Fire response of exterior reinforced concrete beam-column subassemblages

A Review of Precast Concrete Beam‐to‐Column Connections Subjected to Severe Fire Conditions

“…A detailed visual inspection revealed the following defects and damages: (1) insufficient protective concrete layer, (2) rough concrete surface, (3) spalled, fallen, or burnt concrete protection layer, (4) change in the colour of the concrete surface, (5) crumbling and burnt concrete protective layer with the aggregate grains showing a colour change, (6) crumbly longitudinal column edges, ( 7) net-like fissures on the surface of the elements, (8) horizontal cracks along the stirrups, (9) horizontal cracks due to flexion of the columns, (10) vertical cracks and gaps along the column edges (along [68]. Most large-scale fire tests on monolithic concrete beam-to-column were conducted on cantilever beam setup with a furnace or gas burner placed at the joint area [3,22,53,66,67]. However, in the method adopted by Raouffard and Nishiyama [28], the full-length beam is supported by columns at the ends.…”

“…Teja et al [3] used the cantilever beam method identical to that used by Refs. [22,67] to investigate the performance of precast hybrid and corbel connections exposed to high temperatures shown in Figure 11. e specimens were exposed to a constant fire temperature of 400°C provided by a gas burner for 60 minutes.…”

“…Most largescale fire tests for monolithic concrete beam-to-column connection use a cantilever beam setup and a furnace or gas burner at the joint area. e tests adopted the concept of an ideal beam-to-column connection under no lateral thermally induced thrust and no moment redistribution influence by removing the midsection of the reinforced concrete beam and turning it into two separate reinforced concrete cantilever beams [22]. is raises the question of whether similar fire test methods can be used for semirigid and pinned connections.…”

“…Exposure to fire could considerably reduce the strength and stiffness of a building [21]. Severe fires in large buildings are rare and unpredictable incidents but can cause catastrophic loss of life and property damage and affect the structural integrity and robustness of buildings [20,22]. e construction of safer buildings can reduce the risks of loss of life and property in the event of fire [20].…”

“…e research that compared three different methods of precast concrete beam-to-column connections (dry, semidry, and wet) at elevated temperatures [3] was not able to determine the mechanical properties of the connections postfire. Most research focused on rigid connections under moment-resisting frame systems, particularly the top reinforcement continuity in a ductile connection at the support [22,23,[27][28][29].…”