The properties of reactive powder concrete using PP fiber and pozzolanic materials at elevated temperature

•The addition of PP fibers in RPC was effective in preventing the explosive spalling.•The RPC specimens with PP fiber contents of more than 0.5% of binder contents showed no explosive spalling.•The contents of cement in the modified RPC in this study were significantly reduced by up to 766 kg/m3.

This study investigates the effect of a polypropylene (PP) fiber to provide improved spalling protection of practical modified Reactive Powder Concrete (RPC) subjected to fire. And Optimum levels of fiber contents for spalling protection with a less adverse effect on workability are provided based on the results of the fire test. The results showed that the modified RPC significantly reduced the content of cement and silica fume compared to the conventional RPC mixture by the combination of ternary pozzolanic materials (silica fume, blast furnace slag, and fly ash) and the mechanical performance of the modified RPC under high temperatures was superior to that of the conventional RPC mixture with only silica fume. The modified RPC shows no explosion occurring even at 0.2% of PP fiber (PP/Binder %) content and can improve spalling protection by providing connections between low decrease workability.