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504.11 Material Identification and Control Mark steel plates a nd shapes as specified in
AASHTO M 160 (ASTM A 6). Only use material from stock if it ca n be positively identified, properly documented and the direction of rolling ca n be determined. Store material and fabricated items off the ground. Protect th e material and fabricated items from dirt, grease, other foreign materials and significan t corrosion. Store fasteners in a protected e nvironment. Provide four faste ner assemblies for each lot, length and combination to the Fabrication Engineer for tes ting. A fastener assembly consists of a bolt, washer, nut and direct tension indicator (w hen required). Provide the fastener samples to the Fabrication Engineer immediately upon d elivery to the fabrication shop or job site. Provide Certificates of Conformance for welding consumables tha t are not on the Department’s pre-approved electrode list.
504.12 Protective Coatings If paint is specified, apply the co ating in accordance with
Section 506 of the Standard Specifi cations or Special Provision 506 as applicable. When galvanizing is specified, clean the steel in accordance wi th SSPC-SP 6 prior to galvanizing. Galvanize in accordance with AASHTO M 111 (ASTM A 123). Galvanize fasteners in accordance with ASTM F 2329-05 or AASHTO M 198 Cla ss 50 (ASTM B 695 Class 50). Galvanized nuts shall be lubricated with a water-so luble lubricant containing a dye that contrasts with the color of the galvanizing.
504.13 Unpainted Steel Clean all surfaces to a minimum SSPC-SP 6, Commercial Blast
Cleaning. Steel may be abrasive-blast cleaned prior to fabrica tion. Clean steel that is abrasive cleaned prior to fabrication in accordance with SSPC-S P 6 shall be cleaned in accordance with SSPC-SP 1 Solvent Cleaning after fabrication is complete. Disassemble bolted field splices and solvent clean all faying surfaces in a ccordance with SSPC-SP 1 Solvent Cleaning after drilling or reaming is complete. Inspec t the splices prior to re- assembly. HIGHWAY BRIDGE FABRICATION
504.14 Materials for Bridges The grade of steel is designated on the Plans. Do not
substitute material without the approval of the Fabrication Eng ineer.
504.15 Handling Material Handle material in a manner that prev ents nicks, gouges or
other damage from chains, wire ropes or other handling devices during all phases of fabrication.
504.16 Plates for Fabricated Members Cut plates subject to cal culated stress, including
splice plates, so that the direction of rolling is parallel to the primary stresses. The direction of primary stresses for web and field splice material is parall el to the flanges unless 5-70 otherwise shown. Transfer heat numbers to each primary member used in fabrication. Primary members include flanges, webs, splice plates, bearing s tiffeners, connection plates and diaphragm material on curved bridges.
504.17 Correcting Materials Correct material by a method that does not damage the
material. If heating of the steel is required, submit a writte n procedure to the Fabrication Engineer for review. Do not use external force in conjunction with heating unless authorized in the procedure. Following corrective work, inspect the steel with nondestructive testing methods acceptable to the Fabrication En gineer. The presence of cracks or fractures will be cause for rejection of the material .
504.18 Base Metal Repairs Make base metal repairs in accordanc e with the D1.5 Code.
Submit an NCR to the Fabrication Engineer for review if the rep air area exceeds the allowable limits for base metal repairs as specified in the D1. 5 Code. Notify the QAI prior to beginning the repairs.
504.19 Thermal Cutting Thermal cut steel using automatic equip ment or a mechanical
guide. Adjust the rate of travel of the cutting equipment to p revent hardening the steel. Do not cut material freehand.
504.20 Edge Hardness Edge Hardness testing is not required.
504.21 Edge Planing Plane sheared edges of plates greater than 5/8 inch thick to a depth
of 3/16 inch.
504.22 Bent Plates Cold-bend rolled steel plates in accordance with the
AASHTO/NSBA S 2.1 Steel Bridge Fab rication Guide Specifications , Table 4.2 and the following:
a.The bend line will be at right angles to the direction of r olling.
b.The radius of bends shall be such that no cracking of the p late occurs. Measure the radii at the concave surface as follows: MATERIAL Radius in terms of plate thickness (inches)* ASTM Specification Grade T<1 1<t<2 2<t ASTM A709 Gr. 36 1.5t 1.5t 2.0t ASTM A709 Gr. 50, Gr.50W 1.5t 2.0t 2.5t ASTM A709 Gr. 70W 1.5t 2.5t 3.0t * A radius of 5t is required if the plate is subject to calcula ted stresses
c.If a smaller radius is required, heat the bend line to a te mperature between 1000º F and 1150º F before bending. Heat pl ates greater than 2 inches in thickness to a temperature of between 900º F and 1150º F be fore bending. Do not heat HPS7 0W without written approval of the Fabrication Engineer. 5-71
504.23 Die Stamping Die stamp primary members (including splic e material,
diaphragms and cross frames on curved bridges) in no-stress loc ations. No-stress locations include the ends of girders within the cross-sectional area, we b splice plates in the middle third of the plate height and out side the outermost row of bolt holes and flange splice plate ends between the outermost row of holes and the edge. Use blun t-nose, low-stress dies.
504.24 Camber and Curvature When camber or curvature is requir ed for stringers or
girders, it will be specified on the Plans. Measure and record specified c amber or curvature using the same ordinates show n on the reviewed shop drawings af ter all welding is complete. When no camber or curvature is specified, variations in straightness of rolled shapes, with and without cover plates, shall not exceed the tol erances of AASHTO M 160 (ASTM A 6).
504.25 Heat Cambering and Curving Minor correction of camber o r sweep of welded
plate girders is considered part of ordinary shop fabrication p ractice and does not require an approved procedure, however, use the following guidelines:
1.Notify the QAI prior to beginning heat correction 2. Do not use hammers 3. Have suitable temperature indicating crayons at the work sta tion
4.Do not exceed 1150º F 5. Cool in still air to 600 º F. B elow 600 º F compressed air may be used All cambering and curving operations that are not corrective sh all meet the following: Use a camber/curving procedure reviewed by the Fabrication Engi neer. The procedure shall include:
1.The heating pattern and sequencing of heating 2. Method of support of the member 3. Proposed minimum and maximum base metal temperature 4. Method of heating (fuel, nozzle size, etc.) Clean structural steel to SSPC SP-6 prior to heating. Heat bot h the flanges and the web using two torches (one torch on e ither side of the plate). Do not use restraint or jacking devices unless approved by the Fabrication Engineer. Submit ca lculations showing that the nominal bending stress in the member does not exceed 0.60 F y if restraint or jacking is proposed. The target temperature for all ASTM A709 steel is 1100º F. St eel heated in excess of 1200 F will be subject to rejection. Measure the temperature of th e steel with temperature indicating crayons applied to the heated area 10-15 seconds aft er the torch is removed or with a pyrometer that has been calibrated within the past year. Provide temperature- indicating crayons in increme nts of 50 º F between 1050º F and 1250º F to each torch
Source: Maine Standard Specifications for Road and Bridge Construction, 2020 Edition. Pages 361–363 of 817.