1.1 该试验方法用于通过测量从初始平衡温度以恒定速率冷却时的热诱导应力和应变，确定现场取芯或实验室压实沥青混合料试样的热粘弹性和热体积特性。应使用单轴热应力应变测试仪（UTSST）测量热应力和应变。 1.2 本标准试验方法涵盖制备和测试沥青混合料的程序，以测量热应力和应变，并直接计算:( 1. )轴向热收缩系数，以及( 2. )沥青混合料在一定温度范围内的模量。 1.3 本标准中描述的程序提供了估算沥青混合料热裂敏感性所需的信息。该程序适用于最大骨料尺寸为19的试样 毫米或更小。 1.4 本标准适用于常规和非常规沥青混合料，包括但不限于:热沥青混合料、含回收材料的沥青混合料、冷沥青混合料、温沥青混合料和纯或改性沥青混合料（例如聚合物或橡胶）- 已修改）。 1.5 本标准可用于确定以下各项: 1.5.1 单一冷却过程中沥青混合料中的热应力累积。 1.5.2 沥青混合料中的热应变随温度的变化。 1.5.3 轴向热收缩系数。 1.5.4 沥青混合料模量随温度的变化。 1.5.5 沥青混合料的热粘弹性特性:粘性软化、粘性玻璃化转变、玻璃化硬化、裂纹萌生、断裂温度和断裂应力。 1.5.6 UTSST抗裂指数( CRI公司 ). 1.5.7 UTSST公司 CRI公司 根据环境条件进行调整( CRI公司 环境 ). 1.6 单位- 以国际单位制表示的数值应视为标准值。本标准不包括其他计量单位。 1.7 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（不包括表和图中的注释和脚注）不应视为本标准的要求。 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 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 热应变测量允许计算轴向热收缩系数，可直接用于机械经验路面设计方法。 5.2 热应力和应变测量允许在温度域中计算沥青混合料的模量。 5.3 根据模量与温度和热应力与温度的关系，确定沥青混合料的热粘弹性和断裂特性。 5.4 导出的模量、热粘弹性和断裂特性可用于评估沥青混合料的低温抗裂性。 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 D3666 通常认为能够胜任和客观的测试、抽样、检查等。本标准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。

1.1 This method of test is used to determine the thermal viscoelastic and thermal volumetric properties of field-cored or laboratory-compacted asphalt mixture specimens by measuring the thermally induced stress and strain while being cooled at a constant rate from an initial equilibrium temperature. The thermal stress and strain shall be measured using the uniaxial thermal stress and strain tester (UTSST). 1.2 This standard test method covers procedures for preparing and testing asphalt mixtures to measure thermal stress and strain and directly calculate: ( 1 ) the coefficient of axial thermal contraction, and ( 2 ) the modulus of asphalt mixture over a range of temperatures. 1.3 The procedure described in this standard provides required information for estimation of thermal cracking susceptibility of asphalt mixtures. The procedure applies to test specimens having a maximum aggregate size of 19 mm or less. 1.4 This standard can be used for conventional and nonconventional asphalt mixtures including but not limited to: hot asphalt mixtures, asphalt mixture with recycled materials, cold asphalt mixtures, warm asphalt mixtures, and neat or modified asphalt mixtures (for example, polymer or rubber-modified). 1.5 This standard can be used to determine the following: 1.5.1 Thermal stress buildup in asphalt mixture during a single cooling event. 1.5.2 Thermal strain in asphalt mixtures as a function of temperature. 1.5.3 Coefficient of axial thermal contraction. 1.5.4 Modulus of asphalt mixture as a function of temperature. 1.5.5 Thermal viscoelastic properties of asphalt mixture: viscous softening, viscous-glassy transition, glassy hardening, crack initiation, fracture temperature, and fracture stress. 1.5.6 UTSST cracking resistance index ( CRI ). 1.5.7 UTSST CRI adjusted for environmental condition ( CRI Env ). 1.6 Units— The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.7 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. 1.8 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 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 The thermal strain measurements allow for the calculation of the coefficient of axial thermal contraction, which can be directly used in the mechanistic-empirical pavement design methods. 5.2 The thermal stress and strain measurements allow calculations of the modulus of asphalt mixture in the temperature domain. 5.3 From modulus versus temperature and thermal stress versus temperature relationships the thermal viscoelastic and fracture properties are determined for asphalt mixtures. 5.4 The derived modulus, thermal viscoelastic, and fracture properties may be used in evaluating the low-temperature cracking resistance of asphalt mixtures. 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.