[3B05-09] Investigation of Radioactive Contamination

[3B06] Study on Rational Treatment/Disposal of Contaminated Concrete Waste Considering Leaching Alteration

(6)Diffusion of Acetate and Carbonate Ions in Hardened Cement Paste

*Hiromichi Koike¹, Shinichiro Uematsu¹, Naoko Watanabe¹, Tamotsu Kozaki¹, Yuka Morinaga², Daisuke Minato², Toru Nagaoka² (1. Hokkaido Univ., 2. CRIEPI)

Keywords:Cement, C-14, Chemical form, Apparent diffusion coefficient, Imaging plate, Activation energy

We performed non-steady-state diffusion experiments with acetate and carbonate ions labelled with C-14 in hardened cement paste (HCP) using an imaging plate. The activation energy for the diffusion of acetate ions in HCP was determined from the temperature dependence of the apparent diffusion coefficients of acetate ions. The activation energy was nearly the same as that in bulk free water. In contrast, the diffusion of carbonate ions in HCP was not observed, indicating that the diffusion of carbonate ions was very slow. These results confirmed that the diffusion behavior of C-14 is different depending on the chemical form of C-14.