Calculations › Circular RC Column

Circular RC Column

EN 1992-1-1

Checks a short braced circular RC column under axial load and uniaxial moment to EN 1992-1-1.

Example inputs

Diameter400 mm

Clear height3000 mm

Axial load (NEd)500 kN

Moment (MEd)50 kNm

Concrete gradeC30/37

Bar diameter20 mm

Number of bars8 —

Cover40 mm

Link diameter10 mm

National annexUK

Results

Circular RC Column — Ø400mm

C30/37 · 8T20 · 3000mm height · EN 1992-1-1

Results

✓ Slenderness PASS

util 0.8421.00EN 1992-1-1 §5.8.3

i radius of gyration = D / 4	100	mm	EN 1992-1-1 §5.8.3
l0 effective length = 0.7 × h_clear (braced)	2100	mm	EN 1992-1-1 §5.8.3.2
λ slenderness ratio = l0 / i	21	—
n relative axial force = NEd / (Ac × fcd)	0.234	—
λlim slenderness limit = 20 × 0.7 × 1.1 × 0.7 / √n ≥ 25	25	—	EN 1992-1-1 §5.8.3.1

✓ Axial Capacity PASS

util 0.16500.00EN 1992-1-1 §6.1

fck characteristic strength	30	N/mm²
fcd design concrete strength = 0.85 × fck / γC	17	N/mm²	EN 1992-1-1 §3.1.6
fyd design steel strength = fyk / γS	434.78	N/mm²	EN 1992-1-1 §3.2.7
Ac gross concrete area = π × D² / 4	125663.71	mm²
As total steel area = n × π × φ² / 4	2513.28	mm²
NRd axial resistance = (Ac−As)×fcd + As×fyd	3186.28	kN	EN 1992-1-1 §6.1

✓ Combined N+M PASS

util 0.6750.00EN 1992-1-1 §5.8.9

rs radius to bar centroid = D/2 − cover − φ_link − φ/2	140	mm
MRd moment resistance = As × fyd × rs	97.39	kNm	EN 1992-1-1 §5.8.9
NEd / NRd	0.157	—
MEd,eff / MRd	0.513	—
Interaction ratio = NEd/NRd + MEd,eff/MRd	0.67	—

✓ Min. Eccentricity PASS

util 0.0050.00EN 1992-1-1 §6.1(4)

e0 minimum eccentricity = max(D/30, 20mm)	20	mm	EN 1992-1-1 §6.1(4)
MEd,eff effective moment = max(MEd, NEd × e0)	50	kNm

✓ Reinforcement Limits PASS

util 0.502513.28EN 1992-1-1 §9.5.2

As,min minimum steel area = max(0.1×NEd/fyd, 0.002×Ac)	251.33	mm²	EN 1992-1-1 §9.5.2
As,max maximum steel area = 0.04 × Ac	5026.55	mm²	EN 1992-1-1 §9.5.2
As provided	2513.28	mm²

Try it yourself

Run this calc with your own inputs