| Self-compacting concrete (SCC), which is a new kind of high performance concrete(HPC) with excellent deformability and segregation resistance, can flow freely under its own weight during the placing process, while it is cohesive enough to be handled without any segregation or bleeding. SCC in its fresh state is homogeneous and has excellent mechanical performance and durability.Based on the components of SCC are complex, the major factors influencing the properties are many, in this paper, a preliminary experimental study on the compatibility of superplasticizer, cement and mineral admixtures is made first, and rheological parameters of cement paste are studied by using the rotation viscometer, the influence of superplasticizer and mineral admixtures on the rheological behavior of cement paste is also analysed. Base on aforementioned experiments, the influence of the mineral admixtures such as fly ash(FA), ground granulated blast-furnace slag(GBS), superplasticizer on the rheological perfor- mance and workability of SCC is studied at last.Through many experimental researches, the following achievements and conclusions are obtained. The correlativity of cement paste fluidity and rheological properties and workability of SCC is visible. In fact, the properties of cement paste can serve as the basis for SCC design. Superplasticizer is helpless for the workability of the fresh concrete, which depress yield stress and plastic viscosity of SCC, especially polycarboxylate represent well, the optimum content is about 1.0%. Mineral admixture can improve and workability of SCC significantly. According to the result of flow test of binding paste and mix test of SCC,the optimum content of FA should be about 30% when used solely, while the content of GBS is about 15%. The results also indicate that the compound of fly ash and granulated blast-furnace slag mixed into the concrete can produce duplicated effect, which could produce SCC of high quality successfully.
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