Compressive properties of cube for reactive powder concrete with polypropylene fibers at elevated temperature

To improve the explosive spalling and compressive properties of reactive powder concrete (RPC) at elevated temperature, 108 cube specimens (70.7 mm×70.7 mm×70.7 mm) were prepared to study the compressive strength of RPC with polypropylene fibers (PPF). The influences of temperatures and PPF content on the spalling properties of RPC were investigated, and compressive strength of RPC with different temperatures and PPF content were studied. The experimental results show that PPF volume content of 0.3% can prevent explosive spalling of RPC and significantly increase compressive strength. Compressive cube strength drops at 100 °C as compared to 20 °C and increases from 200 to 600 °C, but drops again beyond 600 °C; Compressive cube strength of the RPC was lower if the PPF content increases below 100 °C, but was higher when the PPF content increases between 200 and 800 °C; The relative compressive strength of RPC was lower below 500 °C, but was higher between 600 and 800 °C. Calculation formulas of the compressive strength at elevated temperature were obtained by fitting curve of experimental data considering PPF content when temperature varied.