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.
fc' 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 Nn is determined as the greater of:
for fc' < 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.