the bolt axis. 3.11.5.2 Prior to assembly, all joint surfaces, including surfaces adjacent to the bolt heads, nuts or washers shall be free of scale, and shall also be free of burrs, dirt, other foreign material, and other defects that would prevent solid seating of the connected parts in the snug tight condition. 3.11.5.3 Contact surfaces within slip critical connections shall be free of oil, paint, lacquer, rust inhibitor, and galvanizing. Paint, including any inadvertent overspray, shall be excluded from areas closer than 1 ” from the edge of any hole and all areas within the bolt pattern, including under the bolt head and nut. Paint may be permitted on contact surfaces of slip critical joints , if approved by the Engineer, when the paint has been tested and the joints have been designed in accordance with AASHTO LRFD Bridge Design Specifications, Section 6.13.2.8. 3.11.5.4 The length of bolts shall be such that the end of the bolt will be flush with or up to three threads outside the face of the nut when properly installed. 3.11.6 Installation and Tightening. 3.11.6.1 Handling and Storage of Fasteners. 3.11.6.1.1 Fasteners (i.e. threaded bolts and nuts), washers, and DTI’s shall be protected f rom dirt and moisture at the job site and stored in a building, shed or trailer. Only as many fasteners as are anticipated to be installed and tightened during a work shift shall be taken from protected storage. Fasteners not used shall be returned to protected storage at the end of the shift. Storage in a shipping container covered with plastic sheeting is not acceptable. New Hampshire Department of Transportation Standard Specifications – 2016 3.11.6.1.2 Fasteners shall not be cleaned of lubricant that is present in the as-delivered condition. Fasteners must be “ oily” to the touch when installed. Galvanized nuts shall be checked to verify that a visible lubricant is on the threads. Lubricants hall be removed after bolt installation prior to painting. 3.11.6.1.3 Weathered or rusted fasteners resulting from job site conditions shall be rejected. The Contractor may submit for approval a procedure for cleaning and relubricating rejected fasteners. Recleaned or relubricated bolt, nut and washer assemblies shall be retested in accordance with 3.11.1.8 prior to installation. Relubrication after cleaning may be accomplished with an approved stick wax applied to the bolt threads and to the nut face in contact with the washer. 3.11.6.1.4 All fasteners shall be lubricated immediately prior to o r during installation using an approved paraffin- based stick wax, as listed on the Qualified Products List, applied to the bolt threads and to the nut face in contact with the washer. When the bolt head is the turned element apply the stick wax to the washer face in contact with the bolt head and to the bolt threads. 3.11.6.2 Bolt Tension. 3.11.6.2.1 Fasteners (i.e. threaded bolts and nuts) together with washers of size and quality specified shall be installed in properly aligned holes and tensioned by the Direct Tension Indicator (DTI) method (or at the written request of the Contractor and with approval of the Engineer, the turn-of-nut method or calibrated-wrench method) to not less than the minimum tension specified in Table 550-6 when all the fasteners are tight. Bolts shall be tightened by turning the nut while the bolt is prevented from rotating. Tightening may be done by turning the bolt while the nut is prevented from rotating when i t is impractical to turn the nut. Impact wrenches, if used, shall be of adequate capacity and sufficiently supplied with air to perform the required tightening of each bolt in approximately 10 seconds. Table 550-6 - Required Fastener Tension

Nominal Bolt Size, inches Minimum Bolt Installation Tension1 in 1000’s of pounds (kips) 5 % Greater Than Min. Bolt Tension2 in kips A 325 Bolts A 325 Bolts 1/2 12 12.6 5/8 19 20.0 3/4 28 29.4 7/8 39 41.0 1 51 53.6 1-1/8 56 58.8 1-1/4 71 74.6 1-3/8 85 89.3 1-1/2 103 108.2

1 Equal to 70 percent of specified minimum tensile strength of bolts rounded to the nearest kip. 2 Equal to 5 percent greater than minimum bolt installation tension rounded to the nearest 0.5 kip. 3.11.6.2.2 Washers. Each bolt shall h ave a hardened washer under the element (nut or bolt head) turned in tightening. Where an 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 smoo th beveled washer shall be used to compensate for the lack of parallelism. 3.11.6.3 Tension Calibrator. 3.11.6.3.1 A tension calibrator device capable of indicating actual bolt tension, shall be supplied by the Contractor and shall be required at all job sites where high strength bolts in slip-critical connections are being installed and tightened. 3.11.6.3.2 The bolt tension indicating device shall be used to confirm:

