Abstract:
A “+”-shaped and two “X”-shaped steel reinforced lightweight aggregate concrete (SRLC) columns were tested under low cyclic loading. The loading processes and damage patterns of the SRLC columns were systematically investigated, and the effects of steel section arrangement and axial compression ratio (
nt) on the mechanical properties of the columns, such as load-displacement curves, ductility, energy dissipation capacity and performance degradation, were primarily analyzed. The applicability of the existing standardized calculation methods and truss-arch model for horizontal bearing capacity of steel reinforced concrete (SRC) columns were evaluated, and a model correction method based on the decoupling idea was established. The test results indicate that all the three SRLC columns show flexural-shear failure mode. The hysteresis curves of the specimens are plump, the bearing capacity decreases slowly after the peak value is reached, and the deformation meets the ductility seismic demands. With the increase of
nt, the horizontal bearing capacity of the specimens increases, while the ductility and cumulative hysteresis energy dissipation (
Esum) decrease. The arrangement of cross-shaped steel section has a significant effect on the seismic performance of specimens. The ultimate displacement drifts, horizontal bearing capacity and
Esum of the specimen with “X”-shaped steel are improved significantly, compared with those with “+”-shaped steel. The calculation results of the multi-national codes and the truss-arch model are unsafe, but the modified refined model based on the decoupling idea has an error of less than 5%, which can be adopted to predict the horizontal bearing capacity of SRLC columns.