Dynamic And Static Behavior Of Partially Prestressed Concrete Beams Under Corrosive Environment

In recent years,the number of vehicles in China has gradually increased with the development of highway transportation.Bridge structure in service period not only will be overloaded,but also by the external environment for its corrosion.Overload will cause fatigue damage in the structure,corrosion will reduce the durability of the structure.Therefore,it is necessary to study the corrosion fatigue failure of bridge structures.In this paper,all beams were by some in the existing highway bridge scale,combined with test under corrosive environment of pre-stressed concrete structure research on fatigue performance.The full text is divided into six chapters,the main content is: Firstly,develop the electricity corrosion scheme by manual simulation of the experimental beam;Secondly,do the static load experiment,and get the change of static behavior of the beam after corrosion,including the ultimate bearing capacity of the beam,the development law of the crack,the deflection curve,the load-strain curve,and so on;Finally,the fatigue properties of the tested beams are studied,analyzing the change law of fatigue life,damage form,residual deflection,the load strain curve of the beam and the load strain curve of the beam,and the damage in the beam is monitored by the acceleration test.Experimental study found : Under static loading,after corrosion,the bearing capacity of the pre-stressed concrete beam is about 8%,the maximum deflection is reduced by about 28%,and the cracking load decreases by about 25% and the crack first appears in the most severe local corrosion.When fatigue load is loaded,the corrosion fatigue failure presents obvious "three phase" characteristic;The S-N curve is linear,and the curve fitting equation is: lgN=-1.9809lg?? + 11.104(R2 = 0.9778);And in the beam of the residual deflection of the stable development stage,when the load limit is increased by 0.1 times,the residual deflection of the beam will increase 64%~68.8%;When the beam is damaged,the acceleration of the vibration induced by the beam is increased by 14%~27%.In this paper,the research on the static and dynamic performance of the pre-stressed concrete bridge can provide important technical support for the safety evaluation,design and construction of the bridge,and the service life prediction.