1.1 本试验方法涵盖断裂能的测定( G f )使用圆盘形紧凑拉伸几何形状的沥青混合料。圆盘形紧凑拉伸几何形状是一种圆形试样，具有承受张力的单边缺口。断裂能可以作为描述沥青混合料抗折性能的参数。断裂能参数在评估含韧性沥青粘合剂的沥青混合料（如聚合物改性沥青混合料）时特别有用，并且已证明比间接抗拉强度参数更广泛地区分这些材料（AASHTO T 322，参考 ( 1. ) ). 2. 该测试通常在10℃下有效 °C及以下，或用于产生有效材料断裂的材料和温度组合，如中所述 7.4 . 1.2 试样几何形状和术语（盘形紧密拉伸，DC（T））按照试验方法建模 E399 对于金属材料的平面应变断裂韧性，附录A6，进行了修改，以允许对沥青混合料进行断裂测试。 1.3 本试验方法描述了测定沥青混合料和类似准脆性材料断裂能所需的试验装置、仪器、试样制造和分析程序。 1.4 本试验方法的文本参考了提供解释材料的注释和脚注。这些注释和脚注（不包括表和图中的注释和脚注）不应视为试验方法的要求。 1.5 以国际单位制表示的数值应视为标准。本标准不包括其他计量单位。 1.6 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。 1.7 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 制定了测定沥青混合料抗折性的试验方法。抗折性有助于区分沥青混合料，其使用寿命可能因开裂而受到影响。该试验方法通常适用于在10℃下测试的试样 °C或以下（见 注1 ). 试样几何形状易于适应直径150 mm的试样，例如由Superpave（商标）旋转压实机制成的试样（试验方法 D6925 )，用于沥青混合料设计过程。样本几何形状也可适用于使用存在薄层提升的路面现场核心进行的法医调查。对于标称最大骨料粒径在4.75至19 mm之间的沥青混合料，这种几何形状可以产生令人满意的结果 ( 2. ) . 注1: 沥青结合料的刚度往往会影响中所述的有效试验的评估 7.4 . 例如，极冷气候可能需要的软沥青结合料可能不会产生在+10下产生有效结果的混合物 °C，相反，在炎热气候下使用的硬质沥青粘合剂可能需要更高的温度才能提供任何有意义的信息。 注2: 本试验方法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 D3666 通常认为能够胜任和客观的测试、抽样、检查等。本测试方法的用户应注意遵守规范 D3666 单独使用并不能完全确保可靠的结果。可靠的结果可能取决于许多因素；遵循规范建议 D3666 或一些类似的可接受指南提供了评估和控制其中一些因素的方法。 注3: 由于沥青结合料刚度和骨料质量对断裂路径以及断裂能值的交互作用，本试验中经历的破坏机制受到骨料类型的影响。在沥青结合料刚度较高的情况下，与沥青结合料低温性能等级附近的情况类似，当混合料包括硬质、非吸收性（例如花岗岩、陷阱岩）骨料时，裂缝将围绕骨料移动，从而产生更长的裂缝路径和更高的断裂能值。对于更软、更具吸收性的骨料，裂纹将穿过骨料，缩短裂纹路径，并导致断裂能值较低 ( 3. ) . 由于骨料类型对断裂能的影响，使用较软骨料的混合料中的混合料设计和/或粘合剂等级调整可能不足以提高断裂能以达到目标值。

1.1 This test method covers the determination of fracture energy ( G f ) of asphalt mixtures using the disk-shaped compact tension geometry. The disk-shaped compact tension geometry is a circular specimen with a single edge notch loaded in tension. The fracture energy can be utilized as a parameter to describe the fracture resistance of asphalt mixtures. The fracture energy parameter is particularly useful in the evaluation of asphalt mixtures with ductile asphalt binders, such as polymer-modified asphalt mixture, and has been shown to discriminate between these materials more broadly than the indirect tensile strength parameter (AASHTO T 322, Ref ( 1 ) ). 2 The test is generally valid at temperatures of 10 °C and below, or for material and temperature combinations which produce valid material fracture, as outlined in 7.4 . 1.2 The specimen geometry and terminology (disk-shaped compact tension, DC(T)) is modeled after Test Method E399 for Plane-Strain Fracture Toughness of Metallic Materials, Appendix A6, with modifications to allow fracture testing of asphalt mix. 1.3 The test method describes the testing apparatus, instrumentation, specimen fabrication, and analysis procedures required to determine fracture energy of asphalt mixture and similar quasi-brittle materials. 1.4 The text of this test method 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 test method. 1.5 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard. 1.6 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. 1.7 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 The test method was developed for determining the fracture resistance of asphalt mixtures. The fracture resistance can help differentiate asphalt mixtures whose service life might be compromised by cracking. The test method is generally valid for specimens that are tested at temperatures of 10 °C or below (see Note 1 ). The specimen geometry is readily adapted to 150 mm diameter specimens, such as fabricated from Superpave (trademark) gyratory compactors (Test Method D6925 ), which are used for the asphalt mixture design process. The specimen geometry can also be adapted for forensic investigations using field cores of pavements where thin lifts are present. This geometry has been found to produce satisfactory results for asphalt mixtures with nominal maximum aggregates size ranging from 4.75 to 19 mm ( 2 ) . Note 1: The stiffness of the asphalt binder tends to influence the assessment of a valid test as described in 7.4 . For instance, a soft asphalt binder which may be required for a very cold climate might not lead to a mixture that would produce valid results at +10 °C and, conversely, a hard asphalt binder utilized in hot climates may require higher temperatures to provide any meaningful information. Note 2: The quality of the results produced by this test method 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 test method are cautioned that compliance with Specification D3666 alone does not completely ensure reliable results. Reliable results may depend on many factors; following the suggestions of Specification D3666 or some similar acceptable guidelines provides a means of evaluating and controlling some of those factors. Note 3: The failure mechanism experienced in this test is influenced by the aggregate type due to the interactive effect of asphalt binder stiffness and aggregate quality on the fracture path and, therefore, fracture energy values. At high values of asphalt binder stiffness, similar to those experienced near the low-temperature performance grade of the asphalt binder, the crack will travel around the aggregate when the mixture includes hard, non-absorptive (for example, granite, trap rock) aggregates resulting in a longer crack path and higher values of fracture energy. For softer, more absorptive aggregates, the crack will travel through the aggregate, shortening the crack path and leading to lower values of fracture energy ( 3 ) . Due to the influence of aggregate type on fracture energy, mixture design and/or binder grade adjustments in mixes that use softer aggregates may not be sufficient in improving fracture energy to meet a target value.