Low-strength Self-compacting Concrete And The Experimental Study On The Flexural Performance Of The Beam

The structure system of concrete minitype hollow building blocks with constructional colum and circle beam is the mainstream form of structure instead of brick-concrete structure in multi-story.The brick-wall not only is a bearing member,but also is onlyside-force-resistance member.Since the bond area of block and masonry mortar is only 23 percent of the brick and mortar,and block and masonry mortar belong to brittle materials,so that the structure withstand horizontal seismic load capacity decreased significantly.Therefore the measures by putting ring girders as well as structure column can greatly improve the shear strength.However,in this system,it is ont only the construction speed is low,but also it is sure that vibrating can easily result in dislocation of building block around constructional colum and under ring beam.by using normal concrete according to present operation rules,and this is one of reasons which can lead to dehiscence between building blocks.It can be a very good solution to this problem in theory that low-intensity self-compacting concrete used in small concrete hollow block masonry structure.However, up to now the research of SCC mainly concentrates on the strength degree of C40 and above.The study of low-intensity self-compacting concrete used in constructional ring beam of bearing building blocks is rarely found.But the most prominent feature of self-compacting concrete,which is applicable to the circle beam and the core column,are Low-intensity levels,high mobility,high-filled,high-isolation and high volume stability.At the same time there are the advantages of less construction noise,being able to carry out at night,the concrete quality uniform,smaller workload workload faster construction velocity and so on.This paper,selecting locality material,based on self-compacting concrete preliminary mixing proportion,uses of reasonable compound admixtures and adjusts the water-binder ratio or the content of the fly ash to obtain satisfying high workability and the strength requirements of self-compacting concrete for ring beam,analyzes the impact of the admixtures and its content on low-strength self-compacting concrete performance. Analyzes the impact of water-binder ratio or the content on the strengthof self-compacting concrete. On the basis of the mixture ratio,this paper comparative study on the simple beam bending properties of the self-compacting concrete and common concrete.The results show that the bending destruction do not have clear difference between low-intensity self-compacting concrete beam and ordinary concrete beam.Comparing to the experiment value including cracking load,yield and load limit load is very close;It is The average strain of self-compacting concrete beam can well agree with the assumption of plane section,which provides a strong basis for its theoretical calculation of normal section bending bearing capacity.