1.1 这些试验方法包括实验室压实方法，用于确定4英寸或6英寸压实土壤的成型含水量和干容重（压实曲线）之间的关系。直径为101.6或152.4毫米的模具，10.00磅力。（44.48-N）夯锤从18.00英寸的高度坠落。（457.2毫米），产生56000英尺磅/英尺的压缩力 3. （2700 kN-m/m 3. ). 注1: 设备和程序与1945年美国工程兵团提出的相同。修改后的作用力测试（参见 3.1.3 )有时称为改良普氏压实试验。 1.1.1 土壤和土壤骨料混合物应视为天然细骨料- 或粗粒土壤，或天然土壤的复合物或混合物，或天然和加工土壤的混合物或骨料，如砾石或碎石。以下简称土壤或材料。 1.2 这些试验方法仅适用于具有30 % 或更少的颗粒质量保留在 3. / 4. -在中。（19.0-mm）筛子，之前未在实验室压实；也就是说，不要重复使用压实的土壤。 1.2.1 对于具有30 % 或更少（按保留在 3. / 4. -在中。（19.0-mm）筛分至单位重量，并通过 3. / 4. -在中。（19.0-mm）筛，见实践 D4718/D4718M . 1.3 提供了三种替代方法。所用方法应符合被测材料规范的规定。如果没有规定方法，则应根据材料级配进行选择。 1.3.1 方法A: 1.3.1.1 模具- 4英寸。（101.6-mm）直径。 1.3.1.2 材料- 通过4号（4.75-mm）筛。 1.3.1.3 图层- 五 1.3.1.4 每层锤击数- 25 1.3.1.5 用法- 如果25，则可以使用 % 4号（4.75-mm）筛子上保留的材料质量为或更少。但是，如果5到25 % 根据保留在4号（4.75-mm）筛子上的材料质量，可以使用方法A，但需要进行过大的校正（见 1.4 )在这种情况下，使用方法A没有任何好处。 1.3.1.6 其他用途- 如果无法满足该级配要求，则可以使用方法B或C。 1.3.2 方法B: 1.3.2.1 模具- 4英寸。（101.6-mm）直径。 1.3.2.2 材料- 经过 3. / 8. -在中。（9.5-mm）筛。 1.3.2.3 图层- 五 1.3.2.4 每层锤击数- 25 1.3.2.5 用法- 如果25，则可以使用 % 或更少（按质量计）的材料保留在 3. / 8. -在中。（9.5-mm）筛。但是，如果5到25 % 材料的 3. / 8. -在中。（9.5-mm）筛子，可使用方法B，但需要进行超大尺寸校正（见 1.4 ). 在这种情况下，使用方法B而不是方法C的唯一优点是需要更少的样本量，并且更小的模具更容易使用。 1.3.2.6 其他用途- 如果无法满足该级配要求，则可以使用方法C。 1.3.3 方法C: 1.3.3.1 模具- 6英寸。（152.4-mm）直径。 1.3.3.2 材料- 经过 3. / 4. -在中。（19.0-mm）筛。 1.3.3.3 图层- 五 1.3.3.4 每层锤击数- 56 1.3.3.5 用法- 如果30，则可以使用 % 或更少（参见 1.4 )按材料质量保留在 3. / 4. -在中。（19.0-mm）筛。 1.3.4 6英寸。（152.4-mm）直径的模具不得与方法A或B一起使用。 注2: 研究发现，当在不同尺寸的模具中以相同的压实力测试材料时，结果略有不同，较小的模具尺寸通常会产生较大的单位重量和密度值 ( 1. ) . 2. 1.4 如果试样包含5个以上 % 根据超大粒级（粗粒级）的质量和材料不包括在试验中，必须使用实践对试样的单位重量和成型含水量或适当的现场原位单位重量（或密度）试样进行修正 D4718/D4718M . 1.5 该试验方法通常会为非自由排水土壤产生明确定义的最大干容重。如果本试验方法用于自由排水土壤，则可能无法很好地定义最大单位重量，并且可能小于使用试验方法获得的最大单位重量 D4253 . 1.6 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 ，除非被这些试验方法取代。 1.6.1 为了将测量值或计算值与规定限值进行比较，测量值或计算值应四舍五入至规定限值中最接近的小数或有效数字。 1.6.2 本标准中用于规定如何收集/记录或计算数据的程序被视为行业标准。此外，它们代表了通常应保留的有效数字。使用的程序不考虑材料变化、获取数据的目的、特殊目的研究或用户目标的任何考虑因素； 通常的做法是增加或减少报告数据的有效位数，以与这些考虑因素相称。考虑工程设计分析方法中使用的有效数字超出了这些测试方法的范围。 1.7 以英寸-磅为单位的数值应视为标准值。以国际单位制表示的数值仅供参考，质量单位除外。质量单位仅采用国际单位制，g或kg。 1.7.1 工程专业中的常见做法是同时使用磅来表示质量单位（lbm）和力（lbf）。这隐含地结合了两个独立的单元系统； 也就是说，绝对系统和引力系统。在一个标准中结合使用两套独立的英寸-磅单位在科学上是不可取的。在处理英寸-磅系统时，这些测试方法是使用单位重力系统编写的。在该系统中，磅（lbf）表示力（重量）的单位。然而，使用天平或天平记录磅质量（lbm）或记录密度（lbm/ft） 3. 不应视为不符合本标准。 1.8 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。 1.9 警告- 环保局和许多国家机构已将汞指定为一种有害物质，可导致中枢神经系统、肾脏和肝脏损害。汞或其蒸汽可能对健康有害，并对材料具有腐蚀性。处理汞和含汞产品时应小心。有关详细信息，请参阅适用的产品材料安全数据表（MSDS）和EPA网站(http://www.epa.gov/mercury/faq.htm)了解更多信息。用户应意识到，州法律可能禁止向您所在州销售汞或含汞产品或两者兼而有之。 1.10 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 将作为工程填料（路堤、基础垫层、道路基层）铺设的土壤压实至密实状态，以获得令人满意的工程特性，如抗剪强度、压缩性或渗透性。此外，经常对地基土进行压实，以改善其工程特性。实验室压实试验为确定达到所需工程特性所需的压实百分比和成型含水量以及控制施工以确保达到所需压实度和含水量提供了依据。 注3: 达到预期工程特性所需的土壤压实度通常规定为使用本试验方法确定的修改后最大干容重的百分比。 如果所需压实度大大低于使用本试验方法修改的最大干容重，则使用试验方法进行试验并将压实度指定为标准最大干容重的百分比可能是可行的。由于使用该试验方法进行压实需要更多的能量，因此土壤颗粒比 D698 已使用。总体结果是最大干容重更高，最佳含水量更低，剪切强度更大，刚度更大，压缩性更低，空隙率更低，渗透性降低。但是，对于高度压实的细骨料- 颗粒土，吸水可能会导致膨胀，剪切强度降低，压缩性增加，减少用于压实的增加作用力的益处 ( 2. ) . 使用 D698 另一方面，允许使用较少的作用力进行压实，并且通常在较高的最佳含水量下进行压实。压实的土壤可能不那么脆，更灵活，更具渗透性，更少受到膨胀和收缩的影响。在许多应用中，建筑或施工规范可能会指示哪种测试方法， D698 或者，当指定实验室测试结果与现场现场土壤压实度的比较时，应使用此方法。 5.2 在工程填料的设计过程中，为确定剪切、固结、渗透性或其他特性而进行的测试需要通过将土壤压实到规定的成型含水量来制备试样，以获得预定的单位重量。通常先确定最佳含水量( w 选择 )和最大干容重（γ D最大值 )通过压实试验。在选定的成型含水量下压实试样( w )，最佳湿态或干态( w 选择 )或处于最佳状态( w 选择 )，并在与最大干容重百分比（γ）相关的选定干容重下 D最大值 ). 成型含水量的选择( w )，最佳湿态或干态( w 选择 )或处于最佳状态( w 选择 )和干容重（γ D最大值 )可以基于过去的经验，或者可以调查一系列值，以确定必要的压实百分比。 5.3 经验表明 5.2 或中讨论的施工控制方面 5.1 在处理某些土壤时，极难实施或产生错误结果。