2.2.2 Limitation of Stresses

Limitation of Stresses

The concrete compressive stresses must be limited according to EN 1992-1-1, clause 7.2 (1), in order to avoid cracks or strong creep in case they could affect the structure's function. Therefore, clause 7.2 (2) recommends applying a reduction factor for the characteristic concrete compressive strength.

${\sigma }_c = k_1 · f_{ck }$

The recommended value for k₁ is 0.6.

To avoid inelastic strains, unallowable cracking, and deformations, the tension stresses in the reinforcement must be limited according to EN 1992-1-1, clause 7.2 (4). Clause 7.2 (5) recommends reduction factors for the characteristic tensile strength, which depend on the type of action combination.

• σ_s = k₃ ⋅ f_yk   for characteristic action combination
• σ_s = k₄ ⋅ f_yk   for indirect action (restraint)

The recommended values for k₃ and k₄ are 0.8 and 1.0.