Inspection of ageing, reinforced concrete structures is a world-wide challenge. Existing non-destructive evaluation techniques in civil and structural engineering have limited penetration depth and don’t allow to precisely ascertain the configuration of reinforcement within large concrete objects. The big challenge for critical infrastructure (bridges, dams, dry docks, nuclear bioshields etc.) is understanding the internal condition of the concrete and steel, not just the location of the reinforcement. In most new constructions the location should be known and recorded in the as-built drawings, where these might not exist due to poor record keeping for older structures. Muon scattering tomography is a non-destructive and non-invasive technique which shows great promise for high-depth 3D concrete imaging. Previously, we have demonstrated that individual bars with a diameter of 33.7 7.3 mm can be located using muon scattering tomography. Here we present an improved method that exploits the periodicity of bar structures. With this new method, reinforcement with bars down to 6 mm thickness can be detected and imaged.

检查老化的钢筋混凝土结构是一个世界性的挑战。土木和结构工程中现有的无损评估技术穿透深度有限，无法精确确定大型混凝土物体内的钢筋配置。关键基础设施（桥梁、水坝、干船坞、核生物屏蔽等）面临的一大挑战是了解混凝土和钢材的内部状况，而不仅仅是钢筋的位置。在大多数新建筑中，位置应该是已知的并记录在竣工图纸中，由于旧结构的记录保存不佳，这些可能不存在。介子散射断层扫描是一种非破坏性和非侵入性技术，在高深度 3D 混凝土成像方面显示出巨大的前景。之前，我们已经证明可以使用 μ 子散射断层扫描定位直径为 33.7 7.3 毫米的单个条。在这里，我们提出了一种改进的方法，该方法利用了条形结构的周期性。使用这种新方法，可以检测和成像厚度低至 6 毫米的钢筋。