1.1 本试验方法包括测定含有任何类型骨料的新拌混凝土的空气含量，无论是密实、多孔还是轻质骨料。 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。括号中显示了英寸磅单位。每个系统中规定的值可能不是完全相等的；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。 1.3 本标准的文本引用了提供解释性信息的注释和脚注。这些注释和脚注（不包括表和图中的注释和脚注）不应被视为本标准的要求。 1.4 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。 ( 警告 新鲜的水硬性胶结混合物具有腐蚀性，长时间暴露可能会对皮肤和组织造成化学灼伤。 2. ) 1.5 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》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 4.1 本试验方法包括新拌混凝土空气含量的测定。它测量混凝土砂浆部分所含的空气，但不受多孔骨料颗粒内可能存在的空气的影响。 4.1.1 因此，这是测定含有轻质骨料、气冷矿渣和高度多孔或多孔天然骨料的混凝土空气含量的合适试验。 4.2 该试验方法要求在计量表最初充满水时加入足够的异丙醇，以便在第一次或随后的滚动之后，计量表顶部的颈部几乎没有或没有泡沫。如果存在的泡沫比水位以上2%空气的泡沫多，则该试验被宣布无效，必须使用更多的酒精重复进行。在仪表首次填充至零标记后的任何时候都不允许添加酒精以消除泡沫。 4.3 硬化混凝土的空气含量可能高于或低于该试验方法确定的空气含量。 这取决于硬化混凝土试样所用混凝土的固结力的方法和量；新鲜和硬化混凝土中气泡的均匀性和稳定性；显微镜检查的准确性（如果使用）；比较时间；环境暴露；输送、浇筑和固结过程中确定未硬化混凝土空气含量的阶段，即混凝土通过泵之前或之后；以及其他因素。

1.1 This test method covers determination of the air content of freshly mixed concrete containing any type of aggregate, whether it be dense, cellular, or lightweight. 1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. 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. 1.3 The text of this standard references notes and footnotes that provide explanatory information. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this standard. 1.4 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. ( Warning— Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure. 2 ) 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. ====== Significance And Use ====== 4.1 This test method covers the determination of the air content of freshly mixed concrete. It measures the air contained in the mortar fraction of the concrete, but is not affected by air that may be present inside porous aggregate particles. 4.1.1 Therefore, this is the appropriate test to determine the air content of concretes containing lightweight aggregates, air-cooled slag, and highly porous or vesicular natural aggregates. 4.2 This test method requires the addition of sufficient isopropyl alcohol, when the meter is initially being filled with water, so that after the first or subsequent rollings little or no foam collects in the neck of the top section of the meter. If more foam is present than that equivalent to 2 % air above the water level, the test is declared invalid and must be repeated using a larger quantity of alcohol. Addition of alcohol to dispel foam any time after the initial filling of the meter to the zero mark is not permitted. 4.3 The air content of hardened concrete may be either higher or lower than that determined by this test method. This depends upon the methods and amounts of consolidation effort applied to the concrete from which the hardened concrete specimen is taken; uniformity and stability of the air bubbles in the fresh and hardened concrete; accuracy of the microscopic examination, if used; time of comparison; environmental exposure; stage in the delivery, placement and consolidation processes at which the air content of the unhardened concrete is determined, that is, before or after the concrete goes through a pump; and other factors.