Experimental Research on Seismic Performance of Prefabricated L-shaped Beam-Column Edge Joint With High Strength Bolt-Cogging-Grout Sleeve Composite Connections

To avoid shear failure of top floor L-shaped beam-column edge joints (L-shaped joints), a high strength bolt (HSB) - cogging - grout sleeve composite joint (H-C-S joint) was proposed in this paper. First, two prefabricated L-shaped joint specimens with H-C-S joints (LS1, LS2) and one prefabricated L-shaped joint specimen with cogging - grout sleeve composite joint (C-S joint, CJ1) were designed and manufactured. The H-C-S joint of the LS1 was outside the plastic hinge area of the beam (the outside arrangement), while the H-C-S joint of the LS2 was inside the plastic hinge area of the beam (the inside arrangement). The arrangement of the C-S joint of the CJ1 was also the inside arrangement. Second, pseudo-static tests of these specimens were carried out. The seismic performance of prefabricated L-shaped joints was compared and analyzed through their failure modes, load-displacement relationships, and energy consumption capacities. Results show that compared with the C-S joint, the similar arranged H-C-S joints can delay the seam cracking and stiffness degradation process. The H-C-S joint can also increase the peak load, energy consumption capacity of prefabricated L-shaped joints, as well as improve the bonding performance between rebar and concrete. The outside arrangement of H-C-S joints causes the beam plastic hinge area moving up, and lead serious damage to the joint seam and core area. Moreover, the outside arrangement of H-C-S joints will aggravate joint seam cracking and stiffness degradation, as well as reduce the peak load and energy consumption capacity of prefabricated L-shaped joints. The outside arrangement of the H-C-S joint can better realize the design principle of "strong connection-weak connected member" and ensure the integrity of prefabricated structures to some extents. Thus, H-C-S joints can be applied to prefabricated L-shaped beam-column joints.