1. Anchor
Channel Systems
2. HAC
Portfolio
3. HAC
Applications
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
The behavior of anchor channels loaded towards the free
edge is based on numerical and experimental investigations.
The shear load is initially transferred into the concrete via the
channel and the anchors. Owing to the edge distance from the
front face of the channel closer to the edge, which is smaller
than the edge distance of the anchor, a local concrete failure
starting at the front edge of the channel frequently occurs
before the ultimate load is reached. Thereafter, the entire load is
transferred to the concrete via the anchors. V b
ψ s,V
ψ co,V
ψ c,V
ψ h,V
f V cb ³ V ua a
V cb = V b × ψ s, V × ψ co1, V × ψ co2, V .ψ h, V .ψ c, V
Figure 7.4.2.3 — Projected area of an anchor channel loaded in shear.
V b = l × α ch, V × f c ' × ( c a1 ) 3
= Basic concrete breakout strength in shear
= Modification factor for anchor spacing
= Modification factor for corner effects
= Modification factor cracked/uncracked concrete
= Modification factor for concrete thickness
or a shear force parallel to an edge (as shown in Figure
b) F
7.4.2.4), V cb,y shall be permitted to be 2.5 times the value of
the shear force determined from Eq. (30) with the shear force
assumed to act perpendicular to the edge.
The ultimate load of a channel segment with one anchor
depends on the size of the channel and anchor and is given by :
V b = Basic concrete breakout strength in shear
ESR-3520 Equation (30)
a) For a shear force perpendicular to the edge by Eq. (30)
4
b) α = 2; fixture cannot rotate
Spacing of anchors equal to 5 times the edge distance
Figure 7.4.2.2 — Failure of concrete breakout in shear b 1 , b 2 and b 3 ) close to an edge,
close to an edge and corner, away from the edge b 4 close to an edge, b 5 close to an
edge and two corners in a deep member.
s i
= distance between the anchor under consideration
and the adjacent anchors ≤ s cr,V
s cr,V = 4c a1 + 2b ch
V aua,i = factored shear load of an influencing anchor, lb (N)
V aua,1 = factored shear load of the anchor under
consideration, lb (N)
n
= number of anchors within a distance s cr,V to both sides
of the anchor under consideration
1
é æ s ö 1.5 V a ù
1 + å ê ç ç 1 - i ÷ ÷ × ua, a i ú
s cr, V ø V ua, 1 ú
i = 2 ê è
ë
û
n + 1
ESR-3520 Equation (32)
Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019
179
The value calculated for concrete breakout strength in shear
(V cb ) is based on the location of the anchor element being
considered. The basic concrete breakout strength in shear (V b )
is not dependent on the anchor element being considered, but
it is dependent on the concrete geometry via the parameter c a1 .
However, the calculated value for V b will be the same for each
anchor element if the c a1 value is the same for each element.
The parameter ψ s,V will be dependent on the anchor element
being considered and the concrete geometry. Reference ESR-
3520 Equation (32) for more information on how to calculate ψ s,V .
y s, V =
b 4
ψ s,V : T
he modification factor to account for the influence
of location and loading of adjacent anchors shall be
computed in accordance with Eq. (32).
b 5
The model described for the calculation of the concrete edge
capacity of anchor channels under shear loading towards the
edge assumes that shear forces are transferred by bending
of the channel to the anchors and from the anchors into the
concrete. This approach simplifies the real behavior. It has
been chosen to allow for a simple interaction between tension
and shear forces acting on the channel. Equation 31 gives the
failure load of one anchor of an anchor channel. The influence
of the geometric parameters edge distance, anchor spacing
and component thickness is taken into account with sufficient
accuracy. The nominal concrete breakout strength, V cb,y , in shear
perpendicular to the channel of a single anchor of an anchor
channel in cracked concrete shall be computed as follows:
parallel to the edge.
178
b 3
Figure 7.4.2.4— Anchor channel arranged perpendicular to the edge and loaded
Anchors loaded in shear toward
a proximate free edge may fail by development of a semi-
conical fracture surface in the concrete originating at the point
of bearing and radiating to the free surface Fig. 7.4.2.2 b1. A
group of anchors loaded in shear and proximate to an edge may
develop a common conical fracture surface (Anchors loaded
in shear toward a proximate free edge may fail by development
of a semi-conical fracture surface in the concrete originating
at the point of bearing and radiating to the free surface Fig. b1.
A group of anchors loaded in shear and proximate to an edge
may develop a common conical fracture surface Fig. b2, and
the development of the fracture surface is interrupted by the
presence of a corner Fig. b3 by the limited depth of the member
(Fig. b4) or by proximate edges parallel with the load direction
(Fig. b5). In these cases the failure load associated with the
anchor or one anchor of the group is reduced compared to the
application shown in Fig. b1. Fig. b2) and the development of
the fracture surface may be interrupted by the presence of a
b 1 & b 2
M
odification for lightweight concrete
Lightweight concrete = 0.75
Sand-Lightweight concrete = 0.85
α ch,V … I nfluence factor for channel size (channel factor
depending on dimensions of profile and anchor) (10.50,
max) AC232 test 10 has been used to determine α ch,V
for various anchor channel. Tests may be omitted if the
nominal strength, V b , is computed in accordance with
(17.5.2.10.2, ACI 318-14) with α ch,V = 5.6 lbf 1/2 /in 1/3
(α ch,V = 4.0 N 1/2 /mm 1/3 for SI) (Normal weight concrete)
Concrete Edge Breakout Shear Strength ф V cb,y
Concrete edge breakout failure:
Failure of an anchor channel installed
at the edge of a concrete member
and loaded in shear towards the edge
characterized by the
formation of a fracture surface
originating at the channel and
projecting towards the edge of the
concrete member as shown in the
figure 7.4.2.1.
λ…
Figure 7.4.2.1 — Concrete edge failure due to an anchor channel loaded in shear.
f´ c = the lesser of the specified concrete compressive strength
and 8,500 psi (59 MPa)
Figure 7.4.1.4 — Channel bolt resisting shear forces with stand off.
7.4.2 CONCRETE STRENGTHS IN
PERPENDICULAR SHEAR
ESR-3520 Equation (31)
corner (Fig. b3) by the limited depth of the member Fig. b4 ) or
by proximate edges parallel with the load direction (Fig. b5). In
these cases the failure load associated with the anchor or one
anchor of the group is reduced compared to the application
shown in Fig. b1
a) α = 1; fixture can rotate
4. Design
Introduction