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IBRACON Structures and Materials Journal • 2012 • vol. 5 • nº 5
Flexural strengthening of reinforced concrete beams with carbon fibers reinforced polymer (CFRP) sheet
bonded to a transition layer of high performance cement-based composite
tance. Further information on the development of composites can
be found in Ferrari [6] and Ferrari & Hanai [9].
3.2. Retrofitting of tensile zone and application
of strengthening on beams
The procedures to remove concrete, retrofitting and strengthening of
tensile zone of beam V2C were initiated when the concrete had 23
days. The concrete removal was mechanically performed with elec-
tric breaker hammer and concluded with a sledgehammer, pointer
and chisel Figure [7]. To prepare the tensile zone with composite CP-
M1A2C, two molds of plasticized plywood were positioned on the two
sides of the beam. The composite was manually placed into the molds.
The general methodology used for the application of strengthening
with steel fibers on the beams V1C and V2C are detailed in Ferrari
[5]. The epoxy adhesive used was Sikadur 330 and the sheet was
SikaWrap 300C, both, provided by Sika (Table [4]). The Figure 8
shows the layer aspect after its reconstitution and the strengthening.
3.3 Testing procedures
The RC beams were carried to a simple flexural at four points,
through monotonic loading. The structural behavior of beams was
observed and monitored throughout the test, recording the load,
the corresponding vertical displacements and deformations of con-
crete, steel and strengthening.
The test setup was mounted on the plate reactor of the Laboratory
of Structures of Engineering School of São Carlos (Figure [9]). The
load to request each beam at flexion was introduced through an
hydraulic actuator with 500 kN of nominal capacity, able to control
Figure � � �emo�al of �on�rete from the tensile zone of the beam V2C
Figure � � �ensile layer aspect after the retrofitting and strengthening