AASHTO M290-96 pdf free download
AASHTO M290-96 pdf free download.Acrylic Prismatic Reflectors and| Embossed Aluminum Frames for Signs.
5. MATERIALS
5.1. The reflector lens shall be methyl methacrvlate meeting requirements oft/ic latest version qf one oft/ic following specifications:
5.1.1. Federal Specification L-P-380, Type I, Class 3; and
5.1.2. ASTM D788, Grade 8.
5.2. The purchaser shall specify the type, class, or grade of methyl mcthacrylate to be used in the manufacture of the reflectors.
5.3. Legend frames shall be fabricated from aluminum sheet, ASTM B209, Alloy 3003-H 14.
6. MANUFACTURE
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, water, 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 manufacturer’s trademark shall be molded 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 in 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 contraction 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.l and the plans and specifications for the project. Mounting holes 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 reflectorized, 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 DI 730. Frames shall be finished with the material and color specified by the purchaser.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 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. SAMPLING
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 manufacturer’s lot of 25,000 or fewer reflectors.
8.2. For project acceptance purposes, 53 reflectors of each size, type, and color to be used 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 reflectance tests. If the same specimens are used to perform seal and heat resistance tests, the heat resistance tests shall be performed last.AASHTO M290-96 pdf download.