work to satisfy the requirements of Table 550-6,

New Hampshire Department of Transportation Standard Specifications – 2016 3.11.6.3.3 Confirmation tests shall be performed as specified in 3.11.6.4, 3.11.6.5 and 3.11.6.7, as applicable, to ensure that the as -installed bolt/nut/washer assembly meets installation requirements. The Engineer may require the recalibration of any wrench at any time. 3.11.6.3.4 The Contractor shall deliver the bolt tension-indicating device to the Department’s Laboratory before its use in the work to confirm its accuracy through calibration. 3.11.6.3.5 Bolt/nut/washer assemblies used in calibration and confirmation tests shall not be used in the work. A sufficient number of bolt assemblies shall be supplied for testing. 3.11.6.3.6 Calibration and confirmation testing shall use bolts with the same condition as those in the work at the time of final tightening. If final tightening is to occur after the bolted connection has been exposed to weather for a period of time, then bolts from the work shall be removed for testing. 3.11.6.4 Turn-of-Nut Tightening. 3.11.6.4.1 Testing. A representative sample of not less than three bolt/nut/washer assemblies of each diameter, length and grade to be used in the work , shall be checked at the start of each day’s work in a device capable of indicating bolt tension. The test shall demonstrate that the method for estimating the snug -tight condition and controlling the turns from snug tight to be use d by the bolting crew develops a tension not less than five percent greater than the minimum tension required by Table 550-6. 3.11.6.4.2 Snug tightening. Bolts shall be installed in all holes of the connection and brought to a snug-tight condition. (If the joint is not properly “ snugged”, the tightening procedure will not work.) Snug tight is defined as the tightness that exists when the plies of the joint are in firm contact. This may be attained by a few impacts of an imp act wrench or the full effort of a man using an ordinary spud wrench. Snug tightening shall progress systematically from the most rigid part of the connection to the free edges, and then the bolts of the connection shall be retightened in a similar system atic manner as necessary until all bolts are simultaneously snug tight and the connection is fully compacted. 3.11.6.4.3 Tightening. Following this initial snug tightening operation, all bolts in the connection shall be tightened further by the applicable amount of rotation specified in Table 550-7. During the tightening operation there shall be no rotation of the part not turned by the wrench. Tightening shall progress systematically from the most rigid part of the joint to its free edges. 3.11.6.5 Calibrated-Wrench Tightening. 3.11.6.5.1 The calibrated wrench method includes the use of manual torque wrenches which indicate torque by means of a dial and power wrenches which are adjusted to stall at a specified tension. Calibrated -wrench tightening may be used only when installation procedures are calibrated on a daily basis and when a hardened washer is used under the element turned in tighte ning. This specification does not recognize standard torques determined from tables or from formulas which are assumed to relate torque to tension. Installation torque must be determined directly from calibrations performed at the job site reflecting actual wo rk conditions. 3.11.6.5.2 Calibration. When calibrated wrenches are used for installation, they shall be set to provide a tension not less than five percent in excess of the minimum tension specified in Table 550 -6. The installation procedures shall be calibrated by verification testing at least once each working day for each diameter, length and grade of bolt, using bolt/nut/washer assemblies that are being installed in the work. This verification testing shall be accomplished in a device capable of indicating actual bolt tension by tightening three typical bolts of each diameter, length and grade from the bolts being installed and with a hardened washer from the washers being used in the work under the element turned in tightening. Wrenches shall be recalibrated when a significant difference is noted in the surface condition of the bolts, threads, nuts, or washers. 3.11.6.5.3 Snug tightening. When calibrated wrenches are used to install and tension bolts in a connection, bolts shall be installed with hardened washers under the element turned in tigh tening bolts in all holes of the connection and brought to a snug - tight condition (see 3.11.6.4.2). 3.11.6.5.4 Tightening. Following the initial snug tightening operation, all bolts in the connection shall be tightened using the calibrated wrench to the m inimum bolt installation tension in Table 550- 6. (Power wrenches shall be adjusted to stall or cut out at the required tension. Manual torque wrenches shall tighten the fastener to the torque value corresponding to the cali brated tension.) Tightening shall progress systematically from the most rigid part of the joint to its free edges. The wrench shal l be returned to “ touch up” previously tightened bolts which may have been relaxed as a result of the subsequent tightening of adjacent bolts until all bolts are tightened to the prescribed amount. If manual torque wrenches are used, nuts shall be turned in the tightening direction when torque value is measured. 3.11.6.5.5 Verification. Wrench adjustment shall be verified duri ng actual installation in the assembled steelwork so that the wrench adjustment selected by the calibration does not produce a nut or bolt head rotation from snug tight greater than t hat permitted in Table 550-7. New Hampshire Department of Transportation Standard Specifications – 2016 3.11.6.6 Reuse of bolts. ASTM A 325 bolts shall not be reused after having been tightened to the required fastener tension, Table 6. Touching up or retightening previously tightened bolts which may have been loosened by the tightening of adjacent bolts shall not be considered as reuse provided the snugging up continues from the initial position and does not require greater rotation, including the tolerance, than that required by Table 550-7. ASTM A 490 bolts shall not be reused. Table 550-7 - Nut Rotation from Snug Tight Condition1,2 Disposition of Outer Face of Bolted Parts Bolt Length4,5 BOTH FACES NORMAL to bolt axis ONE FACE NORMAL to bolt axis and OTHER SLOPED not more than1:20 (beveled washer not used) BOTH FACES SLOPED not more than 1:20 from normal to the bolt axis (beveled washer not used) Up to and including 4D (3.5” ) 1/3 turn 1/2 turn 2/3 turn Over 4D to 8D (7” ) 1/2 turn 2/3 turn 5/6 turn Over 8D to 12D3 (10.5” ) 2/3 turn 5/6 turn 1 turn

1 Nut rotation is relative to bolt regardless of the element (nut or bolt) being turned. For bolts installed by 1/2 turn (180 degrees) and less, the tolerance should be plus or minus 30 degrees; for bolts installed by 2/3 turn (240 degrees) and more, the tolerance should be plus or minus 45 degrees. 2 Applicable only to connections in which all material within the grip of the bolt is steel. 3 No research has been performed by the Council to establish the turn -of-nut procedure for bolt lengths exceeding 12 diameters. Therefore, the required rotation must be determined by actual test in a suitable tension measuring device which simulates conditions of solidly fitted steel. 4 Bolt length is measured from underside of head to extreme end of bolt. 5 Bolt lengths in parenthesis ( ) are for a 7/8” diameter bolt. D = nominal bolt diameter (inches) 3.11.6.7 Direct Tension Indicator Tensioning. 3.11.6.7.1 General. These specifications are written to conform to Procedure for Verification and Installation of High Strength Bolts with Direct Tension Indicators (DTIs) in Appendix A 6 of FHWA Report SA -91-031, revised April 1992, and AASHTO LRFD Bridge Design Specifications, except as noted. DTIs installed with high strength bolts to indicate bolt tension shall be subjected to field verification testing (3.11.6.7.2) prior to installation, and the installation requirements (3.11.6.7.3) described below. 3.11.6.7.1.1 When Direct Tension Indicators (DTI's) are to be installed with high-strength bolts to indicate bolt tension, the DTI shall be placed under the head of the bolt with the pro trusions facing the head of the bolt, and the nut shall be turned to tension the fastener with a hardened washer under it. If for reasons of installation or inspection accessibility it is necessary to place the DTI under the turned element, the DTI shall be oriented so that the protrusions face outward from the work, and a hardened washer shall be placed between the DTI and the turned element. 3.11.6.7.1.2 The bolt, DTI, hardened washer, and nut assembly used in the verification testing device and installed in the work shall be such that at least 3 and preferably not more than 5 threads are located in the grip (i.e. between the bearing face of the nut and the bolt head). 3.11.6.7.1.3 Bolts used in the verification test and those installed in the work shall not be tightened to a “ no-visible” gap condition (i.e. a condition when all the DTI protrusions are completely compressed). A visible gap must remain in at least one space after installation. [It is possible to have no entries and yet have a visible gap . The load in the bolt becomes indeterminate when no gap exists and may exceed the capacity of the fastener, possibly causing bolt failure by tensioning beyond complete crushing of the DTI.] 3.11.6.7.1.4 The Contractor shall supply 5 mil tapered feeler ga ges, a calibrated bolt tension -measuring device, and equipment necessary to perform field verification testing and inspection of tensioned bolts. The feeler gages, fasteners, and impact and manual wrenches shall be the same as that to be used in the work. 3.11.6.7.1.5 It is mandatory that the Contractor obtain the services of a qualified technical advisor employed by the DTI manufacturer to make at least one site visit to assist the Contractor and to assure the proper installation and use of DTI's, unless the Contractor can demonstrate to the Department's satisfaction successful use of DTI's on previous projects for the Department.

