HAC_Technical-Guide
408 409
Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019
1. Anchor
Channel Systems
2. HAC
Portfolio
3. HAC
Applications
4. Design
Introduction
5. Base material 6. Loading
7. Anchor Channel
Design Code
8. Reinforcing
Bar Anchorage
9. Special Anchor
Channel Design
10. Design
Software
11. Best
Practices
12. Instructions
for Use
13. Field Fixes
14. Design
Example
Code Discussion Calculations
Step 7: Concrete strength
ESR-3520 Section
4.1.3.3.4.
ACI 318-14 Chapter 17
Concrete breakout strength in perpendicular shear for anchor element #3 continued...
Calculate the modification factor for member thickness (ψ
h,V, 3
).
c
a1
is measured perpendicular to the anchor channel longitudinal axis, and is
considered when calculating the basic concrete breakout strength in shear (V
b
) and
the modification factor for member thickness (ψ
h,V
).
cha1Vcr,
2h2ch +=
ESR-3520 Equation (38)
h
ch
… height of anchor channel
b
1
... Given in ICC-ESR alternatively a default value of 0.50 shall be used
h
ch
… critical member thickness,
1.0
h
h
1
Vcr,
Vh,
£
÷
÷
ø
ö
ç
ç
è
æ
=
b
y
if h < h
cr,V
ESR-3520 Equation (37)
Concrete edge breakout: ФV
cb,y
h
cr,V
= 2 (5.00 in) + 2 (1.22 in)
h
cr,V
= 12.44
1.0694.0
12.44in
6in
Vh,
5.0
Vh,
£=
÷
ø
ö
ç
è
æ
=
y
y
694.0
Vh,
=\
y
Figure 14.1.24 — Design example – height reduction factor h
cr,v
Code Discussion Calculations
Step 7: Concrete strength
ESR-3520 section
4.1.3.3.3
ACI 318-14 Chapter 17
Concrete breakout strength in perpendicular shear for anchor element #3 continued...
Calculate the modification factor for cracked/uncracked concrete (ψ
c,V,3
).
Cracked concrete conditions with no supplementary reinforcement → ψ
c,V,3
= 1.0
Note: if cracked concrete conditions are assumed, and supplementary edge
reinforcement as defined in ESR-3520 Section 4.1.3.3.3 is used, ψ
c,V,3
can be increased
to either ψ
c,V,3
= 1.2 or ψ
c,V,3
= 1.4.
Cracked concrete
No supplementary reinforcement
ψ
c,V
= 1.0
With supplementary reinforcement
• Cracked concrete with edge reinforcement (#4 min.)
ψ
c,V
= 1.2
• Cracked concrete with edge reinforcement (#4 min.) and stirrups (#4 min.) spaced
at 4” O.C.
ψ
c,V
= 1.4
Uncracked Concrete
Anchor channels located in a region of a concrete member where analysis indicates
no cracking at service load levels.
ψ
c,V
= 1.4
Note: in order to activate the reinforcement, concrete has to crack. Therefore, if
uncracked concrete is assumed, supplementary reinforcement does not impact this
factor.
Concrete is typically assumed to be cracked under normal service load conditions.
If cracked concrete conditions are assumed, an increase in V
cb,y
is permitted via the
modification factor ψ
c,V
if supplementary edge reinforcement is used. If uncracked
concrete conditions are assumed, an increase in V
cb,y
is likewise permitted via the
modification factor ψ
c,V
. Reference ESR-3520 Section 4.1.3.3.3 for more information.
Concrete edge breakout: ФV
cb,y
If uncracked concrete conditions are assumed,
ψ
c,V,3
= 1.4.