[1C01-05] Application of Neutron and Ion Beam

[1C02] Development of Moisture Distribution Measurement Technology for Social Infrastructure using Mobile Linac-driven Neutron Source

*Jean-Michel Antoine Bereder¹, Yuya Mitsuya², Katsuhiro Dobashi², Yasushi Tanaka³, Yuya Takahashi⁴, Jo Kusano⁵, Mitsuru Uesaka¹ (1. Dept. of Nuclear Engineering and Management, Tokyo Univ., 2. Dept. of Nuclear Professional School, Tokyo Univ., 3. Institute of Industrial Science, Tokyo Univ., 4. Dept. of Civil Engineering, Tokyo Univ., 5. Accuthera Inc.)

Keywords:Non Destructive Inspection, Mobile Electron Linear Accelerator, Bridge Inspection, Moisture Inspection, Neutron Source

Breakage of iron reinforcing rods in reinforced concrete structures leads to a decrease in the yield strength of the structure, which is a major factor in reducing its remaining life. Detection of moisture inside the concrete is an urgent task because the major cause of corrosion of reinforcing bars is the invasion of oxide ions and chloride ions by the liquid water reaching the rebar. In this research, a backscatter neutron moisture detection system combining a compact linac X - ray source with beryllium and helium 3 detectors as a method of moisture detection inside concrete was developed, and its ability of moisture detection was confirmed by prior experiments. In this research, the authors aim to acquire moisture distribution data inside concrete which was difficult to acquire by the existing nondestructive inspection method. The authors conducted the moisture detection and moisture content evaluation experiment using concrete samples of several water cement ratio and water content ratio as a basic study.