Study On The Flexural Performance Of Reinforced Concrete Beams With Hybrid BFRP And Steel Bars

Since the emergence of concrete materials,various buildings have emerged one after another with the rapid economic development,however,more and more problems have been exposed accordingly.Due to the porosity of concrete materials and the easily corrosion quality of steel bars,many countries waste a lot of money on the corrosion of reinforced concrete structures every year.Owing to BFRP material’s good quality of corrosion resistance,it has become an innovative solution.But the elastic modulus of BFRP bars is small,which makes the concrete beams with BFRP bars prone to cracks and deflection.In order to solve the problem of the durability of reinforced concrete beams and the shortcomings of large deformation of BFRP reinforced concrete beams during normal use,the method of hybrid them came into being.This paper studies the flexural performance of hybrid reinforced concrete beams.The main research contents are as follows:1.Discrimination of destruction mode.According to the geometric deformation conditions of the hybrid-reinforced concrete beams and the constitutive relationship of various materials,the reinforcement ratio of the concrete beams in the two limit states can be obtained.The failure mode can be judged through contrasting the size relationship of hybrid reinforcement ratio and the two limit hybrid reinforcement ratio of the concrete beam,which could lay the foundation for the subsequent work;2.Deduces the calculation formula of cracking load,flexural bearing capacity,crack width and short-term stiffness of hybrid reinforced concrete beams.After taking the specific test data into the verification,we can found the theoretical deduction formula’s results are conform to the real test results,therefore the deduction formula can be applied to actual projects accurately;3.Research of ductility index.All kinds of ductility coefficient methods,involving the traditional ductility coefficient,deformation coefficient and energy ductility coefficient,were used to analyze the ductility of hybrid reinforced concrete beams.Generally speaking,the results obtained by the above methods are decreased in sequence,and these coefficients will increase correspondingly with the increase of the hybrid reinforcement ratio;4.Using ABAQUS to simulate the force and deformation of the beam,it is in good agreement with the test results.Through simulation,the cracking load,flexural capacity and ultimate deflection of the beam can be calculated.Comparing the results with the test results can prove the correctness of the simulation.