Fire Response of Ultra High Performance Concrete Beams

This paper presents a macroscopic finite element model for assessing the fire performance of UHPC beams. In the model, fire resistance analysis is carried out at incremental time steps under the combined effects of fire exposure and structural loading till failure of the beam. The model accounts for high temperature properties of constituent materials and incorporates the progression of fire induced spalling utilizing a hygro-thermo-mechanical spalling sub-model. The developed model is validated by comparing predicted response parameters with measured data from fire tests on UHPC beams. Results from the analysis indicate that UHPC beams can have lower fire resistance, as compared to conventional normal strength concrete beams. The progression of spalling inside the beam section and its effect on failure time is discussed.