Axial capacity of short column

This calculation provides the axial capacity of a rectangular short column

Input:

Output:

    Definitions
    • ϕc = Resistance factor for concrete
    • ϕs = Resistance factor for reinforcing steel
    • fc = Specified concrete strength (psi)
    • fy = Specified reinforcing steel yield strength (ksi)
    • b = Effective width of cross section (in)
    • h = Overall depth of cross section (in)
    • nb = Quantity of reinforcing bars
    Axial capacity
    Pr = 737 kip
    • Ag=b⋅d=12⋅24=288A_g = b\cdot d = 12\cdot24 = 288 in2
    • As=nb⋅Ab=8⋅0.47=3.72A_s = n_{b}\cdot A_{b} = 8\cdot0.47 = 3.72 in2
    • ρ=nb⋅Abb⋅h=8⋅0.46512⋅24=0.013ρ = \frac{ n_{b}\cdot A_{b}}{ b\cdot h} = \frac{8\cdot0.465}{12\cdot24} = 0.013
    • α1=max⁡(0.85−0.0015⋅fc,0.67)=max⁡(0.85−0.0015⋅34.5,0.67)=0.8α_1 = \max\left(0.85-0.0015\cdot f_{c},0.67\right) = \max\left(0.85-0.0015\cdot34.5,0.67\right) = 0.8 (fc in MPa)
    • Pro=α1⋅ϕc⋅fc⋅(Ag−As)+ϕs⋅As⋅fy=920.9P_{ro} = α_{1}\cdot ϕ_{c}\cdot f_{c}\cdot\left( A_{g}- A_{s}\right)+ ϕ_{s}\cdot A_{s}\cdot f_{y} = 920.9 kip
    • Pr=min⁡(0.2+0.05⋅min⁡(b,h),0.8)⋅Pro=736.73P_r = \min\left(0.2+0.05\cdot\min\left( b, h\right),0.8\right)\cdot P_{ro} = 736.73 kip
    User Notes: