Research On Behavior Test And Numerical Analysis Of Concrete Beam Embedded With 635MPa Hot Rolled High Strength Steel Bars Under Bending And Shearing

With the increasing shortage of iron and steel resources in the world,it is an important method to accelerate the construction of resource-saving and environment-friendly society and realize the sustainable development of economy to popularize and apply high strength steel bars in the engineering field.At present,China’s research on high strength rebar is mainly focused on 500 MPa,and there are relatively few of 600 MPa grade and above strength rebar.Moreover,the 600 MPa grade and above high strength rebar studied in China is mostly prepared by heat treatment and cold rolling process,resulting in many limitations on its mechanical properties and less research.The 635 MPa hot rolled high strength steel bar studied in this paper is a new type of high strength steel bar,which has the advantages of high strength,good ductility,stable performance and so on.Therefore,it has a considerable application prospect in practical engineering.In order to popularize the application of this new type of high strength steel bar in engineering field,the bending and shear tests of 635 MPa hot rolled high strength reinforced concrete beams were carried out.The failure mechanism and mechanical performance are studied deeply,and on this basis,the bearing capacity is calculated and analyzed.Specific research contents are as follows:1)In this paper,the bending behavior of eight 635 MPa hot rolled high strength reinforced concrete beams is tested.Taking concrete strength,longitudinal reinforcement ratio,cross section area of concrete beam and longitudinal reinforcement strength as research parameters,the flexural bearing capacity,failure mode,stress-strain distribution and stress mechanism of 635 MPa class hot-rolled high-strength reinforced concrete beam were studied in depth.The bearing capacity,crack width and deflection of specimens were calculated and analyzed.2)In this paper,the shearing behavior of nine 635 MPa hot rolled high strength reinforced concrete beams is tested.Taking concrete strength,stirrup strength,longitudinal reinforcement strength,shear span ratio and stirrup ratio as research parameters,the shear bearing capacity,failure mode and stress mechanism of 635 MPa class hot rolled high strength reinforced concrete beam are studied,and compared with the Chinese and American standard bearing capacity formula.3)The bend numerical model of 635 MPa hot rolled high strength reinforced concrete beam was established by ABAQUS software and its accuracy was verified.The effects of concrete strength,longitudinal reinforcement ratio,height-width ratio,cross-section area and longitudinal reinforcement strength on the flexural mechanical properties of 635 MPa hot rolled high strength reinforced concrete beams were systematically studied.Based on the design code of concrete structure and superposition principle,the calculation formula of flexural capacity is put forward.4)The shear numerical model of 635 MPa class hot-rolled high-strength reinforced concrete beam was established by ABAQUS software and its accuracy was verified.The effects of concrete strength,stirrups reinforcement ratio,shear span ratio,cross section area and stirrups strength on the shear behavior of 635 MPa hot rolled high strength reinforced concrete beams were systematically studied.Based on the code and superposition principle,the calculation formula of shear capacity is put forward.