主管：中华人民共和国应急管理部
主办：应急管理部天津消防研究所
ISSN 1009-0029  CN 12-1311/TU
Fire Science and Technology

Fire Science and Technology ›› 2025, Vol. 44 ›› Issue (4): 476-484.

Previous Articles    

Experimental study on flexural toughness of fiber reinforced concrete with lightweight aggregate after high temperature of fire

You Zhiguo1,2,3, Zhou Yunlong2, Yang Zhinian2,3, Zhang Hongqiang4   

  1. (1. Suzhou City University, Suzhou Jiangsu 215104, China; 2. Civil and Architectural Engineering, North China University of Science and Technology, Tangshan Hebei 063210, China; 3. Hebei Key Laboratory of Earthquake Engineering and Disaster Prevention, North China University of Science and Technology, Tangshan Hebei 063210, China; 4. Jidong Oilfield Exploration and Development Construction Supervision Center, Tangshan Hebei 063004, China)
  • Received:2024-05-20 Revised:2024-08-05 Online:2025-04-15 Published:2025-04-15

Abstract: In order to study the flexural toughness of fiber reinforced concrete with lightweight aggregate after high temperature of fire, the concrete with lightweight aggregate was prepared by adding ceramic fiber, copper-plated steel fiber and ceramic-copper-plated steel fiber. 15 groups of 100 mm× 100 mm × 400 mm test blocks were subjected to open fire temperature rise test for 20 min, 30 min and 60 min according to the international standard ISO-834 temperature rise curve. The four point bending test method was used to conduct the bending test after high temperature. The influence of fiber type and fiber content on the internal temperature, load deflection curve, and bending strength fiber reinforced concrete with lightweight aggregate under different fire time are analyzed. Based on CECS 13:2009, the influence of fiber on the bending toughness of concrete with lightweight aggregate after high temperature is studied. The results show that before the temperature rise lag platform, the higher the content of copper-plated steel fiber, the faster the internal temperature rise of concrete with lightweight aggregate, and the higher the content of ceramic fiber, the slower the internal temperature rise. After high temperature of fire, the greater the content of copper-plated steel fiber, the greater the ultimate bending strength and the better the bending toughness. Copper-plated steel fiber has a better effect on improving the bending toughness of concrete with lightweight aggregate after high temperature. After being fired for 60 min, with the same content of copper-plated steel fiber, the higher the ceramic fiber content, the better the bending toughness. Compared with the bending strength of the single copper-plated steel fiber of D50, the bending strength of the mixed ceramic copper-plated steel fiber D50T13 decreases by 43.6%, and the bending strength of D50T26 and D50T39 increases by 6.39% and 24.40%.

Key words: lightweight aggregate concrete, high temperature of fire, flexural performance, copper-plated steel fiber, ceramic fiber