NZS 3101 Torsional Reinforcement Calculator

Calculate required torsional reinforcement per NZS 3101:2006 Clause 7.6.2 (Eq 7-11)

Materials & Geometry

Concrete f'c (MPa)

Beam width bw (mm)

Total depth h (mm)

Cover to centroid c (mm)

Steel fy (MPa)

Longitudinal Asl provided (mm²)

Stirrup diameter ds (mm)

Stirrup legs n

Stirrup spacing s (mm)

NZS 3101 Eq 7-11(a):
Al,req = (T / (2 × fy)) × cot(θ) × (Ph / Ao)
At,req = (T / (2 × fy × d)) × cot(θ) × (Ph / s)

1. Section Properties

x (mm)-

y (mm)-

Aoh (mm²)-

Ph (mm)-

2. Longitudinal Reinforcement (Al) per Eq 7-11(a)

Al required (mm²)-

Asl provided (mm²)-

Status-

3. Stirrup Reinforcement (At) per Eq 7-11(a)

At required (mm²/m)-

At provided (mm²/m)-

Status-

4. Max Torsional Stress Check (Clause 7.6.1.7)

T (kN·m)-

Tn (kN·m)-

Utilisation-

Based on NZS 3101:2006 Clause 7.6.2 (Eq 7-11). Verify with full design.