Flexural behavior of fiber and nanoparticle reinforced concrete at high temperatures

In this study, the flexural tests were conducted to investigate the effects of temperature, steel fiber, nano‐SiO₂, and nano‐CaCO₃ on flexural behavior of concrete at high temperatures. The load‐deflection curves of fiber and nanoparticle reinforced concrete (FNRC) were measured both at room and high temperatures. Test results show that the load‐deflection curves become flatter, and the flexural strength, peak deflection, and energy absorption capacity decrease seriously with the increase of temperature. Both steel fiber and nanoparticles could significantly improve the flexural behavior of the concrete at room and high temperatures. The energy absorption capacity of FNRC before the peak point increases with the increase of steel fiber volume fraction. The improvement of nano‐SiO₂ on flexural strength of FNRC at high temperature is better than that at room temperature, but the enhancement on energy absorption capacity is reverse. Nano‐SiO₂ is more effective than nano‐CaCO₃ in improving flexural behavior of concrete both at room and high temperatures.