[1C09-13] Concrete 2

[1C11] Study on the Radionuclide Contamination Mechanisms of Concrete and the Estimation of Distribution of Radionuclides

(18) Behavior of water uptake in concrete

Ippei Maruyama¹, *Go Igarashi², Kazuo Yamada³, Kazutoshi Shibuya⁴, Yoshifumi Hosokawa⁵, Yasumasa Tojo⁶, Yoshikazu Koma⁷ (1. UTokyo, 2. NagoyaU, 3. NIES, 4. Taiheiyo Consultant, 5. Taiheiyo cement, 6. Hokkaido Univ., 7. JAEA)

Keywords:C-S-H, Water uptake, Swelling, Cracks, Concrete

In the Fukushima Daiichi Nuclear Power Plants, for evaluating the amount of radioactive elements in concrete, liquid water transport in concrete, water uptake, should be considered, while the proper understanding of water uptake in aged concrete has not been developed. Detailed experiments and developing a numerical calculation method were investigated. The experimental data using 1H-NMR relaxometry, X-ray radiography, and digital image correlation method reveals that the swelling of C-S-H after moisture re-distribution in pore structure is the key phenomenon. From this point of view, we have developed a numerical analysis method that reflects the characteristics of the behavior of water in concrete during the water uptake. This numerical method can take into account mass transfer coefficient change due to crack-closing and change in microstructure associated with the swelling of C-S-H.