AASHTO M 246-15 pdf free download

AASHTO M 246-15 pdf free download.Steel Sheet, Metallic-Coated and Polymer-Precoated, for Corrugated Steel Pipe .
5.2.5. Substrate dimensions (specified thickness; width, either flat or overall corrugated; and length, if cut length);
5.2.6. Grade of polymer coating (Section 3) indicating thickness on each side;
5.2.7. Coil size requirements (specify maximum outside diameter (OD), acceptable inside diameter (ID),
and maximum mass);
5.2.8. Certification, if required (Section 11.1); and
5.2.9. Special requirements.
Note 1—Typical ordering descriptions are as follows: Polymer-precoated steel sheet, aluminum- zinc alloy coated for CSP, conforming to M 246- , 2.77 by 700 mm by coil, with Grade 250 polymer coating (0.25 mm); coil 1200 mm max OD, 600 mm ID. 10000 kg max coil mass. [Polymer-precoated steel sheet, zinc-coated for CSP, conforming to M 246- .1
GENERAL REQUIREMENTS
6.1. The metallic-coated steel substrate shall conform to all applicable requirements of the specification listed below for the kind of metallic coating specified. If the type of metallic coating is not stated in the order, zinc-coated sheet as described in Section 6.1 . I shall be furnished.
6.1 .1. Zinc Coating—Zinc-coated steel sheet shall conform to the requirements of M 218.
6.1.2. Aluminum-Zinc Alloy coating 55—Aluminum-zinc alloy coated steel sheet shall conform to the requirements of M 289 and zinc-5 aluminum-MM alloy coated steel sheets shall conform to the requirements of ASTM A929/A929M.
6.1.3. The steel sheet shall be thoroughly cleaned of any chromate pretreatment or other passivation using a multi-brush cleaning process. All traces of the caustic cleaning solution shall be immediately rinsed from the sheet following caustic cleaning. After drying, the steel sheet shall be treated with chromic acid solution and heat-cured prior to application of the polymer film. The deposited chromium content shall range from 135 to 190 mg/rn2.
6.2. The polymer coating shall be a film coating composed of at least 85 percent ethylene acrylic acid (EAA) copolymer or at least 25 percent Maleic Anhydride (MAH) Grafted Polymer, which is partially hydrolyzed. The polymer coating shall be capable of being applied to the sheet specified in Section 6.1. After application, the polymer coating shall be free of holes, tears, and discontinuities, and shall be sufficiently flexible so that it will withstand the corrugating, forming, and lock-seaming operations as well as the punching of holes for rivets or perforations. Note 2—The MAH grafted polymer coating is only applied over zinc-coated steel conforming to the requirements of Section 6.1.1.
6.3. If the polymer-coated sheet is to be furnished with corrugations, the corrugations shall conform to the requirements stated in the appropriate specification listed in Section 6.1.
7. REQUIREMENTS FOR POLYMER COATINGS
7.1. Adhesion—There shall be no spalling or cracking of the coating when tested in accordance with Section 9.1. There shall be no disbonding of the coating at the cut to be made as described in Section 9.1.
7.2. Impact—There shall be no break in the polymer coating when tested in accordance with Section 9.2.
7.3. Thickness ojcoating—The thickness of the polymer coating shall meet the requirements of Section 3, or as specified in the purchase order, when tested in accordance with Section 9.3.
7.4. Holidays—The polymer coating on the steel shall be substantially free of holidays when tested in accordance with Section 9.4. An average of 22 holidays per square meter of actual surface area on the test specimen shall be permitted.
Note 3—Holidays are pinholes or voids in the polymer coating that are not visually discernible.
7.5. Abrasion Resistance—The average abrasion coefficient, when tested in accordance with Section 9.5, shall be a minimum of 3.9 (expressed in g/jirn of thickness).
7.6. Imperviousness—There shall be no loosening or separation of the polymer coating from the metallic-coated steel substrate when tested in accordance with Section 9.6.
7.7. Freeze—Thaw Resistance—The specimen shall withstand 100 freeze—thaw cycles, as described in Section 9.7, without spalling, disbonding, or other detrimental effects.AASHTO M 246-15 pdf download.