Experimental Study On Seismic Performance Of RC Short Column Retrofitted By Prestressed Steel Strip

Reinforced concrete short column have the disadvantage of poor seismicperformance,brittle shearing destroy offen appear in the RC short columns under seismaction.As a new retrofit technology,prestressed steel strip suitable for seismicstrengthening of reinforced concrete short column,It has much advantages,such as lowcost,easy to install and excellent effectand,it shows wide application prospect.In order to improve the seismic performance of RC column,prestressed steel stripswere adopted to retrofit the columns,which was abbreviated as PSRC column in thefollow.In theory,because enhanced retrofitted by prestressed steel strips,the PSRCcolumn may have good seismic performance.In this paper,pseudo-static experiments of6specimens of PSRC columns and2specimens of RC columns were conducted firstlyto verify the theoretical prediction.According to the experimental results,it could beconcluded that the prestressed steel strip can effectively enhance the ultimatedeformability of concrete material,prevent concrete cover crushing and hold back thelongitudinal bar buckling,and as a result,the crack propagation and stiffness degradationof the specimens were also slowed down.According the experimental results of those9PSRC column specimens,the final failure pattern,hysteresis curves,skeleton curves ofthe specimens were fully analyzed.And a series of seismic performance indexes of thosespecimens such as displacement ductility coefficient,energy consumption values,andequivalent viscous damping coefficient were examined.Furthermore,the influence on theseismic performance of columns of prestressed steel strip spacing were analyzed.Fromthe experimental results,it was concluded that seismic performance of PSRC columnhad been successfully improved by the prestressed steel strip.Contrast with1carbon fiber reinforced concrete column(abbreviated as CFRP column) under the same level oflateral restraint,it firstly verify the seismic performance of the PSRC column is just asgood as CFRP column,and then proved that use prestressed steel strip to retrofit RCshort column is reliability and economic.According to the experiment results,the shear mechanism of the PSRC column hasbeen analysed in this paper.And through theoretical derivation,two shear capabilitydesign formula is presented.The calculation result were well matched with the testsdata.