A new ductile moment-resisting beam-column connection is developed for precast reinforced concrete (RC) frames in high seismic zones. The proposed connection provides good structural integrity in the connections and can reduce construction time by eliminating the need for formworks and welding, and minimizing cast-in-place concrete volume. A series of cyclic loading tests were carried out on six full-scale interior and exterior precast connections and two monolithic connections, all designed for use in high seismic zones. Test variables included the type of stirrups (open and closed) and the stirrup spacing in the beam connection zone. Test specimens were subjected to a constant axial load and a reverse cyclic loading based on a given displacement history. Flexural strength, ductility, strength degradation and energy dissipation capacity of the precast and monolithic connections are compared. The proposed interior and exterior moment-resisting connections proved to be efficient at improving the seismic performance of precast concrete frames in high seismic zones. While the precast connections provided adequate flexural strength, strength degradation and drift capacity, they exhibited considerably higher ductility and energy dissipation compared to similar monolithic specimens.

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Using prefabricated structure in lightweight construction is the new method in both industry and civil engineering. Lightweight Steel Frame (LSF) becomes more valuable in the construction industry due to low cost, low weight, high speed of installation and resistance to environmental conditions. Cold-rolled form lightweight load-bearing wall is consisting of a thin sheet of steel with C-shaped sections (STUD), thermal insulation filler and cover sheets (Plaster Board). However, regardless of existing plasterboard protection the thin-walled steel sections heat up quickly and lose their strength under fire conditions. The main goal of the current study is an evaluation of thermal capacity and bearing strength of lightweight walls in terms of cellulosic fire condition analytically. The variable parameters are insulation filler materials (polystyrene, polystyrene concrete) and axial load. The Abaqus finite element software was used for modeling and analyzing of fire loads. Lightweight concrete fillers increase the axial bearing capacity of walls sustainably and polystyrene filler improved the fire resistance of walls.

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