HAC_Technical-Guide

176 177
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
Shear Load Acting Perpendicular to Channel
7.4.1 STEEL STRENGTHS IN PERPENDICULAR
SHEAR
Steel failure Anchors loaded in shear exhibit steel failure when
the edge distance and the embedment depth are sufficiently
large, whereby conical spalling of the surface concrete
precedes steel failure Figure 7.4.1.1. For a given anchor, steel
failure represents a limit on the maximum shear capacity.
Anchors made of ductile steels can develop relatively large
displacements at failure.
Figure 7.4.1.1 — Steel failure in shear of anchor channel lip.
Shear (ΦV
n,y
)
Steel Concrete
Figure 7.3.1.1— Possible tensile failure modes of an anchor channel.
Table 7.4.1.1 — Test program for anchor channels for use in uncracked and cracked concrete (Table 4.1 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)
[-] [-] [-] [-]
inch
(mm)
[-]
Steel failure under Shear load
8 7.8 Failure of anchor, failure of connection
between anchor and channel, local
rupture of channel lips
6
Low 0 5
1,8
See AC 232 section 7.8.2
9 intentionally left blank
Concrete failure under shear load
10 7.10 Concrete edge failure
7
factor α
ch,V
c
a
= c
a,min
, s = s
max
,
and h > h
cr,V
Low 0 5 See AC 232 section 7.10.2
11 intentionally left blank
1 If the coefficient of variation Vof the failure loads is V ≤ 5 percent, the number of tests can be reduced to n = 3.
6 Tests may be omitted if the nominal shear strength of the channel, V
nsy
, is taken as < N
ns
.
7 Tests may be omitted if the nominal strength, V
ns,y
, is computed in accordance with Eq. (D-24a, ACI 318-05,-08), (D-33a, ACI 318-11), (17.5.2.10.2, ACI 318-14) with αch,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)
8 Five tests need to be conducted with the channel bolt positioned over the anchor and an additional five tests with the channel bolt positioned midway between the two anchors, unless
footnote 1 applies.
7.4 ANCHOR CHANNEL DESIGN IN SHEAR
Channel Lip Strength ϕV
sl,y
The nominal strength of the
channel lips to take up shear loads
perpendicular to the channel
transmitted by a channel bolt, V
sl,y
,
must be taken from Table 8-5 for
HAC and HAC-T with Hilti channel
bolts (HBC-B, HBC-C, HBC-T and
HBC-C-N).
Local rupture of channel lips is
determined from Test 8. The test is
performed on anchor channels cast
into concrete.
ϕV
sl,y
≥ V
a
uay
Anchor Strength ϕ V
sa,y
and Anchor and Channel
Connection Strength ϕV
sc,y
The nominal strength of one anchor, V
sa,y
,
and anchor and channel connection V
sc,y
to take up shear loads perpendicular
to the channel must be taken from
Table 8-5 for HAC and HAC-T with Hilti
channel bolts (HBC-B, HBC-C, HBC-T
and HBC-C-N).
Anchor strength is determined from
Test 8. The test is performed on anchor
channels cast into concrete.
ϕV
sa,y
≥ V
a
uay
ϕV
sc,y
≥ V
a
uay
Tests 8 can be omitted if the nominal shear strength of the
channel, V
ns,y
, is taken as ≤ N
ns
. V
ns
is the nominal steel strength
of anchor channel loaded in shear (lowest value of V
sa
, V
sc
,
and V
sl
. N
ns
is the nominal steel strength of the anchor channel
loaded in tension (lowest value of N
sa
, N
sc
and N
sl
).
V
ns
: Nominal steel strength of anchor channel loaded in shear
(lowest value of V
sa
, V
sc
, and V
Sl
)
Bolt Strength ϕV
ss
, ϕV
ss,M
ϕV
ss
≥ V
b
ua
ϕV
ss,M
≥ V
b
ua
The nominal strength of a channel
bolt in shear, V
ss
, must be taken
from Table 8-12. The maximum
value shall be computed in
accordance with Eq. 17.5.1.4.1a,
ACI 318-14).
V
ss
= 0.6.A
se,V
.f
utb
, lbf (N)
where
f
utb
shall be taken as the smaller of 1.9 f
yb
and 125,000 psi (860
MPa)
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).
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)
f
utb
=minimum [(1.9 fyb and 125,000 psi (860 MPa)], psi (MPa)).
M
0
ss
= nominal flexural strength of channel bolt according to
Table 8-12.
= 1.2(S
chb
)f
utb
, lbf-in (N-mm)
≤ 0.5N
sl.
a
≤ 0.5N
ss.
a
ℓ = lever arm, in. (mm)
a = internal lever arm, in. (mm) as illustrated in Figure 7.4.1.2
T
s
= tension force acting on channel lips
C
s
= compression force acting on channel lips
Figure 7.4.1.2 - Definition of internal lever arm.