Experimental And Theoretical Research On Mechanical Behaviors Of CFRP-PCPs Composite Reinforced Concrete Continuous Beams

Carbon fiber reinforced polymer prestressed concrete prisms (CFRP-PCPs for short)is a new composite material with prestressed effect, which is made up of two kinds ofbuilding materials: carbon fiber reinforced plastic (CFRP for short) bars and ultra-highperformance concrete (UHPC for short).In the middle of CFRP-PCPs, CFRP bars are usedas prestressed tendons and UHPC as pouring material, which is used by pretensioningmethod. It is believed to have a promising application prospect because of its together twokinds of materials excellent properties such as ultra high strength, good durability andhigh toughness of UHPC as well as high tensile strength, corrosion resistance andmagnetic neutrality of CFRP bars.As a new type of composite material, CFRP-PCPs mechanical properties are differentbetween pure FRP (fiber reinforced plastic) bars or common reinforced bars. Because ofthe endemic properties, CFRP-PCPs concrete structural is different from normalreinforced or FRP concrete structural in many ways. Such as the bearing capacity, stiffness,deflection and crack calculation etc. Likewise, CFRP-PCPs concrete beam of staticallyindeterminate structural is also different from traditional steel or FRP reinforced ofstatically indeterminate concrete beam in the mechanical of plastic internal forceredistribution. In consideration of the widespread presence of statically indeterminatestructure in civil engineering, It is particularly necessary and meaningful to study thedesign and calculation theory of the mechanical properties of CFRP-PCPs concretecontinuous beam. So, the main work in this paper is as follows:First of all, based on the research results of home and abroad which about compositereinforced concrete structural element,6CFRP-PCPs concrete continuous beam tests havebeen conducted, the experimental process and phenomenon have been described in detailand the test results have been theoretical calculation analyzed. Through the tests,development and distribution of cracks of each specimen have been described; thecharacteristics of load-deformation curves and flexure lines have been gotten; theload-stress increment contrast curve of the CFRP bar which in the CFRP-PCPs elementhave been draw out; the stress-strain values of steel which at the negative moment area oftest beams have been monitored and the curvature distribution of CFRP-PCPs crosssection from yield to limit have been arrived at.Second, each control section of concrete crack, crack of CFRP-PCPs bars, ordinaryreinforced yielding and ultimate state have been calculated respectively to every testedbeams. Combined with the measured values of beams of average crack spacing andmaximum crack width in serviceability limit state, the numerical comparison andcalculation have been carried out by using the standard formula of home and abroad. Finally, the formal has been appropriately corrected.In the end, through analyzing the values which between measured and theoreticalcalculation of beams support reaction force, the influence factors which the performanceof CFRP-PCPs concrete continuous beam bending moment amplitude modulation havebeen sett forth. On the basis of experiment, it have analyzed the plastic properties ofCFRP-PCPs concrete continuous beam and established the calculation formula whichaccord with CFRP-PCPs concrete continuous beam bending moment amplitudemodulation measured and obtained the general rule of the redistribution law plasticinternal force.Through the experiments of6CFRP-PCPs concrete continuous beam, the systematictheoretical analysis and experimental comparison have been done about the mechanicalproperties, deformation and plastic properties in this thesis. It provides the basis for theCFRP-PCPs concrete structural design code establishment. And it also provides areference for the popularization and application of civil engineering in our country.