Civil Engineering Reference
In-Depth Information
Thickness of concrete cover measured from extreme tension fiber to cen-
ter of bar is
d
c2
:= t
slab
- d
f2
= 1·in.
Bond factor (provided by the manufacturer) is
k
b
= 0.9
The crack width under service loads (Equation (8-9) of ACI 440.1R-06) is
2
w =2
f
E
s
+
fs2
f_bar2
2
c2
β
·k ·d
=0.019·in
.
2
12
b
2
f
The crack width limit for the selected exposure is
w
lim
= 0.028·in.
“OK” if ww
≤
2
lim
Check_Crack2:=
“Not good”otherwise
Check_Crack2 = “OK”
The maximum recommended bar spacing to limit cracking based on
Ospina and Bakis [2] is
:=min 1.2.
E·w
f k
2.5·c,0.95·
E·w
f k
f lim
fs2b
f lim
fs2b
S
−
= 10.4·in
.
Ospina_2
c
“OK” if s
≤
s
f_bar2
Ospina_2
Check_SpacingOspina2 :=
“Not good”otherwise
Check_SpacingOspina2 = “OK”
6.8.3 Case 3—Interior support
Ratio of modulus of elasticity of bars to modulus of elasticity of concrete is
n
f
= 1.4
Ratio of depth of neutral axis to reinforcement depth, calculated per
Equation (8-12), is
k
3
= 0.108
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