2.6.4.11 Design of bar spacing

Design of bar spacing

In the Longitudinal Reinforcement tab of window 1.4 Reinforcement, a bar spacing of a = 100 mm has been specified for both reinforcement directions by using the [Rebars] button.

The maximum bar spacing max s_l,-z,φ1 is determined by interpolation according to EN 1992-1-1, Table 7.3N for the existing tension stress σ_s,-z,φ1 = 208.18 N/mm² and the crack width w_k = 0.3 mm.

$\text{max} s_{l, -z,{\varphi }_1} = 250 + \frac{250 - 200}{200 - 240} · \left(208.18 - 200\right) = 139.8 \text{mm}$

Analogously, the maximum bar spacing for the direction φ₂ is determined from the existing tension stress σ_s,-z,φ2 = 167.09 N/mm² as max s_l,-z,φ2 = 291.1 mm.

The existing bar spacing s_{l,exist,-z,φ1} = 100 mm available for the reinforcement direction φ₁ is smaller than the maximum allowable bar spacing max s_l,max,-z,φ1 = 240 mm.

Therefore, the following check criterion applies for reinforcement direction φ₁:

$\frac{s_{l, \text{exist},-z,{\varphi }_1}}{\text{max} s_{l,\text{max},-z,{\varphi }_1}} = \frac{0.100}{0.240} = 0.417$