Apparent diffusion coefficients of Cs and I in hardened cement paste using mineral admixtures

Mihara, Morihiro  ; Harasawa, Shuichi*; Torii, Kazuyuki*

Hardened cement pastes (HCPs) of water/cement ratio (W/C) 50% and 30% using fly ash (FA), blast furnace slag (BFS) and silica fume (SF) for 28 days were prepared. Apparent diffusion coefficients (D) of Cs and I in HCPs were obtained using electron probe microanalysis. For Cs, BFS and SF contributed to a reduction of D for W/C=50% and 30%, respectively. For I, BFS reduced D for W/C=50%, however a significant reduction in D for W/C=30% was not observed. Using SF enhanced sorption of Cs on HCP, and using BFS slightly improved sorption of Cs on HCP. It was also confirmed that the pore structures of HCP using SF and BFS were connected by fine pores. It was therefore considered that using SF and BFS contributes to the reduction of D in HCP.