New Hampshire Department of Transportation Standard Specifications – 2016 3.11.6.7.2 Field verification testing. Verification testing shall be performed in a calibrated bolt tension-measuring device

allows the DTI to be located on the flat front face of the Skidmore for ease of observation and greater access to measure the DTI gap during testing). 3.11.6.7.2.1 The purpose of verification testing is to ensure that (i) the DTI's were properly manufactured (since it is the performance of the DTI that controls the installed bolt tension) and that the fastener in the work will be at or above the required installation tension when the DTI has been compressed to allow entries for fewer than half the number of spaces; and (ii) the fastener in the work will not plastically deform when the DTI is compressed to the maximum allowable limit for the project. 3.11.6.7.2.2 Three verification tests are required for each combination of fastener rotational -capacity lot, DTI lot, and DTI position (under the nut or bolt head) used on the project. All three tests must pass for the DTI and ass embly combination to be approved. Testing shall be performed at the jobsite by the Contractor and witnessed by the Department. 3.11.6.7.2.3 When testing for the normal DTI position, the nut shall be turned and the bolt head against the DTI shall be restrained from turning with another wrench. When testing with the DTI under the turned element, the turned element shall be placed on the flat front face of the Skidmore and the unturned element will be in the rear held by another wrench. 3.11.6.7.2.4 The verification test shall be conducted in two stages:

of fastener. If an impact wrench is used, tension to a load two-thirds below the required load and use a manual wrench to attain the required tension. (The load-indicating needle of the bolt calibrator cannot be read accurately when an impact wrench is used, due to vibrations).

spaces on a DTI is listed in column 4 of Table 550-8). The number of entries shall meet the number listed in column 3 of Table 550-8 under Verification - Required Number of Entries for the grade and size of bolt for DTI's. [When using coated (galvanized or epoxy coated) DTI's under the turned element there shall be at least one entry of the feeler gage.] The DTI lot is rejected if the number of entries is less than the value in column 3 of the table or if for coated DTI's used under the turned element there are no entries.

manual wrench until there are no entries for the 5 -mil feeler gage but a visible gap exists in at least one space. Note and record the load in the bolt at this condition (the maximum allowable limit of DTI compression) and remove the faste ner from the tension-measuring device.

successful, then the bolt has not undergone significant plastic deformation and the assembly passes the verification test.

is less than 95% of the average load measured in the rotational capacity test of the fastener lot as specified in Article 11.5.6.4.2 of the AASHTO LRFD Bridge Construction Specifications, in which case the assembly is deemed to have passed the test. 3.11.6.7.2.5 Bolts used in verification tests shall be marked and shall not be reused in the work. 3.11.6.7.2.6 Short bolts. If the bolt is too short to be tested in the calibration device, the DTI shall be tested on a longer bolt in a calibrator to determine the number of entries at the Verification Tension listed in column 2 of Table 550- 8. The number of entries shall meet the number listed in column 3 of Table 550-8 under Verification - Required Number of Entries. Another DTI from the same lot shall then be assembled with the short bolt in a convenient hole in the work. The fastener assembly shall be tensioned with a manual wrench until there are no entries for the 5 -mil feeler gage but a visible gap exists in at le ast one space. The fastener shall then be disassembled. Subsequently the nut must be run down, by hand, for the complete thread length of t he bolt excluding thread runout. The DTI lot shall be rejected if the nut cannot be assembled to this thread length. Three verification tests are required as stated above. 3.11.6.7.3 Installation and Inspection. Installation of fasteners using DTI's shall be performed in two stages, initial (joint snugging) and final (bolt tensioning). For normal installation, the bolt head against the DTI shall be held against rotation during each stage of the installation while the nut is turned. Two workers are required, one to operate the wrench, and the other to prevent turning of the element against the DTI and to monitor the gap.

the bolts initially tensioned sufficiently to bring all the plies of the connection into firm contact while the drift. pins remain in the connection. Snugging shall progress systematically beginning at the most rigid part of the connection and progressing to the free edges until the connection is fully compacted, as described in 3.11.6.4.2. New Hampshire Department of Transportation Standard Specifications – 2016

after snugging shall meet the number listed in column 3 of Table 550-8 under Verification - Required Number of Entries. If the number of entries is less than the values in the table, the fastener must be removed and another DTI installed, followed by resnugging of the fastener. [This is required because a fastener's tension may have relaxed during the snugging of adjacent fasteners. A compressed DTI does not rebound if the fastener tension is reduced. If a DTI were left in place, which has fewer entries, it would give a false indication of bolt tension.]

of entries for a 5-mil feeler gage meets the number listed in Table 550-8 under Installation - Required Number of Entries. Tightening shall progress systematically beginning at the most rigid part of the connection and progressing to the free edges. Drift. pins shall be removed during this process. Several cy cles may be required. If the fastener is tightened so that no visible gap in any space remains, the bolt and DTI shall be remove d, and replaced by a new properly tightened fastener and DTI.

specified gap to look for inconsist ency of pattern. Any stickouts greater than the other bolts shall be investigated and discarded (e.g. if necking down of the bolt has occurred or the wrong length bolt was used). The end of the properly installed bolt shall be at least flush with the nut or stick out not more than three threads. Table 550-8 - Direct Tension Indicators Bolt Size (inch) Verification Tension1 (kips) Verification - Required Number of Entries 2,3 Number of DTI Spaces between Protrusions Installation - Required Number of Entries 2,4 A325 A490 A325 A490 A325 A490 A325 A490 1/2 13 16 3-4 3-5 4 5 0-2 0-2 5/8 20 25 3-4 3-5 4 5 0-2 0-2 3/4 29 37 3-5 4-6 5 6 0-2 0-3 7/8 41 51 3-5 4-6 5 6 0-2 0-3 1 54 67 4-6 4-7 6 7 0-3 0-3 1-1/8 59 84 4-6 4-7 6 7 0-3 0-3 1-1/4 75 107 4-7 5-8 7 8 0-4 0-4 1-3/8 89 127 4-7 5-8 7 8 0-4 0-4 1-1/2 108 155 5-8 5-9 8 9 0-4 0-4 Verification tension is 1.05 x the required Table 550-6 installation tension. An entry occurs when a 5 mil tapered feeler gage fits into the space between DTI protrusions and touches the bolt shank. See 3.11.6.7.1.3. For coated DTI's under the turned element at least one entry is required. For coated DTI's under the turned element no entries are allowed. 3.11.7.1 Inspection responsibility. Before the installation of fasteners in the work, the Engineer shall check the marking, surface condition and storage of bolts, nuts and washers and the faying (contact) surfaces of joints for compliance with the above requirements. The Engineer shall observe calibration or testing procedures or both required above as applicable, to confirm that the selected procedure is properly used and that, when so used with the fastener assemblies supplied the tensions specified in Table 550-6 are provided. The Engineer shall monitor the installation of fasteners in the work to assure that the selected procedure, as demonstrated in the initial testing to provide the specified tension, is routinely properly applied. 3.11.7.2 Inspection of completed joints. In addition to the requirements of 3.11.7.1, inspection of completed joints is required according to the following inspection procedure. 3.11.7.2.1 Bolt tension for fasteners with DTIs shall be verified by the use of a manual inspection torque wrench (which indicates torque by means of a dial) or by using 5 mil tapered feeler gages provided and operated by the Contractor . 3.11.7.2.2 Calibration of inspecting wrench. At least once each inspection day, a representative sample of three bolts of each diameter, length and gra de of bolt used in the work shall be tightened in the tension measuring device by any convenient means to an initial (i.e. snug-tight) condition equal to approximately 15 percent of the required fastener tension and then to the minimum tension specified in Table 550-6. There shall be a washer under the part turned in tightening each bolt. Tightening beyond the initial condition must not produce greater nut rotation than 1 -1/2 times that permitted in Table 550- 7. The job -