以下小节描述了典型问题土壤、处理此类土壤时遇到的问题以及这些问题的可能解决方案。 5.3.1 超大分数- 含30%以上的土壤 % 超大部分（保留在 3. / 4. -在中。（19 mm）筛）是一个问题。对于此类土壤，没有ASTM测试方法来控制其压实度，很少有实验室配备来确定此类土壤的实验室最大单位重量（密度）（美国农业部垦务局，科罗拉多州丹佛市和美国陆军工程兵团，密西根州维克斯堡市）。尽管试验方法 D4914/D4914M 和 D5030/D5030M 确定此类土壤的“现场”干容重，很难且成本高昂。 5.3.1.1 设计和控制此类土壤压实的一种方法是使用试验填料来确定所需的压实度和获得该压实度的方法。然后使用方法规范控制压实。 方法规范的组成部分通常包含要使用的压实设备的类型和尺寸、提升厚度、成型含水量的可接受范围和通过次数。 注4: 土方工程项目压实控制的成功实施，尤其是在使用方法规范时，在很大程度上取决于承包商和检查员的质量和经验。 5.3.1.2 另一种方法是使用美国农业部复垦局开发的密度校正系数 ( 3. , 4. ) 和美国工程兵团 ( 5. ) . 这些修正系数可适用于含约50至70%的土壤 % 超大分数。 两个机构对这些密度校正系数使用不同的术语。美国农业部复垦局使用 D 比率（或 D –值），而美国工程兵团使用密度干扰系数( 我 c ). 5.3.1.3 更换技术（试验方法）的使用 D1557 –78，方法D），其中用更细的分数替换过大的分数，不适合确定最大干容重γ D最大值 ，含超大粒级的土壤 ( 5. ) . 5.3.2 降级- 土壤中含有在压实过程中降解的颗粒，这是一个问题，尤其是在实验室压实过程中发生的降解比现场压实过程中发生的降解更多时，这是典型的情况。 降解通常发生在颗粒残余土壤或骨料的压实过程中。当发生降解时，最大干容重增加 ( 1. ) 因此，得出的实验室最大值不能代表现场条件。在这些情况下，通常不可能在现场实现最大干容重。 5.3.2.1 同样，对于易退化的土壤，使用试验填料和方法规范可能会有所帮助。使用替换技术是不正确的。 5.3.3 间隙分级- 间隙级配土壤（包含许多大颗粒和有限小颗粒的土壤）是一个问题，因为压实土壤的空隙比通常情况下更大。 为了处理这些大空隙，通常必须使用工程判断修改标准试验方法（实验室或现场）。 注5: 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 laboratory compaction methods used to determine the relationship between molding water content and dry unit weight of soils (compaction curve) compacted in a 4- or 6-in. (101.6- or 152.4-mm) diameter mold with a 10.00-lbf. (44.48-N) rammer dropped from a height of 18.00 in. (457.2 mm) producing a compactive effort of 56 000 ft-lbf/ft 3 (2700 kN-m/m 3 ). Note 1: The equipment and procedures are the same as proposed by the U.S. Corps of Engineers in 1945. The modified effort test (see 3.1.3 ) is sometimes referred to as the Modified Proctor Compaction Test. 1.1.1 Soils and soil-aggregate mixtures are to be regarded as natural occurring fine- or coarse-grained soils, or composites or mixtures of natural soils, or mixtures of natural and processed soils or aggregates such as gravel or crushed rock. Hereafter referred to as either soil or material. 1.2 These test methods apply only to soils (materials) that have 30 % or less by mass of their particles retained on the 3 / 4 -in. (19.0-mm) sieve and have not been previously compacted in the laboratory; that is, do not reuse compacted soil. 1.2.1 For relationships between unit weights and molding water contents of soils with 30 % or less by weight of material retained on the 3 / 4 -in. (19.0-mm) sieve to unit weights and molding water contents of the fraction passing the 3 / 4 -in. (19.0-mm) sieve, see Practice D4718/D4718M . 1.3 Three alternative methods are provided. The method used shall be as indicated in the specification for the material being tested. If no method is specified, the choice should be based on the material gradation. 1.3.1 Method A: 1.3.1.1 Mold— 4-in. (101.6-mm) diameter. 1.3.1.2 Material— Passing No. 4 (4.75-mm) sieve. 1.3.1.3 Layers— Five. 1.3.1.4 Blows per layer— 25. 1.3.1.5 Usage— May be used if 25 % or less by mass of the material is retained on the No. 4 (4.75-mm) sieve. However, if 5 to 25 % by mass of the material is retained on the No. 4 (4.75-mm) sieve, Method A can be used but oversize corrections will be required (See 1.4 ) and there are no advantages to using Method A in this case. 1.3.1.6 Other Use— If this gradation requirement cannot be met, then Methods B or C may be used. 1.3.2 Method B: 1.3.2.1 Mold— 4-in. (101.6-mm) diameter. 1.3.2.2 Material— Passing 3 / 8 -in. (9.5-mm) sieve. 