HAC_Technical-Guide
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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
9.1 Overview of Hilti Anchor Channel Systems Design
9.2 HAC and HAC-T Design 9.3 HAC CRFoS U Design 9.4 & 9.5 Post Tensioned Slabs 9.6 HAC EDGE Design
Longitudinal shear analysis
When Longitudinal shear is applied on both sides of the anchor
channel towards the corner edge. The longitudinal shear
capacity is determined with the edge distance of c
a1
or with
c
’
a1
which ever controls. Please refer Figure 9.2.3.8 and Figure
9.2.3.9.
Interaction Equation
Interacting the concrete utilization in tension, perpendicular
shear and longitudinal shear of both channels which will include
the effect of all of these breakout cones as described below. 3D
Load Interaction for Front of Slab solutions (verification for every
anchor):
with α=1.67
N
"#
#
ϕ % N
&'
: Tension of anchor channel in consideration
( channel a - anchor a
1
)
• Concrete breakout in tension utilization (anchor, including
influence of the other channels)
• Pull Out Strength Utilization
: Longitudinal shear of anchor
channel on perpendicular edge
(channel b)
• Longitudinal concrete edge failure Utilization
• Anchor reinforcement for concrete edge failure Utilization
V
"#,%
#
ϕ ' V
(),%
: Perpendicular shear of anchor channel in
consideration ( channel a - anchor a
1
)
• Maximum Concrete edge breakout utilization for
Perpendicular shear
!
"#,%
#
&'!
(),%
:
: Longitudinal shear of anchor channel in consideration
( channel a - anchor a
1
)
• Concrete edge (anchor)
• Anchor reinforcement for concrete edge failure
Please note that using this interaction equation is a conservative
method to incorporate longitudinal force utilization in the
analysis. In order to optimize the design contact Hilti. We
will optimize the design using the method that takes into
consideration the longitudinal utilization of both the anchor
channels.
Figure 9.2.3.8 — 90° FoS corner with anchor channels on both sides —
Effect of longitudinal, perpendicular shear and tension.
Figure 9.2.3.9 — 90° FoS corner with anchor channels on both sides —Effect
of longitudinal, perpendicular shear and tension—section view
Acute and obtuse corners
Acute Corner:
Acute angle corners with HAC (rounded headed anchors) loaded
simultaneously in tension, perpendicular shear and longitudinal
shear
Tension analysis: .
The crack will propagate along the path of least resistance at the
corner instead of following idealized failure plane. The side edge
distance used in the analysis should be as shown in the Figure
9.2.3.10. This approach is followed in order to avoid utilizing the
same concrete twice in the analysis, hence generating the results
replicating the real condition. The shaded region of concrete
shown in the figure is not utilized. Please refer Figure 9.2.3.10.
The total distance of (a+b) can be divided between the two
channels, while analysing the individual channels. For example if
channel a is loaded more than channel b than side edge distance
of 3/4(a+b) can be assumed for channel a and side edge distance
1/4(a+b) can be assumed for channel b.
Perpendicular shear analysis:
The reduced side edge distance needed to be considered as
shown in Figure 9.2.3.12. The ideal failure plane for perpendicular
shear breakout is drawn propagating into the slab. The line
is drawn parallel to edge 1 at a distance h
cr,v
(2(h
ch
+c
a1
)). The
intersection point of this line with edge 2 is projected back
to edge 1 in order to determine side edge distance c'
a2
for
the analyses of channel b. Similar line can be drawn parallel
to edge 2 at a distance h
cr,v
(2(h
ch
+c
a1
)) to determine the side
edge distance of channel a. This side edge is measured from
that point to the anchor and is modelled in profis for analysis
for analyses of individual channels. This will reduce the
perpendicular shear capacity by taking into consideration the
small edge introducing the more stringent corner modification
factor. Please refer Figure 9.2.3.11 and Figure 9.2.3.12.
Moreover, the ψ
s,v
is calculated taking into consideration the
respective distances of neighboring anchors with respect to
the anchor that is in consideration. Refer to 90° corner section
describing the method in detail. Please refer Figure 9.2.3.14
Example of spacing factor ψ
s,v
calculation for a
1
with respect to a
1
.
ψ
s,V
modification factor for spacing influence for acute angle
corner: Example of spacing factor ψ
s,v
calculation for b
1
of
anchor channel "b" taking into consideration the presence of
anchor channel a.
=
'()
; ℎ
'()
s
"#,%
= 2 ∗
2
= 2 ∗ 1.13
s,v,a1
1.5 1.5 1.5 1.5
b,1,1 , 1 b,1,2 , 2 b,1,3 , 3 a,1,2 , 2
cr,v , 1 cr,v , 1 cr,v , 1 cr,v , 1
1
ss ss
11 1 1 1
ssss
aa aa
ua b ua b ua b ua a
aaaa
ua a ua a ua a ua a
VVVV
VVVV
y
=
é ùé ùé ùé ù
æö æö æö æö
ê úê úê úê
+ -×+ -×+ -×+ -×
ç÷ ç÷ ç÷ ç÷
ç÷ ç÷ ç÷ ç÷
ê úê úê úê
èø èø èø èø
ë ûë ûë ûë û
1.5
a,1,3 , 3
cr,v , 1
s
1
s
a
ua a
a
ua a
V
V
éù
æö
úê ú
+ -×
ç÷
ç÷
úê ú
èø
ëû
ψ
co,V
modification factor for corner influence for acute angle
corner: A reduced edge distance is taken into consideration
for determination of reduction factor for corner distance C'
a2
is taken as distance in case of a acute angle corner for corner
anchor b
1
. Refer Figure 9.2.3.12
C
a2
=(C'
a2
) distance of the anchor a1 under consideration to the
corner (see Figure 9.2.3.12).
2, ,
0.5
2
2, ,
,
' 1.0
'
' 1.0
a cr v co V
a
a cr v co V
cr V
If C C than
C
If C C than
C
y
y
³ =
æö
<=£
ç÷
ç÷
èø
,1
,, 1
24
0.5 2
cr v ch a
cr v cr v ch a
S bC
C S bC
=+
= =+
Figure 9.2.3.10 — Acute angle FoS corner with anchor channels on both
sides — Tension analysis.
Figure 9.2.3.11 — Acute angle FoS corner with anchor channels on both
sides — Perpendicular shear analysis — Plan view.
Figure 9.2.3.12 — Acute angle FoS corner with anchor channels on both
sides — Perpendicular shear analysis- Section view.