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.