508.03 Construction Requirements.
STRUCTURAL STEEL AND MISCELLANEOUS METALS
508.01 Description.
The work under this Section shall cover the furnishing, fabricating, erecting, and painting (both shop and field) all structu ral steel and metal work. All work shall be in conformity with the dimensions, shapes and designs shown on the plans. Erected materials shall conform to lines and grades shown on the plans. Structural metals covered in this Section shall include structural steel shapes (except piling) and plates, bolts, and other types of fasteners, welding, special and alloy steels, steel forgings and castings, and all types of metal casting as well as any incidental metal construction not covered in other Sections. Weldin g of structural steel and other metals shall conform to the requirements of Article 836.46 and any modification thereto provided in the contract. Applicable requirements of Sections 510 and 521 shall also apply to this Section. Issues concerning non- confor ming work, repair procedures, requests for variances and/or clarification of Contract plans and/or Specifications including approved shop drawings shall be addressed by submitting ALDOT Bridge Bureau form BBF -15 “Request for Approval” (RFA) to the State Br idge Engineer for review and approval along with any supporting documentation.
508.02 Materials.
All materials shall conform to the provisions of Division 800, Materials, specific reference is made to the following: Section 836 - Structural Steel, Fastener s and Miscellaneous Metals. Section 855 - Coatings, Paints, Enamels, and Varnishes For Metal and Wood Structures. Except where otherwise provided, all members shall be of structural carbon steel. Pipe or tubing for railing shall be as specified on the plan s. Forgings shall be of carbon steel and shall be annealed before machine finishing. Castings shall be made of the type metal specified by the plans, but in general, cast iron shall be used only for unimportant parts. High strength steel fasteners shall conform to the requirements of Article 836.33. High strength steel lock -pin and collar fasteners will not be permitted unless noted in the plan details. Materials for bridge deck drainage systems shall conform to the requirements shown on the plans. Galvaniz ing, if required, shall conform to ASTM A 120 for pipe, AASHTO M 111 for forgings, shapes, etc., AASHTO M 232 for miscellaneous hardware and anchor bolt assemblies (anchor bolts, nuts, and washers), and ASTM B 695 Class 50 for bolt assemblies (bolts, nuts, and washers).
508.03 Construction Requirements.
a.General . Attention is directed to the requirements of Sections 105 and 836 concerning approval of "drawings", "mill orders and shipment statements," and "notice and facilities for inspection" before fabrication of structure members. All exposed structural steel surfaces, including piling, not in contact with concrete shall, unless otherwise noted by the plans or proposal, be painted in accordance with the provisions of Section 521 utilizing green bridge p aint for the top coat (or other color as specified by plans). The painting of the steel and the cost thereof is considered incidental to the furnishing of the structural steel. When a structure utilizing AASHTO M 270 Grade 50W (weathering) steel is designa ted to be unpainted, the steel shall be cleaned after fabrication (includes drilling and reaming) in accordance with the provisions of Steel Structures Painting Council specification SSPC- SP-6. All foreign material which adheres to the steel after fabricat ion, including tight mill scale, shall be removed without additional compensation. Tight mill scale on the top of the top flanges of girders and beams may remain except in the locations where studs are to be attached. The surface of the steel shall be clea ned to bright metal just prior to attaching studs. All temporary markings shall be removed before the final acceptance of the structural steel.
b.Shop Fabrication . The requirements for shop fabrication are given in Section 836. Within 30 days after the award of the contract, the Contractor shall submit the following items to the Bridge Engineer:
508.03 Construction Requirements.
• Name, address and location of the plant where the structural steel will be fabricated. • A current copy of the fabricator’s American Institute of Steel Constru ction Certification including Fracture Critical Endorsement (FC) or Sophisticated Paint Endorsement (SPE) where required. • A written statement naming the ALDOT III -1 coating system that will be applied to the structural steel. • Construction survey data if this is shown to be required on the plans. The review of the shop drawings, and the time allowed for the review given in Section 105, will not begin until all of the required items have been received by the Bridge Engineer. Additional e vidence of the fabri cator's qualifications and experience shall be furnished if requested by the Bridge Engineer. No material shall be fabricated before the Department has been notified where the fabrication order has been placed. The Fabricator is responsible for notifying t he Bridge Engineer of any outsourced work to be done by another facility, the name and address of the outside source, and the proposed schedule. Shops fabricating main structural steel members (as defined by Subarticle 836.01(b)) and/or items paid for under Pay Item 508 -B (with the exception of navigational light brackets, inspection catwalks, platforms and ladders) shall be certified by the American Institute of Steel Construction. These facilities shall conform to the AISC Certification Program for Steel Bridge Fabricators for either Intermediate Bridge or Advanced Bridge depending on the complexity of the structure by design for all steel bridges. For fracture critical work, shops shall be certified for either Intermediate Bridge or Advanced Bridge with t he fracture critical endorsement. Shops fabricating expansion dams (finger joints, etc.) for interior and exterior bridge joints shall be certified by the AISC Certification Program for Bridge and Highway Metal Component Manufacturers or by the Intermediat e AISC Bridge Certification program for steel bridge fabrication. Shops producing miscellaneous steel bridge items (other than those described above) shall be qualified to do such work by placement on the ALDOT List I -9: Producers of Inlet Grates and Seats for Drainage Structures and Miscellaneous Fabricated Bridge Items. For the purpose of ALDOT Quality Assurance inspection and scheduling a completed ALDOT Bridge Bureau Form BBF -11 shall be submitted to the Bridge Engineer stating the tentative schedule fo r fabrication no less than 45 days in advance of the actual fabrication of 508B pay items and no less than 7 days for 508A pay items.
