Axial compressive behavior and bearing capacity calculation of spirally reinforced seawater sea-sand concrete-filled aluminum alloy tube stub columns
To investigate the axial compressive behavior of spirally reinforced seawater sea-sand concrete-filled aluminum alloy tube stub columns(ASSCs),16 ASSC specimens and one seawater sea-sand concrete-filled aluminum alloy tube column were designed for axial compression loading test,and test parameters included the ratio of spiral stirrup to longitudinal reinforcement(0.55,1.02,2.20,4.01),the diameter(6,8,10 mm)and spacing(40-210 mm)of spiral stirrup and the number(2,4,6,8)and diameter(6,8,10,14 mm)of longitudinal reinforcement.The failure mode,axial load-deformation relationship,characteristic points and the influences of test parameters on bearing capacity,axial ductility and energy dissipation capacity were presented and analyzed.The results show that the failure process of the above columns is similar and both are shear failure,but ASSC has better axial compression bearing capacity and deformation capacity.The bearing capacity,ductility and energy dissipation capacity of ASSC increase first and then decrease with the increase of ratio of spiral stirrup to longitudinal reinforcement.The axial compressive behavior of specimens is the best when the ratio is 2.2,and specimens with thin and dense spiral stirrups or few and thick longitudinal reinforcements have higher ultimate bearing capacity,ductility and energy dissipation capacity.It is suggested to adjust the diameter and spacing of spiral stirrup to obtain ideal axial compression performance.The axial compression capacity formula derived for ASSC has high calculation accuracy with an average error of 1%.