Art. 1083.02 Elastomeric Bearings manufacturer shall be listed as compliant through the NTPEP program. The Department will maintain a qualified producer list. Shop drawings of the bearing assemblies shall be submitted to the Engineer. The bearing assemblies shall be furnished as a complete unit from one manufacturing source. The bearing manufacturer shall furnish to the Engineer of Concrete, Soils and Metals at the Bureau of Materials (126 East Ash Springfield, IL 62704) a purchase order for each contract. The purchase order shall contain, as a minimum, the quantity and size of each type of bearing to be furnished.
1083.02 Materials. Materials shall be according to the following.
a.Properties of the Elastomer. The elastomer compound used in the construction of the bearings shall contain only virgin crystallization resistant polychloroprene (neoprene) or virgin natural polyisoprene (natural rubber) as the raw polymer. All materials shall be new with no reclaimed material incorporated in the finished bearing. The elastomer compounds shall be classified as being of low-temperature, Grade 3, as specified by the minimum grade requirements of Table 14.7.5.2-1, “Low Temperature Zones and Minimum Grade of Elastomer”, of the AASHTO LRFD Bridge Design Specification. Low temperature zones used in this table are as defined in Figure 14.7.5.2-1, “Temperature Zones”, of the same publication. The cured elastomer shall be according to the following requirements. The properties of the cured elastomeric compound material shall be determined using samples taken from actual bearings. Material 1/ 2/ Property ASTM Standard Test Requirements Polyisoprene (Natural Rubber) Polychloroprene (Neoprene) Physical Properties D 2240 Hardness 55 ± 5 Shore “A” points 55 ± 5 Shore “A” points D 412 Min. Tensile Strength 2250 psi (15,500 kPa) 2250 psi (15,500 kPa) Min. Ultimate Elongation 400% 400% Heat Resistance D 573 at Specified Temp. Specified Temp. of Test 158 °F (70 °C) 212 °F (100 °C) Aging Time 168 hours 70 hours Max. Change in Durometer Hardness +10 Shore “A” points +15 Shore “A” points Max. Change in Tensile Strength -25% -15% Max. Change in Ultimate Elongation -25% -40% Adhesion 3/ to Steel ITP 603 Bond Strength (Peel Test) 40 lb/in. (7 N/mm) 40 lb/in. (7 N/mm) D 429, B Adhesion Failure R-80% R-80% 1/ All material tests shall be conducted at 73 ± 4 °F (23 ± 2 °C) unless otherwise noted. Elastomeric Bearings Art. 1083.02 2/ For the purpose of determining conformance with this specification, an observed or calculated value shall be rounded off to the nearest 10 psi (100 kPa) for tensile strength, to the nearest ten percent of elongation, and to the nearest one percent for change in aged tensile and aged elongation. Hardness and aged hardness shall be rounded off to nearest point according to ASTM E 29. 3/ The adhesion failure requirement is waived if bond strength equals or exceeds 80 lb/in. (14 N/mm).
b.PTFE Material. The PTFE resin shall be 100 percent virgin material, premium grade, meeting the requirements of ASTM D 4894 or D 4895. The PTFE sheet (polytetrafluoroethylene sheet, premium grade) shall consist of pure PTFE resin, compression molded and skived into sheets of the required thickness. The finished sheet shall be according to the following. ASTM Standard Physical Properties D 638 (D 638M) Tensile Strength 2800 psi min. (19,300 kPa) min. D 638 (D 638M) Elongation 200 % min. D 792 Specific Gravity 2.15 - 2.20 D 2240 Hardness, Durometer D 50 - 65 - - - Deformation Under Load 73 °F/100 psi/24 hrs (23 °C/690 kPa/24 hrs) 122 °F/1200 psi/24 hrs (50 °C/8,300 kPa/24 hrs) 73 °F/2000 psi/24 hrs (23 °C/13,800 kPa/24 hrs) 2 - 3 % 4 - 8 % 15 % max. D 570 Water Absorption 0.01 % max. - - - Static Coefficient of Friction at 500 psi (3450 kPa) bearing pressure on stainless steel 0.07 max. D 429, B Adhesion to Steel Peel Strength 25 lb/in. (4.4 N/mm)
c.Stainless Steel Sheets. The stainless steel sheets shall be of the thickness specified and shall be according to ASTM A 240 (A 240M), Type 304. The sliding surface shall have a Type 2B finish or smoother as per the American Society of Metals.
d.Structural Steel. Structural steel components shall be according to the following.
