To research the axial compression behavior of steel reinforced recycled concrete(SRRC)short columns confined by carbon fiber reinforced plastics(CFRP)strips,nine scaled specimens of SRRC short columns were fabricated ...To research the axial compression behavior of steel reinforced recycled concrete(SRRC)short columns confined by carbon fiber reinforced plastics(CFRP)strips,nine scaled specimens of SRRC short columns were fabricated and tested under axial compression loading.Subsequently,the failure process and failure modes were observed,and load-displacement curves as well as the strain of various materials were analyzed.The effects on the substitution percentage of recycled coarse aggregate(RCA),width of CFRP strips,spacing of CFRP strips and strength of recycled aggregate concrete(RAC)on the axial compression properties of columns were also analyzed in the experimental investigation.Furthermore,the finite element model of columns which can consider the adverse influence of RCA and the constraint effect of CFRP strips was founded by ABAQUS software and the nonlinear parameter analysis of columns was also implemented in this study.The results show that the first to reach the yield state was the profile steel in the columns,then the longitudinal rebars and stirrups yielded successively,and finally RAC was crushed as well as the CFRP strips was also broken.The replacement rate of RCA has little effect on the columns,and with the substitution rate of RCA from 0 to 100%,the bearing capacity of columns decreased by only 4.8%.Increasing the CFRP strips width or decreasing the CFRP strips spacing could enhance the axial bearing capacity of columns,the maximum increase was 10.5%or 11.4%,and the ductility of columns was significantly enhanced.Obviously,CFRP strips are conducive to enhance the axial bearing capacity and deformation capacity of columns.On this basis,considering the restraint effect of CFRP strips and the adverse effects of RCA,the revised formulas for calculating the axial bearing capacity of SRRC short columns confined by CFRP strips were proposed.展开更多
Statically push-out tests of 20 steel reinforced concrete short columns （SRCSC） with stud connectors on the surface of shape steel after fire and two SRCSC under ambient temperature were carried out, in order to stu...Statically push-out tests of 20 steel reinforced concrete short columns （SRCSC） with stud connectors on the surface of shape steel after fire and two SRCSC under ambient temperature were carried out, in order to study the failure mode, load-slip relationship and the interfacial shear transfer of SRC members after fire. Experimental results show that the typical failure modes and load-slip curves of SRCSC after fire are almost the same as the case under ambient temperature. The interfacial shear transfer of SRCSC declines exponentially not only with the increase of the peak temperature the specimen experienced but also with the increase of the peak temperature duration. The interfacial shear transfer of the specimens with studs arranged at the steel web is much higher than those with studs arranged at the steel flange. Empirical formulas of SRCSC interfacial shear transfer after fire are proposed, and the calculated results generally agree well with the experimental results.展开更多
基金The financial support of this work came from the project of National Natural Science Foundation of China(Grant No.51408485)the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2022JM-258 and 2021JM-332)+1 种基金the Open Fund Project of Qinghai Provincial Key Laboratory of Plateau Green Building and Eco-community(KLKF-2021-001)thanks a lot for the financial support of the above institutions.
文摘To research the axial compression behavior of steel reinforced recycled concrete(SRRC)short columns confined by carbon fiber reinforced plastics(CFRP)strips,nine scaled specimens of SRRC short columns were fabricated and tested under axial compression loading.Subsequently,the failure process and failure modes were observed,and load-displacement curves as well as the strain of various materials were analyzed.The effects on the substitution percentage of recycled coarse aggregate(RCA),width of CFRP strips,spacing of CFRP strips and strength of recycled aggregate concrete(RAC)on the axial compression properties of columns were also analyzed in the experimental investigation.Furthermore,the finite element model of columns which can consider the adverse influence of RCA and the constraint effect of CFRP strips was founded by ABAQUS software and the nonlinear parameter analysis of columns was also implemented in this study.The results show that the first to reach the yield state was the profile steel in the columns,then the longitudinal rebars and stirrups yielded successively,and finally RAC was crushed as well as the CFRP strips was also broken.The replacement rate of RCA has little effect on the columns,and with the substitution rate of RCA from 0 to 100%,the bearing capacity of columns decreased by only 4.8%.Increasing the CFRP strips width or decreasing the CFRP strips spacing could enhance the axial bearing capacity of columns,the maximum increase was 10.5%or 11.4%,and the ductility of columns was significantly enhanced.Obviously,CFRP strips are conducive to enhance the axial bearing capacity and deformation capacity of columns.On this basis,considering the restraint effect of CFRP strips and the adverse effects of RCA,the revised formulas for calculating the axial bearing capacity of SRRC short columns confined by CFRP strips were proposed.
基金Acknowledgements This research is supported by the National Science Foundation of China （Grant Nos. 50908118 and No. 51308307）, Ningbo Science Foundation （No. 2013A610194） and Ningbo Key Scientific Projects （No. XKL11D2079）.
文摘Statically push-out tests of 20 steel reinforced concrete short columns （SRCSC） with stud connectors on the surface of shape steel after fire and two SRCSC under ambient temperature were carried out, in order to study the failure mode, load-slip relationship and the interfacial shear transfer of SRC members after fire. Experimental results show that the typical failure modes and load-slip curves of SRCSC after fire are almost the same as the case under ambient temperature. The interfacial shear transfer of SRCSC declines exponentially not only with the increase of the peak temperature the specimen experienced but also with the increase of the peak temperature duration. The interfacial shear transfer of the specimens with studs arranged at the steel web is much higher than those with studs arranged at the steel flange. Empirical formulas of SRCSC interfacial shear transfer after fire are proposed, and the calculated results generally agree well with the experimental results.
