1.1 这种做法 2. 如实践中所述，包括在标准的捣棒和内部振动程序下从混凝土中模制圆柱形试样 C31/C31M 和实践 C1176/C1176M ，不可行。本规程适用于在实验室和现场制备的新拌混凝土。 1.2 新拌混凝土使用配备轴和圆板的电动振动锤在圆柱形模具中成型。 1.3 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。在文本中，英寸-磅单位显示在括号中。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。 1.4 本惯例的文本参考了注释和脚注，这些注释和脚注提供了解释性材料。这些注释和脚注（不包括表和图中的注释和脚注）不应视为本惯例的要求。 1.5 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。 1.6 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 本规程用于测试碾压混凝土，可适用于测试其他类型的胶凝材料，如粗粒水泥土。本规程提供了碾压混凝土施工中常用的成型硬至极干稠度混凝土混合物的标准化要求。这种做法用于代替捣棒或内部振捣，因为捣棒或内部振捣无法正确加固这种稠度的混凝土。 注1: ACI 207.5R和ACI 211.3中给出了碾压混凝土稠度的进一步说明。使用振动台的混凝土稠度可根据试验方法确定 C1170/C1170M . 4.2 本规程用于塑造通常用于测试混凝土抗压或抗拉强度的圆柱形试样。 抗压强度和劈裂抗拉强度测试的样本应符合测试方法 C39/C39M 和 C496/C496M 分别地试样也可用于测定新浇混凝土的密度。 注2: 对于一些极干的混合物；（当按照试验方法进行试验时，稠度大于45秒的 C1170/C1170M ) 5. 根据本规程制作的试样密度可能大于碾压混凝土的现场密度，因为现场升降机底部存在更大的孔隙。 注3: 仪器的质量和操作员施加的力可能会显著影响由这些混合物制成的样品的密度； 因此，在解释根据本规程制作的试样的测试结果时，建议谨慎行事。

1.1 This practice 2 covers molding cylindrical test specimens from concrete when the standard procedures of rodding and internal vibration, as described in Practice C31/C31M and Practice C1176/C1176M , are not practicable. This practice is applicable to freshly-mixed concrete, prepared in the laboratory and the field. 1.2 Freshly-mixed concrete is molded in cylindrical molds using an electric vibrating hammer equipped with a shaft and circular plate. 1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the inch-pound units are shown in brackets. 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. 1.4 The text of this practice 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 this practice. 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 This practice, intended for use in testing roller-compacted concrete, may be applicable to testing other types of cementitious material such as coarse-grained, soil-cement. This practice provides standardized requirements for molding stiff to very dry consistency concrete mixtures commonly used in roller compacted concrete construction. This practice is used instead of rodding or internal vibration, which cannot properly consolidate concrete of this consistency. Note 1: Further description of roller compacted concrete consistency is given in ACI 207.5R and ACI 211.3. The consistency of concrete using a vibrating table may be determined in accordance with Test Methods C1170/C1170M . 4.2 This practice is used to mold cylindrical test specimens commonly used for testing compressive or tensile strength of concrete. Specimens tested for compressive strength and splitting tensile strength shall be in accordance with Test Methods C39/C39M and C496/C496M , respectively. Test specimens also may be used to determine density of fresh concrete. Note 2: For some extremely dry mixtures; (those with a consistency greater than 45 s when tested in accordance with Test Methods C1170/C1170M ) 5 the density of specimens made in accordance with this practice may be greater than the in-place density of roller-compacted concrete due to the greater potential for voids at the bottom of the lifts in the field. Note 3: The mass of the apparatus and amount of force applied by the operator may significantly affect the density of specimens made from these mixtures; thus, discretion is advised when interpreting test results on specimens made according to this practice.