CHANGES OF PORE STRUCTURE AND IONIC DIFFUSIVITY OF HARDENED CEMENT PASTE EXPOSED TO CONDITIONS AT SEVERAL LEVELS OF TEMPERATURE AND HUMIDITY
Exposure tests of hardened ordinary Portland cement paste specimens to elevatedtemperature levels such as 60 or 80~C under humidity conditions at 40, 90％RH, or waterimmersion were conducted to gain a better understanding of the influence of radioactivedecay heat generated in wastes on the performance of a cementitious barrier system for low-level radioactive waste disposal in Japan. The pore structure of cement paste specimens,which were exposed to high temperature conditions, was determined by mercury intrusionporosimetry in order to compare to the change of their ionic diffusivity. According to the results, it was confirmed that the exposure to low humidity conditionsunder 60 and 80C can rough pore structure and increase total pore volume. On the other, itwas observed that the high temperature exposure of specimens of W/C=0.35 to higherhumidity conditions such as 90％RH or water immersion changes the pore size smaller due tothe hydration of unreacted cement but increased the total pore volume. The higher thetemperature, the more total pore volume increased. The ionic diffusivity of specimen ofW/C=0.35 increased according to the total pore volume.
Isao Kurashige Takahiro Yoshida Taiji Chida Michihiko Hironaga
Nuclear Fuel Cycle Backend Research Center,Civil Engineering Laboratory,Central Research Institute o Radiation Safety Research Center,Nuclear Technology Research Laboratory,Central Research Institute o
国际会议
南京
英文
1473-1482
2008-10-13（万方平台首次上网日期，不代表论文的发表时间）