c.Storage . All material shall be stored in such manner as to prevent corrosion or loss of minor parts. It shall be plac ed on skids or dunnage a minimum of 1 foot {300 mm} above the ground. It shall be kept clean and properly drained. Girders and beams shall be placed upright and shored (no welding). Long members, such as columns and chords, shall be supported on skids plac ed near enough together to prevent injury from deflection. All storage and storage sites are subject to the approval of the Engineer. Reference is made to Articles 109.07 and 836.17.
d.Erection .
1.Working Drawings . Working drawings outlining a procedure and the equipment to be used for erection of all continuous span steel units, trusses, and other metal work requiring field splices shall be submitted for distribution in accordance with Article 105.02. If any falsework is to be used as part of the steel erection procedure, the drawings and design calculations. shall be submitted along with the erection procedure. If temporary bracing is used on any type of steel girder to stabilize the girder the details and design of the bracing shall be submitted as working drawings in accordance with the requirements given in Article 105.02. Falsework shall be designed and constructed to withstand all imposed loads during erection, construction, usage, and removal. The State Construction Engineer will verify that the l icensed Professional Engineer signature and stamp requirements of Subarticle 105.02(d) are met. Steel Girder erection drawings will be reviewed by the State Construction Engineer and will be forwarded to the Bridge Engineer for review to determine if the r esults of the licensed Professional Engineer's calculations are in compliance with design criteria. If the design criteria are met, the submittal will be returned to the State Construction Engineer to be stamped for distribution and then distributed. All falsework and temporary bracing will be inspected by the Project Manager using the distributed drawings. For all falsework used in connection with steel girder erection, the licensed
508.03 Construction Requirements.
Professional Engineer who signed the falsework submittal shall visually ve rify that the falsework as constructed meets all design criteria prior to any load being placed thereon. A signed statement from the licensed Professional Engineer covering the verification shall be furnished to the Project Manager by the Contractor.
2.Be arings and Anchorage .
a.Uniform Bearing Surface. Bridge bearings shall be set level in exact position and shall have a full and even bearing on the masonry and shall not be placed on masonry bearing areas which are irregular or improperly formed.
b.Beddi ng Material Required Under Rocker Bearings. Where rocker bearings are used, filler or fabric materials, meeting the following, shall be placed as bedding material under masonry plates. Such material shall be of the type specified or as ordered or approved by the Engineer and shall be installed to p rovide full bearing on contact areas. Immediately before placing the bedding material and installing bearings or masonry plates, the contact surfaces of the concrete and steel shall be thoroughly cleaned. Preformed fabric pads used as bedding shall be composed of multiple layers of 8 ounce per square yard {271 g/m²} cotton duck impregnated and bonded with high quality natural rubber or of equivalent and equally suitable materials compressed into resilient pads of uniform thickness. The thickness of the pref ormed fabric pads shall be 3/16 inch ± 1/16 inch {5 mm ± 2 mm}. Cotton duck shall meet the requirements of Military Specification MIL -C882- D for 8 ounce per square yard {271 g/m²} cotton army duck or equivalent. The number of plies shall be such as to produce the specified thickness, after compression and vulcanizing. The finished pads shall withstand compression loads perpendicular to the plane of the laminations of not less than 10,000 psi {69 MPa} without detrimental reduction in thickness or extrusion. Sheet lead used as bedding shall be common desilverized lead conforming to ASTM B 29. The sheets shall be of uniform thickness and shall be free from cracks, seams, slivers, scale, and other defects. Unless otherwise specified, lead sheets shall be 1/8 in ch {3 mm} in thickness with a permissible tolerance of 0.03 inch {0.75 mm} plus or minus.
c.Vertical Positioning of Rocker Bearings. Rocker bearings shall be adjusted so that they will be in vertical position at an ambient temperature of 70 ° F {20 °C}.
d.Installation of Masonry Plates. Masonry plates for self -lubricating bronze bearing plates or PTFE coated bearing plates shall be set 1/2 inch {13 mm} (minimum) into the cap in Portland cement mortar not more than 3/4 inch {19 mm} thick and the depressio n filled with mortar so that no water will be trapped. No superstructure or other load shall be placed thereon until this mortar has been allowed to set for at least 96 hours in a well moistened condition throughout this period. Prior to erecting girders, the top plate shall be rotated to fit the grade of the girder and the bearing plate shall be adjusted for temperature so that it will be centered on the masonry plate at 70 °F {20 °C}.
