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IBRACON Structures and Materials Journal • 2012 • vol. 5 • nº 3
M. R. GARCEZ | G. L. C. P. SILVA FILHO | URS MEIER
The increasing on the load bearing capacity of the beam post-
strengthened with prestressed strips, higher than the one of the
beam post-strengthened with non-prestressed strips, highlights
the efficiency of the prestressing technique.
All post-strengthened beams showed vertical displacements at
mid-span lower to the ones of the control beam. However, the stiffer
behavior showed by all post-strengthened beams was evidenced
only after concrete cracking. Due to the increasing of the concrete
cracking load and the later yielding of the reinforcement steel, the
beam post-strengthened with prestressed CFRP strips showed a
stiffer behavior when compared to the one post-strengthened with
non-prestressed CFRP strips.
Gradual anchorage worked properly, dismissed the use of any ex-
ternal anchorage system and allowed the use of 83% of the tensile
strength of the strip.
In this paper, the efficiency of prestressing was verified by means
of bending tests under static loading. However it is also necessary
to verify the behavior of the prestressed post-strengthening under
cyclic loading, aiming to identify possible changes on the behavior
of prestressed strips and on the gradual anchorage. This topic will
be addressed at the second part of this paper.
6. Acknowledgements
Authors would like to acknowledge CNPq (Portuguese acronym of
the Brazilian Ministry of Science’s National Research Council) and
CAPES (Portuguese acronym of the Brazilian Ministry of Educa-
tion’s Higher Education Human Resources Development Agency)
for providing the financial support needed to develop this project.
Authors would also like to express their appreciation for the techni-
cal support given by the research team at EMPA (Swiss Federal
Laboratories for Materials Testing and Research), in Switzerland.
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