PROFIS ENGINEERING
Force d’ adhérence nominale à la traction( N ag)
N ag =
A Na A Na0 ψ ec, Na ψ ed, Na ψ cp, Na N ba ACI 318-19 Eq.( 17.6.5.1b)
c Na = 10d a τ uncr 1100
conception τ k, uncr =( ESR τ k, uncr)( f’ c / 2500 psi) 0, 25 =( 2 040 psi)( 4 500 psi / 2 500 psi) 0, 25 = 2 363 psi c Na =( 10)( 0,875 po)( 2 363 psi / 1 100 psi) 0, 5
ACI 318-19 Eq.( 17.6.5.1.2b)
Consultez la norme ESR-3814 tableau 11 pour les valeurs τ k, uncr et() xx.
ESR τ k, uncr = 2 040 psi d a = 0,875 po() xx = 0,25 f’ c = 4 500 psi
= 12,83 po
A Na =( c x- + s x1 + s x2 + s x3 + c x +)( c y- + s y12 + s y23 + s x34 + c y +) =( 12,83 + 9,0 + 9,0 + 9,0 + 12,83)( 6,0 + 8,0 + 8,0 + 8,0 + 12,83) = 2 255 po 2
A Na0 =( 2c Na) 2
|
= c Na
ACI 318-19 Fig. R17.6.5.1( b)
|
c x- = ∞ po |
c x + = ∞ po |
= c Na |
|
|
c y- = 6 po |
s x1 = 9 po |
s x2 = 9 po |
s x3 = 9 po |
s y12 = 8 po |
s y23 = 8 po |
s y34 = 8 po |
ACI 318-19 Eq.( 17.6.5.1.2a) |
c y + = ∞ po = c Na
=( 25,66 po) 2 = 658,44 po 2 ψ ec, Na =
1 1 + e ′ N c Na
= 1,0 sans excentricité
ψ ed, Na = 0.7 + 0.3 c a, min c Na c Na = 12,83 po
2c Na = 25,66 po
ACI 318-19 Éq.( 17.6.5.3.1)
e’ N = 0,0 po c Na = 12,83 po
Consultez ACI 318-19 Eq.( 17.6.5.4.1b)
= 0,7 +( 0,3)( 6,0 po / 12,83 po) = 0,84 c a, min = c y- = 6,0 po c Na = 12,83 po ψ cp, Na = MAX c a, min
| c Na c ac c ac
= 1,0 béton fissuré
Consultez ACI 318-19 Eq.( 17.6.5.5.1b)
N ba = λ a α N, seis τ xxxx π d a h e f
ACI 318-19 Éq.( 17.6.5.2.1)
Consultez la norme ESR-3814 tableau 11 pour α N, seis. Béton de poids normal: λ = 1,0 → λ a = 1,0 ACI 318-19 Tableau 17.2.4.1 conception τ k, cr =( ESR τ k, cr)( f’ c / 2 500 psi) 0, 15 =( 1 240 psi)( 4 500 psi / 2 500 psi) 0, 15 = 1 354 psi N ba =( 1,0)( 1,0)( 1 354 psi)( π)( 0,875 po)( 12 po) = 44 664 lb
Consultez la norme ESR-3814 tableau 11 pour les valeurs τ k, cr et() xx.
ESR τ k, cr = 1 240 psi f’ c = 4 500 psi() xx = 0,15
d a = 0,875 po α N, seis = 1,0 h ef = 12,0 po
N ag =
A Na A Na0 ψ ec, Na ψ ed, Na ψ cp, Na N ba
N ag =( 2 255 po 2 / 658,44 po 2)( 1,0)( 0,84)( 1,0)( 44 664 lb) = 128 489 lb
A Na = 2 255 po 2 A Na0 = 658,44 po 2 ψ ec, Na = 1,0 ψ ed, Na = 0,84 ψ cp, Na = 1,0 N ba = 44 664 lb
[ en ] October 2025 74