Static Analysis Of Unbonded Partially Prestressed Reinforced Concrete (PPC) Beam-Column Connection Behavior

Unbonded partially prestressed reinforced concrete (PPC) structure is a new form of Reinforced concrete (RC) structure, which need not set ducts, install tendons and grout in advance, so it is more convenient and quicken the rate of progress.The tendons of unbonded PPC have smaller fraction force and are easier to bend to many shapes, so it is more suited for building these rooms whose span are larger.With the study of the ability of unbonded PPC structure and the development of materials of unbonded PPC and the technique of light jack, the advantage of unbonded PPC structure has been widely recognized.However, as a designer or constructer, we should try our best to reduce the influence of the weakened states of column sections for frame, when we are engage in design or execution.This experimental research of 13 column beam joints takes the rate of ducts as a principal parameter, at the same time, the form of duct, the rate and ways of tendons and prestressing force are also considered.The results show that the influence of those ducts to the ultimate bearing capacity of the weakened section is not serious and the structure is safe if the rate is smaller than 30%. At the same time, we can get the following conclusions of the optimum style of the ducts and the settlements of actual projects.