ACI-349 Approval for KB-TZ2 Expansion Anchor

Applicability of the KB-TZ2 Anchor
10
August 2021
Table 3 - Hilti stainless steel KB-TZ2 design information for hammer and core drilled installations, tension
7
Design
parameter
Symbol Units
Nominal anchor diameter (in)
1/4 3/8 1/2 5/8 3/4 1
Effective min.
embedment
1
h
ef
in. 1-1/2 1-1/2 2 2-1/2 2 2-1/2 3-1/4 2-3/4 3-1/4 4 3-1/4 3-3/4 4-3/4 4 5-3/4
(mm) (38) (38) (51) (64) (51) (64) (83) (70) (83) (102) (83) (95) (121) (102) (146)
Tension, steel failure modes
Strength
reduction factor
for steel in
tension
2
Φ
sa,N
- 0.80 0.80 0.80 0.80 0.80 0.80
Min. specified
yield strength
f
y
lb/in
2
100,900 96,300 96,300 91,600 84,10 0 65,000
(N/mm
2
) (696) (664) (664) (632) (580) (448)
Min. specified
ult. strength
f
uta
lb/in
2
122,400 120,100 120,400 114,6 0 0 100,500 99,900
(N/mm
2
) (844) (828) (830) (790) (693) (689)
Effective tensile
stress area
A
se,N
In
2
0.024 0.051 0.099 0.164 0.239 0.47
(mm
2
) (15.4) (33.2) (63.6) (106.0) (154.4) (303.2)
Steel strength in
tension
N
sa
lb 2,920 6,18 0 11,870 18,835 24,045 46,955
(kN) (13.0) ( 27. 5 ) (52.8) (83.8) (107.0 ) (208.9)
Tension, concrete failure modes
Strength
reduction factor
for concrete and
pullout failure in
tension
Φ
c,N
,
Φ
p,N
- 0.75 0.75 0.75 0.75 0.75 0.75
Effectiveness
factor for
uncracked
concrete
k
uncr
- 24 24 24 24 24 27
5
24 27
Effectiveness
factor for
cracked
concrete
6
k
cr
- 17 21 17 17 21 17 21 17 21 24 21
Modification
factor for anchor
resistance,
tension,
uncracked
concrete
3
Ψ
3
- 1.0 1.0 1.0 1.0 1.0 1.0
Pullout strength
uncracked
concrete
4
N
p,uncr
lb 1,570
N/A N/A
4,18 5 3,380 4,010 5,500 4,085 6,015 8,050
N/A N/A N/A N/A N/A
(kN) ( 7.0 ) (18.6) (15.0) (17.8) (24.5) (18.2) (26.8) (35.8)
Pullout strength
cracked
concrete
4
N
p,cr
lb 670
N/A N/A N/A N/A N/A N/A
6
N/A N/A N/A N/A N/A
8,795
N/A N/A
(kN) (3.0) (39.1)
Pullout strength
seismic
4
N
p,eq
lb 670
N/A N/A N/A N/A N/A N/A
6
N/A N/A N/A N/A N/A
8,795
N/A N/A
(kN) (3.0) (39.1)
Normalization
factor,
uncracked
concrete
n
uncr
- 0.39 N/A N/A 0.37 0.46 0.50 0.50 0.50 0.42 0.47 N/A N/A 0.30 N/A N/A
Normalization
factor, cracked
concrete,
seismic
n
cr
- 0.50 N/A N/A N/A N/A N/A 0.50 N/A N/A N/A N/A N/A 0.50 N/A N/A
Tension, axial stiffness
Axial stiffness
in service load
range
β
uncr
lb/in. 166,491 175,802 137,147 153,923 342,679 105,970
β
cr
lb/in. 33,806 79,861 97,9 83 69,627 75,715 117,6 3 0
For SI: 1 inch = 25.4 mm, 1 lbf = 4.45 N, 1 psi = 0.006895 MPa. For pound-inch units: 1 mm = 0.03937 inches.
1
Figure 2 of this report illustrates the installation parameters.
2
The KB-TZ2 is considered a ductile steel element in accordance with ACI 349-01 Appendix B
3
For all design cases, Ψ
3
= 1.0. The appropriate effectiveness factor for cracked concrete (k
cr
) or uncracked concrete (k
uncr
) shall be used.
4
For all design cases, Ψ
4
= 1.0. Tabular value for pullout strength is for a concrete compressive strength of 2,500 psi (17.2 MPa). Pullout strength for concrete
compressive strength greater than 2,500 psi (17.2 MPa) may be increased by multiplying the tabular pullout strength by (f’c / 2,500)
n
for psi, or (f’c / 17.2)
n
for MPa,
where n is given as n
uncr
for uncracked concrete and n
cr
for cracked concrete and seismic. NA (not applicable) denotes that pullout strength does not need to be
considered for design.
5
For core drill installations, k
uncr
and k
cr
= 17 for 3/4-inch diameter anchors installed at 3-3/4 inches (95 mm) effective embedment.
6
For core drill installations, N
p,cr
= 4245 lb (18.9 kN) and N
p,eq
= 4245 lb (18.9 kN) for 1/2-inch diameter anchors installed at 3-1/4 inches (83 mm) effective embedment.
7
1/4-inch and 1-inch diameter anchors are not permitted for core drilling installations.