1.1 本规程涵盖了可用于检测施加在有或没有导电垫层的混凝土基材上的非导电衬里或其他非导电涂层不连续性的程序。 1.2 不连续性可能包括针孔、内部空隙、漏涂、裂纹和导电夹杂物。 1.3 本规程描述了使用脉冲或连续直流电压的高压火花测试仪检测不连续性。 注1: 有关不连续性测试的更多信息，请参阅NACE标准规程SP0188，测试方法 G62 ，或实践 D5162 . 1.4 以国际单位制表示的值应被视为标准值。括号中给出的值仅供参考。 1.5 本标准并不旨在解决与其使用相关的所有安全问题（如果有的话）。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。 有关具体的危险声明，请参阅第节 7. . 1.6 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》中确立的国际公认的标准化原则制定的。 =====意义和用途====== 5.1 混凝土的电导率主要受水分的影响。影响混凝土结构电气连续性的其他因素包括: 5.1.1 金属钢筋的存在， 5.1.2 水泥含量和类型， 5.1.3 骨料类型， 5.1.4 外加剂， 5.1.5 混凝土内部的孔隙， 5.1.6 高于或低于地面标高， 5.1.7 室内或室外位置， 5.1.8 温度和湿度，以及 5.1.9 混凝土的年龄。 5.2 混凝土本身的电导率可以成功地用于直接施加的衬里的高压连续性测试，而无需安装特定的导电垫层。然而，在结构上，发现不连续性所需的电压可能因点而异。 这种差异可能会降低测试的可靠性。 5.3 尽管最常见的导电底层是用抹子、滚筒或喷雾涂覆的液体底漆，其中含有碳或石墨填料，但其他底层可能采取以下形式: 5.3.1 片状石墨面纱， 5.3.2 导电聚合物， 5.3.3 导电石墨纤维， 5.3.4 导电金属纤维，以及 5.3.5 导电金属屏蔽。 5.4 液体施加的导电垫层可能是理想的，因为它们可以解决混凝土表面的缺陷，并为施加衬里提供更好的基础。 5.5 此做法仅适用于混凝土基材上的新衬里。检查之前暴露在浸没条件下的衬里可能会导致衬里损坏，或者由于衬里的渗透或吸湿而产生不连续性的错误检测。 表面也可能存在沉积物，导致电报。不建议在之前暴露的衬里上使用高压测试仪，因为可能会产生火花，从而损坏原本完好的衬里。 5.6 当特定化学环境中衬里的性能要求要求确保衬里无不连续性时，用户可以考虑这种做法。 5.7 应考虑影响介电性能和试验电压的因素。一些因素是液体应用衬里的固化时间；导电填料或溶剂或两者的可能存在；可能存在空气夹杂物或空隙；以及导电衬垫与指定衬里的兼容性。 5.8 脉冲直流高压可能会导致衬里在比连续直流电压更低的电压下击穿。

1.1 This practice covers procedures that may be used for the detection of discontinuities in nonconductive linings or other non-conductive coatings applied to concrete substrates with or without a conductive underlayment. 1.2 Discontinuities may include pinholes, internal voids, holidays, cracks, and conductive inclusions. 1.3 This practice describes detection of discontinuities utilizing a high voltage spark tester using either pulsed or continuous dc voltage. Note 1: For further information on discontinuity testing refer to NACE Standard Practice SP0188, Test Method G62 , or Practice D5162 . 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.5 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. For a specific hazard statement, see Section 7 . 1.6 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 electrical conductivity of concrete is primarily influenced by the presence of moisture. Other factors that affect the electrical continuity of concrete structures, include the following: 5.1.1 Presence of metal rebar, 5.1.2 Cement content and type, 5.1.3 Aggregate types, 5.1.4 Admixtures, 5.1.5 Porosity within the concrete, 5.1.6 Above or below grade elevation, 5.1.7 Indoor or outdoor location, 5.1.8 Temperature and humidity, and 5.1.9 Age of concrete. 5.2 The electrical conductivity of concrete itself may be successfully used for high-voltage continuity testing of linings applied directly with no specific conductive underlayment installed. However, the voltage required to find a discontinuity may vary greatly from point to point on the structure. This variance may reduce the test reliability. 5.3 Although the most common conductive underlayments are liquid primers applied by trowel, roller, or spray, and which contain carbon or graphite fillers, others may take the form of the following: 5.3.1 Sheet-applied graphite veils, 5.3.2 Conductive polymers, 5.3.3 Conductive graphite fibers, 5.3.4 Conductive metallic fibers, and 5.3.5 Conductive metallic screening. 5.4 Liquid-applied conductive underlayments may be desirable as they can serve to address imperfections in the concrete surface and provide a better base for which to apply the lining. 5.5 This practice is intended for use only with new linings applied to concrete substrates. Inspecting a lining previously exposed to an immersion condition could result in damaging the lining or produce an erroneous detection of discontinuities due to permeation or moisture absorption of the lining. Deposits may also be present on the surface causing telegraphing. The use of a high voltage tester on a previously exposed lining is not recommended because of possible spark through which will damage an otherwise sound lining. 5.6 The user may consider this practice when performance requirements of the lining in a specified chemical environment require assurance of a lining free of discontinuities. 5.7 Factors affecting the dielectric properties and test voltage shall be considered. Some factors are the curing time of liquid-applied linings; the possible presence of electrically conductive fillers or solvents, or both; the possible presence of air inclusions or voids; and the compatibility of conductive underlayments with the specified lining. 5.8 A pulsed dc high voltage may cause a lining to breakdown at a lower voltage than would be the case for a continuous dc voltage.