Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/88660
Título: | Fire behaviour of reinforced concrete slab strips strengthened with prestressed NSM-CFRP laminates |
Autor(es): | Azevedo, Adriana S. Firmo, João P. Correia, João R. Mohammadifirouz, Reza Barros, Joaquim A. O. |
Palavras-chave: | RC slabs CFRP strengthening NSM Prestress Fire behaviour |
Data: | 2023 |
Editora: | Elsevier 1 |
Revista: | Engineering Structures |
Resumo(s): | Carbon fibre reinforced polymer (CFRP) composites are now widely used to strengthen reinforced concrete (RC) structures. Among the strengthening systems available, near-surface mounted (NSM)-prestressed CFRP laminates offer several advantages, as they significantly increase the load carrying capacity and also the serviceability performance of RC structures. However, as for other CFRP systems, there is a concern about their behaviour at elevated temperature and under fire exposure due to the glass transition process undergone by their polymeric components. Nevertheless, the fire performance of NSM-prestressed-CFRP strengthening systems has not yet been investigated. This paper presents an experimental study about the fire resistance behaviour of RC slab strips strengthened with prestressed NSM-CFRP laminates; the slabs were simultaneously subjected to a mechanical (fire) load and the ISO 834 fire curve, and the influence of the following parameters on their fire resistance behaviour was assessed: (i) the prestress level (0 %, 25 % and 50 % of the CFRP tensile strength), and (ii) the presence of passive fire protection, comprising up to 48 mm thick calcium silicate (CS) boards. The results obtained showed that: (i) without fire protection, the strengthening system remained effective during a very low period of fire exposure, which significantly decreased with the prestress level, from 16 min (0 %) to less than 5 min (50 %); (ii) with fire protection, even with 50 % of prestress, the strengthening system remained effective for more than 120 min; and (iii) the “critical” temperatures in the anchorages of the strengthening systems were found to be about 2.5Tg, 2.0Tg and 1.5Tg, for the prestress levels of 0 %, 25 % and 50 %, respectively, with Tg being the glass transition temperature of the adhesive. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/88660 |
DOI: | 10.1016/j.engstruct.2023.116982 |
ISSN: | 0141-0296 |
e-ISSN: | 1873-7323 |
Versão da editora: | https://www.sciencedirect.com/science/article/pii/S0141029623013974 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | ISISE - Artigos em Revistas Internacionais |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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Fire behaviour of reinforced concrete slab strips strengthened with prestressed NSM-CFRP laminates.pdf | 8,96 MB | Adobe PDF | Ver/Abrir |