Product Overview

TECHNICAL GUIDE – MECHANICAL ANCHORS ©2021 DEWALT – REV. E
A
NCHORS & FASTENERS
STRENGTH DESIGN (SD)
15
Mechanical anchors
STRENGTH DESIGN (SD)
Tension Design Information For Screw-Bolt+ Anchor In Concrete
1,2
CODE LISTED
ICC-ES ESR-3889
Design Characteristic Notation Units
Nominal Anchor Diameter
1/4 3/8 1/2 5/8 3/4
Anchor category 1, 2 or 3 - 1 1 1 1 1
Minimum nominal embedment depth h
nom
in.
(mm)
1-5/8
(41)
2-1/2
(64)
2
(51)
2-1/2
(64)
3-1/4
(83)
2-1/2
(64)
3
(76)
4-1/4
(108)
3-1/4
(64)
4
(64)
5
(127)
4-1/4
(108)
Steel Strength in Tension (ACI 318-14 17.4.1 or ACI 318-11 D.5.1)
Steel strength in tension N
sa
10
lb
(kN)
4,535
(20.2)
8,730
(38.8)
20,475
(91.1)
26,260
(116.8)
38,165
(169.8)
Reduction factor for steel strength
3,4
f
- 0.65
Concrete Breakout Strength in Tension (ACI 318-14 17.4.2 or ACI 318-11 D.5.2)
Effective embedment h
ef
in.
(mm)
1.20
(30)
1.94
(49)
1.33
(34)
1.75
(44)
2.39
(61)
1.75
(44)
2.17
(55)
3.23
(82)
2.24
(57)
2.88
(73)
3.73
(95)
3.08
(78)
Critical edge distance
(uncracked concrete)
c
ac
in.
(mm)
4.30
(109)
6.10
(155)
5.00
(127)
6.30
(160)
7.80
(198)
3.30
(84)
5.90
(150)
8.10
(206)
6.30
(160)
7.90
(201)
10.10
(257)
10.90
(277)
Critical edge distance, topside of
concrete-filled steel decks with
minimum topping thickness
9
c
ac,deck,top
in.
(mm)
3.00
(76)
4.00
(102)
3.50
(89)
-
11
-
11
6.00
(152)
-
11
-
11
-
11
-
11
-
11
-
11
Effectiveness factor for
uncracked concrete
k
uncr
- 27 24 30 24 24 30 24 24 30 24 24 27
Effectiveness factor for cracked concrete k
cr
- 17 17 17 21 17
Modification factor for
cracked and uncracked concrete
5
Ψ
c,N
- 1.0 1.0 1.0 1.0 1.0
Reduction factor for concrete
breakout strength
3
f
- 0.65 (Condition B)
Pullout Strength in Tension (Non-Seismic Applications) (ACI 318-14 17.4.3 or ACI 318-11 D.5.3)
Characteristic pullout strength,
uncracked concrete (2,500 psi)
6,10
N
p,uncr
lb
(kN)
See Note 7 See Note 7 See Note 7 See Note 7
See
Note 7
Characteristic pullout strength,
cracked concrete (2,500 psi)
6,10
N
p,cr
lb
(kN)
765
(3.4)
1,415
(6.3)
See Note 7
1,645
(7.3)
2,515
(11.2)
4,700
(20.9)
3,080
(13.7)
4,720
(21.0)
6,900
(30.7)
See
Note 7
Reduction factor for pullout strength
3
f
- 0.65 (Condition B)
Pullout Strength in Tension for Seismic Applications (ACI 318-14 17.2.3.3 or ACI 318-11 D.3.3.3)
Characteristic pullout strength,
seismic (2,500 psi)
6,8,10
N
eq
lb
360
(1.6)
1,170
(5.2)
900
(4.0)
1,645
(7.3)
2,765
(12.3)
1,645
(7.3)
2,515
(11.2)
4,700
(20.9)
1,910
(8.5)
2,445
(10.9)
3,370
(15.0)
4,085
(18.2)
Reduction factor for pullout strength
3
f
- 0.65 (Condition B)
For SI: 1 inch = 25.4 mm; 1 ksi = 6.894 N/mm
2
; 1 ft-lb = 1.356 N-m; 1 lb = 0.0044 kN.
1. The data in this table is intended to be used with the design provisions of ACI 318-14 Chapter 17 or ACI 318-11 Appendix D, as applicable; for anchors resisting seismic load combinations the
additional requirements of ACI 318-14 17.2.3 or ACI 318-11 D.3.3, as applicable, shall apply.
2. Installation must comply with published instructions and details.
3. All values of f were determined from the load combinations of IBC Section 1605.2, ACI 318-14 Section 5.3, or ACI 318-11 Section 9.2. If the load combinations of ACI 318-11 Appendix C
are used, then the appropriate value of f must be determined in accordance with ACI 318-11 D.4.4. For reinforcement that complies with ACI 318-14 Chapter 17 or ACI 318-11 Appendix
D requirements for Condition A, see ACI 318-14 17.3.3(c) or ACI 318-11 Section D.4.3(c), as applicable for the appropriate f factor when the load combinations of IBC Section 1605.2, ACI
318-14 Section 5.3 or ACI 318-11 Section 9.2 are used.
4. The anchors are considered a brittle steel elements as defined by ACI 318-14 2.3 or ACI 318-11 D.1, as applicable.
5. Select the appropriate effectiveness factor for cracked concrete (k
cr
) or uncracked concrete (k
uncr
) and use Ψ
c,N
= 1.0.
6. For all design cases Ψ
c,P
= 1.0. The characteristic pullout strength, N
pn
, for concrete compressive strengths greater than 2,500 psi for 1/4-inch-diameter anchors may be increased by
multiplying the value in the table by (f’c / 2,500)
0.3
for psi or (f’c / 17.2)
0.3
for MPa. The characteristic pullout strength, N
pn
, for concrete compressive strengths greater than 2,500 psi for
3/8-inch- to 3/4-inch-diameter anchors may be increased by multiplying the value in the table by (f’c / 2,500)
0.5
for psi or (f’c / 17.2)
0.5
for MPa.
7. Pullout strength does not control design of indicated anchors and does not need to be calculated for indicated anchor size and embedment.
8. Reported values for characteristic pullout strength in tension for seismic applications are based on test results per ACI 355.2, Section 9.5.Y
9. Anchors are permitted in the topside of concrete-filled steel deck assemblies in accordance with the Installation Detail for Anchors in the Top of Concrete Over Steel Deck Floor and Roof
Assemblies with Minimum Topping Thickness.
10. Anchors are permitted to be used in lightweight concrete provided the modification factor λ a equal to 0.8 λ is applied to all values of f'c affecting N
n
.
11. Tabulated critical edge distance values, c
ac,deck,top
, are for anchors installed in the top of concrete over steel deck profiles with a minimum concrete thickness, h
min,deck
, of 2.5 inches above the
upper flute (topping thickness). For minimum topping thickness greater than or equal to the minimum concrete member thicknesses, h
min
, given in the Installation Specifications table, the
associated critical edge distance, c
ac
, for indicated anchor diameters and embedment depths may be used in the calculation of Ψ
cp,N
as applicable.