Residual flexural behavior of fiber reinforced concrete after heating
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In this study, the effects of fire on the flexural performance and residual strength of plain and fiber reinforced concrete are investigated. Three types of concrete are tested: plain, polypropylene (PFRC) and steel fiber reinforced concrete (SFRC). Prior to the flexural test, the specimens were exposed to fire for 15, 30, 45, and 60 min on a furnace. The burnt specimens were then tested under flexural load to measure their toughness and residual strength. Results indicate the reduction of flexural strength for both plain and FRC after being subjected to fire. For FRC, the effect of fire on the flexural response depends mainly on the fiber type and fire exposure duration. For PFRC, the flexural strength is found to drop significantly for every exposure duration, while toughness is found to increase at short exposure duration and then, drop quickly after long exposure duration due to the fiber evaporation effect. For SFRC, the flexural strength and toughness are found to drop gradually for every exposure duration due to the deterioration of cement paste and reduction in bond strength. SFRC exhibits a more consistent ability to maintain load carrying capacity after long exposure to fire than PFRC.
KeywordsFire Toughness and residual strength Polypropylene fiber reinforced concrete Steel fiber reinforced concrete
This project is funded by King Mongkut’s University of Technology North Bangkok under contract no. KMUTNB-60-GOV-003 (Prof. Piti Sukontasukkul) and TRF Distinguished Research Professor Grant No. DPG6180002 (Prof. Prinya Chindaprasirt). The authors declare that they have no conflict of interest. The authors would like to thank SR. Fiber Co., Ltd. for providing steel and polypropylene fibers.
- 5.Powers-Couche L (1992) Fire damaged concrete-up close. Concr Repair Digest 1:241–248Google Scholar
- 6.Gustafero AH (1983) Experiences from evaluating fire-damaged concrete structures—fire safety of concrete structures. American Concrete Institute SP-80Google Scholar
- 11.Morsy NMA-E-F, El Kady HMG, Mokhtar ASA, El Nawawy OAM (2016) Enhancement of fire resistance of reinforced concrete beams using steel fibers. ARPN J Eng Appl Sci 11(19):11782–11789Google Scholar
- 13.Bashir J, Singh K (2017) Experimental inquest for improving the fire resistance of concrete by the addition of polypropylene fibers. Int J Civ Eng Technol 8(8):129–139Google Scholar
- 15.Li Q, Gao X, Xu S, Peng Y, Fu Y (2016) Microstructure and mechanical properties of high-toughness fiber-reinforced cementitious composites after exposure to elevated temperatures. J Mater Civ Eng. https://doi.org/10.1061/(ASCE)MT.1943-5533.0001647 Google Scholar