New Hampshire Department of Transportation Standard Specifications – 2016 inspecting torque shall be taken as the average of the torque required for all three bolts. The inspecting wrench shall then be applied to the tightened bolts in the work and the torque necessary to turn the nut or head 5 degrees (approximately 1” at 12” radius) in the tightening direction shall be determined. 3.11.7.2.3 Inspection of turn- of-nut or calibrated- wrench tightened bolts. Bolts represented by the sample in the foregoing paragraph which have been tightened in the structure shall be inspected by applying, in the tightening direction, the inspecting wrench and its job torque to 10 percent of the bolts, but not less than 2 bolts, selected at random in each connection in question. If no nut or bolt head is turned by application of the job inspecting torque, the connection shall be accepted as properly tightened. If any nut or bolt is turned by the application of the job inspecting torque, all bolts in the connection shall be tested, and all bolts whose nut or head is turned by the job inspecting torque shall be tightened and reinspected. Alternatively, it is the fabricator or erector's option to retighten all of the bolts in the connection and then resubmit the connection for the speci fied inspection. 3.11.7.2.4 Inspection of DTI tensioned bolts. All bolts installed using DTI's shall be inspected after snug tightening and again after full tensioning with 100% visual inspection and 10% of the bolts in any connection (but not less than two) shall be inspected by feeler gage. If the installation of inspected bolts is accepted, then the connection shall be accepted as properly tensioned. If any bolt in a connection does not pass inspection, then all (100%) of the bolts in that connection shall be inspected with the feeler gage. Any bolt which does not pass inspection, as described herein, shall be further tensioned, if required, or if over tensioned, shall be removed and replaced by a new properly tensioned bolt and DTI. 3.11.7.2.5 This specification does not recognize standard torques determined from tables or from formulas which are assumed to relate torque to tension. Testing using such standard torques shall not be considered valid. Inspection torques must be determined directly from calibrations performed at the job site reflecting actual work conditions. 3.11.7.3 Delayed verification inspection. The procedure specified in 3.11.7.2 is intended for inspection of bolted connections and verification of pretension within 24 hours of tensioning the joint. If verification of b olt tension is required after a passage of a period of time and exposure of the completed joints, the procedures of 3.11.7.2 will provide an indication of bolt tension that is of questionable accuracy . Procedures appropriate to the specific situation shou ld be used for verification of bolt tension. This might involve use of the inspection procedure contained in 3.11.7.2, or might require the development and use of alternate procedures.

3.12Surface Preparation.

3.12.1 General Requirements. 3.12.1.1 Scope. All structural steel included in Section 550 shall be blast cleaned. 3.12.1.2 Preblast. Structural steel shall be blast cleaned prior to fabrication except as permitted in 3.12.3. 3.12.1.3 Blast cleaning. Blast cleaning shall be performed in conformance with the requirements of SSPC-SP 10, Near-White Blast Cleaning, unless otherwise directed. 3.12.1.4 Method. Blast cleaning shall be performed by either the centrifugal wheel or the air pressure blast method, unless permission is given to use other methods. 3.12.2 Material condition. Upon inspection of the cleaned steel, evidence of rolled -in scale or slag, pits, other surface imperfections, or laminations may indicate that certain material is unacceptable in accordance with ASTM A 6. The dispositio n of such unacceptable material shall be governed by 106.09. The welded repair of discontinuities shall be performed in conformance with the requirements of the AASHTO Welding Specifications and with 3.6.9 . Welded repairs of main members in tension shall also be inspected by radiographic testing. 3.12.3 Preparation for welding. Mill scale shall be removed by blast cleaning from all structural steel surfaces to be welded. At the fa bricator's option all mill scale may be removed from the faying (contact) surfaces by first grinding them to bare metal (e.g. girder flange -to-web and stiffener -to-web welds) before blast cleaning the rest of the steel. However, grinding is at the fabricator's own risk if subsequent blast cleaning reveals material conditions that are unacceptable. 3.12.4 Unpainted Weathering Steel. 3.12.4.1 Initial cleaning. High strength low alloy structural weathering steel shall be blast cleaned before fabrication to remove all mill scale or other foreign material in order to allow uniform oxidation to occur when exposed to the atmosphere. It will be necessary to remove all heavy coatings of oil or grease with suitable solvent prior to blast cleaning operations. 3.12.4.2 Cleaning after fabrication. Care shall be taken to keep weathering steel clean of all foreign matter such as grease, oil, chalk marks, crayon marks, and dirt during and after fabrication . Slag, flux, and spatter resulting from welding operations shall be removed. Identification markings on surfaces to be exposed to view in finished structures will not be permitted. Natural oxidation of the steel will not be considered foreign matter. Steel which becomes contaminated by foreign matter after it has been blast cleaned, shall be cleaned as soon as possible with the proper solvent according to the requirements of SSPC -SP 1, Solvent New Hampshire Department of Transportation Standard Specifications – 2016 Cleaning, or SSPC-SP 2, Hand Tool Cleaning, or SSPC -SP 3, Power Tool Cleaning, or SSPC -SP 10, Near-White Blast Cleaning depending upon the severity of the surface condition. Fascia girders will require cleaning by SSPC -SP 10, Near -White Blast Cleaning, if the above methods are notable to produce a uniform, acceptable surface on the fascia surfaces. 3.12.4.3 Store to weather. The cleaned high strength low alloy weathering steel shall be stored in a position and at a location allowing optimum weathering of the surfaces of the steel which will be exposed to public view. Water shall not be allowed to collect in puddles on such surfaces. The duration of exposure to the weather shall be as long as practicable prior to erection.

3.13Shop Painting.

3.13.1 General. 3.13.1.1 Shop painting shall conform to the requirements of AASHTO “ LRFD Bridge Construction Specifications” Section 13 and SSPC-PA 1 and the special provision, whichever provisions are more stringent. 3.13.1.2 Structural steel conforming to AASHTO M 270 Gr 36 or 50 shall be painted, unless noted otherwise on the plans. 3.13.1.3 Structural steel conforming to M 270 Gr 50W (weathering) shall not be painted, unless otherwise noted on the plans. 3.13.1.4 Surfaces to be painted shall include bridge shoes (except sliding surfaces). Surfaces in direct contact with cast -in- place-concrete shall be painted with primer only. 3.13.1.5 After paint has been applied, material shall not be handled until paint has thoroughly dried. 3.13.1.6 See the special provision for paint sampling and testing requirements. 3.13.2 Surface preparation. Surface preparation for painting shall confo rm to the requirements of 3.12. If the steel surface after preblast and fabrication is not suitable for painting, it shall be blast cleaned again in accordance with SSPC -SP 10, Near - White Blast Cleaning. 3.13.3 Paint System. 3.13.3.1 When structural steel is required to be painted, the work shall conform to the painting requirements detailed in a special provision. 3.13.4 Expansion joint. When an expansion joint is included as part of the structural steel, it shall be painted with one shop coat of approved zinc-rich primer, to a minim um dry film thickness of 3 mils . Surfaces in direct contact with the seals shall be left unpainted. Surfaces in contact with concrete shall be primed only. 3.13.5 Pier nose protection . Pier nose protection steel (usually an angle) shall be galvanized in conformance with the requirements of AASHTO M 111 (ASTM A 123). 3.13.6 Neutralizing welded surfaces. Welded surfaces shall be neutralized by power wire brushing or blast cleaning prior to shop painting. 3.13.7 Bearing protective coatings. Machine finished surfaces in sliding contact, including surfaces in sockets at the top of rocker bearings, shall receive one coat of approved low temperature grease as soon as machining is complete. The Contractor shall maintain all protective coatings to prevent corrosion. All other machine finished surfaces shall be blasted and painted if p ainting of the structural steel is required.

