1、Standard Specification for Acrylic Prismatic Reflectors and Embossed Aluminum Frames for Signs AASHTO Designation: M 290-96 (2013) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001TS-4d M 290-1 AASHTO Standard Specifica
2、tion for Acrylic Prismatic Reflectors and Embossed Aluminum Frames for Signs AASHTO Designation: M 290-96 (2013) 1. SCOPE 1.1. This specification covers acrylic prismatic reflectors and embossed aluminum frames used in cutout letters, symbols, and accessories on signing projects. 1.2. The values sta
3、ted in SI units are to be regarded as the standard. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standard: T 257, Instrumental Photometric Measurements of Retroreflective Materials and Retroreflective Devices 2.2. ASTM Standards: B117, Standard Practice for Operating Salt Spray (Fog) Apparatus B209, Standard
4、 Specification for Aluminum and Aluminum-Alloy Sheet and Plate D788, Standard Classification System for Poly(Methyl Methacrylate) (PMMA) Molding and Extrusion Compounds D1730, Standard Practices for Preparation of Aluminum and Aluminum-Alloy Surfaces for Painting 2.3. ANSI Standard: ANSI D6.1, Manua
5、l on Uniform Traffic Control Devices 2.4. Federal Standard: L-P 380, Plastic Molding Material, Methacrylate 3. TERMINOLOGY 3.1. legendthe entire message and border for a sign. 3.2. messagea group of words, numbers, and/or symbol for a sign. 4. ORDERING INFORMATION 4.1. Orders for material under this
6、 specification shall include the following information: 4.1.1. Quantity; 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4d M 290-2 AASHTO 4.1.2. Name of material; 4.1.3. Style of letter and size, or
7、size of reflector; 4.1.4. Color (colorless, yellow, red, green); 4.1.5. Legend description; and 4.1.6. AASHTO designation and date of issue. 5. MATERIALS 5.1. The reflector lens shall be methyl methacrylate meeting requirements of the latest version of one of the following specifications: 5.1.1. Fed
8、eral Specification L-P-380, Type 1, Class 3; and 5.1.2. ASTM D788, Grade 8. 5.2. The purchaser shall specify the type, class, or grade of methyl methacrylate to be used in the manufacture of the reflectors. 5.3. Legend frames shall be fabricated from aluminum sheet, ASTM B209, Alloy 3003-H14. 6. MAN
9、UFACTURE 6.1. Reflectors shall consist of a transparent acrylic plastic face, herein referred to as the lens, and a light-colored, opaque back of similar material fused to the lens under heat and pressure around the entire perimeter. The reflector shall form a unit permanently sealed against dust, w
10、ater, and water vapor. The reflector lens shall be colorless, yellow, red, or green as required by the plans. 6.2. The lens shall consist of a smooth front surface free from projections or indentations, which are detrimental to the reflectance of the unit. The manufacturers trademark shall be molded
11、 legibly into the face of the lens. The rear surface of the lens shall have a prismatic configuration such that it will cause adequate internal reflection of light. 6.3. Reflectors shall be designed so as to facilitate insertion into accurately sized holes in embossed legend frames. When installed i
12、n the legend frame, reflectors shall be restrained so as to prevent their displacement. The retention of reflectors in frames by use of adhesive tape is not acceptable. The reflector size shall be such as to permit free movement in the mounting hole to allow for differences of expansion and contract
13、ion between plastic reflector and aluminum sign frame. 6.4. Frames shall be embossed and shall be fabricated from aluminum sheet having a thickness of 1 mm (0.040 in.). The form of the legend shall conform to the requirements of ANSI D6.1 and the plans and specifications for the project. Mounting ho
14、les shall be provided within the frames to permit the use of an approved fastener. The size and spacing of reflector holes for reflectorized frames shall be such as to afford maximum night legibility and visibility to the finished cutout figure. Legend frames, which are not intended to be reflectori
15、zed, shall not contain holes for reflectors. After metal fabrication has been completed, the frames shall be degreased, etched, neutralized, and treated with an amorphous chromate coating in accordance with ASTM D1730. Frames shall be finished with the material and color specified by the purchaser.
