Study On The Effect Of Particle Size And Content Of Coarse And Fine Aggregates On Properties Of Self-Compacting Concrete

Self-compacting concrete(SCC)is one of the most innovative high performance concrete in the 21st century.It has good working performance and compactness.It can be filled into every part of the model only by self-weight,and it can also prevent aggregate segregation and bleeding.Compared with common concrete,self-compacting concrete has excellent performance,mechanical properties and durability.At present,a lot of research has been done on SCC at home and abroad.However,the research on SCC generally uses a large number of cementitious materials to obtain high fluidity,and the amount of cement is also large,which can produce concrete with high design strength,but at the same time,it can only be used as "special concrete".Therefore,in order to make self-compacting concrete more widely used and expand its application field,this paper studies the influence of coarse aggregate size and sand ratio on the performance and mechanical properties of SCC under the condition of constant water-cement ratio.Measurement of SCC fluidity and anti-segregation by slump bucket and bottom plate,V-shaped instrument and U-shaped instrument,and through test adjustment,find out the influence of sand efficiency,high-efficiency water reducer and cementitious material on SCC mechanical properties,and finally determine the best mix ratio of sand ratio 45%,water reducer dosage 1.2%and water-cement ratio 0.28.After obtaining the optimum mix ratio,mechanical tests were carried out to study the effects of fine aggregate size,coarse aggregate size and sand ratio on the performance of SCC,and the relationship between the compression ratios of SCC.The conclusions are as follows:coarse aggregate particle size weakens the quality of interface transition zone and reduces the strength of SCC;fine aggregate affects the strength of SCC through different water requirements;sand ratio affects the strength of SCC through coarse aggregate.Study the fracture and fracture characteristics of SCC specimens after compression,and study the micro-structure of the specimens to explore the intrinsic characteristics of the specimens.It is found that the interface between coarse aggregate and cementitious material has a great influence on the strength of SCC.Figure 34 Table 23 Reference 53...