1.1 本试验方法包括测量4英寸的塑性流动阻力。（102 mm）沥青混合料圆柱形试样，通过马歇尔装置沿垂直于圆柱形轴线的方向加载。本试验方法适用于用沥青粘合剂（改性和未改性）制备的密实级配沥青混合料，最大粒径骨料不超过1英寸。（25 mm）尺寸（通过1 in.（25 mm的筛子）。 1.2 单位- 以英寸-磅单位表示的数值应视为标准值。括号中给出的数值是国际单位制的数学转换，仅供参考，不被视为标准。 1.3 本标准的文本引用了提供解释材料的注释和脚注。这些注释和脚注（表和图中的注释除外）不应视为本标准的要求。 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建立适当的安全、健康和环境实践，并确定监管限制的适用性。 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》中确立的国际公认标准化原则制定的。 =====意义和用途====== 4.1 马歇尔稳定性和流动值以及密度、总混合料中的空隙、矿物骨料中的空隙或填充沥青粘合剂的空隙，或两者兼而有之，用于沥青混合料的实验室混合料设计和评估。 此外，马歇尔稳定性和流动性可用于监测生产沥青混合料的工厂过程。马歇尔稳定性和流动性也可用于相对评估不同的混合物和调节（如用水）的效果。 4.1.1 马歇尔稳定性和流动性是沥青混合料的特性，由特定几何形状的压实试样的试验确定。马歇尔试验可使用两种不同类型的设备进行:( 1. )方法A-使用带有加载环和千分表的加载框架进行变形或流量计（传统方法）；或( 2. )方法B——使用载荷变形记录仪与称重传感器和线性可变差分传感器（LVDT）或其他自动记录装置（自动化方法）结合使用。 4.1.2 通常，马歇尔稳定性是在恒定变形率加载序列中获得的峰值阻力载荷。 然而，根据混合物的成分和行为，观察到了一种不太明确的失效类型，如 图1 作为另一种方法，马歇尔稳定性也可以定义为当载荷增加率开始降低，使得曲线开始变得水平时获得的载荷，如下图所示 图1 马歇尔稳定性的大小随骨料类型和级配以及沥青类型、级配和用量而变化。各个机构都有马歇尔稳定性的标准。 图1 两种试样失效的流量测定 4.1.3 马歇尔流是在稳定性试验期间测定的沥青混合料变形（弹性加塑性）的量度。在这两种失效类型中，马歇尔流是从曲线线性部分的投影切线与 x（x） -轴（变形）到曲线开始变为水平的点。如所示 图1 后一点通常对应于峰值稳定性；然而，作为一种备选方案，当失效条件没有明确定义时，可以将其选为曲线上的六个流动点或0.01英寸的点。（1.5 mm）至切线右侧。没有理想值，但有可接受的限制。如果选定的最佳粘结剂含量下的流动高于上限，则认为混合物太塑或不稳定，如果低于下限，则认为其太脆。 4.1.4 马歇尔稳定性和流动试验结果适用于最大粒径骨料达1英寸的密实级配沥青混合料。尺寸为（25 mm）。为了配合比设计，马歇尔稳定性和流动试验结果应包括粘合剂含量每增加一次至少三个试样的平均值，其中粘合剂含量在粘合剂含量范围内以0.5%的增量变化。 粘合剂含量范围通常根据经验和组分材料的历史测试数据进行选择，但可能需要反复试验，以包括所需的混合性能范围。在测试的粘合剂含量范围内，密实级配混合物通常会出现稳定性峰值。稳定性、流动性、密度、空隙率和沥青粘合剂填充的空隙率可根据粘合剂含量绘制，以便为混合物选择最佳粘合剂含量。上述测试特性也可以不同地加权，以反映特定的混合设计理念。此外，可能需要混合物设计，以满足矿物骨料中基于混合物中标称最大骨料尺寸的最小空隙。 4.1.5 由于工厂拌合与实验室拌合的差异，工厂拌合实验室压实（PMLC）沥青混合料制成的样品的现场实验室马歇尔稳定性和流动试验可能与实验室设计值有很大差异。 这包括混合效率和老化。 4.1.6 从一组试验到另一组试验，或从工厂生产的混合料制备的多组数据或试样的平均值，马歇尔稳定性和流动性的显著差异可能表明取样不良、测试技术不正确、级配变化、粘合剂含量变化或工厂工艺故障。应解决偏差的来源并纠正问题。 4.1.7 通常使用惯例制备样品 第6926页 ，但可以使用其他类型的压实程序制备，只要试样满足几何要求。其他类型的压实可能导致试样具有与马歇尔冲击压实制备的试样不同的应力应变特性。马歇尔稳定性和流动性也可使用来自 原位 路面信息或评估。然而，这些结果可能无法与实验室拌合实验室压实（LMLC）沥青混合料、工厂拌合实验室碾压（PMLC）沥青混合物或再加热工厂拌合室压实（RPMLC）沥青混合物样品的结果进行比较，且不得用于规范或验收目的。当岩芯侧面不光滑或不垂直于岩芯表面时，测试现场岩芯时会产生一个误差源。这样的条件会在加载时产生应力集中和低马歇尔稳定性。 注1: 本标准产生的结果质量取决于执行程序的人员的能力以及所用设备的能力、校准和维护。符合规范标准的机构 第3666页 通常认为能够胜任和客观的测试、取样、检验等。本标准的用户应注意遵守规范 第3666页 单独使用并不能完全确保可靠的结果。可靠的结果取决于许多因素；遵循规范的建议 第3666页 或一些类似的可接受的指南提供了评估和控制这些因素中的一些因素的方法。

1.1 This test method covers measurement of resistance to plastic flow of 4 in. (102 mm) cylindrical specimens of asphalt mixture loaded in a direction perpendicular to the cylindrical axis by means of the Marshall apparatus. This test method is for use with dense-graded asphalt mixtures prepared with asphalt binder (modified and unmodified) with maximum size aggregate up to 1 in. (25 mm) in size (passing 1 in. (25 mm) sieve). 1.2 Units— The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 The text of this standard 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 the 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. 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 Marshall stability and flow values along with density, air voids in the total mix, voids in the mineral aggregate, or voids filled with asphalt binder, or both, filled with asphalt binder are used for laboratory mix design and evaluation of asphalt mixtures. In addition, Marshall stability and flow can be used to monitor the plant process of producing asphalt mixture. Marshall stability and flow may also be used to relatively evaluate different mixes and the effects of conditioning such as with water. 4.1.1 Marshall stability and flow are asphalt mixture characteristics determined from tests of compacted specimens of a specified geometry. The Marshall Test can be conducted with two different types of equipment: ( 1 ) Method A—using a loading frame with a load ring and a dial gauge for deformation or flow meter (Traditional Method); or ( 2 ) Method B—using a load-deformation recorder in conjunction with a load cell and linear variable differential transducer (LVDT) or other automatic recording device (Automated Method). 