4.1 Mechanically stabilized earth walls (MSEW) are engineered earth retaining structures comprised of pre-fabricated wall facing elements and select backfill that is reinforced with inextensible steel elements. The complete system consists of the original ground, concrete leveling pads, wall facing panels, coping, soil reinforcement, and select backfill. A MSEW is typically subjected to earth loads and surface loads (surcharges). The MSEW relies on self-weight and friction to resist the destabilizing earth forces acting at the back of the reinforced soil zone. They are used frequently in transportation-related civil engineering applications. Fig. 1 shows a cross section of a typical panel faced MSEW, and Fig. 2 shows the components. Fig. 3 shows a cross section of a typical wire faced MSEW cross section, and Fig. 4 shows the components.FIG. 1 Typical Panel Faced MSEW Cross SectionFIG. 2 Components of Typical Panel Faced MSEWFIG. 3 Typical Wire Faced MSEW Cross SectionFIG. 4 Components of Typical Wire Faced MSEW1.1 Mechanically stabilized earth walls (MSEW) covered in this standard practice are engineered earth retaining structures comprised of pre-fabricated wall facing elements and select backfill reinforced with inextensible steel elements. This practice covers procedures and components for the construction of MSEW including soil reinforcement, connections to panels, and selection and placement of granular backfill. Such walls may have a segmental precast concrete (SPC) facing or a flexible wire facing. This standard practice does not address the design of MSEW.1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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6.1 Corrosion Resistance, General—This functional coating is used to provide corrosion resistance. The performance of this coating depends largely on its thickness and the kind of environment to which it is exposed. Published results of environmental corrosion studies have demonstrated that the coating provides corrosion resistance greater than equivalent thicknesses of zinc coatings in industrial environments and greater corrosion resistance than equivalent thicknesses of cadmium coatings in marine environments.46.2 Galvanic Corrosion Resistance—The galvanic couple that results in the corrosion of steel and aluminum parts in contact with each other in corrosive environments can also be minimized by plating the steel parts with this mechanically deposited coating.6.3 Hydrogen Embrittlement, Absence of—The mechanical coating process does not produce any permanent hydrogen embrittlement in products made from high-strength steels, for example, fasteners or lock washers.AbstractThis specification covers the requirements for cadmium-zinc coatings deposited on metallic products by mechanical deposition. The coating shall be classified in four thickness classes namely, Class 7, Class 12, Class 25, and Class 50. The coating shall also be classified according to coating types defined as Type I, Type IIa, Type IIb, Type IIc, and Type IId. The materials shall be subjected to the following test methods: coating composition determination; thickness measurement; adhesion test; corrosion resistance test; appearance test; and hydrogen embrittlement test.1.1 General—This specification covers the requirements for a coating that is a mixture of cadmium and zinc deposited on metallic products by mechanical deposition. The coating is provided in four thickness classes (see Table 1) and several finish types (see Table 2).1.2 Toxicity—Warning: Cadmium is toxic; therefore these coatings should not be used on articles that will contact food or beverages, or for dental and other equipment that may be inserted into the mouth. Also, the coatings should not be used on articles that will be heated to high temperatures, because cadmium will form toxic fumes. Similarly, if coated articles are welded, soldered, or otherwise heated during fabrication, adequate ventilation should be provided to exhaust toxic fumes.1.3 Similar Documents—Other kinds of mechanically deposited coatings are covered by Specifications B635, B695, and B696.1.4 The following precautionary caveat pertains only to the test method portion, Section 9, of this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车