| There are many advantages of unbonded prestressed concrete structure, such as low deadweight and convenient to construct; so it will have a flourishing prospect. But now, there are few experimental researches on prestressed concrete beam-column joint, especially the exterior prestressed beam-column joint. It baffles the development of unbonded prestressed concrete structure.In this paper, three exterior unbonded prestressed and one reinforced concrete beam-column joint assemblies were tested under reversed cyclic load. Joints'main parameters are prestressing in the beam and stirrups in joint core. Based on the analysis of the hystersesis curve, strain of reinforcements and etc., the mechanical and seismic behaviors of assemblies were appraised. The effects of different pestressing and stirrups in joint core to assemblies were investigated, and some correlative seismic constructions in criterions were amended. Based on correlative datas, some formulas of beam-column joint's seismic design were tested; a new shear strength formula of joint core was made, and its calculational results accord well with the experimental results. And the force-transferring mechanisms in reinforced concrete beam-column joint core were summarized.The research shows: The hystersesis curves of unbonded prestressed concrete beam-column exterior joints have shuttle figures, and they are plump and steady-going. So the unbonded prestressed concrete beam-column exterior joint has nice mechanical and seismic capacity, it can be used in seismic structures of grade two. Diameter of seismic compellent stirrups in its joint core is same as reinforced concrete joint; but the minimum spacing of stirrups can be enhanced. The shear strength produced by unbonded prestressed tendon in prestressed concrete beam-column joint should be calculated by 0.6Npe.
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