Effect Of Composite Aggregate On Performance Of Self-compacting Steel Tubular Concrete Short Columns Under Axial Compression

Self-compacting steel tube composite aggregate concrete short column is a new type of self-compacting steel tube concrete composite structural member formed by partially replacing ordinary gravel aggregate with light aggregate shale ceramsite aggregate.The structural member not only has the advantages of self-compacting concrete and light aggregate concrete,but also has the advantages of concrete-filled steel tubes.Advantages,while overcoming the mechanical shortcomings of light aggregate shale ceramsite concrete with relatively low strength,low elastic modulus and obvious brittle failure.This thesis carried out a study on the effect of composite aggregates on the performance of self-compacting concrete filled steel tube axial compression short columns.Reduced the consumption of ordinary gravel aggregates,and reduced the weight of structural members and the overall cost.Through the working performance and mechanical performance tests of self-compacting composite aggregate concrete,the fluidity,gap clearance and segregation resistance were studied for its working performance;the compressive strength of the cubic axis and the axial resistance of the prism were studied for its mechanical performance Compressive strength and elastic modulus,with the increase in the replacement of light aggregates,its working performance is becoming more and more excellent.The changes in mechanical properties are not very obvious,but the lateral expansion effect is greatly improved.In the study of self-compacting steel tube composite aggregate concrete short column under axial compression,the main experimental research parameter is the replacement volume of ceramsite volume of light aggregate shale,the whole process of the experiment is described,and its axial compression performance is analyzed,When the volume replacement of light aggregate is more reasonable,its ultimate axial compression bearing capacity will not be lower than that of ordinary steel tube concrete.Finally,the nonlinear finite element ABAQUS is used to model and calculate the axially compressed short column.The calculation results are compared with the ultimate bearing capacity and the load-strain relationship curve measured by the test.The difference is not too large,which can be used as a reference for the actual project.