1.Structural Steel Bearing Plates. The structural steel bearing plates shall be according to the requirements of AASHTO M 270 Grade 36 (M 270M Grade 250).
2.Internal Steel Laminates. The internal steel laminates for the laminated elastomeric bearings shall be rolled mild steel sheets according to AISI 1015 - 1025 inclusive, ASTM A 1008 (A 1008M), or ASTM A 1011 (A 1011M) for less than 3/16 in. (5 mm) thick sheets; or AASHTO M 270, Grade 36 (M 270M, Grade 250) or ASTM A 283 (A 283M) Grade D for 3/16 in. (5 mm) and thicker sheets. Art. 1083.03 Elastomeric Bearings
3.Shear Restrictor Pin. The shear restrictor pin, when required, shall be press fit into the bearing plate and shall be alloy steel, quenched, and tempered to a minimum yield strength of 210,000 psi (1,450,000 kPa) or RC hardness of 50 to 55.
4.Threaded Stud. The threaded stud, nuts, and washers, when required, shall be according to the requirements of ASTM A 449 or A 193-B7 and shall be galvanized according to Article 1006.08.
1083.03 Fabrication Requirements. Bearings with steel laminates shall be
cast as a unit in a mold and bonded and vulcanized under heat and pressure. The molds shall have standard shop practice mold finish. The internal steel laminates shall be blast cleaned to a condition matching that of SSPC-Vis 1-01, Pictorial Standard SP6, and additionally cleaned of any oil or grease before bonding. External load plates shall be protected from rusting by the manufacturer, and shall be hot bonded to the bearing during vulcanization. The bond of steel components to and within the elastomeric pads shall be continuous throughout the plan area with no voids or air spaces greater than 0.10 in. (2.5 mm) within the bonding material. Bearings with steel laminates which are designed to act as a single unit with a given shape factor must be manufactured as a single unit. Corners and edges may be rounded with a radius at the corners not exceeding 3/8 in. (10 mm) and a radius at the edges not exceeding 1/4 in. (6 mm). Bonding of PTFE sheets shall be done as noted on the plans. No rubber flash will be permitted on the edges of PTFE bearing surfaces. All burrs or raised edges along the perimeter of the PTFE surface shall be removed before shipment. All dimension tolerances shall be according to the following. Dimensions Tolerances Overall vertical dimensions: Design thickness - 1 1/4 in. (32 mm) or less Design thickness - over 1 1/4 in. (32 mm) - 0, + 1/8 in. (- 0, + 3 mm) - 0, + 1/4 in. (- 0, + 6 mm) Overall horizontal dimensions: For measurements 36 in. (914 mm) and less For measurements over 36 in. (914 mm) - 0, + 1/4 in. (- 0, + 6 mm) - 0, + 1/2 in. (- 0, + 13 mm) Thickness of individual layers of elastomer at any point within the bearing: ± 20 % of design value but no more than ± 1/8 in. (3 mm) Variation from a plane parallel to the theoretical surface: (as determined by measurements at the edge of the bearings) Top Sides Slope relative to the bottom of no more than 0.005 radians. 1/4 in. (6 mm) Position of exposed connection members: ± 1/8 in. (± 3 mm) Edge cover of embedded steel laminates, restraining devices, holes, and slots: + 1/8 in. (+ 3 mm) min. + 1/4 in. (+ 6 mm) max. Size of holes, slots, or inserts: ± 1/8 in. (± 3 mm) Position of holes, slots, or inserts: ± 1/8 in. (± 3 mm) Elastomeric Bearings Art. 1083.03 Structural steel bearing plates shall be fabricated according to Article 505.04. Prior to shipment of the bearing assemblies, the exposed edges and other exposed portions of the structural steel bearing plates shall be cleaned and painted according to Articles 506.07 and 506.09. Painting shall be with the inorganic zinc-rich primer according to Article 1008.02. During the cleaning and painting, the stainless steel and PTFE sheet sliding surfaces and the elastomer shall be protected from abrasion and paint.
