Page 44 - Riem-Vol6_nº2

215 IBRACON Structures and Materials Journal • 2013 • vol. 6 • nº 2
C. M. PALIGA | M. V. REAL | A. CAMPOS FILHO
ratio of 0.905% (3ø12mm), compression ratio of 0.419% (2ø10mm)
and strengthening ratio of 0.018% (a 6.75mm2 layer). According to
Ombres [1], rupture load of the first prototype was 87.42kN, and fail-
ure was caused by concrete crushing. The second prototype failed
also due concrete crushing at 87.60kN ultimate load. The rupture
load obtained by the numerical model was 86.25kN, representing
an average difference of -1.4% relative to the experimental values.
Figure 5 shows the load-deflection curves obtained experimen-
tally, which are compared with the beam performance numerically
calculated.
Figure 6 shows the comparison between the experimental and the
numerical values for concrete compressive strain (sample point
near node 77) and for maximum strengthening tensile strain (sam-
ple point near node 94).
4.2 Series S2
In this series, three numerically simulated beams were reinforced
with a tension reinforcement ratio of 0.419% (2ø10mm), compres-
sion ratio of 0.268% (2ø8mm) and PBO-FRCM reinforcement ratio
of 0.018% (one 6.75mm2 layer), 0.036% (two 13.5mm2 layers) and
0.054% (three 20.25mm2 layers).
4.2.1 Beam strengthened with one PBO-FRCM layer
According to Ombres [1], the beam strengthened with one PBO-
FRCM layer failed at a 54.24kN load due to concrete crushing.
The rupture load numerically obtained by finite element model was
52.25kN, representing a difference of -3.7% relative to the experi-
mental value.
Figure 7 shows the load-deflection curves obtained experimentally
and numerically.
Figure 8 shows the comparison between the experimental and the
numerical values for concrete compressive strain (sample point
near node 77) and for maximum strengthening tensile strain (sam-
ple point near node 94).
4.2.2 Beam strengthened with two PBO-FRCM layers
According to Ombres [1], the beam strengthened with two PBO-
FRCM layers collapsed at a 66.00kN load due to the debonding of
the strengthening system from the concrete substrate. The rupture
load numerically obtained by finite element model was 68.75kN, rep-
resenting a difference of +4.2% relative to the experimental value.
Figure 5 – Load-deflection curves (node 73 – Figure 4)
for Beam Serie S1
Figure 6 – Load versus Strain in the mid-span
section for Beam Serie S1
Figure 7 – Load-deflection curves (node 73 – Figure 4)
for Beam Serie S – One layer2