16、2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4d M 290-3 AASHTO 7. PHYSICAL REQUIREMENTS 7.1. Specific Intensity per Unit Area (SIA): 7.1.1. The SIA of each colorless reflector intended for use in c
17、utout letters, symbols, and accessories shall be equal to or exceed the minimum values in Table 1 when tested in accordance with T 257. SIA is expressed in candelas per lux per square meter (candelas per foot-candle per square foot). Table 1Required Specific Intensity per Unit Area Values for Colorl
18、ess Reflectors Observation Angle, Degrees Entrance Angle, Degrees Specific Intensity per Unit Area cd/lx/m2cd/fc/ft21/100 2020 2020 1/1020 806 806 1/60 1440 1440 1/620 576 576 1/30 1010 1010 1/320 403 403 Note: For yellow reflectors, the SIA shall be 60 percent of the listed value. For green or red
19、reflectors, the SIA shall be 25 percent of the listed value for colorless reflectors. 7.2. Seal: 7.2.1. The seal test shall be used to determine if a reflector is adequately sealed against dust and water. Not more than four percent of the reflectors tested shall show evidence of water intake when te
20、sted as specified in Section 10.2. 7.3. Heat Resistance: 7.3.1. The heat resistance test shall be used to determine the durability of the reflectors. No specimen shall show significant change in shape and general appearance when tested as specified in Section 10.3 and compared with unexposed control
21、 standards. 7.4. Corrosion: 7.4.1. The salt fog cabinet test of the legend specimen shall be used to evaluate the durability of the legend and its coating. No significant peeling, cracking, or disbonding of the coating shall be observed after 1000 h under test as specified in Section 10.4. 8. SAMPLI
22、NG 8.1. For qualification of product, 53 sample reflectors of each size, type, and color to be used shall be submitted by the manufacturer for testing from each manufacturers lot of 25,000 or fewer reflectors. 8.2. For project acceptance purposes, 53 reflectors of each size, type, and color to be us
23、ed shall be sampled at random by the purchaser from each shipment of reflectors, when they are received separately from the legend frames, or from the finished legend when these are received already made up. Specimens used in the seal and heat resistance tests shall not be used to perform reflectanc
24、e tests. If the same specimens are used to perform seal and heat resistance tests, the heat resistance tests shall be performed last. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4d M 290-4 AASHTO
25、8.3. The sampling procedure for reflectors incorporated into legend shall be such as will provide the desired degree of randomness, but not unduly delay the production or delivery of signs. Note 1One method could be to list in the plans or specifications the extra legend that the manufacturer is to
26、furnish, which will provide the required number and size of reflectors for test. The engineer will substitute this extra legend at random for the legend intended for sign usage. The legend for which substitutions are thus made shall be the legend used for laboratory testing as set forth in this spec
27、ification. A degree of randomness of sampling is obtained in that the supplier does not know which of several letters or symbols intended for sign usage will ultimately be used to supply reflectors for testing. 9. RETESTING 9.1. Specific Intensity per Unit Area (SIA): 9.1.1. Failure of a reflector t
28、o meet the SIA minimum shall constitute failure of the reflector being tested. Upon failure of exactly 3 of the 50 specimens tested, a resample of 100 reflectors shall be tested. Failure of 4 or more of the reflectors in the original sample of 50 shall be cause for rejection of the lot without retes
29、t. 9.2. Seal: 9.2.1. Upon failure of exactly 3 of the specimens, a resample of 100 reflectors shall be tested. Failure of 4 or more of the reflectors in the original sample of 50 shall be cause for rejection of the lot without retest. 9.3. Heat Resistance: 9.3.1. No failure of the initial three spec
30、imens will be permitted, and no retest will be allowed. 9.4. Corrosion: 9.4.1. No failure of the initial three specimens will be permitted, and no retest will be allowed. 10. TEST PROCEDURES 10.1. Optical (Photometric) Tests: 10.1.1. Photometric tests shall be conducted in accordance with T 257, wit
31、h the reflector spinning at a rate such that the meter reading is steady. 10.2. The seal test is performed by submerging 50 specimens in a water bath at room temperature. The submerged specimens are subjected to a vacuum of 16.9 kPa (5 in. of mercury) for 5 min. Restore atmospheric pressure and leav
32、e the specimens submerged for an additional 5 min. Examine the specimens for water intake. 10.3. The heat resistance test is performed by placing three reflectors in a horizontal position on a grid or perforated shelf in a circulating air oven. The oven shall be operated at 52 3C (125 5F). The speci
33、mens shall remain in the oven for 4 h and shall not interfere with the free flow of air. At the conclusion of the test, the samples shall be removed from the oven and permitted to cool to room temperature in air and visually examined. 10.4. Corrosion TestThree assembled cutout letters, symbols, or a
34、ccessories shall withstand the combined corrosion test set forth in ASTM B117. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-4d M 290-5 AASHTO 11. PACKAGING 11.1. Each cutout letter, symbol, or acce
35、ssory, completely assembled with reflectors, shall be supplied in an individual package with contents marked thereon. 11.2. Individual reflectors and separate legends, if so furnished, shall be packed so as to avoid damage by abrasion or other means. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
