Citation

Abdulrahman AS, Kadir MRA. Ain Shams Eng. J. 2022; 13(6): e101767.

Copyright

(Copyright © 2022, Ain Shams University, Publisher Elsevier Publishing)

DOI

10.1016/j.asej.2022.101767

PMID

unavailable

Abstract

This investigation presents an experimental study of the flexural behaviour of fire -damaged high strength reinforced concrete beams under several fire exposure periods, then strengthened with carbon fibre reinforced polymer CFRP. This experimental work aims to study the fire impact on the residual mechanical characteristics and flexural behaviour of fire-damaged high strength reinforced concrete beams under several fire exposure periods CFRP. Twelve simply supported high-strength reinforced concrete beams 2000 mm in length, with a cross-section width 200 mm and height of 250 mm, were tested after exposure to standard fire ISO-834 for 45, 90,120 min and strengthened with CFRP sheets. The beams were classified into three groups. In addition to the control beams, a series of nine beams were exposed to standard fire for different exposure times. Six beams were subsequently strengthened with two different carbon fibre reinforced polymer patterns, namely, continuous sheet at the soffit and U-shaped wrapping with addition strips. The test results showed that all specimens showed the flexural mode of failure, with minor spalling. The beam exposed to fire for 120 minutes resulted in a 12% decrease in strength without severe explosion, while the deflection at failure was nearly the same as the control beam. After strengthening, the capacity was notably restored, and the effect of fire was alleviated, especially for pattern II of strengthening, which reached 34% more than the control beam. The use of EB- CFRP to strengthen fire-damaged beams has been proven to reduce the consequences of fire exposure significantly. Also, it was sufficient to regain the majority of the initial rigidity.

Language: en

Keywords

Fire damage; Fire endurance; Flexural behaviour; High and normal strength concrete; Reinforced concrete beam; Strengthening with CFRP sheets