Experimental Study On Assembling Frame Joints Under Different Prestressing Force

Assembling structures have many advantages, such as high production efficiency, good product quality and so on. The development of assembling structures is the best way to realize the industrialization of buildings in China. Pre-stressed assembling frame is a frame that pre-cast beams and columns are produced in factory, and then transported to the construction site to assembly and apply pre-stress. Compared with cast-in-situ structure, it has both advantages of assembling structure and pre-stressed structure, such as good cracking resistance, small deflection, good deformation recovery ability and so on. Because of the poor reliability of the traditional assembling joints, the assembling structures severely damaged in the earthquake, while pre-stressed structure generally has low energy dissipation capacity and large seismic response. So it is necessary to develop a new connecting way to overcome the shortcomings of the traditional pre-stressed assembling structure.To overcome the shortcomings of pre-stressed assembling structure, this experiment assembly angle steels or dampers on the assembling frame joints to improve the reliability and the rotational stiffness of the joints, and it can also increase the energy consumption in earthquake. Through the low cyclic loading tests on assembling frame joints with additional angle steels or dampers under different pre-stressed force and use the cast-in-situ joints as contrast, we study the effects of different pre-stress on joints' crack development, failure mode, hysteretic curves, skeleton curves, stiffness degradation curve and energy dissipation and ductility. The study shows that: the energy dissipation capacity of the assembling frame joints is not better than the cast-in-situ joints, but they have good energy dissipation capacity in the case of large displacement and also have good seismic performance on the whole. The increase of pre-stress can improve the joints' anti cracking ability, bearing capacity, deformation recovery ability and reducing the rate of stiffness degradation, but it can weaken the energy dissipation capacity of the joints.