Experimental Study of Ultra-high Performance Fibre Reinforced Concrete under ISO 834 Fire

Ultra-high performance fibre reinforced concrete (UHPFRC) is a relatively new construction material that possesses favourable mechanical properties over ordinary concrete. Although enormous strides have been achieved in understanding the performance and behaviour of UHPFRC at ambient temperature, there's little literature and experimental data on their behaviour when submitted to fire. This study presents experimental results of four, 2m long, singly reinforced UHPFRC beams subjected to an ISO 834 fire curve for 60 minutes under a constant load. Two beams contained steel fibres with 2% volumetric ratio while the other set had 4%. Two load ratios of 0.4 and 0.6 were imposed prior to heating and kept constant throughout the fire test. Spalling was observed in all beams, being more severe in beams with steel dosage of 2%. The failure modes, displacement patterns, temperature profiles and corresponding fire endurance for each beam have been presented in this study.