# Experimental Study of a New Precast Prestressed Concrete Joint
## 1 Introduction  
The precast concrete structure is one of the most important structural forms of modern architecture. A precast concrete structure has advantages over a cast-in-place concrete structure that include less wet work on site, better control of component quality, rapid construction, and good economic and environmental benefits. However, there are challenges posed to the application of precast concrete structures, such as poor connection reliability and structural integrity, that limit its use in seismic zones. A precast concrete frame structure is distinguished from a cast-in-place structure by the connection method of columns, beams, and floors, and especially by the connection method of the beam-column joints. These joints significantly affect the seismic performance of the whole structure. The design principle of \"strong joint weak component\" is realized by ensuring that the assembled part of the beam-column joint region has sufficient strength, rigidity, and ductility to meet the requirements of bearing capacity and deformation capacity under the conditions of normal use and during earthquakes. The precast concrete frame joints must effectively transmit the bending moment and shear force between the precast components, and they also should have good ductility and energy dissipation capacity. Research on precast concrete structures mainly focused on the connection mode of joints, the mechanical properties of joints, and the seismic performance of prefabricated structures for different connection modes [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17]. [PERSON] et al. [1] studied precast elements that were joined by high-performance fiber reinforced concrete and short steel bars. The studies by [PERSON] et al. [2] and [PERSON] et al. [3] investigated precast concrete beam-column joints connected by sleeves and with anchor plates. [PERSON] et al. [4] and [PERSON] et al. [5] both proposed beam-column joints in which steel plates or U-shaped steel bars were placed in the joint zone and engineered cementitious composite (ECC) materials were poured. An improved hybrid H-steel-precast concrete beam system was proposed by [PERSON] et al. [6], and tests of five fixed-end beam specimens under reversed cyclic one-point concentrated top loads at the mid-span were performed to determine their bending capacity and ductility. [PERSON] et al. [7] studied the seismic behavior of welded joints in a frame beam. Five specimens with welded joints and two monolithic reference specimens were tested to study their behavior under seismic action. [PERSON] et al. [8] and [PERSON] et al. [9] developed joints with steel plates embedded at the precast beam ends and bolted to the precast columns. The precast joints with T-section steel plates that were pre-buried in the beam ends and connected by welded steel plates with post-pouring concrete at the joints were studied by [PERSON] et al. [10]. The works by [PERSON] et al. [11] and [PERSON] et al. [12] determined the performance of the joints with precast columns and steel beams. [PERSON] et al. [13] evaluated the performance of a proposed steel connected precast concrete joint by experimental and numerical analysis. A precast concrete beam-column joint with energy-absorbing ductile connectors was developed by [PERSON] et al. [14]. [PERSON] et al. [15] performed a comparative test for four ductile, moment-resisting precast concrete frame connections and one monolithic concrete connection for high seismic zones. The studies of [PERSON] et al. [16] and [PERSON] et al. [17] proposed a precast concrete beam-column joint with corbel and cleat angle, and a reversed cyclic loading test of the scaled model was performed. In the above researches, the precast members were connected by steel bars or steel plates through overlapping, welding, or bolting. The seismic performance of most of these joints is comparable to the conventional cast-in-place joints.