e.Anchor Bolt Installation. The reinforcing steel in the concrete shal l be adjusted as directed by the Engineer prior to pouring in order to permit the correct placement of the anchor bolts. If the required details of the anchor bolt installation are not given on the plans the Contractor shall have the following options for installing the bolts: - supporting the bolts with a template during the placement of concrete; - casting anchor bolt wells in the concrete; - drilling holes in the concrete after the concrete has cured. The Contractor shall notify the Engineer in writing of the option selected for the installation of the bolts. Anchor bolt wells shall be large enough to allow adjustments to the location of the bolts to fit adjustments to the superstructure unit but shall not exceed 4 inches {100 mm} in diameter unless approved otherwise by the Bridge Engineer. The form for the anchor bolt wells shall be removed before wells are filled. Water shall not be allowed to enter the wells or the drilled holes. Freezing water may crack the concrete. If anchor bolt wells are used, a 4000 psi {28 MPa}, 28 day compressive strength Portland cement grout mix, or a proprietary non -shrink grout mix shall be used to fill the wells. If anchor bolts are installed in drilled holes, a 4000 psi {28 MPa}, 28 day compressive strength Portland cemen t grout
508.03 Construction Requirements.
mix, a proprietary non -shrink grout mix or an approved epoxy adhesive shall be used to fill the wells. The grout shall not be placed until after the superstructure unit has been erected and adjusted. A description of the grout mix (Portland cement or proprietary) shall be submitted to the Materials and Tests Engineer for approval prior to installation of the anchor bolts.
f.Location of Anchor Bolts. Anchor bolts shall be located as shown on the plans and shall be set vertical to the plane of the bridge bearing seat. Anchor bolts required at expansion bearings shall be installed so that the centerline of the anchor bolt aligns with the center of the slotted hole of the expansion bearing at 70 °F (20 °C).
3.Handling Members . All members shall be car efully handled to prevent damage to them and in a manner that any camber put into them will not be changed. One pick -up point will be permitted on pieces 50 feet {15 m} or less in length. Two pick -up points, located at or between the 1/4 and 1/3 points, wi ll be required on pieces over 50 feet {15 m} in length. Calculations showing that the pieces will not be damaged, along with erection plans, will be required when pick -up points are requested to be located outside of these areas. This data shall be submitt ed in accordance with Subarticle 105.02(d). Reference is made to Article 836.17.
4.Erection Assembly. The parts shall be accurately assembled as shown on the plans and any match marks shall be strictly followed. Splices and field connections shall have at least 50% of the holes filled using bolts (either erection or untorqued permanent bolts) and an adequate number (Minimum 10%) of forged barrel or drift type erection pins for fit up and alignment. The diameter of the erection pins shall be 1/32 inch {1 mm } larger than the diameter of the bolts. Splices and connections carrying traffic during erection shall have 75% of the holes so filled. Erection bolts shall be tightened to snug tight condition. 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 impact wrench or the full effort of a person using an ordinary spud wrench. Before beginning high strength bolting, the structure shall be adjusted to correct grade and ali gnment. Bolts and nuts for bolted beam and girder splices shall be placed so that (1) flange splices have nuts on the exterior face of the splice, (2) web splices have bolt heads on the outside face of exterior beams or girders. Filler plates for bolted beam and girder splices have been based on theoretical dimensions, the thickness of the plates shall be adjusted in the shop to take care of any difference greater than 1/16 inch {1.6 mm} between the theoretical and actual dimensions. Splices in members of t he same theoretical size will require filler plates if the actual dimensions vary more than 1/16 inch {1.6 mm}.
5.Defective or Damaged Material . Any material that is damaged, distorted or in any way defective and is considered to be repairable shall be corrected by means approved by the Central Office. The Contractor shall submit a detailed proposed procedure for approval prior to making any corrections. Minor misfits involving occasional reaming of a hole will not require Central Office approval. Wholes ale reaming of holes will require Central Office approval.
6.High Strength Bolting .
a.General. High tensile strength heavy hex bolts shall be used for all field fasteners unless otherwise noted on the plans or in the proposal. The bolts, nuts, washers an d direct tension indicators shall conform to the requirements of Article 836.33. All requirements for testing of materials and for calibration of equipment shall be met prior to installation.
b.Bolted Parts. Surfaces of bolted parts in contact with the bo lt head and nut shall not have a slope of more than 1:20 with respect to a plane normal to the bolt axis. Bolted parts shall fit solidly together when assembled and shall not be separated by gaskets or any other interposed compressible material. When asse mbled, all joint surfaces, including those adjacent to the washers, shall be free of scale. They shall be free of dirt, loose scale, burrs, and other defects that would prevent solid seating of the parts. Contact surfaces within friction -type joints shall be free of oil, paint, lacquer, or galvanizing unless noted otherwise on the plans or in the proposal.