1.3.2.3 Layers— Five. 1.3.2.4 Blows per layer— 25. 1.3.2.5 Usage— May be used if 25 % or less by mass of the material is retained on the 3 / 8 -in. (9.5-mm) sieve. However, if 5 to 25 % of the material is retained on the 3 / 8 -in. (9.5-mm) sieve, Method B can be used but oversize corrections will be required (See 1.4 ). In this case, the only advantages to using Method B rather than Method C are that a smaller amount of sample is needed and the smaller mold is easier to use. 1.3.2.6 Other Usage— If this gradation requirement cannot be met, then Method C may be used. 1.3.3 Method C: 1.3.3.1 Mold— 6-in. (152.4-mm) diameter. 1.3.3.2 Material— Passing 3 / 4 -in. (19.0-mm) sieve. 1.3.3.3 Layers— Five. 1.3.3.4 Blows per layer— 56. 1.3.3.5 Usage— May be used if 30 % or less (see 1.4 ) by mass of the material is retained on the 3 / 4 -in. (19.0-mm) sieve. 1.3.4 The 6-in. (152.4-mm) diameter mold shall not be used with Method A or B. Note 2: Results have been found to vary slightly when a material is tested at the same compactive effort in different size molds, with the smaller mold size typically yielding larger values of unit weight and density ( 1 ) . 2 1.4 If the test specimen contains more than 5 % by mass of oversize fraction (coarse fraction) and the material will not be included in the test, corrections must be made to the unit weight and molding water content of the test specimen or to the appropriate field in-place unit weight (or density) test specimen using Practice D4718/D4718M . 1.5 This test method will generally produce a well-defined maximum dry unit weight for non-free draining soils. If this test method is used for free-draining soils the maximum unit weight may not be well defined, and can be less than obtained using Test Methods D4253 . 1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 , unless superseded by these test methods. 1.6.1 For purposes of comparing measured or calculated value(s) with specified limits, the measured or calculated value(s) shall be rounded to the nearest decimal or significant digits in the specified limits. 1.6.2 The procedures used to specify how data are collected/recorded or calculated in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of these test methods to consider significant digits used in analytical methods for engineering design. 1.7 The values in inch-pound units are to be regarded as the standard. The values stated in SI units are provided for information only, except for units of mass. The units for mass are given in SI units only, g or kg. 1.7.1 It is common practice in the engineering profession to concurrently use pounds to represent both a unit of mass (lbm) and a force (lbf). This implicitly combines two separate systems of units; that is, the absolute system and the gravitational system. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. These test methods have been written using the gravitational system of units when dealing with the inch-pound system. In this system, the pound (lbf) represents a unit of force (weight). However, the use of balances or scales recording pounds of mass (lbm) or the recording of density in lbm/ft 3 shall not be regarded as a nonconformance with this standard. 1.8 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. 