Abstracts
The application of FRP for post-strengthening of concrete structures induces the use of elevated temperatures to minimize the curing time of the adhesive. The replacement of traditional adhesives by Heat-Activated Films (HAF), with higher glass transition temperatures (Tg), is na interesting prospect, and has been motivating studies regarding the viability of applying termo-activated adhesives. For this study, notched beams post-strengthened with CFRP bonded with two types of heat-activated films (epoxy and phenolic based) and one classical adhesive were tested in bending at EMPA (Swiss Federal Laboratories for Material Testing and Research). To verify the stress redistribution on the notched beams, a computational model, which divides the structure in solid elements, was implemented. The analysis of the behavior of the concrete-laminate interface demonstrates that numerical models are an efficient tool to supplement and explain experimental data.
CFRP; heat-activated films; epoxy resin; phenolic resin; concrete
A aplicação de PRF no reforço de estruturas de concreto pode requerer a utilização de elevadas temperaturas para minimizar o tempo de cura dos adesivos. A possibilidade de substituição dos adesivos tradicionais utilizados na colagem de laminados de PRF por Filmes Termo- Ativados (FTA), que apresentam temperaturas de transição vítrea (Tg) mais elevadas que a dos adesivos tradicionais, vem estimulando o desenvolvimento de estudos acerca da sua viabilidade de aplicação. Para o presente estudo, testes em vigas de concreto entalhadas, reforçadas com laminados de PRFC, foram realizados no EMPA (Swiss Federal Laboratories for Material Testing and Research), analisando o comportamento de dois FTA, baseados em resinas termofixas fenólica e epoxídica. Visando verificar a redistribuição de tensões nos elementos estudados, um modelo computacional foi implementado. Os resultados da análise do comportamento da interface concreto-laminado demonstram que os modelos numéricos são ferramentas eficazes para complementar e explicar os dados obtidos experimentalmente.
PRFC; filmes termo-ativados; resina epóxi; resina fenólica; concreto
Application of heat-activated films as a new generation of adhesives used for bonding fiber reinforced polymers to concrete
M. R. GarcezI; U. C. M. QuininoII; L. C. P. Silva FilhoIII; U. MeierIV
IProfessor Dr., Federal University of Pampa, Reseracher at LEME (Portuguese acronym of the Laboratory of Testing and Structural Modeling), Federal University of Rio Grande do Sul, mrgarcez@hotmail.com, Brazil
IIProfessor MSc., University of Vale dos Sinos, Researcher at LEME, Federal University of Rio Grande do Sul, uziel_quinino@yahoo.com.br
IIIProfessor PhD., Professor at Federal University of Rio Grande do Sul and Researcher at LEME, lcarlos66@gmail.com, Brazil
IVProfessor Dr. Honoris Causa, Swiss Federal Laboratories for Materials Testing and Research - EMPA, urs.meier@empa.ch, Überlandstrasse 129, CH-8600, Dübendorf - Switzerland
ABSTRACT
The application of FRP for post-strengthening of concrete structures induces the use of elevated temperatures to minimize the curing time of the adhesive. The replacement of traditional adhesives by Heat-Activated Films (HAF), with higher glass transition temperatures (Tg), is na interesting prospect, and has been motivating studies regarding the viability of applying termo-activated adhesives. For this study, notched beams post-strengthened with CFRP bonded with two types of heat-activated films (epoxy and phenolic based) and one classical adhesive were tested in bending at EMPA (Swiss Federal Laboratories for Material Testing and Research). To verify the stress redistribution on the notched beams, a computational model, which divides the structure in solid elements, was implemented. The analysis of the behavior of the concrete-laminate interface demonstrates that numerical models are an efficient tool to supplement and explain experimental data.
Keywords: CFRP, heat-activated films, epoxy resin, phenolic resin, concrete.
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REFERENCES
- [01] MEIER, U., STÖCKLIN, I., TERRASI, G. P. Making better use of the strength of advanced materials in structural engineering. In: FRP Composites in Civil Engineering, Hong Kong, 2001, Anais. [CD-ROM]
- [02] CALLISTER, W. D. Materials Science and Engineering - An Introduction, United States of America: WILEY, 2003. 820p.
- [03] RILEM TECHNICAL COMMITTEE. Test and design methods for steel fibre reinforced concrete: RILEM TC 162-TDF, Bagneux, 2002.
- [04] FÉDÉRATION INTERNATIONALE DU BETÓN. Design and Use of Externally Bonded FRP Reinforcement (FRP EBR) for Reinforced Concrete Structures. Lausane, FIB, 2001, Progress Report - Fédération Internationale du Betón.
- [05] ADVANCED COMPOSITES GROUP. Data Catalogue, 2005. [CD-ROM]
- [06] TESA. Fitas fílmicas termo-ativadas. www.tesatape.com.br , acesso em novembro de 2005.
- [07] SIKA. Sika® Carbodur - Sistema de reforço com lâminas de fibra de carbono. www.sika.com.br, acesso em abril de 2005.
Publication Dates
-
Publication in this collection
18 Sept 2014 -
Date of issue
Dec 2008