Theoretical And Finite Element Analysis On Shear Capacity Of BFRP Bars Recycled Aggregate Concrete Beams Without Stirrups

The ordinary Reinforced concrete structures or components are prone to be seriously damaged due to steel reinforcement corrosion in the corrosive environment.The Fiber-Reinforced Polymer(FRP)bars have good corrosion resistance and can effectively solve the corrosion problem of Reinforced concrete structures or components.With the development of society,human beings are faced with the severe situation of shortage of natural resources such as stone materials and environmental pollution caused by the accumulation of construction wastes.The application of recycled concrete can effectively solve the problems of resource shortage and environmental pollution.Basalt fiber reinforced plastic bars(BFRP bars)are substituted for steel bars in this study,and recycled concrete is substituted for ordinary concrete.The BFRP bars and recycled concrete are organically combined.Through theoretical analysis and finite element analysis,the shear capacity of 12 BFRP bars recycled concrete beams without stirrups is studied.Based on modified compression field theory(MCFT),a new calculation model of shear capacity of the test beams is presented.It is also compared with the United codes,Japan,China and MCFT.In ANSYS numerical simulation,separate modeling is adopted to consider the bond slip mode between BFRP bars and recycled concrete.The characteristics of the recycled concrete stress,BFRP bars stress,crack development,cracking load,shear capacity and load-mid-span deformation curve of the test beam are studied.The influences of shear span ratio,BFRP bars ratio and replacement ratio of recycled coarse aggregate on shear capacity are analyzed.The results show that the cracking load of the test beams decrease with the increase of the shear span ratio and the replacement rate of the recycled coarse aggregate,and the BFRP bars ratio has no obvious influence on the cracking load.The shear capacity of the test beams decrease with the increase of the shear span ratio and the replacement ratio of recycled coarse aggregate,and the increase with the increase of the BFRP bars ratio.The calculation model proposed in this paper provides the shear capacity of the recycled concrete with the compression area,the tensile area and the BFRP bars.It is better than different codes and the MCFT.The shear capacity calculated in this paper is mainly provided by the compression area,followed by the tensile area and the BFRP bars.The simplified calculation model in this paper can be used for shear calculation and analysis of the BFRP bars recycled concrete beams without stirrups.The nonlinear model based on ANSYS can well simulate the shear capacity of the test beam.However,the influence of descending section of the recycled concrete constitutive relation is not considered,so the prediction of the shear capacity and the deformation of the test beam still have some deviation.