Cement-based materials used at radioactive waste disposal sites are required to possess long-term stability. However, when these materials come in contact with groundwater, calcium leaching from the solid occurs, and the material becomes porous. The use of mineral admixtures is recommended to minimize porosity. However, few studies have focused on the diffusion performance of cement-based materials blended with mineral admixtures after leaching. Therefore, in this study, the diffusion performance of such materials using blended cement after leaching was evaluated. It was found that the diffusion coefficient of the blended cement increased with leaching, and when leaching progressed considerably, the diffusion coefficient of the blended cement was close to that of ordinary Portland cement. Furthermore, the diffusion coefficient after leaching demonstrated good correlation with the pore volume when the pore diameter was 50 nm or larger.

放射性废物处置场所使用的水泥基材料必须具有长期稳定性。但是，当这些材料与地下水接触时，就会发生钙从固体中浸出的现象，并且材料变得多孔。建议使用矿物掺合料以减少孔隙。但是，很少有研究关注浸出后与矿物掺合料掺混的水泥基材料的扩散性能。因此，在本研究中，评估了浸出后使用掺合水泥的此类材料的扩散性能。结果发现，随着浸出，混合水泥的扩散系数增加，当浸出进行得相当大时，混合水泥的扩散系数接近于普通硅酸盐水泥。此外，