1.1 该分类定义了用作薄膜屋顶系统压载物的标准骨料尺寸的力学分析中骨料尺寸的名称和范围。 1.2 本分类的文本参考了提供解释材料的注释和脚注。这些注释和脚注（不包括表和图中的注释）不应视为本标准的要求。 1.3 关于使用试验筛确定的筛子尺寸和骨料尺寸，为了方便用户，以英寸磅为单位显示数值；然而，括号中所示的标准筛号是规范中规定的标准值 第11页 . 1.4 以国际单位制或英磅单位表示的数值应单独视为标准值。 每个系统中规定的值可能不完全相等；因此，每个系统应独立使用。将两个系统的值合并可能导致不符合标准。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 =====意义和用途====== 4.1 压载薄膜屋顶系统的风阻主要取决于所用压载物的尺寸和重量。ANSI/SPRI RP-4提供了一种有砟单层薄膜屋顶系统的风设计方法，并包括用作压载的骨料尺寸和重量的具体指南。本标准中提供的骨料尺寸分类旨在与ANSI/SPRI RP-4中提供的指南一起用于设计骨料压载单层薄膜屋顶系统的抗风性。 4.2 本分类中提供的骨料尺寸分类旨在为合同文件的合规性提供依据，这些合同文件规定了用于压载膜系统的特定骨料尺寸。

1.1 This classification defines the aggregate size designations and ranges in mechanical analyses for standard sizes of aggregate used as ballast for membrane roof systems. 1.2 The text of this classification references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard. 1.3 With regard to sieve sizes and the size of aggregate as determined by the use of testing sieves, the values in inch-pound units are shown for the convenience of the user; however, the standard sieve designations shown in parentheses are the standard values as stated in Specification E11 . 1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 1.5 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. 1.6 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. ====== Significance And Use ====== 4.1 The wind resistance of ballasted membrane roof systems is determined largely by the size and weight of the ballast used. ANSI/SPRI RP-4 provides a method for the wind design of ballasted single-ply membrane roof systems and includes specific guidelines for the size and weight of aggregate used as ballast. The aggregate size classifications provided in this standard are intended for use with the guidelines provided in ANSI/SPRI RP-4 in designing the wind resistance of aggregate ballasted single-ply membrane roof systems. 4.2 The aggregate size classifications provided in this classification are intended to provide a basis of compliance for contract documents that specify certain aggregate sizes for use on ballasted membrane systems.