1.1 本试验方法包括使用轻型弯沉仪（LWD）测定铺砌和未铺砌表面的挠度。该装置也称为便携式落锤式挠度计（PFWD）。LWD重量轻、轻便，通常用于测试未结合的路面层。使用随钻测量的挠度可用于使用适当的反向或正向计算分析技术确定结合和非结合路面的刚度。 1.2 以国际单位制表示的数值应视为标准值。括号中给出的值仅供参考。 1.3 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。 1.4 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 本试验方法涵盖了由于施加冲击载荷而导致的表面挠度的测定。产生的挠度在施加荷载的中心测量，也可以在远离荷载的不同距离处测量。挠度可以直接与路面性能相关，也可以用于确定 现场 路面层的材料特性。数据的一些用途包括压实层的质量控制和质量保证，承载能力的结构评估，以及确定公路和机场路面的厚度要求（见指南） D4695 ). 注1: 由于路面和路基材料可能与应力有关，因此在分析未结合材料的随钻测井测试数据时必须小心，以便施加的应力与路面上设计车轮荷载施加的应力值密切匹配。 注2: 受荷载影响的路面和路基材料的体积是荷载大小的函数。因此，在分析结果时必须小心，因为LWD获得的数据可能是从较小体积的非粘结材料中获得的，而不是在路面上沉重的移动车轮载荷的影响下获得的。

1.1 This test method covers the determination of deflections of paved and unpaved surfaces with a Light Weight Deflectometer (LWD). This device is also referred to as a Portable Falling-Weight Deflectometer (PFWD). The LWD is lightweight, portable, and generally used for testing unbound pavement layers. The deflections measured using an LWD can be used to determine the stiffness of bound and unbound pavement surfaces using appropriate back or forward calculation analysis techniques. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.3 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. 1.4 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 This test method covers the determination of surface deflections as a result of the application of an impulse load. The resulting deflections are measured at the center of the applied load and may also be measured at various distances away from the load. Deflections may be either correlated directly to pavement performance or used to determine in-situ material characteristics of the pavement layers. Some uses of data include quality control and quality assurance of compacted layers, structural evaluation of load-carrying capacity, and determination of thickness requirements for highway and airfield pavements (see Guide D4695 ). Note 1: Since pavement and subgrade materials may be stress dependent, care must be taken when analyzing LWD test data on unbound materials so that the applied stress will closely match the stress value applied by the design wheel load at the pavement surface. Note 2: The volume of the pavement and subgrade materials affected by the load is a function of the magnitude of the load. Therefore, care must be taken when analyzing the results, since the data obtained by the LWD may be obtained from a smaller volume of the unbound materials than under the influence of a heavy moving wheel load at the pavement surface.