Development of Two Candidate Concrete Mixtures (Salt, Nonsalt) for Repository Sealing Applications

摘要

Two concrete mixtures were developed in 1983 for possible use in nuclear waste repository sealing application. The salt concrete was basically an adaptation of BCT 1-F salt grout made by adding aggregate. The nonsalt mixture was a similar adaptation of nonsalt BCT 1-FF grout. The basic requirement was continued workability after 2 hr of intermittent mixing. Tests of hardened specimens included strength, modulus of elasticity (E), permeability, coefficient of linear thermal expansion, thermal conductivity, expansion, creep, and examinations by X-ray diffraction for phase composition and by scanning electron microscopy for microstructure. Some of the physical tests were done on specimens that had been kept at 23 + or - 1.7 deg C and on other specimens kept at 61 + or - 2 deg C. Tests for expansion and examinations for phase composition and microstructure are being continued at 6-month or yearly intervals. It was concluded that each concrete mixture was a viable candidate for use in repository sealing applications. (Author)