Minimum Longitudinal Bar Diameter

For design in accordance with EC2 Recommendations, Finnish NA and Swedish NA;

φ_long,min = 8mm

For design in accordance with Malaysian NA and Norwegian NA;

φ_long,min = 10mm

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

φ_long,min = 12mm

Minimum Longitudinal Bar Spacing

For design to EC2 Recommendations, UK NA, Irish NA¹, Malaysian NA, Singapore NA and Swedish NA;

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

For design to Finnish NA;

s_cl,min ≥ MAX[ maximum longitudinal bar diameter, 20mm, d_g + 3mm ]

For design to Norwegian NA;

s_cl,min ≥ MAX[ 2*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 Settings > Column > Reinforcement Layout.

Minimum Longitudinal Total Steel Area

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

For design to EC2 Recommendations, UK NA, Irish NA², Malaysian NA, Singapore NA and Finnish NA;

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

For design to Norwegian NA;

A_sl,min = MAX[ MIN({0.2*Ac*fcd} / fyd, 0.5*NEd / fyd), 1.0%*column area ]

For design to Swedish NA;

A_sl,min = 0.2%*column area

Else

A_sl,min = 0.45% * column area

Maximum Longitudinal Total Steel Area

For design to EC2 Recommendations, UK NA, Irish NA³, Malaysian NA and Singapore NA;

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

For design to Finnish NA;

A_sl,max = 6% * column area (12% in lap regions)

For design to Norwegian NA;

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

For design to Swedish NA;

Maximum area of reinforcement is not limited

Long Term Compressive Strength Factor

For design in accordance with UK NA, Irish NA, Malaysian NA, Singapore NA, Finnish NA and Norwegian NA⁴;

α_cc = 0.85

For design in accordance with EC2 Recommendations and Swedish NA;

α_cc = 1.0

Design Concrete Compressive Strength for Shear

f_cd = α_cc* f_ck /γ_C

For design to ⁵ EC2 Recommendations, UK NA, Irish NA, Malaysian NA, Singapore NA, Finnish NA, Norwegian NA and Swedish NA;

γ_C = 1.50

Footnotes