Experimental Study Of The Bending Performance Of The Prest Ressed High-strength Concrete Beams With High-strength Bars

Reinforced concrete structures are widely used in the field of engineering field.However, the common concrete has been difficult to meet the demand of engineeringapplications, so the popularization and application of high-strength steel andhigh-strength concrete has been inevitable. The prestressed technology cansignificantly increase the structure’s stiffness. So it is necessary to carry out theresearch and analysis of the prestressed high-strength concrete beams withhigh-strength reinforcement, and it is an important value in engineering, conducive toenergy conservation and pollution reduction.By the bending performance test of12prestressed high strength-concrete beamswith high-strength bars, the reasons which influence the bending performance of thebeam such as the concrete strength grade, non-prestressed reinforcement ratio and theprestressed reinforcement ratio were searched, the experiment date included thevertical load, the deflection, the strain of steel and concrete, the crack width and itsevolution. The test results show that:(1) The fracture model of the prestressedhigh-strength concrete beam with high-strength bars is ductile fracture model, itincluded three stages: the stage before cracking, the working stage with cracks andthe damage stage after yielding.(2) The concrete strength grade has an influence onthe bending performance mainly after yield, The higher the concrete strength was, theless the bearing capacity of beam decreased.(3) The unprestressed reinforcement ratiohave little effection on the flexural test beams before cracking, after cracking thehigher reinforcement ratio, the bigger bearing capacity.(4) With the same tensioncontrol stress, the higher the prestressed tendon reinforcement ratio, the greater thecracking moment, and under the act of the same bending moment, the smallerdeformation and the higher ultimate bearing capacity.This article is also based on the ANSYS finite element software to carry out thesimulation study of prestressed high-strength concrete beams with high-strength bars,based on the analysis of the numerical model, the parameters which influence thebending performance of the beam such as the concrete strength grade, non-prestressed reinforcement ratio and the prestressed reinforcement ratio were searched, and got theconclusion:(1) The concrete strength grade has an influence on the bendingperformance mainly after yield.(2) The unprestressed reinforcement ratio have littleeffection on the flexural test beams At the early stage, after the load application thehigher reinforcement ratio, the bigger bearing capacity.(3) The size of the prestresshas a great influence on the deformation performance of the prestressed high-strengthconcrete beams with high-strength bars. With the reduction of the prestress, thedeflection of the beam increases, and growth become faster.The experimental study and numerical calculation results is helpful not only tomake us have a deep understand of the flexural properties of high strength reinforcedconcrete prestressed beams, but also the result can be directly served in theengineering practice. It should be further studied at in the field of constructiontechnology, construction measures, and seismic performance.