508.03 Construction Requirements.
c.Bolt Assemblies. The Contractor shall take special care in storing the bolt assemblies (bolts, nuts, washers and direct tension indicators) to prevent them from rusting. Any components of the bolt assemblies that are rusted shall be thoroughly cleaned or replaced prior to installation. Bolts that have been cleaned shall be lubricated in the field prior to installation. Plain (ungalvanized) bolts shall be "oily" to the touch when installed. Galvanized nuts shall be lubricated with a lubricant (Beeswax or equivalent) containing a visible dye so that a visual check can be made for proper lubrication prior to installation. Special care shall be taken in stor ing galvanized bolts with water soluble lubricants.
d.Installation. Galvanized nuts shall be checked to verify that a visible lubricant is on the threads. High strength fasteners, plain and galvanized, shall be subjected to jobsite rotational -capacity tests performed in accordance with Item 836.33(c)4. prior to the start of any bolt installation. Washers are required as part of the test. A Skidmore -Wilhelm Gage or equivalent, a standard torque wrench, a suitable steel joint (to conduct test on short bolts if needed) and any other miscellaneous tools or materials required for this test shall be provided by the Contractor. This test shall be performed by the Contractor and witnessed by the Engineer. Prior to beginning the tensioning operation each day, a mini mum of one rotational -capacity test shall be performed to verify that the bolt assemblies are still properly lubricated. The bolt assembly to be tested will be determined by the Engineer and may come from any that are in question, including erection bolts which have been placed, but not tensioned. If this test fails, any assemblies which have been subjected to similar conditions as the failing sample shall be either cleaned and lubricated or replaced prior to tensioning. Additional rotational -capacity tests may be required at the discretion of the Engineer. Bolts shall be installed with a hardened washer under the nut or bolt head, whichever is the element turned in tightening. If the markings on the nuts are raised then the nuts shall be installed with the markings to the outside. A flat washer may be used when the abutting surface adjacent to the bolt head or nut does not have a slope of more than 1:20 with respect to a plane normal to the bolt axis. Where an outer face of the bolted parts has a slope of mo re than 1:20 with respect to a plane normal to the bolt axis, a smooth beveled washer shall be used to compensate for lack of parallelism. Before tightening the bolts to the required minimum tension, all bolts shall first be tightened to snug tight conditi on, progressing from the most rigid part of the joint towards the free edges. See Item 508.03(d)4. for a definition of snug tight condition. At snug tight, all joining pieces shall be in firm contact. All bolts shall then be tightened to give the minimum t ension values shown in Table 1. Tightening shall be done by either the Calibrated Wrench Method, Turn -Of-Nut Method or Direct Tension Indicator Method. The element not being turned (bolt or nut) shall be held with a wrench during tightening to prevent rota tion of the fixed element.
508.03 Construction Requirements.
TABLE 1 NOMINAL BOLT DIAMETER & THREAD PITCH REQUIRED MINIMUM BOLT TENSION ASTM A 325 high strength bolts only. 1/2 inch 12,050 pounds 5/8 inch 19,200 pounds 3/4 inch 28,400 pounds 7/8 inch 39,250 pounds 1 inch 51,500 pounds 1 – 1/8 inches 56,450 pounds 1 - 1/4 inches 71,700 pounds 1 - 3/8 inches 85,450 pounds 1 - 1/2 inches 104,000 pounds ASTM A 325M high strength bolts only. M16 x 2 91.0 kN M20 x 2.5 142.1 kN M22 x 2.5 175.7 kN M24 x 3 205.1 kN M27 x 3 266.7 kN M30 x 3.5 327.2 kN M36 x 4 474.6 kN
e.Calibrated Wrench Method. The Contractor shall furnish all wrenches necessary to install the high strength bolts. He shall also furnish a calibration device (Skidmore -Wilhelm Calibrator or equivalent) and use it to calibrate the wrenches used for bolt installation and inspection. The calibration device shall be calibrated by the State Testing Laboratory or other approved laboratory prior to being used. The calibration results w ill be valid for a period of six (6) months after the date of calibration under normal conditions. The Engineer may require that the calibration device be recalibrated at any time. Wrenches shall be calibrated on the project at least once daily and for eac h lot of nuts and bolts to be used. Calibration shall be accomplished by the tightening in the calibration device of not less than 3 typical bolts of each lot to be installed. Power wrenches shall be adjusted to stall or cutout at a tension slightly greate r than the minimum required. If manual torque wrenches are used, the torque indication corresponding to the calibration tension shall be noted and used in the installation of all bolts of the tested lot. Nuts shall be in tightening motion when torque is me asured. When using calibrated wrenches to install several bolts in a single joint the wrench shall be returned to touch up bolts previously tightened, which may have been loosened by the tightening of subsequent bolts, until all are tightened to the prescr ibed amount. Impact wrenches shall be of adequate capacity and sufficiently supplied with air to perform the required tightening in approximately 10 seconds. The Contractor shall spot check the completed bolt assembly installations at the direction and under the supervision of the Engineer. The spot checking shall be done to insure that the minimum bolt tension has been achieved in all of the bolts in the completed connection. The spot checks shall be made with a manual torque wrench that has been furnished by the Contractor and calibrated as noted herein to measure the minimum required bolt tension.
