Study On The Performance Of C90 Self-compacting Concrete Based On Total Algorithm

High-strength self-compacting concrete is a kind of high-performance concrete with the demand of the large-span structure,high-rise structure and super high-rise structure.By mixing active mineral admixture and polycarboxylates superplasticizer,the flowability of high-strength concrete is improved.It has certain cohesion and limits the aggregate sinking,Making it a homogeneous,dense,stable concrete mix.Excepting the characteristics of bearing large span and super heavy load,High-strength self-compacting concrete can be filled with thin-walled,narrow space,reduce the cross-sectional area of the buildings,increase the reinforcement ratio,and improve the bending resistance of the structure,improve the compressive strength,at the same time,so that the structure more secure and stable.The study of high-strength self-compacting concrete is of great significance to the development of modern concrete.In this paper,combined with the requirements,we testt and select the raw materials of C90 high-strength self-compacting concrete.Then,the best combination of fly ash,slag powder and silica fume was tested by orthogonal experimental design,and the optimum proportion of active mineral admixture was determined:fly ash 10%,slag powder 10%,silica fume 6%.Using the total algorithm combined with the absolute volume method for the reference mix design,the prepared high performance concrete meets the workability,compressive strength and durability requirements of the C90 high-strength self-compacting concrete.On this basis,the work performance and mechanical properties of C90 high-strength self-compacting concrete were studied,such as coarse aggregate gradation and granularity,fine aggregate gradation and sand rate,total amount of cementitious material,admixture dosage,water-cement ratio.The deformation performance and resistance to chloride ion permeability of C90 high strength self-compacting concrete were studied by shrinkage test,early cracking test and resistance to chloride ion penetration test and the test results reached a higher level.Finally,SEM microstructure observation and mechanism analysis of C90 high-strength self-compacting concrete were made,and the macroscopic properties were explained.