Study On Bending Behavior And Durability Of SFCB Reinforced Concrete Beam

In recent years,with the rapid development of the construction industry,China's consumption of natural coarse aggregates?river sand and river water has increased rapidly.In this respect,the exploitation of natural resources has led to the shortage of these resources,as well as much construction waste,which has a bad impact on the environment.On the other hand,it takes a lot of manpower and material resources in the mining process,which also has an adverse impact on the development of the ecology.Therefore,the recycled coarse aggregate replacing the natural coarse aggregate,and the sea sand seawater replacing the river sand river water,which are more and more widely used in the actual construction of buildings,but the natural disadvantage of the performance of recycled concrete,and the corrosion of reinforcement bars resulted from chloride salt in the sea sand seawater need to be solved by researchers.Steel-Fiber Composite Bar(SFCB)is an excellent method to solve the above problems because of its corrosion resistance,high ductility and high strength.In this paper,the recycled coarse aggregate,sea sand seawater and steel-fiber composite bar(SFCB)are combined to form SFCB enhanced recycled aggregate sea sand seawater concrete beam,and the basic properties of this composite structural beam are theoretically tested.And the main work is:In order to study the short-term bending ability of SFCB enhanced recycled aggregate sea sand seawater concrete beam,12 specimens were designed,and the parameters of the test are: type of tensile reinforcement(common steel?FRP?SFCB),type of FRP wrapped on reinforcing bars(CFRP,GFRP),thickness of FRP wrapped on reinforcing bars(2mm,3mm),type of coarse aggregate in concrete(recycled aggregate,natural aggregate),and they are all under bending test.Then,the failure modes,ultimate loads crack development and ductility of different specimens after the test were compared to nalyze the short-term bending ability of SFCB enhanced recycled aggregate sea sand seawater concrete beams.And it is c-oncluded that the SFCB enhanced recycled aggregate sea sand seawater concrete beam has a stable secondary stiffness,and its bending failure mode is affected by FRP/Steel and FRP types.In order to explore the long-term bending ability of SFCB enhanced recycled aggregate sea sand seawater concrete beam after electrification corrosion,this paper designed 6 test pieces,and the parameters of the test are: type of tensile reinforcement(CFRP?C-SFCB?G-SFCB),rate of electric corrosion(5%?15%).Then ananlyze the long-term bending ability of SFCB enhanced recycled aggregate sea sand seawater concrete beams after electric corrosion from various aspects such as load carrying capacity,crack development and ductility.It is concluded that the long-term bending performance of the SFCB enhanced recycled aggregate sea sand seawater concrete beam is affected by the base resin and FRP type.Based on the above experimental research,the calculation model of the bearing capacity of SCFB enhanced recycled aggregate sea sand seawater concrete is established.The experimental comparison shows that the model has higher prediction accuracy.