| Our country has a vast sea area.The sea provides abundant resources and important transportation routes.The development and construction of islands is an inevitable trend.However,there is a shortage of building materials on the island.If the island’s coral reefs and coral sands are used instead of ordinary aggregates to pour concrete,the project cost can be reduced and the project progress can be accelerated.Because the aggregate contains Cl-,the combination of steel and coral concrete will cause corrosion of the former.The corrosion resistance and mechanical properties of 6061-T6 aluminium alloy commonly used in buildings are better.In this paper,6061-T6 aluminium alloy tube is used instead of steel tube and coral aggregate to pour short columns and study its compressive performance.The specific contents are as follows:Firstly,taking aluminium content,eccentricity and coral concrete strength as parameters,the axial compression and eccentric compression tests of aluminium alloy circular tube coral concrete short columns were carried out respectively,and the effects of various parameters on their compressive properties were studied.The results show that shear failure occurs in the axial compression short columns,overall bending failure occurs in the eccentric compression short columns,and the stress of the aluminium alloy tube can reach the conditional yield strength.The greater the aluminium content,the higher the bearing capacity,the greater the initial stiffness and the better the later ductility,the greater the strength of coral concrete,the bigger the initial stiffness and the worse the later ductility.the bigger the eccentricity of eccentrically compressed short columns,the lower the bearing capacity,the smaller the initial stiffness and the better the later ductility.The lateral deflection curve tends to sinusoidal half-wave curve.The assumption of plane section is applicable.At the initial stage of loading,the whole section is compressed,and the neutral and axial compression zone of the cross-section moves.The larger the eccentricity,the faster the movement is.The transverse deformation coefficient of axially compressed short columns is basically unchanged in the early stage,obviously increased in the later stage,and the effect of tightening hoop is remarkable.The effect of tightening hoop of eccentrically compressed short columns is smaller than that of axially compressed short columns,and there are differences in different regions.The most significant is in the compression region.The larger the eccentricity,the smaller the range and area of tightening hoop action in.Secondly,using ABAQUS finite element modeling verification and parameter analysis,the results show that the simulation results are in good agreement with the test results,the model is reasonable,the calculation accuracy is high,and the test results are reliable.The bigger the eccentricity and slenderness ratio,the lower the bearing capacity of the column,the smaller the flexural rigidity in the early stage and the better the ductility in the later stage.The bigger the hoop coefficient and the strength of coral concrete,the higher the bearing capacity of columns,the greater the flexural rigidity in the early stage,and the bigger the hoop coefficient,the better the ductility in the later stage,the bigger the strength of coral concrete,the worse the ductility in the later stage.Finally,combined with the experimental and finite element analysis data,the calculation formulas of the axial and eccentric compressive bearing capacity of aluminium alloy tube coral concrete short columns are established. |