f.Turn -Of-Nut Method. All bolts shall first be brought to snug tight condition as described in Item 508.03(d)4. The element being turned (bolt or nut) shall th en be turned an additional fraction of a turn as specified in Table 2. Where the exterior faces of the members to be joined are sloped from normal to the bolt axis up to a 1:20 slope and beveled washers are not specified, a minimum 3/4 turn from snug tight is required for all bolts. The Contractor shall furnish a calibration device (Skidmore -Wilhelm Calibrator or equivalent) and manual torque wrench. This equipment shall be calibrated and used to spot check the completed bolt assemblies as required under th e Calibrated Wrench Method.
508.03 Construction Requirements.
TABLE 2 NUT ROTATION FROM THE SNUG -TIGHT CONDITION a, b GEOMETRY OF OUTER FACES OF BOLTED PARTS Bolt length measured from underside of head to end of bolt. Both faces normal to bolt axis. One face normal to bolt axis and other face sloped not more than 1:20. Beveled washer not used. Both faces sloped not more than 1:20 from normal to bolt axis. Beveled washers not used. Up to and including 4 diameters 1/3 turn 1/2 turn 2/3 turn Over 4 diameters but not exceeding 8 diameters 1/2 turn 2/3 turn 5/6 turn Over 8 diameters but not exceeding 12 diameters c 2/3 turn 5/6 turn 1 turn a Nut rotation is relative to bolt, regardless of the element (nut or bolt) being turned. For bolts installed by 1/2 turn and less, the tolerance should be plus or minus 30 degrees; for bolts installed by 2/3 turn and more, the tolerance should be plus or minus 45 degrees. b Applicable only to connections in which all material within grip of the bolt is steel. c No research work has been performed by the Research Council Riveted and Bolted Structural Joints to establish the turn -of-nut procedure when bo lt lengths exceed 12 diameters. Therefore, the required rotation must be determined by actual tests in a suitable tension device simulating the actual conditions.
g.Direct Tension Indicator Method. The Contractor shall furnish direct tension indicator washers (also called load indicator washers) to be installed as a part of the final bolt assembly. He shall also furnish the gap measuring devices (feeler gages) to be used for inspection purposes. The direct tension indicator washers, noted herein as DTI washers, shall be installed by one of the following methods, however, they shall not in any case be installed in a position where the extrusions or cleats are in contact with the pieces being joined: Plain Finished Bolts: The nut is the turned el ement, the hardened washers are placed adjacent to the nuts, and the extrusions or cleats on the DTI washers are placed in contact with the bolt heads. The nut is the turned element, the hardened washers are placed adjacent to the nuts, and the extrusions or cleats on the DTI washers are placed in contact with the hardened washers. The bolt head is the turned element, the hardened washers are placed adjacent to the bolt heads, and the extrusions or cleats on the DTI washers are placed in contact with the hardened washers. Galvanized Bolts: The nut is the turned element, the hardened washers are placed adjacent to the nuts, and the extrusions or cleats on the DTI washers are placed in contact with the bolt heads. All bolts shall first be brought to snug tight condition as described in Item 508.03(d)4. The bolts shall then be tightened to compress the extrusions on the DTI washers. The DTI washers shall be compressed to the point that the gap between the DTI washer (on the extrusion side of the washer) and the adjacent element is reduced to that shown in Table 3. The maximum allowable gap (minimum allowable bolt tension) is the condition where the feeler gage can be entered to the shank of the bolt in only one half of the number of places where inserted around t he circumference of the washer. The minimum allowable gap is the condition where the feeler gage cannot be entered in one half or more of the applied places and the gap is not completely closed.
508.03 Construction Requirements.
The Contractor shall furnish a calibration device (Skidmore -Wilhelm Calibrator or equivalent) to be used at the job site to determine the acceptability of the DTI washers. This calibration device shall be calibrated as noted under the Calibrated Wrench Method. Three bolt assemblies of each diameter, length and grade shall be checked at the job site in the calibration device. These bolt assemblies shall be installed in the calibration device in the same manner as the intended installation in the structure and shall be tightened with the same equipment intended for job use. A calibration test shall be conducted by tensioning a bolt assembly to the point that the maximum allowable gap is present between the DTI washer and the adjacent element. At this point the tension reading taken from the calibration device shall not be less than five percent greater than the tension required. The Engineer will use the feeler gages to spot check the completed bolt assembly installations. The Contractor shall furnish a manual torque wrench which shall be calibrated and used to spot check the completed bolt assemblies as required under the Calibrated Wrench and Turn -Of-Nut Methods. TABLE 3 DIRECT TENSION INDICATOR METHOD Uncoated Bolts w/DTI Under Turned Element Maximum Allowable Gap = 0.005 in. {0.127 mm} Minimum Allowable Gap * Uncoated Bolts w/DTI Under Unturned Element Maximum Allowable Gap = 0.015 in. {0.381 mm} Minimum Allowable Gap * Galvanized Bolts w/DTI Under Unturned Element Maximum Allowable Gap = 0.005 in. {0.127 mm} Minimum Allowable Gap * * See fourth paragraph of this Subitem (508.03(d)6.g.) above
h.Correction of Deficiencies. All deficiencies found during calibration, installation and spot checking of the bolt assemblies shall be corrected by the Contractor.
i.Cleaning. All exposed surfaces of bolt assemblies shall be cleaned prior to painting with a cleaning solvent such as mineral spirits or turpentine. This cleaning shall not damage the existing primer coats of paint.
