Design guide for considering concrete breakout in shear using ACI 318 anchoring-to-concrete provisions October 2025 | Page 90

PROFIS ENGINEERING
Table 14. Design Strengths
Tension
steel strength N sa( lb / anchor) 41,365
concrete breakout
Reference ESR-4266 Table 4 for ϕ steel( tension) and ϕ concrete( tension) values.
Reference ESR-4266 Table 6 for ϕ steel( shear) and ϕ concrete( shear) values. nominal strength design strength factored load % utilization comments
N cbg( lb) 92,221 ϕ steel = 0.75 ϕN sa( lb / anchor) 31,024 ϕ seismic = N / A ϕ concrete = 0.65
ϕN cbg( lb) 59,943 ϕ seismic = N / A
N ua, i( lb / anchor) 625
N ua, g( lb) 10,000
( N ua, i / ϕN sa) 2.0 %
( N ua, g / ϕN cbg) 16.7 %
OK
OK CONTROLS
pullout strength
N pn( lb / anchor) 14,939
ϕ cocrete = 0.65 ϕN pn( lb / anchor)
N ua, i( lb / anchor) 625
( N ua, i / ϕN pn) 6.4 %
OK
9710
Shear
steel strength
V sa( lb / anchor) 22,825
ϕ steel = 0.65 ϕV sa( lb / anchor) 14,836
V ua, i( lb / anchor) 937.5
( V ua, i / ϕV sa) 6.3 %
OK
concrete breakout( row 1)
V cbg, row 1( lb) 25,089
ϕ concrete = 0.70 ϕV cbg, row 1( lb) 17,562
V ua, row 1 = V ua, g( lb) = 15,000
( V ua, row 1 / ϕV cbg, row 1) 85.4 %
OK CONTROLS
concrete pryout
V cpg( lb) 184,442
ϕ concrete = 0.70 ϕV cpg( lb) 129,109
V ua, g( lb) 15,000
( V ua, g / ϕV cpg) 11.6 %
OK
Table 15. Interaction
Tri-Linear: N ua ϕN n
+ V ua ϕV n
≤ 1.2
0.167 + 0.854 = 1.02 < 1.2 OK
Parabolic: N 5 5
ua 3 V ua + 3 ≤ 1. 0 ϕN n ϕV n
ACI 318-19 Eq.( 17.8.3)
Reference ACI 318-19 commentary R17.8.
( 0.167) 5 / 3 +( 0.854) 5 / 3 = 0.051 + 0.769 = 0.82 < 1.0 OK FASTENING MEETS THE DESIGN CRITERIA.
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