1.9 Warning— Mercury has been designated by EPA and many state agencies as a hazardous material that can cause central nervous system, kidney, and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet (MSDS) for details and EPA’s website (http://www.epa.gov/mercury/faq.htm) for additional information. Users should be aware that selling mercury or mercury containing products or both into your state may be prohibited by state law. 1.10 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 Soil placed as engineering fill (embankments, foundation pads, road bases) is compacted to a dense state to obtain satisfactory engineering properties such as shear strength, compressibility, or permeability. In addition, foundation soils are often compacted to improve their engineering properties. Laboratory compaction tests provide the basis for determining the percent compaction and molding water content needed to achieve the required engineering properties, and for controlling construction to assure that the required compaction and water contents are achieved. Note 3: The degree of soil compaction required to achieve the desired engineering properties is often specified as a percentage of the modified maximum dry unit weight as determined using this test method. If the required degree of compaction is substantially less than the modified maximum dry unit weight using this test method, it may be practicable for testing to be performed using Test Method and to specify the degree of compaction as a percentage of the standard maximum dry unit weight. Since more energy is applied for compaction using this test method, the soil particles are more closely packed than when D698 is used. The general overall result is a higher maximum dry unit weight, lower optimum moisture content, greater shear strength, greater stiffness, lower compressibility, lower air voids, and decreased permeability. However, for highly compacted fine-grained soils, absorption of water may result in swelling, with reduced shear strength and increased compressibility, reducing the benefits of the increased effort used for compaction ( 2 ) . Use of D698 , on the other hand, allows compaction using less effort and generally at a higher optimum moisture content. The compacted soil may be less brittle, more flexible, more permeable, and less subject to effects of swelling and shrinking. In many applications, building or construction codes may direct which test method, D698 or this one, should be used when specifying the comparison of laboratory test results to the degree of compaction of the in-place soil in the field. 5.2 During design of an engineered fill, testing performed to determine shear, consolidation, permeability, or other properties requires test specimens to be prepared by compacting the soil at a prescribed molding water content to obtain a predetermined unit weight. It is common practice to first determine the optimum water content ( w opt ) and maximum dry unit weight (γ dmax ) by means of a compaction test. Test specimens are compacted at a selected molding water content ( w ), either wet or dry of optimum ( w opt ) or at optimum ( w opt ), and at a selected dry unit weight related to a percentage of maximum dry unit weight (γ dmax ). The selection of molding water content ( w ), either wet or dry of optimum ( w opt ) or at optimum ( w opt ) and the dry unit weight (γ dmax ) may be based on past experience, or a range of values may be investigated to determine the necessary percent of compaction. 