Conclusions

(1)As the axial compression ratio increases,the failure mode of confined RC column changed from bending to shearing.The ductility increased with the number of CFRP layers,but when the number of layers exceeded 3,the increment was no more obvious.As the shear span ratio increased,the deformation capacity of the confined column increased,but the growth trend gradually disappeared when it reached a certain value.

(2)The results showed that the yielded rebar zone Lsy decreased with the increase of axial compression ratio;it also increased first and then decreased with the FRP layers;and it increased with the shear span ratio,while the increment gradually disappeared with high shear span ratio value.The crushed concrete zone Lcs increased with the increasing axial compression ratio,but it decreased with the increasing FRP layers;it also increased first with the shear span ratio,and the increment gradually disappeared with high shear span ratio value.