| Reactive Powder Concrete(RPC)is a cement-based composite material with high strength,high toughness and high durability.Compared with Normal Concrete(NC),RPC has unsurpassed compressive strength and durability.But its high cost is about 10 times the price of ordinary concrete.Fiber Reinforced Polymer(FRP)has the advantages of corrosion resistance and high tensile strength.Use full of FRP reinforced RPC beam economic cost is higher,and the use of ordinary reinforced concrete tend to need more and more of the reinforcement,the section size of,therefore,puts forward mixed reinforcement(steel and FRP)and composite beams(to use RPC tensile and compressive zone,the use of NC fill)can not only in the form of ordinary reinforced concrete on the basis of improving performance to decrease the size of cross section,Compared with the full RPC beam,the economic benefit is better.The RPC-NC composite beams with hybrid reinforcement are mainly studied in the field of prefabricated components.Make full use of the industrialization of prefabricated components,mechanization to achieve safety,speed,quality,environmental protection,cost and other advantages.The static load bending test and theoretical analysis of RPC-NC composite beams with hybrid reinforcement were carried out.The main work and conclusions are as follows:(1)5 full RPC beams with different reinforcement ratios and 9 composite beams with different reinforcement forms were made in the experiment.The loading data of the test beam were collected and the stress process was observed.Through cracking load,yield load,ultimate bearing capacity,deflection and crack width,draw all kinds of data curves.The results show that the failure modes and load-deflection curves of composite beams with hybrid reinforcement are similar to those of ordinary concrete beams,that is,the elastic stage,elasticplastic stage and failure stage with concrete cracking and reinforcement yielding as the boundary points.In the load-deflection curve of composite beams with mixed reinforcement,the proportion of linear stage in ultimate load is 10.5%-13.4%,and the composite beams have good stiffness reserve and crack resistance.Composite plane section assumption of strain distribution of composite beams.(2)Based on the test results and section assumption,the contribution of RPC tension zone to the flexural capacity of normal section was reasonably considered,and the ultimate bending moment of composite beams with hybrid reinforcement was calculated.The results show that the theoretical ultimate bending moment is in good agreement with the experimental data.Using MATLAB software,the initial strain method was used to carry out strip integration for the composite beams with hybrid reinforcement.Considering the tensile contribution of RPC and NC,the moment-curvature curve was derived and compared with the moment curvature obtained from the test value.The curve was in good agreement,indicating that the software program was reliable.(3)The finite element simulation software ABAQUS was used to simulate the test beam,and the load-deflection curve of the simulation results was compared with the test curve.The curve trend was basically the same,which was in good agreement. |
