1.1 这些试验方法包括实验室测定土壤、岩石和类似材料的水（水分）含量，其中干燥导致的质量减少是由于失水，除非另有说明 1.4 , 1.5 和 1.8 . 为简单起见，“材料”一词应指土壤、岩石或骨料，以最适用者为准。 1.2 一些学科，如土壤科学，需要根据体积确定含水量。此类测定超出了本试验方法的范围。 1.3 材料的含水量是土壤或岩石材料孔隙中包含的水质量与颗粒固体质量的比率，以百分比表示。 1.4 岩土工程中使用的术语“固体材料”通常被认为是指土壤和岩石中不易溶于水的天然矿物颗粒。因此，含有外来物质（如水泥等）的材料的含水量可能需要特殊处理或合格的含水量定义。此外，对于该方法（110），一些有机材料可以在标准干燥温度下通过烘箱干燥进行分解 ± 5°C）。含有石膏（二水硫酸钙）或具有大量水合水的其他化合物的材料可能会出现特殊问题，因为这种材料在标准干燥温度（110）下缓慢脱水 ± 在极低的相对湿度下，形成一种化合物（如半水硫酸钙），该化合物通常不存在于天然材料中，但在某些沙漠土壤中除外。 为了降低含有石膏的材料中石膏的脱水程度或减少在高纤维有机土壤中的分解，可能需要在60°C或室温下在干燥器中干燥材料。当使用不同于本试验方法规定的标准干燥温度的干燥温度时，所得含水量可能不同于在110的标准干燥温度下测定的标准含水量 ± 5°C。 注1: 试验方法 D2974 提供了测定泥炭材料含水量的替代程序。 1.5 当使用该方法进行测试时，含有大量可溶固体（如海洋沉积物中的盐）的水的材料将产生大量固体，其中包括以前可溶的溶解固体。这些材料需要进行特殊处理，以去除或解释试样干物质中存在的沉淀固体，或者必须使用合格的含水量定义。例如，参见测试方法 D4542 关于海洋沉积物的信息。 1.6 本试验标准要求适当干燥含水量样本数小时。 试验方法 D4643 , D4944 和 D4959 提供更少耗时的过程来确定含水量。见吉尔伯特 2. 有关测试方法背景的详细信息 D4643 . 1.7 本标准提供了两种试验方法。这些方法在报告的有效数字和所需的样本大小（质量）方面有所不同。使用的方法可由请求机构指定；否则，应执行方法A。 1.7.1 方法A- 记录质量含水量，精确到1 %. 对于争议案件，方法A是仲裁方法。 1.7.2 方法B- 记录质量含水量，精确至0.1 %. 1.8 本标准要求在烘箱中干燥材料。如果正在干燥的材料受到某些化学品的污染，这些化学品在加热时可能会发生剧烈反应或释放有害气体，则可能存在健康和安全隐患。因此，除非采取适当的健康和安全预防措施，否则本标准不应用于确定受污染土壤的含水量。 1.9 单位- 以国际单位制表示的数值应视为标准值，但下列替代筛孔尺寸除外: 表1 使用。本试验方法中不包括其他测量单位。 1.10 所有观察值和计算值应符合实践中确定的有效数字和舍入准则 D6026 ，除非被本试验方法取代。 1.10.1 如果将使用含水量计算其他关系，例如湿质量与干质量或反之亦然、湿容重与干容重或反之亦然，以及总密度与干密度或反之亦然，则这一点尤为重要。例如，如果在上述任何计算中需要四个有效数字，则必须将含水量记录到最接近的0。 1. %. 这是因为1加上含水量（不是百分比）将有四个有效数字，无论含水量的值是多少；也就是说，1加0.1/100=1.001，一个具有四个有效数字的值。而如果三个有效数字是可接受的，则可以将含水量记录到最接近的1 %. 1.10.2 如果要使用含水量数据来计算其他关系，例如湿质量或干质量、湿或干单位重量或总密度或干密度，则必须使用精确到0的天平测定高达200 g的试样质量。 01克。 1.11 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。 1.12 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====== 5.1 对于许多材料而言，含水量是用于建立土壤行为与其指数特性之间相关性的最重要特性之一。 5.2 材料的含水量用于表示给定体积材料中空气、水和固体的相关系。 5.3 在细粒土中，给定土壤类型的稠度取决于其含水量。土壤的含水量，以及通过试验方法确定的液限和塑限 D4318 ，用于表示其相对一致性或流动性指数。 注2: 本标准产生的结果的质量取决于执行该标准的人员的能力，以及所用设备和设施的适用性。符合实践标准的机构 D3740 通常认为能够胜任和客观的测试/采样/检查等。本标准的用户应注意遵守惯例 D3740 本身并不能保证可靠的结果。可靠的结果取决于许多因素； 实践 D3740 提供了一种评估其中一些因素的方法。

1.1 These test methods cover the laboratory determination of the water (moisture) content by mass of soil, rock, and similar materials where the reduction in mass by drying is due to loss of water except as noted in 1.4 , 1.5 , and 1.8 . For simplicity, the word “material” shall refer to soil, rock or aggregate whichever is most applicable. 1.2 Some disciplines, such as soil science, need to determine water content on the basis of volume. Such determinations are beyond the scope of this test method. 1.3 The water content of a material is the ratio of the mass of water contained in the pore spaces of soil or rock material, to the solid mass of particles, expressed as a percentage. 1.4 The term “solid material” as used in geotechnical engineering is typically assumed to mean naturally occurring mineral particles of soil and rock that are not readily soluble in water. Therefore, the water content of materials containing extraneous matter (such as cement etc.) may require special treatment or a qualified definition of water content. In addition, some organic materials may be decomposed by oven drying at the standard drying temperature for this method (110 ± 5°C). Materials containing gypsum (calcium sulfate dihydrate) or other compounds having significant amounts of hydrated water, may present a special problem as this material slowly dehydrates at the standard drying temperature (110 ± 5°C) and at very low relative humidity, forming a compound (such as calcium sulfate hemihydrate) that is not normally present in natural materials except in some desert soils. In order to reduce the degree of dehydration of gypsum in those materials containing gypsum or to reduce decomposition in highly/fibrous organic soils, it may be desirable to dry the materials at 60°C or in a desiccator at room temperature. When a drying temperature is used which is different from the standard drying temperature as defined by this test method, the resulting water content may be different from the standard water content determined at the standard drying temperature of 110 ± 5°C. Note 1: Test Method D2974 provides an alternate procedure for determining water content of peat materials. 