3.14Handling, Storing, and Shipping Material.

3.14.1 General. 3.14.1.1 Structural members shall be handled, stored and shipped in such a manner as to prevent damage to the material and to keep construction stresses within allowable values. 3.14.1.2 Softeners. Structural members shall be handled with suitable clamps o r plate hooks which will not leave nicks, gouges, or depressions during handling. Chains shall not be used for handling structural members unless a protective shield (such as steel angles) is used between the chain and the steel. 3.14.1.3 Girders and beams shall be handled, stored and shipped with their webs vertical and shall be adequately shored, braced, or clamped or braced and clamped to resist any lateral forces which might occur. Members other than girders shall be handled, stored and shipped at all times so that the stronger axis is vertical to resist the dead load of the member. 3.14.1.4 Permanent distortion resulting from improper handling or storage will be cause for rejection. 3.14.2 Handling. 3.14.2.1 Shallow nicks, gouges, or dog marks 1/8” deep or less on structural material caused by lifting devices shall be repaired by grinding to produce a smooth, flared surface with a minimum 1:10 slope in the longitudinal direction. On main members, th is ground repair area shall be nondestructively tested by the magnetic particle or dye penetrant method.

New Hampshire Department of Transportation Standard Specifications – 2016 3.14.2.2 Nicks and gouges deeper than 1/8” shall be repaired by filling with weld metal and grinding flush and smooth. The extent and method of repair of defects shall be consistent with the requirements for delivery of structural steel as specified in ASTM A 6. Welded repairs shall use a preheat of 250 °F and shall be inspected by ultrasonic and dye penetrant testing. 3.14.2.3 Damage deformations outside of usual tolerances shall be reported to the Engineer. Kinks shall result in rejection of the member. 3.14.2.4 Lifting. Proper consideration shall be given to guard against lateral buckling when lifting beams and girders. Generally speaking, straight beams and girders 30 ” in depth or deeper, lifted according to the following criteria should be stable. Dimensions for length/width ratios are in feet and b equals the minimum width of the flange in compression.

overhang length, d, the maximum d/b ratio should not exceed 35 nor should the overhang length exceed 50 ft.

between beam clamps on a two -point pickup, the a/b ratio should not exceed 85 nor should the distance between pickup points exceed 100 feet. 3.14.2.5 Field connection holes shall not be used for lifting the material or for tie-down. 3.14.2.6 Coated steel shall be insulated from lifting devices and from the scraping and rubbing of parts that would damage the coating by the use of lifting softeners, padded slings, storage pallets, separators, cushioners, tie -downs, and other approved supports. 3.14.3 Storage. 3.14.3.1 Structural material and fabricated members shall be stored at the fabrication shop or construction site above the ground on platforms, skids, blocking or other supports and shall be protected as far as practicable from surface deterioratio n by exposure to conditions producing rust. Material shall be kept free from accumulations of dirt, oil, and foreign matter and s hall be positioned to permit proper drainage. See 106. 07. 3.14.3.2 Horizontally curved fabricated girders in storage shall be secured in an acceptable manner to prevent overturning. 3.14.4 Shipping. 3.14.4.1 Marking and shipping shall conform to the requirements of AASHTO 11.4.15. 3.14.4.2 Shipping bolts shall be removed and disc arded at the construction site and not incorporated in the final assembled structure. 3.14.4.3 Structural material shall be clean and free from deformities upon arrival on the project. 3.14.4.4 Hold-down softeners shall be used to prevent chain marks on the structural material during shipment. Such softeners shall be durable enough to perform adequately. 3.14.4.5 Structural members shall be shipped in the upright position (with the webs vertical), unless there are unusual circumstances and written permission from the Administrator, Bureau of Bridge Design is obtained to do otherwise. 3.14.4.6 Structural members shipped on truck beds or supported on dollies shall not cantilever behind same in excess of 25 percent of their length. Other shipping configuratio ns shall require calculations that demonstrate that the member will not be overstressed during shipment and submitted for documentation in accordance with 105.02. The calculations shall account for impact by adding 200% to the calculated actual stress.

3.15Erection of Structural Steel.

3.15.1 Delivery and Field Inspection. 3.15.1.1 Material, workmanship, and condition after shipment will be inspected after delivery to the construction site, with this and any previous inspections constituting only partial acceptance. 3.15.1.2 All work of handling, assembling and erecting structural steel shall be subject to the inspection and approval of the Engineer, who shall be furnished with necessary facilities, including scaffolding and supports, to provide access to the structure to allow for inspection of workmanship and testing of field connections. 3.15.2 Handling and Storage. 3.15.2.1 The provisions of 3.14 on handling and storage shall apply. 3.15.2.2 No material shall, at any time, be dropped, thrown, dragged, or stored on the ground. New Hampshire Department of Transportation Standard Specifications – 2016 3.15.3 Falsework, Scaffolding and Erection Plans. 3.15.3.1 Falsework and Scaffolding . Falsework and scaffolding shall be properly designed and substantially constructed and maintained, without detrimental settlement or deformation, for the full loads that will come upon it. The Contractor shall prepare and submit plans for falsework and scaffolding for documentation in accordance with 105.02. 3.15.3.2 Erection Plans. Before starting the work of erecting all structures with welded girders or rolled beams, and prior to the erection of other structures when ordered, the Contractor shall submit an erection plan for documentation in accordance w ith

105.02. The erection plan shall describe the method of erection proposed and the amount and character of equipment proposed

3.15.3.3 The structural steel for the bridge may be used as supports for equipment and er ection operations only when it is in its permanent position in the structure. 3.15.4 Setting anchor rods. Unless otherwise indicated on the plans, anchor rod holes having a diameter at least 1 ” larger than that of the anchor bolts shall be drilled normal to the plane of the bridge seat. Anchor rods shall be placed in the holes prior to final setting to assure proper fit. During freezing weather, the holes shall be kept free from ice in a satisfactory manner. Unless otherwise permitted, the final setting of anchor rods shall be made after all the structural steel has been erected. 3.15.4.1 Anchor rods shall be set in one of the following materials:

and the ambient temperature are kept at 40 °F or above until the grout has cured.

