Design code:
TCVN 5574:2018 - Vietnamese RC section design: flexure, axial + bending, shear, torsion, crack width & deflection.
Input Parameters
Design actions
Moment M [kN·m]
Axial N [kN]i
Eccentricity
Effective length l0 [mm]i
e_a = max(h/30, l0/600). Added to the load eccentricity e1 = M/N to form e0 - this raises the design moment.
Longitudinal bending (slenderness)
η = 1/(1 - N/Ncr), applied when slenderness λ = l0/h > 8 (η = 1 otherwise). It amplifies the moment further.
GEOMETRY
Width b [mm]
Depth h [mm]
Materials
Concrete
Reinforcement
Rb17.0
Rbt1.20
Eb32,500
Rb,ser22.0
Rbt,ser1.75
Rs435
Rsc435
Rsw300
Es200,000
γbi
γsi
The values above are the TCVN 5574 table design strengths after γb / γs (TCVN already tabulates design values, so there is no 1.5 / 1.15 partial factor to apply - those are baked into the table; γb / γs are the working-condition coefficients, default 1.0). You may also override the elastic moduli Eb / Es.
LAYER 2 - TOP
Cover c₂ [mm]i
Bars / rowi
Dia. Φ [mm]i
LAYER 1 - BOTTOM
Cover c₁ [mm]i
Bars / rowi
Dia. Φ [mm]i
LAYER 3 - SIDES
Side bars (per side)5
No. barsi
Dia. Φ [mm]i
●ULS - moment + axialPASS
Flexure at N=0 (8.1.2)
Moment capacityMRd736.5kN·m
Applied momentM1000.0kN·m
Compression depthx100.5mm
0.110 / 0.493
Eccentric compression (8.1.3)
Static eccentricitye1500.0mm
Accidental eccentricityea33.3mm
Total eccentricitye0533.3mm
Initial momentM01000.0kN·m
With accidental ecc.MI1066.6kN·m
Slenderness factorη1.063
Design momentMII1133.8kN·m
Moment build-up: 1000 → 1067 (accidental ecc.) → 1134 (longitudinal bending) kN·m
Eccentricity (lever)e979.3mm
Eccentricity caseLarge eccentricity
Moment capacityMgh2294.4kN·m
Demand N·e1958.6kN·m
Reinforcement
Tension steel As1963mm²
Comp. steel As'1963mm²
Ratio ρ0.86%
Internal forces
Concrete forceFb2000.0kN
Comp. steel forceFsc854.1kN
Tension steel forceFs854.1kN
Steel stressσs435MPa
Material design values - B30/CB500-V
Concrete compressionRb17.0MPa
Concrete tensileRbt1.20MPa
Steel tensileRs435MPa
Steel compressiveRsc435MPa
Concrete modulusEb32500MPa
Steel modulusEs200000MPa
0.493
Section properties
AreaA500000mm²
Second momentI41666666667mm⁴
Squash loadNRd,c10208kN
Pure tensionNRd,t1708kN
Effective depthh0912.5mm