1.1 本规程涵盖了三种方法，用于将大样本骨料减少至适当尺寸以进行测试。这些技术旨在最大限度地减少所选测试样本和大样本之间测量特性的变化。 1.2 以国际单位制或英寸-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是精确的等效值；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。 注1: 筛孔尺寸由规范中的标准名称确定 E11 . 括号中给出的替代名称仅供参考，并不代表不同的标准筛孔尺寸。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）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 骨料规范要求获得供应材料的代表性部分进行测试。 在其他因素相同的情况下，较大的样本往往更能代表总供应量。本规程提供了将现场获得的或实验室生产的大样本减少到便于进行大量描述性和质量测试的尺寸的程序。如果不仔细遵守本规程中的程序，可能会导致提供不具有代表性的样品用于后续测试。单独的测试方法规定了待测试材料的最小数量。 4.2 在某些情况下，不建议在测试之前减小大样本的尺寸。有时无法避免所选测试样本之间的实质性差异，例如，在样本中具有相对较少大尺寸颗粒的骨料的情况下。 机会定律表明，这几个颗粒可能在减小尺寸的试样中分布不均匀。同样，如果正在检查试样是否存在某些仅以小百分比出现的污染物，则在解释缩小尺寸试样的结果时应谨慎。所选测试样本中仅包含或排除一个或两个颗粒的机会可能会对原始样本特征的解释产生重要影响。在这些情况下，应测试整个原始样品。

1.1 This practice covers three methods for the reduction of large samples of aggregate to the appropriate size for testing. These techniques are intended to minimize variations in measured characteristics between the test samples selected and the large sample. 1.2 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 non-conformance with the standard. Note 1: Sieve size is identified by its standard designation in Specification E11 . The alternative designation given in parentheses is for information only and does not represent a different standard sieve size. 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. ====== Significance And Use ====== 4.1 Specifications for aggregates require obtaining representative portions of the supply material for testing. Other factors being equal, larger samples will tend to be more representative of the total supply. This practice provides procedures for reducing the large sample obtained in the field, or produced in the laboratory, to a convenient size for conducting a number of descriptive and quality tests. Failure to carefully follow the procedures in this practice could result in providing a non-representative sample to be used in subsequent testing. The individual test methods provide for minimum amount of material to be tested. 4.2 Under certain circumstances, reduction in size of the large sample prior to testing is not recommended. Substantial differences between the selected test samples sometimes cannot be avoided, for example, in the case of an aggregate having relatively few large size particles in the sample. The laws of chance dictate that these few particles may be unequally distributed among the reduced size test samples. Similarly, if the test sample is being examined for certain contaminants occurring in only small percentages, caution should be used in interpreting results from the reduced size test sample. Chance inclusion or exclusion of only one or two particles in the selected test sample may importantly influence interpretation of the characteristics of the original sample. In these cases, the entire original sample should be tested.