Moment Redistribution In Prestressed Continuous Steel-concrete Composite Beams With External Tendons

Continuous steel-concrete composite beams have demonstrated several advantages over simple supported ones, such as improving structural rigidity, increasing the ultimate load carrying capacity, and improving internal force redistribution. The extent or the amplitude value required for moment redistribution in prestressed continuous steel-concrete composite beams with external tendons is essential to be capable of moment redistribution design for the beams. In this paper, amplitudes of modulation required for moment redistribution in conventional continuous steel-concrete composite beams and prestressed continuous steel-concrete composite beams are analyzed both in theoretical study and test. The main works been done as following:1. Amplitude Modulation forma of both common and external prestressed Continuous supported steel-concrete composite beams under Concentrated Loading of two same spans are deduced.2. Amplitude Modulation forma of both common and external prestressed Continuous supported steel-concrete composite beams under distributed Loading of two different spans are deduced.3. Amplitude Modulation value of both common and external prestressed Continuous supported steel-concrete composite beams under same conditions are compared with each other.4. Theoretical and practical amplitude Modulation value of both common and external prestressed Continuous supported steel-concrete composite beams are compared with each other.5. According to the test, Stiffness of external prestressed Continuous supported steel-concrete composite beams surpass that of common ones a little in elastic stage, but is obviously higher than that of common ones in elastic-plastic stage.6. According to the test, both elastic limit bearing capacity and Ultimate Bearing Capacity of external prestressed Continuous supported steel-concrete composite beams is obviously higher than that of common ones. It is concluded that, external prestress improve the force performance of common Continuous supported steel-concrete composite beams greatly.7. According to the test, strain increment of prestressing tendon is very great andcan not be neglected. Otherwise, the theoretical amplitude modulation requirement value will be lower than that of practical ones.