1.5 Materials containing water with substantial amounts of soluble solids (such as salt in the case of marine sediments) when tested by this method will give a mass of solids that includes the previously soluble dissolved solids. These materials require special treatment to remove or account for the presence of precipitated solids in the dry mass of the specimen, or a qualified definition of water content must be used. For example, see Test Method D4542 regarding information on marine sediments. 1.6 This test standard requires several hours for proper drying of the water content specimen. Test Methods D4643 , D4944 and D4959 provide less time-consuming processes for determining water content. See Gilbert 2 for details on the background of Test Method D4643 . 1.7 Two test methods are provided in this standard. The methods differ in the significant digits reported and the size of the specimen (mass) required. The method to be used may be specified by the requesting authority; otherwise Method A shall be performed. 1.7.1 Method A— The water content by mass is recorded to the nearest 1 %. For cases of dispute, Method A is the referee method. 1.7.2 Method B— The water content by mass is recorded to the nearest 0.1 %. 1.8 This standard requires the drying of material in an oven. If the material being dried is contaminated with certain chemicals that may react violently or emit hazardous gases when heated, health and safety hazards may exist. Therefore, this standard should not be used in determining the water content of contaminated soils unless adequate health and safety precautions are exercised. 1.9 Units— The values stated in SI units shall be regarded as standard except the Alternative Sieve Sizes listed in Table 1 are used. No other units of measurement are included in this test method. 1.10 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 , unless superseded by this test method. 1.10.1 This is especially important if the water content will be used to calculate other relationships such as moist mass to dry mass or vice versa, wet unit weight to dry unit weight or vice versa, and total density to dry density or vice versa. For example, if four significant digits are required in any of the above calculations, then the water content must be recorded to the nearest 0.1 %. This occurs since 1 plus the water content (not in percent) will have four significant digits regardless of what the value of the water content is; that is, 1 plus 0.1/100 = 1.001, a value with four significant digits. While, if three significant digits are acceptable, then the water content can be recorded to the nearest 1 %. 1.10.2 If water content data is to be used to calculate other relationships, such as moist or dry mass, wet or dry unit weight or total or dry density, then the specimen mass up to 200 g must be determined using a balance accurate to 0.01 g. 1.11 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. 1.12 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 ====== 5.1 For many materials, the water content is one of the most significant properties used in establishing a correlation between soil behavior and its index properties. 5.2 The water content of a material is used in expressing the phase relationships of air, water, and solids in a given volume of material. 5.3 In fine-grained soils, the consistency of a given soil type depends on its water content. The water content of a soil, along with its liquid and plastic limits as determined by Test Method D4318 , is used to express its relative consistency or liquidity index. Note 2: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.