7.Bolted Connections. The bolt length used shall be such that the end of the bo lt is flush with but does not extend more than ¼” beyond the outer face of the nut when properly installed. In bolted connections, other than high strength steel bolts, the bolts shall be drawn up tight and the threads burred at the face of the nut with a pointed tool.
8.Welded Shear Connector Studs. In compliance with OHSA safety requirements structural steel bridges which would require welded shear connector studs shall have the studs installed on all steel girder top flanges at the project site after fo rmwork has been totally installed between all completely set and erected girder lines, thus minimizing fall hazards for workers. The required locations of the studs shall be marked at the bridge fabrication shop. The fabricator shall center punch the steel at the center of all stud locations to provide a durable marking. A highly visible indelible paint marker shall also be applied over the center punch points prior to shipment of girders to the project. The Contractor shall notify the Project Manager of th e date that installation of the studs will begin in the field. This notification shall be given a minimum of five calendar days prior to the date of installation. The Project Manager will notify the Bridge Engineer of the installation date so that the insp ection of the installation can be made by a representative of the Bridge Engineer. Studs shall not be installed until the representative of the Bridge Engineer is given the opportunity to inspect the preparation of base metal, layout and the location of th e studs including the studs and ceramic ferrules to be used in the operations. The fusion areas on the top flange to which studs are to be welded shall be cleaned to bright metal before welding. The fusion area of the studs should be clean and free of rust . Once the stud welding operations are underway one stud out of every tenth row of studs on each girder line will require bend testing to 30 ° from its original axis for assurance that the studs are being applied properly. Any
508.04 Method of Measurement.
stud that exhibits a failure w ill be replaced with a new stud after the base metal location of the failed stud is repaired by grinding to bright and sound metal. Studs shall be one of those shown in List II -4 of the ALDOT manual "MATERIALS, SOURCES, AND OTHER DEVICES WITH SPECIAL ACCEP TANCE REQUIREMENTS". Studs shall be attached in accordance with the requirements given in the AASHTO/AWS D1.5M/D1.5:2015, Bridge Welding Code, Seventh Edition.
9.Painting. Painting shall conform to requirements of Section 521.
10.Name Plates. No permanen t plates or markers other than those shown on the plans or approved will be permitted on any structure. Any marks or signs painted on structural steel by the fabricator or contractor shall be obliterated prior to applying the first field coat by cleaning a nd/or painting over the marks or signs with paint of the same type used for the shop coat.
e.Field Inspection . All work shall be subject to the inspection of the Engineer who shall be given all facilities required for all necessary inspection. Material and workmanship not previously inspected will be inspected after its delivery to the site of the work. Whether shop inspection is made or not, workmanship and materials which do not conform to the Specifications may be rejected at any time prior t o acceptance of the project.
f.Cleaning up of Worksite . Upon completion and before final acceptance, the Contractor shall remove all falsework and other temporary construction, and shall leave the site in a condition acceptable to the Engineer.
508.04 Method of Measurement.
a.Items No. 508-A, and 508-D. The theoretical poundage {mass} of accepted metal in the per pound {kilogram} price items, complete in place, will be computed in conformity with the following:
1.The weight {mass} of steel shall be assumed at 0.2833 pounds per cubic inch {7850 kg/m³}. The weight {mass} of cast iron shall be assumed at 0.26 pounds per cubic inch {7200 kg/m³}. The weight {mass} of bronze shall be assumed at 0.315 pounds per cubic inch {8150 kg/m³}.
2.The weights {masses} of rolled shapes in the completed structure, shall be calculated on the basis of their theoretical weights {masses} and dimensions given in the handbooks of the mills rolling the various sections and shapes. The weights {masses} of steel plates shall be computed on the basis of their detailed dimensions as shown on the approved shop drawings. Weights shown on the approved shop drawings shall not be used for payment purposes.
3.The weight {mass} of castings shall be calculated from the detail dim ensions shown on the approved shop drawings, with an addition of 10 percent for fillets, overrun and finishing.
4.Only the weight {mass} of materials used in the completed, permanent work will be measured for payment.
5.No allowance in weight {mass} will be made for shop or field paint.
6.For the purpose of measurement and payment, incidentals such as bearing plates, pedestals, and other minor metal parts shall, unless otherwise provided, be considered as structural steel even though made of other materi als except the bronze bearing plates and the PTFE coated bearing plates will be paid for under Item 508 -C.
