Flexural Behavior Of GFRP Reinforced Rubber Granular Concrete Beams

The light weight,high strength,fatigue resistance,corrosion resistance and low specific gravity of FRP reinforcement make it widely used in civil engineering.Replacing reinforcement in reinforced concrete structure can effectively solve the corrosion problem of reinforcement.Rubber granular concrete is a new type of environmental protection concrete with excellent performance.In this paper,rubber granular concrete is introduced into FRP reinforced concrete structure,at the same time steel fiber is introduced into this new structure.Through the coordination of the three,the deformability of FRP reinforcement,rubber granular concrete and steel fiber is fully utilized,which can not only effectively solve the problem of reinforcement corrosion,but also improve the crack resistance of FRP reinforced concrete beam,enhance the bearing capacity of FRP reinforced concrete beam and make full use of the tensile strength of FRP reinforcement.To improve the brittleness of concrete beam with FRP reinforcement,provide experimental basis and theoretical basis for the application of FRP reinforcement in concrete structure engineering.In this paper,the flexural behavior of GFRP reinforced rubber granular concrete beam is studied.Six GFRP reinforced rubber granular concrete beams are fabricated through the test.Through finite element software ABAQUS analysis,the influence of rubber granules with 0%,5% and 10% volume fraction,reinforcement ratio of GFRP reinforcement 1.69% and 2.43%,and steel fiber with 0%,0.5% and 1% volume fraction on the flexural behavior of GFRP reinforced rubber granular concrete beam is investigated.The results show that:(1)Compared with rubber particle concrete without steel fibers,the cubic compressive strength of rubber particle concrete with steel fibers increased by 7.64%to 12.1%.Within the range of 0% to 1% volume fraction,it increased with the increase of the addition amount.(2)Compared with ordinary concrete beams,the cracking load of concrete beams with a volume fraction of 5% and 10% of rubber particles increases by16.46% to 31.19%,and the deflection under ultimate load increases by 6.5% to12.4%.Within the range of 0% to 1% of the volume fraction,the corresponding value of concrete beams increases with the increase of the addition amount;The increase in ultimate load is not significant.By adjusting and optimizing the concrete mix ratio,the beam can achieve the same flexural bearing capacity as ordinary concrete beams,and the rubber particle concrete beam has better deformation performance.(3)Adding different volume fractions of steel fibers can increase the cracking load of rubber particle concrete beams by 8.88%～11.31%,the ultimate load by10.08%～21.95%,and the deflection under ultimate load by 21%～36.65%.Within the range of 0%～1% volume fraction,their performance improves with the increase of the addition amount.(4)The finite element model established by ABAQUS can effectively simulate the failure of GFRP reinforced rubber particle concrete beams,and establish more parameter models to conduct finite element analysis and research on the rubber particle content,reinforcement ratio,and steel fiber volume content of GFRP reinforced rubber particle concrete beams.The simulation results are consistent with the experimental results.(5)Based on the assumption of a flat section,the equivalent rectangular stress height coefficient for the compression zone of rubber particle concrete beams is given β Equivalent coefficient of compressive stress for rubber particle concrete αThe formula for calculating the flexural bearing capacity of GFRP reinforced concrete beams was derived,and the theoretical values were compared with experimental values.The results showed that the calculation formula was somewhat conservative.