4.1.2 Typically, Marshall stability is the peak resistance load obtained during a constant rate of deformation loading sequence. However, depending on the composition and behavior of the mixture, a less defined type of failure has been observed, as illustrated in Fig. 1 . As an alternative method, Marshall stability can also be defined as the load obtained when the rate of loading increase begins to decrease such that the curve starts to become horizontal, as shown in the bottom graph of Fig. 1 . The magnitude of Marshall stability varies with aggregate type and grading and bitumen type, grade, and amount. Various agencies have criteria for Marshall stability. FIG. 1 Flow Determination for Two Types of Specimen Failure 4.1.3 Marshall flow is a measure of deformation (elastic plus plastic) of the asphalt mixture determined during the stability test. In both types of failure, the Marshall flow is the total sample deformation from the point where the projected tangent of the linear part of the curve intersects the x -axis (deformation) to the point where the curve starts to become horizontal. As shown in Fig. 1 , this latter point usually corresponds to the peak stability; however, as an alternative when the failure condition is not clearly defined, it can be selected as the point on the curve which is six flow points or 0.01 in. (1.5 mm) to the right of the tangent line. There is no ideal value but there are acceptable limits. If flow at the selected optimum binder content is above the upper limit, the mix is considered too plastic or unstable and if below the lower limit, it is considered too brittle. 4.1.4 The Marshall stability and flow test results are applicable to dense-graded asphalt mixtures with maximum size aggregate up to 1 in. (25 mm) in size. For the purpose of mix design, Marshall stability and flow test results should consist of the average of a minimum of three specimens at each increment of binder content where the binder content varies in one half percent increments over a range of binder content. The binder content range is generally selected on the basis of experience and historical testing data of the component materials, but may involve trial and error to include the desirable range of mix properties. Dense-graded mixtures will generally show a peak in stability within the range of binder contents tested. Stability, flow, density, air voids, and voids filled with asphalt binder may be plotted against binder content to allow selection of an optimum binder content for the mixture. The above test properties may also be weighted differently to reflect a particular mix design philosophy. In addition, a mixture design may be required to meet minimum voids in the mineral aggregate based on nominal maximum aggregate size in the mixture. 4.1.5 Field laboratory Marshall stability and flow tests on specimens made with plant mix laboratory compacted (PMLC) asphalt mixture mix may vary significantly from laboratory design values because of differences in plant mixing versus laboratory mixing. This includes mixing efficiency and aging. 4.1.6 Significant differences in Marshall stability and flow from one set of tests to another or from an average value of several sets of data or specimens prepared from plant-produced mix may indicate poor sampling, incorrect testing technique, change of grading, change of binder content, or a malfunction in the plant process. The source of the variation should be resolved and the problem corrected. 4.1.7 Specimens will most often be prepared using Practice D6926 , but may be prepared using other types of compaction procedures as long as specimens satisfy geometry requirements. Other types of compaction may cause specimens to have different stress strain characteristics than specimens prepared by Marshall impact compaction. Marshall stability and flow may also be determined using field cores from in situ pavement for information or evaluation. However, these results may not compare with results from lab mix lab compacted (LMLC) asphalt mixture, plant mix laboratory compacted (PMLC) asphalt mixture, or reheated plant mix lab compacted (RPMLC) asphalt mixture specimens and shall not be used for specification or acceptance purposes. One source of error in testing field cores arises when the side of the core is not smooth or perpendicular to the core faces. Such conditions can create stress concentrations in loading and low Marshall stability. Note 1: The quality of the results produced by this standard are dependent on the competence of the personnel performing the procedure and the capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of Specification D3666 are generally considered capable of competent and objective testing, sampling, inspection, etc. Users of this standard are cautioned that compliance with Specification D3666 alone does not completely ensure reliable results. Reliable results depend on many factors; following the suggestions of Specification D3666 or some similar acceptable guideline provides a means of evaluating and controlling some of those factors.