7.For purposes of measurement and payment when payment is on a per pound {kilogram} basis, required welded shear connection studs will be included i n the quantity of structural steel.
b.Item No. 508-B.
1.The number of units measured will be the accepted number of structural span units complete in place.
2.Any estimated weights {masses} shown on the bidding plans or proposal are approximate only and the contract price for each item shall include full compensation for the specified structural unit, complete in accordance with the plans and specifications, regardless of the final weight {mass} required and no claim will be allowed for any increase over the estimated weight {mass} of a structural unit unless same is caused by a change in plans or specifications. The cost of any additional work caused by a change in plans or specifications will be paid for as Extra Work.
508.05 Basis of Payment.
c.Item No. 508-C. Unless otherw ise specified on the plans, the Contractor will have the option of furnishing either self-lubricating bronze bearing plates or PTFE coated bearing plates. The bearing plates furnished will be measured in sets complete in place. A set shall include all the bearing plates required for each structure. Steel plates used in the bronze plate assembly or any other steel plates used in the PTFE plate assembly will be measured as Item 508 -A, 508- B or 508- D, whichever is applicable.
d.Item No. 508-E. Inspection lad ders, when specified for separate payment, shall consist of all ladders required in accordance with plan details for the locations designated measured as one unit. When no separate payment is designated, the cost of such shall be included in the unit price bid for the Item of Structural Steel provided in the contract.
e.Item No. 508-F. When separate payment is designated for a bridge deck drainage system, the complete system required to drain each separate structure in accordance with plan details will be measured as one unit per bridge structure. When no separate payment is designated for a bridge deck drainage system, the cost of such will be considered incidental to the work and absorbed in the unit prices bid for other items of work.
508.05 Basis of Pa yment.
a.Items No. 508-A and 508-D. The accepted theoretical poundage {mass} of metal in the per pound {kilogram} price items, computed as prescribed, will be paid for at the contract unit price bid for structural steel complete in place, which will be payment in full for fabricating, furnishing, transporting, erecting, and painting (field painting not included in Item No. 508 -D) all material, and for all labor, equipment, tools, falsework, cleaning up and incidentals necessary to complete the work. Unless noted otherwise on the plans, these items shall include the following: • bridge joint armor plates (both sides of the joint) • pile cap channels and plates • connection angles (clip angles) used with prestressed concrete girders • swedged anchor bolts, nuts and washers • smooth and swedged dowels • pipe sleeves
b.Item No. 508-B. Accepted metal superstructure span units will be paid for at the contract unit price bid for each respective unit, complete in place, which shall be payment in full for furnishing, fab ricating, transporting, erecting and painting all materials and for all labor, equipment, tools, falsework, cleaning up and incidentals necessary to complete the work. Unless noted otherwise on the plans, this item shall include the following: • All structur al steel in the superstructure unit • Structural steel in the bearing devices, except the PTFE coated bearing plates • Expansion dams (finger joints , etc.) for interior and exterior open bridge joints Where separate pay items are not provided, this item shall also include furnishing, fabrication, painting or galvanization, transporting and installing ladders, platforms, catwalks, and navigational lighting brackets. Joint armor plates, channels, angles, anchor bolts, etc. for sealed interior and exterior bridge joint design shall be as specified in Section 522 and are not as a part of this item. This item does not include reinforcing steel and concrete. Structural steel bearing plates for Type 3, 4 and 5 elastomeric bearings shall be included in the payment fo r elastomeric bearings under Pay Item 511 -A and are not a part of this item.
c.Item No. 508-C. Payment for bearing plates furnished, complete and installed as shown on the plans, will be made at the contract unit price per set which shall be compensation in full for furnishing and installation and for all tools, labor and incidentals necessary to complete the item.
508.05 Basis of Payment.
d.Item No. 508-E. Accepted ladders, measured as noted above, will be paid for at the contract lump sum price bid for this item. Said lu mp sum price bid shall be full compensation for all ladders designated complete in place and including all cost for furnishing, fabricating, painting, galvanizing, erection and installing the ladders, and for all materials, tools, equipment, labor and inci dentals necessary to complete the work.
e.Item No. 508-F. Accepted bridge deck drain systems, measured as noted above, will be paid for at the contract lump sum price bid for each system, complete in place. Said lump sum price bid shall be payment in full for furnishing and installing of all materials, fabrication of materials, erection of materials, paint (if required) and for all tools, equipment, labor and incidentals necessary to complete the work.
f.Partial Payment .
