Research on seismic behavior and shear strength of SRHC frame columns

The seismic behavior of steel reinforced high strength and high performance concrete (SRHC) frame columns was investigated through pseudo-static experiments of 16 frame columns with various shear span ratios, axial compression ratios, concrete strengths, steel ratios and stirrup ratios. Three kinds of failure mechanisms are presented and the characteristics of experimental hysteretic curves and skeleton curves with different design parameters are discussed. The columns’ ductility and energy dissipation were quantitatively evaluated based on seismic resistance. The research results indicate that SRHC frame columns can withstand extreme bearing capacity, but the abilities of ductility and energy dissipation are inferior because of SRHC’s natural brittleness. As a result, the axial load ratio should be restricted and some construction measures adopted, such as increasing the stirrup ratio. This research established effect factors on the bearing capacity of SPHC columns. Finally, an algorithm for obtaining ultimate bearing capacity using the flexural failure mode is established based on a modified plane-section assumption. The authors also established equations to determine shearing baroclinic failure and shear bond failure based on the accumulation of the axial load force distribution ratio. The calculated results of shear bearing capacity for different failure modes were in good agreement with the experimental results.