5-137 Pay Item P a y U n i t
522.06 Modular Expansion Devices Each
SECTION 523 - BEARINGS
523.01 Description This work shall consist of designing, furni shing, testing and
installing bearings in accordance with this specification and i n conformance with the details shown on the Plans.
523.02 Materials
E l a s t o m e r 711.11 S t a i n l e s s S t e e l 711.12 P o l y t e t r a f l u o r o e t h y l e n e ( P T F E ) 711.13 S t r u c t u r a l S t e e l 713.01 P r e f o r m e d P a d s 713.03 Bronze or Copper-Alloy Bearing and Expansion Plates 713.04 A n c h o r R o d s 720.07 Miscellaneous materials, caulking or lubricant shall be as reco mmended by the manufacturer of the bearings.
523.03 Submittals The Contractor shall prepare shop detail, er ection and other
necessary Working Drawings in accordance with Section 105.7, Wo rking Drawings. The drawings will be reviewed in accordance with the applicable req uirements of Section 105.7. Changes and revisions to the reviewed Working Drawings shall re quire further review by the Fabrication Engineer.
523.04 General Requirements Requirements for the type of beari ng furnished are as
follows: S t e e l B e a r i n g s S e c t i o n s 523.10 thru 523.19 E l a s t o m e r i c B e a r i n g s S e c t i o n s 523.20 thru 523.29 P o t o r D i s c B e a r i n g s S e c t i o n s 523.30 thru 523.39 S p h e r i c a l B e a r i n g s S e c t i o n s 523.40 thru 523.49 Design of bearings shall be in accordance with AASHTO LRFD Brid ge Design Specifications and AASHTO/NSBA S teel Bridge Collaboration G9.1 Steel Bridge Bearing and Design Guidelines.
523.05 Fabrication Steel fabrication work, for all types of be arings, shall comply with
Section 504, Structural Steel. 5-138 523.051 Protective Coating Steel parts of bearings shall have protective coating applied to the areas described within this section in accordance with S ection 506, Shop Applied Protective Coating- Steel. Masonry plates shall, at the Contractor’s option, be galvanized or metalized. The masonry plates shall be top coate d to match the coating of the superstructure beams when beams are coated. Portions of bearings between the masonry plate and sole plate t hat will be exposed after installation shall, at the Contractor’s option, be galvanized o r metalized. Steel between the masonry and sole plates shall be top coated to match the color of the superstructure beams when the adjacent superstructure beams are coated. Stainless st eel and /or machined surfaces with a roughness height of 125 micro-inches or smoother shall n ot be coated. Machined surface finishes with a roughness height of 125 micro-inches or smoother, except stainless steel, shall be lubricated wit h a non-corrosive, waterproof, hi gh pressure lubricant having a temperature range of -30 oF to 150 oF, National Lubrication and Grease Institute number not lower than 2 and an OK load of not less than 20 lbs., as measur ed by the requirements of ASTM D2509. Metal surfaces designed for sliding in contact with Teflon (PTFE) coated surfaces shall not be lubricated. Sole plates shall have the same finish as the adjacent structur al steel. When adjacent structural steel is coated, the sole plate shall be galvanized/ or metalized, at the option of the contractor. Sole plates shall be top coated to match the color of the superstructure beams. When the adjacent structural steel is bare and uncoated, the so le plate shall be bare and uncoated. When the adjacent beams are concrete, the sole plates shall be galvanized. Areas to be field welded shall not be c oated prior to welding; they s hall be touched up after welding. Anchor rods shall be galvanized. When anchor rods are designate d to secure bare unpainted steel, a dielectric coating (epoxy or bituminous type coatings are acceptable) shall be applied to the anchor rod and/or adjacent steel to prevent c ontact between galvanized surfaces and bare unpainted steel. When bearings, or portions o f bearings, are painted to match adjacent structural steel, the anchor rods shall also be painted.
523.06 Fabrication Tolerances Fabrication tolerances for all b earings shall comply with
Section 18.1 of AASHTO, LRFD Bri dge Construction Specifications (Table 18.1.4.2-1) unless otherwise noted on the Plans or in this Section 523, Bea rings. 523.061 Material Friction Test The coefficient of friction (‘c of’) between the two mating surfaces shall be measured. Tests shall be made either o n samples taken from the same batch of materials as those used in the prototype bearings or the tests may, at the manufacturer’s option, be conducted on finished bearings. Only new materials shall be used; material that has been previously tested shall not be used. The surfaces shall be thoroughly cleaned with a degreasing solv ent. No lubrication, other than that specified for t he prototype bearings, shall be used. The mating surfaces for