3.15.4.2 Non-shrinking, non-ferrous, cement base grout or fast setting anchor cement shall be a product as included on the Qualified Products List. Unless otherwise directed, the recommendations of the manufacturer of the product shall be followed exactly, so as to completely fill the space around the bolt. 3.15.4.3 Anchor rods in expansion shoes shall be located in relation to the slotted holes as required by the prevailing temperature. The nuts on anchor rods at the expansion ends of spans shall permit the free movement of the span. 3.15.5 Setting Bearings. 3.15.5.1 Bridge bearings shall be set level and must have full and uniform bearing on the substructure masonry. They shall not be placed on masonry bearing areas that are irregular or improperly cured or finished. Under no condition will the beari ng area be acceptable at an elevation below that of the surrounding masonry. 3.15.5.2 Unless otherwise indicated on the plans, bearing plates shall be placed on preformed fabric bearing pads meeting the requirements of 2.6. Each pad shall be the same size as the bearing plate it is to support. Holes for anchor rods shall be cleanly and accurately punched before setting the pad in place. 3.15.5.3 Care shall be taken that full and free movement of the superstructure at the expansion bearings is not restricted by improper setting or adjustment of bearings or anchor rods and nuts. 3.15.5.4 All protective grease applied in the shop to sliding bearing surfaces shall be removed immediately prior to erection of the superstructure. When the protective coating is removed, the parts shall be thoroughly cleaned and then recoated with the required grease (see 3.12.5.8) before erection of the superstructure. 3.15.5.5 Shim plates, if required, shall be weathering steel or painted with shop-applied primer. 3.15.5.6 Tightening anchor rods. Unless directed otherwise, use a lock washer directly under the nut and tighten bridge bearing anchor rods to a “ snug condition”, which is defined as the full effort of an iron worker using a wrench with a handle length equal to 14 times the diameter of the bolt (minimum 18” ). All the anchor rods in a bearing shall be snugged in a star pattern, and then the pattern repeated a second time to check that no nuts have loosened. 3.15.6 Assembling Steel. 3.15.6.1 Structural steel members shall be carefully handled during assembly so that no parts are bent, broken, or otherwise damaged. Slight defects may be repaired, if approved, and shall be corrected prior to erection. More severe damage and kinks will be cause for rejection of the damaged member. All repairs to structural steel shall be subject to approval by the Engin eer. 3.15.6.2 Structural steel shall not be erected before the bridge abutments have been backfilled to the elevation of the bridge seats, unless otherwise permitted. The final adjustment of bridge shoes shall be performed after approach slabs are constructed, unless otherwise permitted. 3.15.6.3 The component parts of a structure shall be accurately assembled as shown on the plans and any match -marks shall be followed. 3.15.6.4 Hammering which will injure or distort the members shall not be done.

New Hampshire Department of Transportation Standard Specifications – 2016 3.15.6.5 If surfaces which are to be connected by field bolting have been painted or contaminated with any foreign material or become moderately or heavily rusted that would make these connecting procedures unacceptable, the Contractor shall clean the surfaces of contaminants and loose rust at no additional cost to the Department. A tight coating o f light rust will be permitted on faying (contact) surfaces of bolted joints. 3.15.6.6 Fitting-up bolts shall be the required high strength bolts or bolts of the same nominal diameter as the high strength bolts. Cylindrical erection pins shall be 1/32” larger. 3.15.6.7 Curved girders and long span straight girders shall be stabilized with falsework, temporary braces, or holding cranes until a sufficient number of adjacent girders are erected with all diaphragms and crossframes connected to provide the necessary lateral stability. 3.15.6.8 Splices and field connections of main stress carrying members shall be made with a minimum of 50 percent of the holes filled with approved high strength bolts and full size erection pins before the external support systems are released. At least one-half of this percentage shall be bolts, tightened to specification requirements. The bolts and pins shall be installed unifo rmly throughout the connection except that erection pins shall be used in the extreme corners of all m ain connections. 3.15.6.9 Members to be assembled on the ground before erection shall be blocked to their proper no- load profile and 100 percent of the approved high strength bolts shall be installed and tightened to specification requirements before erecting the member. The “ no-load” profile is the fully cambered condition with no dead load deflections. When members are assembled with their webs vertical, they shall be supported at intervals of 20 ft., or two tenths of the span length, whichever is less . 3.15.6.10 Diaphragms and crossframes shall be installed as the work progresses to ensure lateral stability of the members during all phases of the erection procedure. 3.15.6.11 Between the first two lines of straight girders, each diaphragm or crossframe to girder connection shall be made with at least 50 percent of the holes filled with approved high strength bolts. The bolts shall be tightened until there is no gap between the connected parts. After the first two lines of girders are erected and stabi lized, diaphragms or crossframes installed between subsequent lines of girders may have each of their connections made with a minimum of two approved high strength bolts installed in each connection unless a greater number of bolts is required for stability. The bolts shall be tightened until there is no gap between the connected parts. 3.15.6.12 Between all lines of curved girders, each diaphragm or crossframe to girder connection shall be made with at least 50 percent of the holes filled with approved high strength bolts. The bolts shall be tightened until there is no gap between the connected parts. 3.15.6.13 In bolted field splices, bolts shall be oriented so that the heads are visible to public view, unless directed otherwise. On fascia girders and b eams, the bolt head shall be located on the outer web face. On all flanges, the bolt head shall be located on the bottom face. 3.15.7 Field Reaming and Drifting of Holes. 3.15.7.1 Members shall be subject to only light drifting to align holes. Any members subjected to drifting that results in distortion of the member or elongation of the holes will be rejected. 3.15.7.2 No field reaming shall be performed on main member splice connections. 3.15.7.3 Secondary members, i.e. diaphragms, crossframes, lateral bracing, etc., that have standard holes may be subjected to limited field reaming when approved by the Engineer. If approved, reaming shall not elongate holes by an amount greater than 1/16” for 75 percent of the holes in any erection sub-assembly and 1/8” for the remaining 25 percent. The following requirements shall also be met:

3.15.7.4 Additional reaming of secondary members may be approved provided adequate edge distances and fastener spacing’s are maintained. In such case, the next larger fastener size shall be used. The edge distance shall be considered to be that governed by the original fastener size for a rolled or planed edge. 3.15.7.5 Field reaming producing results exceeding the limits previously described, will be cause for rejection of the member. 3.15.7.6 Secondary members with oversize holes (see Table 550-5) shall not be field reamed without approval. New Hampshire Department of Transportation Standard Specifications – 2016

3.16Field Welding.

