PROFIS ENGINEERING
Nominal Concrete Breakout Strength in Tension( N cbg)
N cbg =
A ACI 318-19 Eq.( 17.6.2.1b) Nc ψ A ec, N ψ ed, N ψ c, N ψ cp, N N b Nc0 h ef = 14.0 in 1.5h ef = 21.0 in 3.0h ef = 42.0 in
A Nc =( c x- + s x12 + s x23 + s x34 + c x +)( c y- + s y12 + s y23 + s x34 + c y +) =( 21.0 + 4.0 + 4.0 + 16.0 + 21.0)( 6.0 + 4.0 + 8.0 + 8.0 + 21.0) = 3102 in 2 c x- = ∞ in = 1.5h ef
ACI 318-19 Fig. R17.6.2.1 b) c x + = ∞ in = 1.5h ef c y- = 6 in
s x12 = 4 in s x23 = 4 in s x34 = 16 in s y12 = 4 in s y23 = 8 in s y34 = 8 in
A Nc0 = 9( h ef) 2 = 9( 14 in) 2 = 1764 in 2 ACI 318-19 Eq.( 17.6.2.1.4)
ψ ec, N =
1 1 + e ′ N
1.5h e f ACI 318-19 Eq.( 17.6.2.3.1) c y + = ∞ in = 1.5h ef eccentricity in x direction: ψ ec1, N = 0.875 eccentricity in y direction ψ ec2, N = 0.955 x direction: e c1, N = 3.0 in 1.5h ef = 21.0 in y direction: e c2, N = 1.0 in 1.5h ef = 21.0 in ψ ec, N =( ψ ec1, N)( ψ ec2, N) =( 0.875)( 0.955) = 0.836
ψ ed, N = 0.7 + 0.3 c a, min 1.5h e f
ψ ed, N = 0.7 +( 0.3)(( 6.0 in / 21.0 in) = 0.786
ACI 318-19 Eq.( 17.6.2.4.1b) c a, min = c y- = 6.0 in 1.5h ef = 21.0 in
ψ c, N = 1.0 cracked or uncracked concrete Reference ACI 318-19 17.6.2.5.1
ψ cp, N = MAX c a, min | 1. 5h e f
= 1.0 cracked concrete Reference ACI 318-19 17.6.2.6.1. c ac c ac
N b = k c, xxxx λ a f ′ c h e f
1.5
normal weight concrete: λ = 1.0 → λ a = 1.0 N b =( 17)( 1.0)( 3500 psi) 0. 5( 14.0 in) 1. 5
N cbg =
A Nc A Nc0
= 52,684 lb
ψ ec, N ψ ed, N ψ c, N ψ cp, N N b
N cbg =( 3102 in 2 / 1764 in 2)( 0.836)( 0.786)( 1.0)( 1.0)( 52,684 lb) = 60,877 lb
ACI 318-19 Eq.( 17.6.2.2.1) ACI 318-19 Table 17.2.4.1 k c, cr = 17 Reference ESR-4868 Table 12 f ' c = 3500 psi h ef = 14.0 in
A Nc = 3102 in 2 A Nc0 = 1764 in 2 ψ ec, N = 0.836 ψ ed, N = 0.786 ψ c, N = 1.0 ψ cp, N = 1.0 N b = 52,684 lb
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