Experimental research on fire-damaged RC continuous T-beams subsequently strengthened with CFRP sheets. (15th March 2019)

• Record Type: Journal Article
• Authors: Xu, Qingfeng; Chen, Lingzhu; Han, Chongqing; Harries, Kent A.; Xu, Zhimin
• Is Part Of: Engineering structures. Volume 183(2019)
• Page Start: 135
• Page End: 149
• Publication Date: 2019-03-15
• Subjects: RC continuous T-beam -- Temperature distribution -- Strengthening -- CFRP sheets -- Moment redistribution; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2019.01.025
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Performance of RC continuous T-beams after fire were experimentally studied. Performance of EB-CFRP strengthened fire-damaged RC continuous T-beams were studied. Simplified calculation methods based on the 500 °C isotherm method were validated. Abstract: This paper presents experimental results of the structural performance of fire-damaged continuous reinforced concrete (RC) T-beams subsequently strengthened with externally bonded carbon fiber reinforced polymer (EB-CFRP) sheets. A series of seven specimens were tested with different fire exposure time and subsequent strengthening techniques. Experimental results showed that both the unexposed control beams and unstrengthened fire-damaged continuous RC T-beams exhibited flexure failure modes and significant redistribution of moment between hogging and sagging regions. The fire-exposed beams had notably degraded strength and stiffness attributable to the internal temperatures exceeding 500 °C for some portion of the exposure. The EB-CFRP strengthening of fire damaged beams was shown to mostly mitigate the effects of fire exposure. The EB-CFRP retrofit measures successfully restored the virgin capacity of the beam and were sufficient to also restore most of the lost initial stiffness. Simple prediction using plane sections analysis and the assumptions of the 500 °C isotherm method [1] were shown to accurately predict the behaviour of the fire-damaged specimens.