Basalt fibre reinforced polymer bars as main reinforcement of axially compressed concrete column – experimental and numerical considerations of fire resistance

Abstract

The study aimed to highlight the possibility of achieving satisfactory level of fire resistance in concrete column reinforced with Basalt Fibre Reinforced Polymer (BFRP) bars as a main reinforcement.The literature data [1] of steel reinforced columns was used for preliminary validation of the numerical model. Full scale BFRP-reinforced column was analyzed experimentally and numerically along with experimental evaluation of thermo-mechanical parameters of the BFRP bars and concrete.Fire resistance of the element was calculated by means of numerical simulation, as the time when further sustaining of the mechanical load was no longer possible. The Concrete Damaged Plasticity (CDP) model for concrete was used.The model appeared to be effective in predicting fire resistance of concrete columns with steel reinforcement with various spacings of stirrups (differences up to 12%). In terms of element reinforced with BFPR, the fire resistance of the column tested was about 30% higher than the numerically determined value. Also, the calculated temperatures were compared to values measured by means of thermocouples. Finally, the possibility of achieving over 3 h of fire resistance for columns with BFRP main reinforcement has been proven in both – numerical and experimental investigations.