Effects of Load Level on the Structural Fire Behaviour of GFRP-Reinforced Concrete Beams with Straight-End bar Lap Splices

Fire Behavior of GFRP-Reinforced Concrete Structural Members: A State-of-the-Art Review

“…There are however reports of studies where members reinforced with spliced GFRP reinforcing bars demonstrated better fire performance than those mentioned above, as was the case of the slab tested by Weber (2008), which failed after 60 min of fire exposure, and the beams of Gurung and Salem (2021) and Nour et al (2021) that collapsed 90 min after the onset of fire; these members also failed due to the debonding of the spliced reinforcing bars shortly after the Tg was attained. These studies had in common the adoption of a thick concrete cover of 60 mm (as recommended in (CSA 2017)), unlike the remaining studies from the literature, which comprised cover thicknesses of less than 35 mm (cf.…”

“…As far as the fire behavior of GFRP-RC members is concerned, detailing of lap splices has received comparatively little attention to date. The available research, conducted on beams and slabs reinforced with spliced GFRP (Weber 2008;Carvelli et al 2013;McIntyre 2019;Rosa et al 2020Rosa et al , 2022cGurung and Salem 2021;Nour et al 2021) or CFRP bars (Kiari et al 2015(Kiari et al , 2016 has demonstrated that the presence of tension lap splices in zones of the structure directly exposed to heating can considerably reduce the members' fire resistance. Furthermore, both the location and geometry of the splices, including their length and shape (straight or bent), are important details that must be considered in design.…”

“…showed that the thermal response during fire exposure of members cast with carbonate aggregates is better than that of concrete members with siliceous aggregates (owing to the lower thermal conductivity of the former (Kodur and Sultan 2003)). The effect of the load level on the fire resistance of FRP-RC members was assessed in (Nigro et al 2011b(Nigro et al , 2012aRafi et al 2011;Gurung and Salem 2021;Nour et al 2021). Gurung and Salem (2021) tested GFRP-RC beams with straight-end lap splices exposed to fire and subjected to 85% of the design load at ambient temperature and compared their results with those obtained by Nour et al (2021) in identical beams, however loaded to 40% of the design load.…”

“…The effect of the load level on the fire resistance of FRP-RC members was assessed in (Nigro et al 2011b(Nigro et al , 2012aRafi et al 2011;Gurung and Salem 2021;Nour et al 2021). Gurung and Salem (2021) tested GFRP-RC beams with straight-end lap splices exposed to fire and subjected to 85% of the design load at ambient temperature and compared their results with those obtained by Nour et al (2021) in identical beams, however loaded to 40% of the design load. They found that varying the load level did not affect the fire resistance of the beams because the governing failure mechanism was the loss of bond in the spliced reinforcing bars.…”

“…;Gurung and Salem 2021;Nour et al 2021). However, some authors(Nigro et al 2012a;Rosa et al 2020Rosa et al , 2022c have shown that more efficient designs can be accomplished by using thinner concrete cover thicknesses, as long as the anchoring of the continuous reinforcement is duly executed in cool zones of the structure (see Section Anchorage zones).…”