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IBRACON Structures and Materials Journal • 2012 • vol. 5 • nº 3
P. P. NASCIMENTO | R. B. GOMES
|
L. L. J. BORGES
|
D. L. DAVID
lithic column P2. Similarly to this column, it failed to reach the steel
yield strain.
Figure 14 shows load curves x concrete strain on all the columns
assayed, with the exception of column P7; two strain gauges on
this column located on the compressed face suffered damages.
Strains were measured at mid-height on the compressed face of
columns. The monolithic reference column P2 reached concrete
crushing strain. Despite failing to reach concrete crushing values,
column P1 showed a curve which followed this tendency.
Strains measured on the concrete of columns P3, P4 and P5, all
strengthened with a single pair of connectors did not reach con-
crete crushing strength on the compressed face. In this case, re-
sults show that the closer the pair of connectors is to the centre of
the column, the greater the strain of the compressed concrete. Col-
umn P6A, which was strengthened with two pairs of connectors,
also failed to reach concrete crushing strength. Of all the strength-
ened columns, only P8 showed concrete crushing strain (3.5 ‰).
4. Conclusions
All the strengthened models showed a reduction in horizontal dis-
placements, which were measured at mid-height of the columns’
Figure 11 – Location of column failure on compressed face
P1
140 kN
P2
450kN
P3
390kN
P4
470kN
P5
500kN
P6
370kN
P8
520kN
P6A
430kN
P7
480kN
Concrete
crushing
Failure
cracking
Debonding
of
strengthening
Concrete
crushing
Debonding
of
strengthening
Debonding
of
strengthening
Debonding
of
strengthening
Debonding
of
strengthening
Debonding
of
strengthening