1.Partial Payment for Steel Pla tes and Shapes prior to Fabrication. Partial payment may be made for steel plates and shapes prior to fabrication. The requirements given in Article 109.07 shall be applicable to these partial payments except as amended or supplemented by the following: • a written request for partial payment shall be submitted by the Contractor that shall include the number of pounds {kilograms} of steel for which payment is requested and the dollar amounts and percentages of partial payment for each contract pay item affe cted by the request; • the request for partial payment shall include the dimensions, heat numbers, purchase order numbers, and inventory markings for all plates and shapes; • only one request per fabricator for partial payment for steel plates and shapes fo r fabrication will be considered prior to fabrication; • the written request must be approved by the Construction Engineer and Bridge Engineer before further consideration will be given to making partial payment; • all of the plates and shapes required for fabrication on the project shall be available for inventory prior to the beginning of fabrication and shall be clearly marked with an inventory identification; • plates and shapes shall be stored in a manner that will allow the easy identification of each plate and shape; • the Contractor shall make arrangements with the Engineer for the inventory to be made by the ALDOT Bridge Bureau's Structural Steel Inspection personnel;
2.Partial Payment after Fabrication . Partial payment will be allowed after the completion of fabrication in accordance with the requirements given in Article 109.07.
3.Partial Payment after Installation. After the structural steel is installed, all connections are complete, all splice plates and bolts have been cleaned and painted, and the en tire shop coating has been acceptably applied and cured, 95 % of the payment may be made for the structural steel.
4.Final Payment. After the completion of installation, the acceptable application and curing of the field coating, and the cleaning of the s uperstructure, 100 % of the payment may be made. If weathering steel is installed and painting is not required, 100 % of the payment may be made after the superstructure concrete is placed and the superstructure has been cleaned.
g.Payment will be made u nder Item No .: 508-A Structural Steel - per pound {kilogram} 508-B Structural Steel Superstructure, * , ** , *** (SPECIALTY ITEM) - per each 508-C Bearing Plates **** - per set 508-D Structural Steel (Except Field Painting) - per pound {kil ogram} 508-E Furnishing, Fabrication & Installation of Ladders - per lump sum 508-F Bridge Deck Drainage System - per lump sum
509.01 Description.
* Length of Continuous/Simple Span ** Lane, if applicable *** Approximate weight {mass} of structural steel **** If a specific type of bearing plate is required, so designate (Bronze or PTFE) Example: 508 -B Structural Steel Superstructure, 100'- 100'-100' Continuous Span, Left Lane, Approx. 373,100 pounds (SPECIALTY ITEM) SECTION 509 TIMBER
509.01 Description.
This Section shall cover the work of furnishing, preparing, and erection of timber or lumber of the stress values, grade, size, and dimensions designated by the plans or proposal. The timber may be treated or untreated as specified by the plans and may require painting if so specified. It shall also include all structural steel, iron, casting, other metal parts, and all hardware required by the Specifications and plans. The type of preservative used shall be th e type called for in the plans and/or proposal form. Where more than one type of preservative is included in the contract, each type shall be used as indicated by the plans.
509.02 Materials.
All materials shall conform to the appropriate provisions of Div ision 800, Materials. Specific reference is made to Section 833, Lumber and Timber, Untreated and Treated
509.03 Construction Requirements.
a.Handling and Storage . Timber and lumber shall be carefully handled without dropping, breaking of outer fibers, b ruising, or penetrating the outer surface with tools. Tongs, cant hooks, peavys, hooks, pike poles, or other equipment likely to break the surface shall not be used.
b.Workmanship . Only competent carpenters shall be employed and all framing shall be true and exact. Nails and spikes shall be driven with just sufficient force to set the heads flush with the surface of the wood. Deep hammer marks in wood surfaces shall be considered evidence of poor workmanship and sufficient cause for the removal of workmen causing them. Any metal work required in conjunction with timber construction shall conform to the requirements of Section 508.
c.Holes for Bolts, Dowels, Rods, and Lag Screws . Holes for round drift bolts and dowels shall be bored with a bit 1/16 inch { 1.6 mm} less in diameter than the bolt or dowel to be used. The diameter of holes for square drift bolts or dowels shall be equal to the least dimension of the bolt or dowel. Holes for machine bolts shall be bored with a bit of the same diameter as the bol t. Holes for rods shall be bored with a bit 1/16 inch {1.6 mm} greater in diameter than the rod. Holes for lag screws shall be bored with a bit 1/16 inch {1.6 mm} less in diameter than the nominal diameter and for a depth not greater than 1/2 the length of the lag screws being used. Countersinking shall be done wherever smooth faces are required. Recesses formed for countersinking shall be painted with hot creosote oil, and after the bolt or screw is in place, shall be filled with an asphalt base roofing pa tch.
d.Bolts and Washers for Timber Construction . One washer of the size and type specified shall be used under all bolt heads and nuts which would otherwise come in contact with wood. Cast iron washers shall have a thickness equal to the diameter of the bolt, and a diameter of four times the thickness. For malleable or plate washers, the diameter or side size of the square shall be equal to four times the diameter of the bolt, and the thickness of the washers shall be equal to one -half the diameter of th e bolt. Cast iron washers shall be used when the timber is in contact with the earth . All bolts shall be checked after the nuts have been finally tightened. Bolts shall be of such length that not more than 1 inch {25 mm} will protrude beyond the nut when finally tightened.
Source: Alabama Standard Specifications for Highway Construction, 2022 Edition. Pages 350–360 of 934.