Research On Shear Behavior Of Recycled Fiber Reinforced Concrete Beams With BFRP Reinforcement

In order to improve the safety and durability of the structure,it is necessary to solve the structural crack caused by the difficulty of concrete vibration caused by the small spacing of structural reinforcement and the decrease of bond force between the concrete reinforcement.Fiber reinforced concrete(FRC)has been widely used in engineering structures.Adding a certain amount of fiber into the concrete can improve the performance of the concrete and has a positive significance for the actual project.Fiber recycled concrete is to evenly mix the appropriate short cut fiber into the recycled concrete.Basalt fiber reinforced composite(BFRP)bars,as an effective substitute of traditional steel bars,have been widely used in engineering structures due to their corrosion resistance and high strength.FRP reinforced concrete structure has a bright future because of its excellent performance,and there are engineering examples put into application and corresponding specifications.In this paper,the shear properties of 11 recycled concrete beams reinforced with BFRP are tested.The shear properties of the beams are analyzed with different basalt fiber volume,shear span ratio and stirrup ratio as reference factors,and the calculated values and test results are compared.The results show that when the fiber volume fraction is 2%,the mechanical properties reach the peak value;when the load is fixed,the larger the shear span ratio is,the larger the midspan deflection is;when the fiber volume fraction is higher,the midspan deflection first increases and then decreases;when the fiber volume fraction is 2%,the midspan deflection is the largest;the larger the stirrup ratio is,the larger the midspan deflection is;under the same load,the BFRP fiber is The larger the shear span ratio is,the larger the stirrup strain is,and its change trend is similar to the load deflection curve;the larger the fiber volume fraction is,the smaller the stirrup strain is;the larger the stirrup ratio is,the smaller the stirrup strain is;for the cracking load of the fiber reinforced recycled concrete beam with BFRP reinforcement,the negative correlation exists with the shear span ratio and the cracking load;the positive correlation exists between the fiber volume fraction,the reinforcement ratio and the cracking load For the ultimate load of fiber reinforced recycled concrete beam with BFRP reinforcement,the shear span ratio has a negative correlation with the ultimate load of the test beam,and the fiber volume content,reinforcement ratio and the ultimate load of the test beam have a positive correlation;Consider?_v?_f?empirical formula of shear capacity of BFRP reinforced fiber recycled concrete beams is more accurate in checking the shear capacity,followed by the Chinese code(GB50608-2010),the American code(ACI440.1R-06)which is more stable,and the Canadian code(CSA.S806-2012)which is less consistent with the test value;the Canadian code(CSA.S806-12)which is more accurate in calculating the mid span deflection of the test beam,and the American code(ACI 440.1R-03)followed by Chinese code(GB 50608-2010);American code(ACI 440.1R-03)was more accurate in calculating the maximum crack width of test beam,followed by the empirical formula considered,while Chinese code(GB 50608-2010)is poor.