Researching The Mix Design Of Self-compacting Concrete Based On Special Surface Area Method Of Aggregates And Testing Its Basic Performance

Self-compacting concrete(SCC), which is a new kind of high performance concrete(HPC), can flow freely under its own weight during the placing process and flow through the gaps of reinforcement filling up the formwork, while it is cohesive enough to be handled without any segregation or bleeding. SCC in its fresh state is homogeneous and after hardened has excellent mechanical performance and durability.In view of lack of unified mix design criterion of SCC in China, the mix design of SCC was studied theoretically in this paper. The influences of different aggregates on SCC workability are very much. But the mix design of SCC now only considers the max particle diameter of coarse aggregate and fineness modulus of sand. However, the surface area and void fraction of aggregate influes the volume of paste . So the specific surface area criterion of aggregates and the excess paste volume were studied in this paper based on the experimental material, and then the specific surface area criterion mix design for SCC was proposed. Based on the mix design criterion, C35 and C50 SCC which affected actual needs were compounded. This paper did the further research on mechanics , shrinkage and durability performance of the C35 and C50 SCC and compared these performances with the compared concrete offered by Qinshan nuclear power plant. After that, micro-performance of the C35 and C50 SCC was also be studied by the methods of XRD and SEM.