3.16.1 General. Welding performed in the field on material that will become an integral part of the finished work or on any material used in a temporary capacity that will affect public safety shall be subject to all of the applicable requirements within this specification. 3.16.2 Welder qualification. Field welding shall only be pe rformed by welders who have passed the qualification tests in conformance with the AASHTO Welding Specifications for the welding process and position, and material type and thickness required for the work. The minimum qualification shall be for “ all-position” groove welding on “ limited thickness ” (3/4” maximum) plate. (The qualification test consists of vertical-up and overhead groove welds on 3/8” plate.) The welder must furnish acceptable proof of qualification, namely, AWS Certification or sworn copies of a satisfactory qualification test record or both. A welder’s qualification shall be considered as remaining in effect indefinitely unless the welder is not engaged in a given process of welding for which he is qualified for a period exceeding six months, or unless there is some specific reason to question the welder's ability. 3.16.3 Process. The shielded metal arc welding process (SMAW) is the only process approved for the field welding of structural steel. Welding shall only be done with low hydro gen electrodes (E 8018-C 3 with weathering steel or E 7018 with all other steels, unless approved otherwise). 3.16.4 Approval. Field welding of structural steel will not be permitted without approved drawings and welding procedures, unless approved otherwise. 3.16.5 Weather conditions. Welding shall not be performed when surfaces to be welded are wet from condensation, rain, snow or ice, when rain or snow is falling on the surfaces to be welded, or during periods of high wind unless the welder and the work are properly protected. Welding shall not be permitted when the temperature in the immediate vicinity of the welding is below 32 °F . (The environmental temperature may be below 32 °F but a heated structure or shelter around the area being welded shall maintain the temperature adjacent to the weldment at 32 °F or higher.) 3.16.6 Surface preparation. Surfaces to be welded and surfaces adjacent to the weld shall be free from loose or thick scale, slag, rust, moisture, grease, paint and other foreign material that would prevent proper welding. Surfaces shall be cleaned by blast cleaning or grinding to bare metal. 3.16.7 Tack welds. Tack welds are subject to the same quality requirements as the final weld, including preheat. 3.16.8 Electrode storage and u se. Low hydrogen electrodes (E 7018) shall be kept until used in a portable holding oven heated and maintained at 250 °F. Once removed from the oven for use, the electrodes may not be exposed to the atmosphere for more than 4 hours or they must be discarded. Wet electrodes shall not be used. 3.16.9 Preheat and interpass temperatures. All base metal being welded shall be preheated to a minimum of 150 °F (max. 400 °F ) within an area 3 ” minimum in all directions from the point of welding. This temperatur e must be maintained along the entire length of weld if more than one pass is required. Preheat temperatures shall be monitored with temperature indicating crayons. 3.16.10 Clean up. All weld slag shall be removed and the weld area suitably cleaned. Bef ore painting, the weld area shall be power wire brushed or abrasively blast cleaned. 3.16.11 Nondestructive Testing & Weld Repair. 3.16.11.1 Nondestructive testing of field welds shall be performed when so required by the plans, special provisions, specifications or the Engineer. Each test shall be witnessed by an authorized representative of the Department. 3.16.11.2 Welds or sections of welds containing imperfections and judged unacceptable by the Department shall be removed and rewelded at the Contractor's expense. Welds so removed and replaced will be reinspected by the Department by the same method of inspection and judged by the same criteria, or the entire piece shall be rejected as determined by the Engineer. 3.16.11.3 All costs for the reinspection of defective welds shall be at the Contractor's expense. 3.16.11.4 The Contractor shall furnish and properly locate suitable scaffolding, platforms or other means of accessibility to the area where testing is required. 3.16.12 Stud Welding. 3.16.12.1 Shear connectors used in composite beam construction shall be welded in place in accordance with the requirements of 547. Preheat shall not be required with the field use of automatically timed stud welding equipment, unless directed otherwise. 3.16.12.2 Threaded fasteners (e.g. as stay-in-place form holddowns), if used, shall meet the requirements of Section 547, and torque tested as per AASHTO Welding Specifications, Chapter 7.

New Hampshire Department of Transportation Standard Specifications – 2016

3.17Field Painting.

3.17.1 General. Field painting when called for on the plans shall include the proper preparation of the metal surfaces, the application, protection, and drying of the paint coatings, the protection of pedestrian, vehicular, or other traffic upon or beneath the bridge structure, and the protection of all portions of the structure against disfigurement. Surfaces other than those where paint has been permitted to remain shall be primed the same day that the steel is cleaned. In case cleaned surfaces are left overnight without priming, the steel shall be blast cleaned again and then cleaned in accordance with 3.12.4 before priming. See the special provision for paint sampling and application requirements. 3.17.1.1 Existing dirt, dust and the debris from cleaning operations shall be removed from the roadway and structure to prevent the contamination of surfaces either prepared for paint or surfaces freshly painted. It may be necessary to remove or allay the dust on each end of the bri dge to prevent traffic from picking it up. Repetitive operations will be required for the distance deemed necessary to assure protection for the paint surfaces. 3.17.1.2 All necessary precautions shall be taken to prevent pollution and contamination of air and water during cleaning and painting operations. The precautions shall include, but not be limited to tarpaulins, plastic sheeting, plywood, and the lik e. The Contractor shall take prompt action to correct any noted deficiencies in methods. In populated areas, it may become necessary to control noise emissions from compressors. 3.17.1.3 Care shall be taken to prevent damage to vegetation, water supplies, traffic, utilities, abutting properties, and the structure by equipment, personnel, and cleaning and painting operations. Any damage shall be promptly rectified. Any paint spattering shall be removed and the surfaces shall be repaired. 3.17.1.4 Materials shall be stored in an area protected from traffic. Approved storage areas shall be secured by the Contractor. 3.17.1.5 The Contractor shall furnish an approved dry film thickness gauge with which to measure the dry paint film. 3.17.2 Cleaning. When all field connections have been completed and approved and before applying the first field coat of paint, the surface of the shop coat shall be thoroughly cleaned of all loose or foreign substances. Oil and grease shall be re moved by the use of SSPC -SP 1, Solvent Cleaning. All unpainted or damaged surfaces including all areas showing any evidence of the presence of rust, shall be blast cleaned as specified in SSPC -SP 10, Near-White Blast Cleaning, unless other effective means are permitted. The blast cleaned surface shall be painted the same day it is blast cleaned. 3.17.3 Retouching. After the steel has been cleaned, all surfaces not covered by the full thickness of shop coat paint, including areas from which the paint has been previously omitted, has been worn off or removed, or has become damaged, shall be thoroughly prepared and coated with the primer and intermediate coats of the specified paint system. See 3.13.3 . 3.17.4 Weather conditions. During surface preparation, coating application and four hours thereafter, the ambient environmental and steel temper ature shall be between 50º and 100 ° F, the steel temperature shall be at least 5 ° F above the dew point temperature, and the relative humidity shall not exceed 80 percent, unless manufacturer's recommendations state otherwise. 3.17.5 Mixing and Thinning. 3.17.5.1 All ingredients in any container of paint shall be thoroughly mixed before use and shall be agitated often enough during application to keep the paint in a uniform condition. 3.17.5.2 All pigmented paint shall be strained after mixing except where application equipment is provided with adequate strainers. Strainers shall be of a type to remove only skins and undesirable matter but not to remove the pigment. 3.17.5.3 If it is necessary in cool weather to have the paint of a thinner consistency than when delivered in the containers, the paint may be thinned to spread more freely by heating in hot water or on steam radiators. No thinner shall be added to the paint unless necessary for proper application. Paints to be applied by brush will usually require no thinning. Paints to be sprayed, if not specifically formulated for spraying, may require thinning when proper adjustment of the spray equipment and air pressure does not result in satisfactory paint application. 3.17.5.4 The type of thinner shall comply with the paint specification or manufacturer’s recommendations. 3.17.5.5 When the use of thinner is permissible, thinner shall be added to paint during the mixing process. All thinning shall be done under the supervision of one acquainted with the correct amount and type of thinner to be added to the paint. 3.17.6 Application. Painting shall be done in a neat and workmanlike manner. Paint shall be applied with hand brushes or rollers, by spraying, or with permission, by other methods. By any method, the coating of paint applied shall be smoothly and uniformly spread so that no excess paint will collect at any point and the paint shall evidence no defects which detract from the system’s performance. 3.17.6.1 When brushes are used, the following provisions shall apply to both field coats: To secure a maximum thickness of paint film upon rivet and bolt heads and nuts (connectors), and upon edges of shapes, the edges shall first be striped with a New Hampshire Department of Transportation Standard Specifications – 2016 longitudinal motion and the connectors with a rotary mo tion of the brush. General painting of the whole surface, including the edges and connectors, may follow immediately. 3.17.6.1.1 During general painting, the paint shall be so manipulated under the brush as to produce a smooth, uniform, even coating in close contact with the previously applied paint and the paint shall be worked into all corners and crevices. 3.17.6.1.2 On all surfaces which are inaccessible to paint brushes, the paint shall be applied by spraying, with sheepskin daubers, or by other approved methods to ensure thorough covering. 3.17.6.2 When spray equipment is used, the power equipment shall be capable of applying the paint in a fine, even spray. Connectors and edges of shapes shall be covered with preliminary passes of the spray gun or s hall be striped by brushing as per 3.17.6.1. Care shall be exercised that adequate thickness of wet paint is deposited. When it becomes necessary to build the film thickness, the areas to be painted shall be sprayed horizontally and vertically, with ample overlapping. This may be repeated to gain film build. Areas inaccessible to the spray pattern shall be spot primed before spraying or shall be touched up by the use of brushes or the like after spraying. 3.17.7 Field coats. Field coats shall be applied as detailed in a special provision. All oil, grease, dirt, or salt deposited on the surfaces to be painted shall be removed before applying each successive coat of paint. Special recommendations of the manufacturer shall be followed exactly. 3.17.7.1 Prior to painting, weld surfaces shall be power wire brushed or abrasively blast cleaned. Prior to painting, galvanized surfaces shall be pretreated with SSPC -SP1, Solvent Cleaning, using zinc phosphate or a light acid without attacking the zinc, to remove soluble contaminants, and abrasive blasting or other mechanical means to remove insoluble contaminants such as zinc hydroxide (i.e. white rust) and to thoroughly roughen the entire surface and produce a uniform anchor profile of 1 to 1.5 mils without remo ving the zinc layer. Alternate pretreatments or tie- coats may be considered if recommended by the coatings manufacturer and approved by the Department. 3.17.7.2 Surfaces which have been galvanized or shop painted with an approved zinc rich paint and have become damaged after being coated shall be pretreated as specified in 3.17.7.1 and shall be repaired with 2 coats of approved zinc-rich primer. The second coat shall not be applied until the first coat has been approved. 3.17.8 Paint thickness. The total dry film thickness of the complete system (shop and field coats) shall be as specified in a special provision. The procedure to measure the dry film thickness shall be in accordance with SSPC -PA 2. 3.17.9 Removal of paint. If the painting is unsatisfact ory, the paint shall be removed and the metal thoroughly cleaned and repainted.

