Abstract

The performance of recycled aggregate concrete(RAC)is usually inferior compared with the normal aggregate concrete(NAC).Using RAC in composite member is an easy and promising way to avoid the unfavourable effects(e.g.reduced strength and durability)of including recycled aggregates.In this study,RAC was in combination with steel and fibrereinforced polymer(FRP)to form an FRP-RAC-steel hybrid column.In such hybrid column,the FRP tube and steel tube were placed outside and inside,respectively,with the concrete filling inbetween.Existing studies already showed that if NAC was used,the said hybrid column possessed many good properties such as enhanced strength and deformation capacity.The compressive behavior of both DTCCs and DTSCs with RAC(under axial compression loading)was tested.For comparison purpose,plain concrete columns(CC),concrete filled steel tubes(CFST)and concrete filled FRP tubes(CFFT)were also tested.The test results showed favourable ef fects existed due to the beneficial interaction among the difference components(FRP,steel and RAC)of the said hybrid column members.As a result,FRP-RAC-steel hybrid column has a similar compressive behavior as FRP-NAC-steel hybrid column although including recycled aggregates which had a certain adverse effects.