Civil Engineering Reference
In-Depth Information
14
"
2@4 =9
"
1
2
1
2
1
2
2
"
2
"
1
2
4
"
2
"
1
2
6#9
6#9
(6.00
in.
2
)
20
"
13
"
Figure 7.15
SOLUTION
(a) Straight Bars
1.3 for top bars
1.5 for coated bars with cover
3
d
b
or clear spacing
6
d
b
(1.3)(1.5)
1.95
1.7
Use 1.7
1.0 for #9 bars
1.0 for normal weight concrete
c
side cover
2.5 in.
c
one-half of c. to c. spacing of bars
2.25 in.
k
c
K
tr
d
b
2.25
0
1.128
1.99
2.5
OK
d
60,000
(1.7)(1.0)(1.0)
1.99
3
40
d
b
4000
61 diameters
d
(61)(1.128)
69 in.
(b)
Using 180
hooks (see Figure 7.16) note that
1.2 as required in ACI Section 12.5.2 for
epoxy-coated hooks
dh
0.02
f
y
d
b
(0.02)(1.2)(1.0)(60,000)(1.128)
4000
c
f
25.68 in. Say 26 in.
dh
=
26
"
Critical section
4
d
b
5
8
5
d
b
=
5
"
1
2
= 4
"
Figure 7.16
180
hook.
