Column sizes 80/30
fck = 30 mpa
fywk = 420 mpa
concrete cover = 5 cm.
net concrete cover = 3.5 cm.
Hugging zone stirrup calculation
Ac = 30 * 80 = 2400 cm2
Ack = (80-2 * 3.5) * (30-2 * 3.5) = 1679 cm2 (Core concrete area within the confinement reinforcement)
bk = 80-2 * (5-0,8-0,5) = 72.6 cm
number of stirrups in critical direction = 5 (including crotch)
Ash / s ≥ 0.3 * bk * [(Ac / Ack) - 1] * (fck / fywk)
Ash / s ≥0.3*72.6*((2400/1679)-1)*(30/420)=0,667 cm2
Required range when using 10 stirrups
Required range (s) = 5 * 0.785 / 0.663 = 5.92 cm. → 6 cm
Regulation checks:
s>5 cm
s<15 cm
s<bmin/3 = 30/3 =10 cm
s <6 fi = 6 * 1.4 = 8.4 cm
selected = 6 cm
Middle zone stirrup calculation
Asw/s > 0.3 bw * fctd/fwd
Asw/s = 0.3 * 130.322 * 80 / 372341,81 =0.084 cm2/cm
s= 5*0.78/0.084 =46cm
Regulation checks:
s<=20 cm
s<bmin/2 = 30/3=10 cm
10 cm selected
Report of the SZ02 column:
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