The mix proportions of mortar raw materials for solidified dry low-level radioactive wastes

As a part of study on leaching behavior of solidified dry Low-Level Radioactive Waste (LLW), effects of the mix proportions of mortar raw materials on mortar fluidity, compressive strength, bleeding and shrinkage were examined. The relation between mortar fluidity and other properties, and the mix proportion of mortar raw materials for solidified dry LLW were also examined. Better mortar fluidity, low compressive strength, high bleeding and high shrinkage showed when water/cement ratio was high. Large effects of water/blast furnace cement ratio on these properties were clarified. This difference between blast furnace cement and ordinary portland cement results from the existence of the fine blast furnace particles and small contents of cement in blast furnace cement. Mortar fluidity was also improved as chemical agent/cement ratio increased up to a certain value. Shrinkage decreases with increasing fine aggregate/cement ratio. This must be caused by the volume reduction while cement hydration. Furthermore, production of bleeding water, segregation and drastic decrease of compressive strength were recognized when mortar fluidity of blast furnace cement was good. The mix proportion of mortar raw materials for solidified dry LLW was proposed in consideration of mortar fluidity, compressive strength, bleeding and shrinkage. (author)