1.1 本试验方法涵盖了几种探地雷达（GPR）评估程序，可用于评估沥青混凝土磨耗表面覆盖的混凝土桥面状况。这些程序也可用于覆盖硅酸盐水泥混凝土的桥面和无覆盖层的桥面。具体而言，该试验方法可预测钢筋顶层水平或以上是否存在混凝土或钢筋劣化。 1.2 混凝土桥面的劣化表现为嵌入钢筋的腐蚀或混凝土的分解，或两者兼而有之。最严重的劣化形式是由预埋钢筋腐蚀引起的劣化。腐蚀可能是由冰盐引发的，冰盐在冬季用于控制冰雪，渗透混凝土。在干旱气候下，混合成分中含有的氯离子会引发腐蚀。 水的侵入也可能引发劣化，随后的冻融循环也会加剧劣化，导致混凝土受损，随后钢筋与周围受损的混凝土脱胶。 1.2.1 当钢筋腐蚀时，它会膨胀，并在钢筋水平面或钢筋上方的混凝土中产生裂缝或地下断裂面。断裂面或分层可能是局部的或可能延伸到相当大的区域，特别是当钢筋的混凝土保护层很小时。在混凝土表面和钢筋之间的不同平面上发生一次以上分层的情况并不少见。混凝土表面不可见分层。然而，如果不进行修复，分层会发展为打开的剥落，并且随着持续的腐蚀，最终会影响甲板的结构完整性。 1.2.2 与未受污染的混凝土相比，受过量氯化物污染的混凝土部分通常存在结构缺陷。此外，氯离子污染的混凝土提供了氯离子引发钢筋腐蚀的途径。因此，在桥面条件调查中，不仅要确定活跃钢筋腐蚀区域，还要确定氯化物污染和其他劣化混凝土区域，这一点尤为重要。 1.3 本试验方法可能不适用于评估钢筋直径上局部存在分层的桥梁，也不适用于那些在桥梁上安装了阴极保护（焦炭粉作为阴极）或在沥青中使用了导电骨料（即高炉矿渣）的桥梁。这是因为金属是电磁波的完美反射器，因为金属的波阻抗为零。 1.4 由于尚未制定本标准的精度估算，因此试验方法仅用于研究和信息目的。因此，本标准不应用于验收或拒收用于采购目的的材料。 1.5 以国际单位表示的值应视为标准值。本标准不包括其他计量单位。 1.6 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）不应视为本标准的要求。 1.7 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。 第节给出了具体的预防说明 5. . 1.8 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====== 3.1 本试验方法提供了沥青混凝土覆盖的混凝土桥面状况信息，无需移除覆盖层或其他破坏性程序。 3.2 该试验方法还提供了无覆盖层和有波特兰水泥混凝土覆盖层的桥面状况的信息。 3.3 桥面修复的系统方法需要桥面状况的大量数据。过去，数据收集采用传统的目视检查方法，辅以物理测试和取芯。 这些方法已经被证明是乏味、昂贵且精度有限的。因此，探地雷达提供了一种以高效、无损的方式快速测量桥梁的机制。 3.4 需要有关沥青混凝土桥面状况的信息，以估计维护和修复的桥面状况，为修复合同提供必要的成本效益信息。 3.5 探地雷达是目前唯一能够评估含沥青覆盖层桥面上桥面状况的无损检测方法。

1.1 This test method covers several ground penetrating radar (GPR) evaluation procedures that can be used to evaluate the condition of concrete bridge decks overlaid with asphaltic concrete wearing surfaces. These procedures can also be used for bridge decks overlaid with portland cement concrete and for bridge decks without an overlay. Specifically, this test method predicts the presence or absence of concrete or rebar deterioration at or above the level of the top layer of reinforcing bar. 1.2 Deterioration in concrete bridge decks is manifested by the corrosion of embedded reinforcement or the decomposition of concrete, or both. The most serious form of deterioration is that which is caused by corrosion of embedded reinforcement. Corrosion may be initiated by deicing salts, used for snow and ice control in the winter months, penetrating the concrete. In arid climates, the corrosion can be initiated by chloride ions contained in the mix ingredients. Deterioration may also be initiated by the intrusion of water and aggravated by subsequent freeze/thaw cycles, causing damage to the concrete and subsequent debonding of the reinforcing steel with the surrounding compromised concrete. 1.2.1 As the reinforcing steel corrodes, it expands and creates a crack or subsurface fracture plane in the concrete at or just above the level of the reinforcement. The fracture plane, or delamination, may be localized or may extend over a substantial area, especially if the concrete cover to the reinforcement is small. It is not uncommon for more than one delamination to occur on different planes between the concrete surface and the reinforcing steel. Delaminations are not visible on the concrete surface. However, if repairs are not made, the delaminations progress to open spalls and, with continued corrosion, eventually affect the structural integrity of the deck. 1.2.2 The portion of concrete contaminated with excessive chlorides is generally structurally deficient compared with non-contaminated concrete. Additionally, the chloride-contaminated concrete provides a pathway for the chloride ions to initiate corrosion of the reinforcing steel. It is therefore of particular interest in bridge deck condition investigations to locate not only the areas of active reinforcement corrosion, but also areas of chloride-contaminated and otherwise deteriorated concrete. 1.3 This test method may not be suitable for evaluating bridges with delaminations that are localized over the diameter of the reinforcement, or for those bridges that have cathodic protection (coke breeze as cathode) installed on the bridge or for which a conductive aggregate has been used in the asphalt (that is, blast furnace slag). This is because metals are perfect reflectors of electromagnetic waves, since the wave impedances for metals are zero. 1.4 Since a precision estimate for this standard has not been developed, the test method is to be used for research and informational purposes only. Therefore, this standard should not be used for acceptance or rejection of a material for purchasing purposes. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 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. 1.7 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. Specific precautionary statements are given in Section 5 . 1.8 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 ====== 3.1 This test method provides information on the condition of concrete bridge decks overlaid with asphaltic concrete without necessitating removal of the overlay, or other destructive procedures. 3.2 This test method also provides information on the condition of bridge decks without overlays and with portland cement concrete overlays. 3.3 A systematic approach to bridge deck rehabilitation requires considerable data on the condition of the decks. In the past, data has been collected using the traditional methods of visual inspection supplemented by physical testing and coring. Such methods have proven to be tedious, expensive, and of limited accuracy. Consequently, GPR provides a mechanism to rapidly survey bridges in an efficient, nondestructive manner. 3.4 Information on the condition of asphalt-covered concrete bridge decks is needed to estimate bridge deck condition for maintenance and rehabilitation, to provide cost-effective information necessary for rehabilitation contracts. 3.5 GPR is currently the only nondestructive method that can evaluate bridge deck condition on bridge decks containing an asphalt overlay.