Summary Adopting glass fibre‐reinforced polymer (GFRP) rebars as a replacement of conventional steel reinforcement in different infrastructure applications is mainly attributed to its corrosion resistance and considerable lightweight‐to‐high strength ratio. However, the use of FRP rebars in construction is still limited due to the degradation of its mechanical properties at elevated temperatures. The experimental work presented in this paper aimed to investigate the structural fire behaviour of concrete beams reinforced with GFRP bars having lap splices at the beam mid‐span. Four identical 2750‐mm long concrete beams with cross‐sectional dimensions of 300 mm × 350 mm were experimentally examined under four‐point flexure bending. A 60‐mm thick concrete cover was used on the bottom, front and back sides of all beams. Two beams were tested as control specimens in ambient condition, while the other two beams were exposed to standard fire while subjected to a transverse load equivalent to 40% of the beam ultimate design moment. Experimental results show that concrete beams sustained the applied loads for a minimum of 53 minutes in standard fire conditions. Also, both test beams failed due to slippage of the spliced bars when the temperature measured at the top of the middle bar approached its glass transition temperature.

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