1083.04 Testing and Acceptance. The rubber laminates shall be of uniform
integral units, capable of being separated by mechanical means into separate, well- defined elastomeric layers. The ultimate breakdown limit of the elastomeric bearing under compressive loading shall be not less than 2000 psi (13,800 kPa). The bearing manufacturer shall load test each completed steel laminated elastomeric bearing pad assembly prior to shipment. The bearings shall be loaded to 1500 psi (10,300 kPa) and under this loading shall exhibit relatively uniform bulging of the rubber layers on all sides and shall show no bond loss or edge splitting. Bearing assemblies under this loading showing nonuniform bulging from one side of the pad to the other, nonuniform bulging along any vertical face of a pad, bulging extending across the specified location of one or more of the internal steel laminates or edge splitting shall be replaced. Nonuniform bulging from one side of the pad to the other may be an indication of lateral misalignment of the internal steel laminates and would not be cause for replacement if probing shows that the edge cover of the steel laminates are within the specified tolerances. Nonuniform bulging along any vertical face of the pad may be an indication of vertical misalignment of the steel laminates and would not be cause for replacement if measurement of the bases of the nonuniform bulges show that the thickness of the elastomeric layers are within the specified ± 20 percent tolerance. Bulging across the specified location of one or more steel laminates indicates missing steel laminates or lack of bond and pads exhibiting these characteristics shall always be replaced. The Contractor shall furnish certified copies of the bearing manufacturer's test reports on the physical properties of the component materials for the bearings to be furnished and a certification by the bearing manufacturer that the bearings furnished have been load tested and be according to all requirements. When directed by the Engineer, the Contractor shall furnish random samples of component materials used in the bearings for testing. In addition, when requested in writing by the Engineer, the Contractor shall furnish an additional project bearing assembly to the Department for testing. When the additional bearing assembly is requested, the Engineer retains the right to select the bearing assembly for testing at random from the project lot. The Contractor will be paid for the additional bearing assembly as specified in Article 521.09. If the bearing assembly tested is found to be unacceptable, two additional bearing assemblies will be tested. If both are acceptable, the lot will be accepted. If either of the two additional bearing assemblies are unacceptable, the lot will be rejected. The Contractor shall have a new lot produced, including one additional test bearing. No payment will be made for the original failed bearing assembly or any subsequent test assemblies. Art. 1084.01 Illuminated Sign SECTION 1084. ILLUMINATED SIGN
1084.01 Illuminated Sign. The illuminated sign shall be as follows.
a.Housing. The sign housing shall be made of extruded aluminum alloy with a minimum thickness of 0.063 in. (1.5 mm). All corners and seams shall be heli-arc welded and weatherproof. Doors shall be made of 0.125 in. (3.1 mm) thick extruded aluminum with a 0.188 x 1 in. (5 x 25 mm) neoprene gasket and sun hood. Hinges shall be continuous full-length stainless steel. Drainage shall be provided by four drain holes at the corners of the housing. The housing shall have stainless steel hardware and provide tool free access to the interior. The exterior surface of the housing shall be acid-etched and shop painted with one coat of zinc-chromate primer and two coats of yellow enamel. The painting shall be according to Section 851.
b.Sign Display. The lens panel shall be 0.125 in. (3.1 mm) ±10 percent in thickness and shall be made of Plexiglas or other plastic material with equivalent or better weathering, structural, and optical properties. Colors and size of the legend, background, and letters used in the legend shall conform to the MUTCD. Turn prohibition signs shall be according to MUTCD “R3-1” or “R3-2”. When illuminated, the message shall be legible and highly visible within a 15 degree cone centered about the optic axis under any ambient light condition. When the sign is not illuminated, the sign display shall blank-out such that no symbol can be seen under any ambient light condition.
c.Illumination. Illumination for the sign shall be as follows.
1.Fiber-Optic. The fiber-optic sign shall consist of fiber-optic glass bundles arranged to define the required message. The glass bundles shall be ground smooth and optically polished at the input and output ends for maximum light transmission. The output ends of the fiber-optic glass bundles that form the sign message shall be terminated using glass lenses or glass end caps. The fiber-optic sign shall control the lamp intensity utilizing the photo control according to Article 1078.01(c)(2)d. The lamp intensity control device shall be wired in series with the step-down transformers in the sign, on the input (120 VAC) side of the transformer. The lamp intensity control device shall be mounted in the bottom of the sign housing. Each fiber-optic sign shall have a separate lamp intensity control device. The lamps shall have a rated minimum life of 5,000 hours.
2.Light Emitting Diode (LED). The LED sign shall consist of standard T–13/4 (5 mm) LED lamps and have an expected lamp life of 100,000 hours. Operating wavelengths shall be Red – 626 nm, Amber – 590 nm, and Bluish/Green – 505 nm. The luminance shall be a minimum of 345 candelas/sq ft (3,700 candelas/sq m) when measured
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Source: Illinois Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 1077–1081 of 1,217. View official source ↗