WEPP08  ポスターセッション①  9月2日 ポスター会場 12:40-14:40
Highway PC Bridge Inspection using 950keV/3.95MeV Portable X-ray/Neutron Source
○楊 健,上坂 充,三津谷 有貴,土橋 克広(東大),草野 譲一(アキュセラ)
○Jian Yang, Mitsuru Uesaka, Yuki Mitsuya, Katsuhiro Dobashi (Univ.of.Tokyo), Joichi Kusano (Accuthera Inc.,)
The 950keV portable LINAC-based X-Ray source is applied to cut-samples from a particular highway PC bridge in Japan. The advanced flat-panel detector adopts a longer data stacking time. For the first time, the inner structure of the 570mm-thick PC concrete is successfully visualized, which is the typical thickness for highway PC bridges. The use of X-ray mesh collimators reduces soft X-ray scattering noises, which improves the X-ray image quality. Grout-filling flaws inside the PC sheath could be confirmed through the visualization as well. When the grout is not adequately filled, the risk of moisture condensation would further damage the wire. As water is a competent moderator, neutrons generated by the beforementioned X-Ray source could be used to detect water inside the sheath. Based on the inspection data acquired and the grout filling condition, a structural numerical analysis could be performed to evaluate the strength degradation of the bridge inspected quantitatively. We propose the guideline of maintenance consisting of (i) screening by eye and hammering, (ii) X-ray and optional neutron inspection, (iii) structural analysis, and (iv) maintenance planning.