Minimum Longitudinal Bar Diameter

For design in accordance with EC2 Recommendations;

φ_long,min = 8mm

For design in accordance with Malaysian NA;

φ_long,min = 10m

For design in accordance with UK NA, Irish NA and Singapore NA;

φ_long,min = 12mm

Minimum Longitudinal Bar Spacing

For design to¹ EC2 Recommendations, UK NA, Irish NA, Malaysian NA and Singapore NA;

s_cl,min ≥ MAX[ maximum longitudinal bar diameter, 20mm, d_g + 5mm ]

Where d_g is the maximum aggregate size.

Maximum Longitudinal Bar Spacing

You are given control over this value by specifying an upper limit in Design Options > Column > Reinforcement Layout.

Minimum Longitudinal Total Steel Area

For design to² EC2 Recommendations, UK NA, Irish NA, Malaysian NA and Singapore NA;

If N_Ed >= 0 (i.e. compression)

A_sl,min = MAX[ (0.1 * N_Ed) / f_yd, 0.2% * column area ]

Else

A_sl,min = 0.45% * column area

Maximum Longitudinal Total Steel Area

For design to³ EC2 Recommendations, UK NA, Irish NA, Malaysian NA and Singapore NA;

A_sl,max = 4% * column area (8% in lap regions)

Long Term Compressive Strength Factor

For design in accordance with⁴ UK NA, Irish NA, Malaysian NA and Singapore NA;

α_cc = 0.85

For design in accordance with EC2 Recommendations;

α_cc = 1.0

Design Concrete Compressive Strength for Shear

For design to⁵ EC2 Recommendations, UK NA, Irish NA, Malaysian NA and Singapore NA;

f_cd = α_cc* f_ck /γ_C