Study on the Influence of Fly-Ash Quality on the Properties of Cementitious Materials and the Applicability of Nondestructive Tests for Quality Control at Radioactive Waste Disposal Facility in Japan

This paper describes the method for quality control of the cementitious materials used in radioactive waste disposal facility in Japan. The influence of the fly-ash quality and the methods of the early-age curing on the fresh properties, mechanical properties and the effective tritium diffusion coefficient is investigated. In addition, the applicability of nondestructive test for quality control of these cementitious materials is also investigated. The test for the those investigation are done in the simulated actual conditions during construction and exposure environment of the disposal facilities. Test results indicate that the variability in the quality of fly-ash has no remarkable influence on the property of the cementitious materials in this case, and that the compressive strength can be calculated from the surface strength tested with the rebound hammer of the nondestructive test.