ABSTRACT
Granulated blast furnace slag (GBF slag) generated in the manufacture process of pig iron has a high shear strength, light weight, and high permeability. Inside the particle, however, a lot of air bubbles are included and therefore, as compared with natural sand, the particle is easy to be crushed by the applied load. In this study, to clarify the effect of particle crushing on the geotechnical properties, firstly, the particle size distribution curve, maximum and minimum void ratio, particle density, compaction properties, shear strength and permeability characteristics were investigated. Secondly, the change of the particle distribution curve induced by the compaction was investigated and the particle shape of compacted GBF slag was visualized and compared with those of non-compacted slag. In the triaxial compression test, the effect of particle crushing on the shear strength induced by the confining pressure was observed. Furthermore, to find the effect of direction of cyclic shear strain on the vertical strain and also on the particle crushing, multi-directional simple shear tests were carried out. In conclusion, following results were obtained. 1) Apparent difference in the particle shape of GBF slag was observed as a result of compaction. 2)A larger particle crushing in the triaxial shear test occurs for GBF slag compared with natural sand, and the shear strength decreases with the confining pressure. 3) The amount of particle crushing and the vertical strain induced by the multi-directional cyclic shear test are larger than those induced in the uni-directional shear test.