3.18Field Cleaning of Weathering Steel.

3.18.1 All detrimental substances such as oil, dirt, grease, chalk and the like remaining after erection shall be removed as soon as possible. Concrete spatter shall be washed off immediately. To obtain a uniformly rusted appearance, the entire exterior fascia of the outside beams or girders shall be cleaned by means of brush-off blast cleaning in accordance with SSPC-SP 7.

3.19Removal of Rust and Stains from Concrete.

3.19.1 In the final stage of construction, all rust and other stains shall be removed from the exposed surfaces of the substructure, using approved methods as described in 534.3.2.3.

3.20Fracture Control Plan.

3.20.1 Specifications. Fracture critical members shall conform to the following requirements and the AASHTO Welding Specifications, Chapter 12. 3.20.2 Modifications to ASTM A 6. The quality of steel plates shall meet the general requirements of Article 9, ASTM A 6, with the following modifications:

Specifications. 3.20.3 Additions to ASTM A 6. The quality of steel plates shall meet the general requirements of Article 9, ASTM A 6, with the following additions:

cut length plates.

New Hampshire Department of Transportation Standard Specifications – 2016

of the ground plate shall not be reduced below the minimum thickness permitted.

be cause for rejection of the plate; however, by agreement with the purchaser, the metal so removed may be replaced with weld metal as provided in ASTM A 6 9.5. 3.20.4 Qualification of fillet welds. Prior to welding Fracture Critical Members the use of a 90 degree included angle shall be specified in qualification testing fillet-welding procedures, with the test plate welded in the position(s) of welding to be used in fabrication. The test weld shall be made with the same procedure and the same number of pas ses as will be used in production. Method of Measurement

4.1Structural steel and bridge shoes will not be measured, but shall be the pound or Each, respectively, final pay quantities in

accordance with 109.11 for structural steel and bridge shoes required as shown on the plans. 4.1.1 Pier nose protection steel shall be included as part of the item of structural steel unless otherwise shown on the plans. Basis of Payment

5.1Except as provided in 544.5.2, structural steel and bridge shoes are final pay quantity items and will be paid for at the Contract

unit price per pound or each respectively complete in place in accordance with 109.11. 5.1.1 The cost of inspection facilities, quality control inspection, tests, including equipment, supplies and technicians, to evaluate material, retests of unacceptable work, any necessary repairs, painting, and other items necessary for the proper completion of the work in accordance with the Contract shall be subsidiary. Pay items and units: 550.1 _ _ Structural Steel (F) Pound 550.2 _ _ Bridge Shoes (F) Each

New Hampshire Department of Transportation Standard Specifications – 2016

Description

This work shall consist of field cleaning, and painting existing structural steel and bridge shoes that have been erected by

others, using pollution control methods, as shown on the plans and specified in a special provision.

1.2The location of the structures and the painting requirements will be described on the plans and in a special provision.

Materials

Paint shall conform to NEPCOAT Qualified Products List A or B, unless superseded by a Special Provision for Item 556 -

Painting Existing Structural Steel. Construction Requirements

Field Painting.

3.1.1 General. Requirements for field painting shall be as specified in 550.3.17 and a Special Provision.

Special Requirements.

3.2.1 Loading and unloading of materials on the bridge will be permitted only with appropriate safeguards for traffic, such as construction signs and warning devices as required in the Manual on Uniform Traffic Control Devices (MUTCD), uniformed officers, and the like, and only at such times as may be permitted. 3.2.2 Temporary suspension of work may be required during periods when the traffic load is such that hazardous conditions would result from interference with the normal flow of traffic. 3.2.3 During field painting the Con tractor shall provide appropriate safety measures, approved by the Department, for the protection of the public against damage due to paint drippings, paint spatter, windblown paint, falling objects, etc. The Contractor shall be fully responsible for property damage or personal injury which may result from operations incidental to the field painting of structural steel. The State shall be protected and indemnified in accordance with Section 107. 3.2.4 The applicable portions of Sections 618 and 619 will apply to this item as though contained herein and will be subsidiary unless these items are included in the Contract. 3.2.5 Special signing requirements may be detailed in a special provision. 3.2.6 The paint system shall at all times during its application or repair be protected from dust, either caused by construction activities or by traffic, that may adhere to the uncured coating. When ordered the en tire upper surface of concrete bridge seats shall be cleaned of all dirt and debris before beginning to paint the bridge shoes. Method of Measurement

This item will be measured as a unit. When more than one unit is specified in the Contract, separate item numbers will appear

for each separate and complete unit. Basis of Payment

The accepted quantity of painted structural steel will be paid for at the Contract unit price.

Pay item and unit: 556. Painting Existing Structural Steel Unit