8−165827.05 BASIS OF PAYMENT. The accepted quantity of "Thermal Sprayed Zinc Coating" will be paid for at the contract unit price per square feet as listed in the Proposal. The price so-stated constitutes full and complete compensation for all labor, materials, equipment, tools, technical supervision, and all incidentals required to finish the work, complete and accepted by the Engineer. BRIDGE BEARINGS 828.01 DESCRIPTION. This work consists of furnishing and installing bridge bearings. Bearing types specified in this provision include elastomeric pads, pot and disc bearings and sliding bearings. Other types of bridge bearings, if required, will be specified in the Special Provisions. Included as components of bridge bearings are masonry, sole and shim plates, anchor bolts, elastomeric elements, TFE (teflon) sheets or surfacing, lubricants and adhesives. Bridge bearings shall be fabricated and installed in accordance with the details indicated on the Plans, or as directed by the Engineer, all in accordance with these Specifications. 828.01.1 Elastomeric Pad Bearings. Elastomeric bearings shall include unreinforced pads (consisting only of elastomer) and bearings reinforced with steel or fabric laminates. 828.01.2 Pot and Disc Bearings. Pot and disc bearings provide both rotation in all directions and sliding in those specific directions indicated on the Plans. Rotation is provided by an elastomeric element and sliding is provided by a sheet of polytetrafluoroethylene (TFE). Manufacturers of pot and disc bearings are included in the Department's Approved Materials List. The pot and disc bearings detailed on the Plans are of a conceptual nature only. Minimum bearing capacities are indicated on the tables on the Plans. Bearings fabricated by manufacturers listed in the Department's Approved Materials List or other qualified manufacturers will be accepted. The overall width and/or length of pot and disc bearings must fit within the limits of the concrete beam seats. The overall height of the bearings must be known before the precise beam seat elevation can be determined. Therefore, basic details of the bearings shall be submitted to the Engineer within sixty days after Contract award, all in accordance with the provisions of Subsection 105.02; Plans and Shop Drawings, of these Specifications.
828.01.3 Sliding Bearings. Sliding bearings consist of the following types.
a.Expansion Bearings. Type A bearings prevent transverse movement, and Type B bearings allow transverse movement.
b.Fixed Bearings . Type C bearings prevent transverse movement, and Type D bearings allow transverse movement. 8−166 828.02 MATERIALS.
828.02.1 Elastomeric Bearings.
a.Elastomer. The raw elastomer shall be virgin neoprene (polychloroprene). The elastomer compound shall be classified as being of low temperature grade 0, 2, 3, 4, or 5 as defined by the testing requirements in Table 18.2.3.1A in Section 18 of the AASHTO Standard Specifications for Highway Bridges (Fifteenth Edition).
b.Steel Laminates. Steel laminates used for reinforcement shall be fabricated from rolled mild steel conforming to the requirements of ASTM A36 or A570 unless otherwise specified by the Engineer. The steel laminates shall have a minimum nominal thickness of 16 gauges. Holes in plates for manufacturing purposes will not be permitted unless they have been accounted for in design, and indicated as such on the Plans.
c.Fabric Reinforcement . Fabric reinforcement shall be woven from 100 percent glass fibers of "E" type yarn with continuous fibers. T he minimum thread-count in either direction shall be 25 threads per inch. The fabric shall have either a crowfoot or an 8 Hardness Satin weave. Each ply of fabric shall have a minimum breaking strength of 800 lb/in. of width in each thread direction. Holes in the fabric will not be permitted.
d.Bond. The vulcanized bond between fabric and reinforcement shall have a minimum peel strength of 30 lb/in. Steel laminated bearings shall develop a minimum peel strength of 40 lb/in. Peel strength tests shall be performed by ASTM D429 Method B. 828.02.2 Pot and Disc Bearings. All materials used in the manufacture of pot and disc bearings shall be new and unused. No reclaimed materials shall be incorporated in the finished bearings. All pot and disc bearings required for the Contract shall be fabricated by a single manufacturer. Materials, including the elastomeric rotational element, sealant, sealing rings, steel, stainless steel, and TFE sheet shall conform to the requirements of Subsection 18.3.3 of the AASHTO Standard Specifications for Highway Bridges (Fifteenth Edition). 828.02.3 Sliding Bearings.
a.Carbon Steel. Sole, pivot and masonry plates shall conform to the requirements of AASHTO M270, Grade 36.
b.Stainless Steel. Stainless steel shall conform to the requirements of ASTM A240, Type 304 or ASTM A167, Type 304.
c.Polytetrafluoroethylene (TFE). TFE resin shall be virgin material (not reprocessed) conforming to the requirements of ASTM D1457. Specific gravity shall be between 2.13 and 2.19. The melting point shall be 623 OF ±2O.
d.Bedding of Masonry Plates.
1.Preformed Fabric Pads used as bedding shall be composed of multiple layers of 8- ounce cotton duck impregnated and bonded with high quality natural rubber or of equivalent and 8−167equally suitable materials compressed into resilient pads of uniform thickness. 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 pounds per square inch without detrimental reduction in thickness or extrusion.
