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Verification of Rectangular Cross Section Made of Plain Concrete

The cross-section is rectangular, loaded by the bending moment M^*, normal force N^* (applied in the cross-section centroid) and by the shear force V^*. The shear strength is provided by:

where:

for cross-sections with height smaller than 200mm

for cross-sections with height greater than 400mm

intermediate values are obtained using linear interpolation method.

f_c^' is limited to value 50MPa.

Strength of concrete cross-section subject to the combination of bending moment and normal force is derived from the following expressions depending on the normal force eccentricity e:

Where N_n is determined as the greater of:

for f_c^' < 55MPa is α₁ = 0.85

for concrete with greater strength is

Interaction diagram N-M

Usage ratio of concrete cross-section subject to the combination of bending moment and normal force is determined as |0L| / |0R₁| or |1L| / |1R₂|. Where L is load, R₁ is strength with prescribed eccentricity and R₂ is strength with prescribed normal force.