5.3 Experience indicates that the methods outlined in 5.2 or the construction control aspects discussed in 5.1 are extremely difficult to implement or yield erroneous results when dealing with some soils. The following subsections describe typical problem soils, the problems encountered when dealing with such soils and possible solutions for these problems. 5.3.1 Oversize Fraction— Soils containing more than 30 % oversize fraction (material retained on the 3 / 4 -in. (19-mm) sieve) are a problem. For such soils, there is no ASTM test method to control their compaction and very few laboratories are equipped to determine the laboratory maximum unit weight (density) of such soils (USDI Bureau of Reclamation, Denver, CO and U.S. Army Corps of Engineers, Vicksburg, MS). Although Test Methods D4914/D4914M and D5030/D5030M determine the “field” dry unit weight of such soils, they are difficult and expensive to perform. 5.3.1.1 One method to design and control the compaction of such soils is to use a test fill to determine the required degree of compaction and the method to obtain that compaction. Then use a method specification to control the compaction. Components of a method specification typically contain the type and size of compaction equipment to be used, the lift thickness, acceptable range of molding water content, and number of passes. Note 4: Success in executing the compaction control of an earthwork project, especially when a method specification is used, is highly dependent upon the quality and experience of the contractor and inspector. 5.3.1.2 Another method is to apply the use of density correction factors developed by the USDI Bureau of Reclamation ( 3 , 4 ) and U.S. Corps of Engineers ( 5 ) . These correction factors may be applied for soils containing up to about 50 to 70 % oversize fraction. Both agencies use a different term for these density correction factors. The USDI Bureau of Reclamation uses D ratio (or D – VALUE), while the U.S. Corps of Engineers uses Density Interference Coefficient ( I c ). 5.3.1.3 The use of the replacement technique (Test Method D1557 –78, Method D), in which the oversize fraction is replaced with a finer fraction, is inappropriate to determine the maximum dry unit weight, γ dmax , of soils containing oversize fractions ( 5 ) . 5.3.2 Degradation— Soils containing particles that degrade during compaction are a problem, especially when more degradation occurs during laboratory compaction than field compaction, the typical case. Degradation typically occurs during the compaction of a granular-residual soil or aggregate. When degradation occurs, the maximum dry-unit weight increases ( 1 ) so that the resulting laboratory maximum value is not representative of field conditions. Often, in these cases, the maximum dry unit weight is impossible to achieve in the field. 5.3.2.1 Again for soils subject to degradation, the use of test fills and method specifications may help. Use of replacement techniques is not correct. 5.3.3 Gap Graded— Gap-graded soils (soils containing many large particles with limited small particles) are a problem because the compacted soil will have larger voids than usual. To handle these large voids, standard test methods (laboratory or field) typically have to be modified using engineering judgement. Note 5: 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.