Experimental study on demountable and reusable steel beam-to-column joints with bolted-pinned connections

With the aim of reusing assembled steel structures at the end of their service life or after experiencing earthquake damage, a novel demountable and reusable steel beam-to-column joint with bolted-pinned connection has been proposed herein. Its configuration is quite beneficial to the installation and disassembly due to its use of highstrength bolts and pins. The energy-dissipating connection plate (EDCP) is strategically placed in the predetermined energy dissipation area, of which the yield section is wrapped by an external restraining plate, allowing for concentrated damage and deformation of the main structural members within the elastic range under earthquake actions. The EDCP is fabricated from a low-yield-point (LYP) steel material that has excellent ductility and high energy dissipation capacity. To clarify the joint's static and seismic performance, ten joint specimens were designed and prepared, and both monotonic and cyclic loading tests were conducted. The failure mode, load versus displacement response, ductility, and energy dissipation capacity were obtained and analyzed experimentally. Furthermore, the cyclic behaviour of the same tested joints after disassembly and re-assembly were investigated to verify their reusability. The test results indicated that welding stiffening ribs in the unrestrained section of the EDCP can significantly enhance the joint's static loading capacity and seismic performance. Additionally, the damage of all the joints was localized within the EDCP, and no failure was observed in the beam, column components and column seat, which remained within the elastic range based on strain data analysis. It was found that the joint specimens could be disassembled effortlessly and efficiently with nearly no damage to the friction surface and bolt holes within the connection zone. Furthermore, the seismic performance of the re-assembled specimens was essentially identical to that of the original specimens, demonstrating the ability of reuse.