Quality assurance and condition assessment of concrete structures is an important topic world-wide due to the aging infrastructure and increasing traffic demands. Common topics include, but are not limited to, localisation of rebar or tendon ducts, geometrical irregularities, cracks, voids, honeycombing or other flaws. Non-destructive techniques such as ultrasound or radar have found regular, successful practical application but sometimes suffer from limited resolution and accuracy, imaging artefacts or restrictions in detecting certain features. Until the 1980s X-ray transmission was used in case of special demands and showed a much better resolution than other NDT techniques. However, due to safety concerns and cost issues, this method is almost never used anymore. Muon tomography has received much attention recently. Novel detectors for cosmic muons and tomographic imaging algorithms have opened up new fields of application, such as the investigation of freight containers. Muon imaging also has the potential to fill some of the gaps currently existing in concrete NDT. As a first step towards practical use and as a proof of concept we used an existing system to image the interior of a reference reinforced 600 kg concrete block. Even with a yet not optimized setup for this kind of investigation, the muon imaging results are at least of similar quality compared to ultrasonic and radar imaging, potentially even better. The data acquisition takes more time and signals contain more noise, but the images allowed to detect the same important features that are visible in conventional high energy X-ray tomography. In our experiment, we have shown that muon imaging has potential for concrete inspection. The next steps include the development of mobile detectors and optimising acquisition and imaging parameters.

由于基础设施老化和交通需求增加，混凝土结构的质量保证和状况评估是世界范围内的一个重要课题。常见主题包括但不限于钢筋或腱管的定位、几何不规则性、裂缝、空隙、蜂窝状或其他缺陷。诸如超声波或雷达之类的非破坏性技术已经找到了常规、成功的实际应用，但有时会受到分辨率和准确性的限制、成像伪影或检测某些特征的限制。直到 1980 年代，X 射线透射才用于特殊需求，并显示出比其他无损检测技术更好的分辨率。然而，由于安全问题和成本问题，这种方法几乎不再使用。介子断层扫描最近受到了很多关注。用于宇宙μ子的新型探测器和断层成像算法开辟了新的应用领域，例如货运集装箱的调查。Muon 成像也有可能填补目前混凝土无损检测中存在的一些空白。作为实际应用的第一步和概念验证，我们使用现有系统对参考钢筋 600 公斤混凝土块的内部进行成像。即使对于此类调查尚未优化设置，与超声波和雷达成像相比，μ 子成像结果至少具有相似的质量，甚至可能更好。数据采集​​需要更多时间并且信号包含更多噪声，但图像允许检测在传统高能 X 射线断层扫描中可见的相同重要特征。在我们的实验中，我们已经证明μ子成像具有用于混凝土检测的潜力。下一步包括开发移动探测器以及优化采集和成像参数。