Civil Engineering Reference
In-Depth Information
90
"
36
"
54
"
10
"
2-1/2
"
NA (
n
= 8)
NA (
n
= 24)
85
"
66.18
"
54.84
"
5/8
"
2-1/2
"
20
"
FIGURE E7.3
Composite section with
n
=
8
and
n
=
24
(elastic modular ratio and plastic
modular ratio).
TABLE E7.5
Composite Steel and Concrete Section Properties—Short-Term Loads
(Includes Live Load)
Element
A
(in.
2
)
(in.
3
)
y
)
2
(in.
4
)
I
o
(in.
4
)
y
b
(in.)
Ay
b
y
b
−
y
(in.)
A
(
y
b
−
Steel section
153.13
45.00
6891
−
21.18
68,667
223,444
Concrete slab (
n
=
8)
112.50
95.00
10,688
28.82
93,467
938
265.6
17,578
162,134
224,382
TABLE E7.6
Composite Steel and Concrete Section Properties with
n
=
8
I
(Gross or Net Depending on
Location of NA) (in.
4
)
nS
(Gross or Net) (in.
3
)
Location (Figure E7.2)
nc
(in.)
Top concrete
8
33.82
386,516
91,429
Bottom concrete
8
23.82
386,516
129,812
Top steel
1
23.82
386,516
16,227
Bottom steel
1
66.18
363,234
5489
Note:
NA
=
neutral axis.