2.Sheet Lead used as bedding shall be common desilverized lead conforming to ASTM B29. 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-inch in thickness with a permissible tolerance of ±0.03-inch.
e.Anchor bolts, including nuts and washers, shall be galvanized and shall conform to the applicable requirements of Subsection M.05.04.4 of these Specifications.
828.03 Construction Methods.
828.03.1 Elastomeric Bearings.
a.Fabrication. Bearings with steel laminates shall be cast as a unit in a mold and shall be bonded and vulcanized under heat and pressure. The mold finish shall conform to standard shop practice. The internal steel laminates shall be sandblasted and cleaned of all surface coatings, rust, mill scale, and dirt before bonding, and shall be free of sharp edges and burrs. External load plates (sole plates) shall be protected from rusting by the manufacturer, and preferably shall be hot bonded to the bearing during vulcanization. Bearings that are designed to act as a single unit with a given shape factor must be manufactured as a single unit. Plain pads may be molded, extruded, or vulcanized in large sheets and cut to size. Cutting shall not heat the material, and shall produce a smooth finish.
b.Fabrication Tolerances. Plain pads and laminated bearings shall be fabricated to the dimensions indicated on the Plans within the tolerances set forth in the table of Subsection 18.2.5 of the AASHTO Standard Specifications for Highway Bridges (Fifteenth Edition).
c.Compression Tests. Bearing pads will be selected at random at the project site for testing. Two samples of complete pads will be tested. Testing shall be performed by the Engineer and conducted in accordance with Subsection 18.2.7.6; Short-Duration Compression Tests on Bearings, of the AASHTO Standard Specifications for Highway Bridges (Fifteenth Edition). The Contractor shall furnish additional complete pads to replace those taken for testing. Sample pads used for testing shall be provided by the Contractor at no additional cost to the State. Pads will be available for testing at least three weeks in advance of installation.
d.Installation. Bearing pads are to be cemented to the beam seats on abutments and pier caps with a two-part epoxy glue which is compatible with the materials of the bearing pad and the concrete and which is recommended by the manufacturer for the intended use. The bearing seat is to be finished straight and true with the plane of contact as detailed on the Plans. The concrete surface of the beam seat is to be thoroughly cleaned of all laitance and construction residue prior to attaching the pads. Pads shall be cemented to the beam seats prior to the application of concrete protective coating to bent caps. The Contractor shall follow the manufacturer's recommendations for treatment of neoprene surfaces before applying adhesive. Pads are not to be cemented to the 8−168 girders. The Contractor shall exercise care to ensure that the pads are not deformed during the setting of the girders in their final position. If bearing pads are so-deformed during the setting operation, the girders shall be lift ed, thereby allowing the pads to resume their proper configuration, and then carefully reset. When further adjustment of elastomeric type bearing pads is necessary to accommodate for variations in ambient temperature at the time of erection, the Contractor shall make those adjustments in accordance with the alignment scheme provided on the Plans. The method of adjusting the alignment shall be proposed by the Contractor and approved by the Engineer. 828.03.2 Pot and Disc Bearings.
a.Fabrication. The Contractor shall provide the Engineer with written notification thirty days prior to the start of bearing fabrication. The finish of the mold used to produce the elastomeric rotational element for pot bearings and elastomeric disc for disc bearings shall conform to the practice in modern machine shops. After fabrication, steel surfaces exposed to the atmosphere, except stainless steel surfaces, shall be shop painted or coated to protect against corrosion in accordance with the Plans or Specifications. Prior to coating, the exposed steel surfaces shall be cleaned in accordance with the recommendations of the coating's manufacturer. Me tal surfaces to be field welded shall be given a coat of clear lacquer or other protective coating approved by the Engineer, if the time of exposure before welding takes place is to exceed three months. The lacquer coating shall be removed at the time of welding. The final painti ng or coating of these surfaces shall be done after the completion of welding. Stainless steel sheet shall be attached to its steel substrate with an approved epoxy to insure complete contact, and then sealed with a continuous seal weld. For pot bearings, the steel piston and the steel pot shall each be machined from a solid piece of steel. The steel base pot of all bearings shall be either integrally machined, recessed into, or continuously welded to its bottom steel masonry plate. The outside diameter of the piston shall be no more than 0.030-inch less than the inside diameter of the pot at the interface level of the piston and elastomeric rotational element. The sides of the pistons shall be beveled to facilitate rotation. All welding shall conform to, and all welders shall be qualified in accordance with the requirements of the ANSI/AASHTO/AWS D1.5 Bridge Welding Code. Except as noted, all bearing surfaces of steel pl ates shall be finished or machined flat within 0.010-inch per foot. Out-of-flatness greater than 0.010-inch per foot on any plate shall be cause for rejection. The bottom surfaces of lower bearing plates (masonry plates) designed to rest on bearing pads shall not exceed an out-of-flatness value of 0.0625 inch per foot. Oxygen cut surfaces shall not exceed a surface roughness value of 1,000 micro-inches, as defined by ANSI B-46.1. Every bearing shall have the Project Identification Number, Lot Number, and individual bearing number indelibly marked with ink on a side that will be visible after erection.
