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Volume 6, Number 1 (February 2013) p. 1-12 • ISSN 1983-4195
© 2013 IBRACON
This paper presents the experimental data of the behavior of reinforced concrete beams strengthened to shear with carbon fiber composites. The
tests were composed of eight T beams, b
w
=15 cm, h=40 cm, flange width 40 cm, flange height 8 cm, and length 300 cm, divided into two series
with the same longitudinal steel reinforcement and a reference beam without strengthening in each series. The beams had two types of arrange-
ment of internal steel stirrups. The test variables were the internal and external geometric ratio of the transverse reinforcement and the mechanical
ratio of carbon fiber composites stirrups. All the beams were loaded at two points. The strengthened beams were submitted to a preloading and
the strengthening was applied to the cracked beam. All the beams were designed in order to guarantee shear failure, and the ultimate load of the
strengthened beams was 36% to 54% greater than the reference beams. The Cracking Sliding Model applied to the strengthened beams was
evaluated and showed good agreement with the experimental results.
Keywords
: shear strengthening; reinforced concrete; external strengthening; carbon fiber composites.
Este artigo apresenta os dados de ensaios de vigas de concreto armado reforçadas à força cortante com compósito de fibras de carbono. Os
ensaios de oito vigas T, b
w
=15 cm, h=40 cm, largura da mesa igual a 40 cm, altura da mesa 8 cm, comprimento de 300 cm, divididos em duas
séries com a mesma armadura longitudinal e uma viga de referência sem reforço externo para cada série. As vigas tinham dois tipos de arranjos
de estribos internos de aço. As variáveis dos ensaios foram as taxas geométricas das armaduras transversais internas e externas, e a taxa me-
cânica da armadura em estribos de compósito de fibras de carbono. Todas as vigas foram carregadas em dois pontos. As vigas reforçadas foram
submetidas a um carregamento prévio e reforçadas após a fissuração. Todas as vigas foram projetadas para garantir a ruptura por força cortante,
e as forças últimas das vigas reforçadas foram de 36% a 54% superiores às das vigas de referência. O Modelo da Fissura Deslizante foi avaliado
e mostrou boa concordância com os resultados experimentais.
Palavras-chave:
reforço à força cortante; concreto armado; reforço externo; compósito de fibras de carbono.
RC T beams strengthened to shear with carbon
fiber composites
Vigas T de concreto armado reforçadas à força cortante
com compósito de fibras de carbono
L. A. SPAGNOLO JR
a
spagnolojr@petrobras.com.br
E. S. SÁNCHEZ FILHO
b
emilsanchez@uol.com.br
M. S. L. VELASCO
c
marta@puc-rio.br
a
LUIS ALBERTO SPAGNOLO JR. is a Structural Engineer at Petrobras, Rio de Janeiro, Brazil. He received his M. Sc. in Structural Engineering from
PUC Rio. Contact: spagnolojr@petrobras.com.br
b
EMIL DE SOUZA SÁNCHEZ FILHO is an Associate Professor of Civil Engineering at the Fluminense Federal University, Niterói, Rio de Janeiro, Brazil.
He is member of ACI, PCI, FIB, IABSE, IBRACON, ABPE and ABCM. He received his M. Sc. and D. Sc. in Structural Engineering from COPPE-Federal
University of Rio de Janeiro. Contact: emilsanchez@uol.com.br
c
MARTA DE SOUZA LIMA VELASCO is an Associate Professor of Civil Engineering at PUC-Rio. She received her M. Sc. from PUC-Rio, and her D. Sc.
in Structural Engineering from COPPE-Federal University of Rio de Janeiro.
Received: Received: 10 Jun 2012 • Accepted: 04 Oct 2012 • Available Online: 08 Feb 2013
Abstract
Resumo