Fire behaviour of rc slab strips strengthened with advanced cfrp strengthening systems

Adriana Azevedo, João Firmo, João Correia, Carlos Chastre, Hugo Biscaia, Noel Franco

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Carbon fibre reinforced polymer (CFRP) composite systems are widely used to strengthen reinforced concrete (RC) structures through bonding strips/sheets on the concrete surface – externally bonded reinforcement (EBR) technique, or through strips/rods bonded inside slits in the concrete cover – near-surface mounted (NSM) technique. Although both techniques provide high strength increases, it is usually not possible to use the CFRPs’ full strength due to premature debonding, especially with EBR. This limitation can be overcome when using CREatE (continuous reinforcement embedded at ends) technique (developed by the last three authors), which consists of (i) bonding the central part of the CFRP strip (as in EBR), or the CFRP rod (as in NSM), and (ii) anchoring both ends of the strip/rod inside the concrete section, after a transition curve, enhancing its anchorage capacity. However, all these techniques are susceptible to fire, due to the polymeric nature of CFRP materials and epoxy adhesives. This paper presents the results of an experimental study regarding the fire behaviour of RC slab strips strengthened with EBR, NSM and CREatE techniques, in which the influence of applying different fire protection systems was investigated. The specimens were strengthened with those systems and simultaneously subjected to a service load and the ISO 834 fire curve. The following main results were obtained: (i) without fire protection, the CREatE technique presented the highest fire resistance due to the better anchorage of the CFRP; (ii) when protected, the NSM technique presented higher fire resistance compared to EBR and CREatE techniques; and (iii) “critical” temperatures were proposed for each technique, 1.0Tg, 2.5Tg, and 3.0Tg for EBR, NSM and CREatE techniques, respectively.

Original languageEnglish
Title of host publicationConcrete Structures
Subtitle of host publicationNew Trends for Eco-Efficiency and Performance - Proceedings of the fib Symposium 2021
EditorsEduardo Júlio, Jonatas Valença, Ana Sofia Louro
Publisherfib. The International Federation for Structural Concrete
Pages1306-1315
Number of pages10
ISBN (Electronic)978-294064308-0
Publication statusPublished - 2021
Event2021 fib Symposium of Concrete Structures: New Trends for Eco-Efficiency and Performance - Virtual, Lisbon, Portugal
Duration: 14 Jun 202116 Jun 2021

Publication series

Namefib Symposium
Publisherfib. The International Federation for Structural Concrete
Volume2021-June
ISSN (Print)2617-4820

Conference

Conference2021 fib Symposium of Concrete Structures: New Trends for Eco-Efficiency and Performance
Country/TerritoryPortugal
CityVirtual, Lisbon
Period14/06/2116/06/21

Keywords

  • Advanced CFRP strengthening techniques
  • CREatE technique
  • EBR technique
  • Fire behaviour
  • NSM technique

Fingerprint

Dive into the research topics of 'Fire behaviour of rc slab strips strengthened with advanced cfrp strengthening systems'. Together they form a unique fingerprint.

Cite this