HAC_Technical-Guide
184 185
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
7.1 & 7.2 Introduction to
Anchor Channel Design
7.3 Anchor Channel Tension Design 7.4 Anchor Channel Shear Design (y) 7.4 Anchor Channel Shear Design (X)
7.5 Interaction Equations
(Combined Loading)
7.6 Seismic Design
Steel Concrete Steel Concrete Steel Concrete
7.4.3 STEEL STRENGTHS IN LONGITUDINAL
SHEAR
Shear (ΦV
n,x
)
Steel Concrete
Figure 7.4.3.1 — Possible tensile failure modes of an anchor channel.
Anchor Strength ϕV
sa,x
and Anchor and Channel
Connection Strength ϕV
sc,x
ϕV
sa,x
≥ V
a
uax
ϕV
sc,x
≥ V
a
uax
The nominal strength of one anchor,
V
sa,x
, and anchor and channel
connection V
sc,x
to take up shear
loads acting in longitudinal channel
axis must be taken from Table 8-5
for HAC and HAC-T with Hilti channel
bolts (HBC-C, HBC-T and HBC-C-N).
Table 7.4.3.1 — Test program for anchor channels for use in uncracked and cracked concete (Table 4.2 of AC232)
Test no. Test Ref Test description f
c
∆w
Minimum
No. of
tests
Channel Anchor Material
Channel bolt
d
s
strength
[-]
Secion
in Annex
A
[-]
psi
[N/mm
2
]
[-] [-] [-] [-]
inch
(mm)
[-]
Steel failure under shear load acting in longitudinal chaennel axis
15 7.14 Failure of connection between channel
lips and channel bolt
Low 0 5 see AC232 Section 7.14.2 1
16 7.16 Failure of connection between channel
lips and channel bolt — influence of
level of prestressing force
Low 0 5 see AC232 Section 7.16.2 1
17 1.17 Failure of connection between channel
lips and channel bolt — influence of
channel below concrete surface
Low 0 5 see AC232 Section 7.17.2 1
Channel Lip Strength ϕV
sl,x
ϕ V
sl,x
≥ V
b
uax
The nominal strength of the
connection between channel lips and
channel bolt to take up shear loads
acting in longitudinal channel axis,
V
sl,x
, must be taken from ESR-3520
Table 8-7 , 8-8 or 8-9, as applicable.
Table 8-9 gives steel strength
information for shear acting in
longitudinal direction of the channel
axis for anchor channel HAC-T and channel bolts HBC-T. Please
note the following:
The ϕ value is 0.65 for in which periodical inspection is provided
for M12 to M20 t-bolts.
The ϕ value is 0.75 for in which continuous inspection is
provided for M12 to M20 t-bolts.
Table 8-8 gives steel strength information for shear acting in
longitudinal direction of the channel axis for anchor channel
HAC and channel bolts HBC-C-N. Please note the following:
The ϕ value is 0.55 for which periodical inspection is provided
for all t-bolts.
The ϕ value is 0.65 for which continuous inspection is provided
for M16 and M20 t-bolts. The steel strength for M12 t-bolts
used with continuous inspection an increased value of 2,021lbs
should be used with ϕ value of 0.55. Test No 15, 16 and 17 of
AC-232 table 4.2, is performed.
Table 8-7 gives steel strength information for shear acting in
longitudinal direction of the channel axis for anchor channel
HAC and channel bolts HBC-B.
Figure 7.4.3.1 — Definition of lever arm.
Channel Bolt in Shear, ϕV
ss
, ϕV
ss,M
ϕV
ss,x
≥ V
b
uax
ϕV
ss,M,x
≥ V
b
uax
The nominal strength of a channel
bolt in shear, V
ss
, must be taken from
ESR-3520 Table 8-6 of this report.
Shear load with lever arm In stand-
off installations, t-bolt are clearly
subjected to cantilever bending.
Flexural failure of the steel rod
generally defines the capacity.
If the fixture is not clamped against the concrete but secured
to the channel bolt at a distance from the concrete surface (e.g.
by double nuts), the nominal strength of a channel bolt in shear,
V
ss,M
, shall be computed in accordance with Eq. (28).
The coefficient αM depends on the degree of rotational fixity of
the anchor where it joins the baseplate.
lb(N),
.
V
Mss,
l
M
ssM
a
=
ESR-3520 Equation (28)
α
M
= factor to take into account the restraint condition of the
fixture
= 1.0 if the fixture can rotate freely (no restraint)
= 2.0 if the fixture cannot rotate (full restraint)
mm)-(Nin-lb,1MM
ss
0
ss
÷
÷
ø
ö
ç
ç
è
æ
-=
ss
ua
N
N
f
ESR-3520 Equation (29)
M
0
ss
= nominal flexural strength of channel bolt according to
Table 8-12.
≤ 0.5N
sl.
a
≤ 0.5N
ss.
a
ℓ = lever arm, in. (mm)
α = internal lever arm, in. (mm) as illustrated in Figure 7.4.3.1
Figure 7.4.3.2— Channel bolt resisting shear forces with stand off.