Effect of fiber types on fire-induced spalling and thermal performance of UHPC circular columns

Ultra-high-performance concrete (UHPC) emerged as a promising material for modern construction, offering unparalleled strength, durability, and versatility. However, there is limited research regarding UHPC's response to fire, prompting urgent investigation and analysis. This paper presents an experimental study focused on evaluating the effect of different types of fibers on the fire performance of UHPC circular columns. The fiber types considered in this study included steel fibers (SF), a hybrid mix of steel and polypropylene fibers (SPPF), and polyvinyl alcohol fibers (PVAF). Additionally, a control column was cast without the inclusion of any fibers. All UHPC specimens were subjected to standard fire exposure, following the ASTM E119 fire test. The results indicated a substantial resistance to spalling with the incorporation of fibers. Moreover, the column featuring PVAF exhibited the lowest internal temperature readings among the columns. Columns reinforced with SF and SPPF exhibited uniform spalling on all sides.