Basic HTML Version
185
IBRACON Structures and Materials Journal • 2012 • vol. 5 • nº 2
R. M. F. CANHA |
G. M. CAMPOS |
M. K. EL DEBS
4(a) referring to specimen IR1, and the other with dimensions
a little less than the minimum values indicated in Figure 4(b)
for specimen IR2.
Detailed experimental-theoretical studies of the socket foundation
carried out by Canha [4] showed that the behavior of specimens
with rough interfaces is similar to that of monolithic connections.
The observed experimental strengths for the two tested specimens
were verified to agree closely. Besides, the specimen with small
shear keys (IR2) was found to present a higher stiffness (relative
to rebar strains) than the specimen with large shear keys (IR1),
as shown in Figure 5. The abovementioned observation indicates
that the modification of shear key dimensions within the ranges
indicated in Figure 4 does not influence, except the connection
stiffness, the connection strength.
largest shear key base dimension be twice the maximum size of
the coarse aggregate and the shear key height be at least half
the aggregate size, as illustrate in Figure 4(b), to guarantee that
the coarse aggregate fits into the shear key during the concrete
placement. In the case of symmetrical keys, it is necessary to
consider the maximum size of the coarse aggregate relative to
the largest of the three “concretes” of the connection (socket,
column and joint).
To define the roughness to be adopted in the specimens
tested by Canha [4], the shear keys were manufactured ac-
cording to the limits imposed by NBR 9062:2006 [6] and the
results presented regarding the parametric evaluation with
the Rizkalla et al. [7] model. Two shear key configurations
were used, one with maximum dimensions shown in Figure
Figure 3 – Parametric evaluation of the shear keys using the model proposed by RIZKALLA et al. [7]
0
500
1000
1500
0 10 20 30 40 50 60 70 80 90
a
(º)
V (kN)
Small shear key
Large shear key
RIZKALLA
et al.
(1989) Model
l
and h constants
sk
sk
sk
0
500
1000
1500
0
5
10
15
20
l
V (kN)
Small shear key
Large shear key
RIZKALLA
et al.
(1989) Model
sk
l
increasing , h and
a
constants
sk
sk
sk
0
500
1000
1500
2000
2500
0
5
10
15
20
l
V (kN)
Small shear key
Large shear key
RIZKALLA
et al.
(1989) Model
l
and
a
constants , h decreasing
sk
sk
sk
sk
0
500
1000
1500
2000
0
300
600
900
1200
e (mm)
V (kN)
Small shear key
Large shear key
RIZKALLA
et al.
(1989) Model
n =10
sk
n =20
sk
n =1
sk
n =1
sk
sk
l
and h constants , n decreasing
sk
sk
sk
B
BD
A
C