Experiment on the Axial Compressive Behavior of Corroded RC Stub Columns Strengthened with Duplex Stainless Steel Jackets
Corrosion of reinforced concrete(RC)bridge columns poses a significant threat to the safety and service life of bridges,therefore,corrosion protection and strengthening must be carried out simultaneously.This paper proposed using duplex stainless steel jackets to strengthen corroded RC bridge columns.To investigate the axial compressive behavior of these strengthened columns,axial compression tests were conducted on 10 corroded RC stub columns strengthened with duplex stainless steel jackets,2 corroded RC stub columns strengthened with low-carbon steel jackets and 4 unstrengthened RC stub columns for comparison.The failure modes and load-displacement curves of the specimens were obtained.On this basis,the effects of rebar corrosion rate,steel jacket thickness,steel jacket material and infill concrete type(self-compacting self-stressing concrete and self-compacting concrete)on the axial compressive behavior of specimens were analyzed.A formula for calculating the axial compressive capacity of corroded RC stub columns strengthened with duplex stainless steel jackets was derived.The predicted results are in good agreement with the test results,which provide a reference for practical engineering applications and future research.The study results indicate that the strengthened specimens exhibited two distinct failure modes:(1)local bulging of duplex stainless steel jacket in the upper or lower region of the specimens,(2)simultaneous local bulging and local buckling failure in the upper region of the specimens.The load-displacement curves,load-strain curves and bearing capacity of strengthened column specimens are greatly affected by the jacket thickness and material,while the rebar corrosion rate and infill concrete type have minimal impact.The bearing capacity and deformation capacity of corroded RC columns can be significantly improved by the duplex stainless steel jackets,and the bearing capacity of strengthened columns increases with the increase of the thickness of duplex stainless steel jackets.Under the same other conditions,the increase in the bearing capacity of specimens strengthened with duplex stainless steel jackets is higher than that of those strengthened with low-carbon steel jackets.
万方数据
维普
