抄録
On March 11, 2011, a very big earthquake occurred in the Tohoku district in Japan. As a result, a large amount of tsunami sludge was generated and radiation contamination due to the nuclear power plant disaster also became a serious problem. To ensure the safety of living environments, it became necessary to decontaminate the radiation-contaminated waste and soil, and for the radioactive pollutant to be stored at temporary storehouses. However, because ordinary cover soil or sheets deteriorate under rainfall or ultraviolet light, further improvement of this system was required. This study focused on the “Fiber-cement-stabilized soil method”. This method is a new recycling method for high water content mud such as construction sludge by using paper debris and cement. Thus, if the cover soil for radiation-contaminated soil could be produced from the tsunami sludge, we could make effective use of the tsunami sludge and store the radiation-contaminated soil securely. The cover soil requires high failure strength, high durability for drying and wetting, high durability for erosion by rainfall and low permeability. To evaluate the durability of the cover soil made of tsunami sludge against erosion by rainfall, the indoor artificial rainfall test and the outdoor test under natural rainfall were carried out. As a result, it was confirmed that the durability of Fiber-cement-stabilized soil against erosion by rainfall was very high.
