Experimental Study Of The Shear Behavior Of Basalt Fiber Reinforced RAC Beams Without Stirrups

The basalt fiber reinforced polymer(BFRP)bars have good corrosion resistance.If the BFRP bars are applied to the traditional reinforced concrete structure,it can solve the problem of steel corrosion.Recycled aggregate concrete(RAC)comes from waste concrete.The recycled concrete formed by recycled aggregate replacing whole or part of natural aggregate is applied to concrete structure,which plays an important role in protecting ecological environment.Therefore,the study on the shear behavior of basalt fiber reinforced RAC beams without stirrups which using BFRP bars and recycled concrete has certain theoretical and engineering value.In this paper,with the contrast tests of 12 full-scale simple supported basalt fiber reinforced concrete beams without stirrups under four-point bending to investigate the shear behavior of basalt fiber reinforced RAC beams without stirrups.The effects of shear-span ratio,reinforcement ratio and replacement ratio of recycled aggregate on the failure mode,shear capacity,initial crack load,deformation and crack propagation of the basalt fiber reinforced RAC beams without stirrups are investigated with the experimental study and theoretical analysis.The results show that:(1)The shear failure process of the basalt fiber reinforced RAC beams without stirrups and BFRP reinforced concrete beams are similar to the ordinary reinforced concrete beams.(2)The load-deflection curve of the basalt fiber reinforced RAC beams without stirrups is similar to the load-longitudinal reinforcement strain curve,which occurs rapidly after the occurrence of the crack.The maximum deflection of the basalt fiber reinforced RAC beams without stirrups is slightly smaller than BFRP reinforced concrete beam.(3)The shear capacity of the basalt fiber reinforced RAC beams without stirrups decreases with the increase of shear span ratio,and increases with the increase of longitudinal reinforcement ratio,and decreases with the increase of replacement ratio of recycled aggregate.The initial cracking load is greatly affected by the replacement rate of recycled aggregate,and the maximum reduction of initial cracking load is 23.6% with the increase of the replacement rate of recycled aggregate.(4)Compared with other existing Fiber Reinforced Polymer(FRP)code,Canadian code(CSA.S806-12)predicts the shear capacity of basalt fiber reinforced RAC beams without stirrups,which is in good agreement with the experimental values and has high stability.It shows that Canadian code(CSA.S806-12)is still applicable to the calculation of the shear capacity of basalt fiber reinforced RAC beams,and there is a certain degree of safety.The method of calculating initial crack load of beams in the American code(ACI 318M-05)is no longer applicable to basalt fiber reinforced RAC beams without stirrups.Compared with the Chinese code(GB 50608-2010),the American code(ACI 440.1R-06)has better consistency and stability in calculating the crack width of basalt fiber reinforced RAC beams,but it has greater conservativeness.The deflection of basalt fiber reinforced RAC beams is calculated by Chinese code(GB 50608-2010)with high coincidence.