In this large‐scale field study we use a prototype impact‐echo scanner to detect delaminations on a concrete bridge deck surveying in total over 17,000 m². Delaminated bridge sections are known from manual sounding and coring. A large‐scale damage assessment is necessary to identify the need of repair work. Based on first results, two lanes of the bridge are repaired and in subsequent tests the bonding of fresh and old concrete is examined. It shows that delaminations found on the bridge deck surface are unevenly distributed with more defects on the southbound lanes. This indicates constructional problems during the concrete placement. The developed scanner excites stress waves by dropping steel solenoids on the surface and recording the impact‐echo frequency by air‐coupled microphone arrays. It is pushed at a speed of 600 m/h, hitting the surface 300 times per square meter. The recorded data is preprocessed on site with an automated delamination detection threshold implemented. Found delaminations are transferred to a bridge map to allow an overall damage assessment.

中文翻译：

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使用冲击回波扫描检测混凝土桥梁甲板上的分层

在这项大规模的现场研究中，我们使用原型冲击波回波扫描仪来检测混凝土桥面板上的分层，总共进行了超过17,000 m ^2的测量。从手动测深和取芯可以知道分层的桥段。为了确定维修工作的必要性，必须进行大规模的损坏评估。根据最初的结果，修复了桥梁的两个车道，并在随后的测试中检查了新旧混凝土的粘结性。结果表明，在桥面表面发现的分层不均匀，在南行车道上出现了更多的缺陷。这表明在混凝土浇筑过程中存在施工问题。研发的扫描仪通过将钢螺线管滴在表面上并通过空气耦合麦克风阵列记录冲击回波频率来激发应力波。它以600 m / h的速度被推动，每平方米撞击表面300次。记录的数据在现场进行了预处理，并实现了自动分层检测阈值。