Response of high-strength concrete columns under design fire exposure

The behavior of RC columns, especially those fabricated from high-strength concrete (HSC), under design fire exposure is not well quantified. Results from fire resistance experiments on six RC columns are presented in this paper. The test variables include concrete strength (permeability), fire scenario, load ratio and the presence of polypropylene fibers in concrete mix. Data from these fire tests is used to validate a macroscopic finite element model specifically developed for tracing the fire response of RC columns. Results from fire tests and numerical studies are used to illustrate the comparative performance of HSC and normal-strength concrete (NSC) columns under design fire conditions. Results from fire experiments show that HSC columns exhibit lower fire resistance than that of NSC columns. However both HSC and NSC columns do not experience failure under most design fire scenarios. The addition of polypropylene fibers to concrete mitigates fire-induced spalling and enhances fire resistance of HSC columns.