b.Testing and Acceptance. The manufacturer shall select, at random, sample bearings from completed lots of bearings for testing by the manufacturer. The manufacturer shall complete 8−169the required testing and determine compliance with this Specification before submitting the lots(s) for quality assurance inspection, testing, and acceptance consideration. The results of the manufacturer's tests shall be furnished to the Engineer.
c.Installation. The Contractor shall certify to the Engineer that a skilled representative of the bearing manufacturer will be ava ilable to the Contractor to provide advice and instruction during the installation of bearings. The manufacturer's representative shall be present during the initial installation of the bearings. The representative shall remain on the job until, in the opinion of the Engineer, the bearing installation is proceeding smoothly and the wo rkmen are familiar with the work required for each installation. The Contractor shall also arrange to have the representative present at such other times as the Engineer may request. The bearing shall be placed at the predetermined locations at the time of structural steel erection. All temporary restraints shall be removed as directed by the bearing manufacturer. The expansion bearings shall be adjusted from the normal position to allow for the ambient temperature at the time of erection in accordance with the alignment scheme as indicated on the Plans. After all adjustments and at the approval of the Engineer, the bearing sole plate shall be welded to the bottom flange.
828.03.3 Sliding Bearings.
a.Fabrication. Fabrication of sliding bearings shall conform to the details indicated on the Plans. Fabrication shall be performed in a workmanlike manner in conformance with the practice in modern commercial shops. Burrs, rough or sharp edges and other flaws shall be removed. Horizontally installed TFE sheet shall be bonded to and recessed into its steel substrate. TFE sheet shall have a minimum thickness of 1/8- inch and shall be recessed for at least one-half of its thickness into its steel substrate. Stainless steel matting surfaces shall have a surface finish less than 20 micro-inches (rms) and shall be polished as necessary to meet the friction requirements indicated on the Plans.
b.Testing and Acceptance. The manufacturer shall furnish facilities for testing and perform testing and inspection of the completed bearings or representative samples of bearings with TFE surfaces in its plant or at an independent test facility. Inspectors, if appointed, shall be allowed free access to the necessary parts of the manufacturer's plant and test facility. When testing is performed by the manufacturer, copies of the test results shall be submitted to the Engineer.
c.Installation. Sliding bearings shall be installed in accordance with the alignment scheme as indicated on the Plans. The setting of sliding bearings shall take into account any variation from mean temperature of the supported span at the time of setting. Care shall be exercised such that full and free movement of the superstructure at movable bearings is not restricted by improper settings or adjustment of the bearings.
828.04 METHOD OF MEASUREMENT. "Elastomeric Bearings," both plain and reinforced, "Pot
8−170 Bearings," "Disc Bearings," and "Sliding Bearings " will be measured by the number of each type of bearing actually installed in accordance with the Plans and/or as directed by the Engineer.
828.05 BASIS OF PAYMENT. The accepted quantities of "Elastomeric Bearings," both plain and
reinforced, "Pot Bearings," "Disc Bearings," and "Sliding Bearings" will be paid for at their respective contract unit prices per each such bearing as listed in the Proposal. The prices so-stated constitute full and complete compensation for all labor, materials, and equipment, including testing, services of the manufacturer's representative, when required, bedding pads, anchor bolts, and all incidentals required to finish the work, complete and accepted by the Engineer. SECTION 829 BRIDGE SCUPPER PIPING
829.01 DESCRIPTION. This work consists of providing polyvinyl chloride scupper piping on
bridges at the locations indicated on the Plans, or as directed by the Engineer, all in accordance with these Specifications. 829.02 MATERIALS. 829.02.1 Polyvinyl Chloride Scupper Piping.
a.Pipe shall conform to the requirements of ASTM D 1785; PVC 1120; Schedule 80. Solvent cement fittings shall conform to the requirements of ASTM D 2467; Schedule 80.
b.Hardware. Straps, angles, etc, shall conform to the requirements of SECTION M.05; METALS , and shall be galvanized in accordance with AASHTO M111.
c.Manufacturer's Certification. The Contractor shall furnish the manufacturer's certification that the materials provided meet specification requirements. 829.03 CONSTRUCTION METHODS. 829.03.1 Polyvinyl Chloride Scupper Piping.
a.Field Measurements. The Contractor shall make all appropriate field measurements and evaluate special conditions for installation prior to the preparation of shop drawings.
b.Shop Drawings. The Contractor shall submit shop drawings of the pipe assembly in accordance with Subsection 105.02 of these Specifications.
c.Handling. Special care shall be taken during handling and storage to avoid damage to
Source: Rhode Island Standard Specifications (Bluebook), 2024 Edition. Pages 499–504 of 826.