Verification of rectangular RC cross-section
The cross-section is rectangular, unilaterally reinforced and loaded by the bending moment and normal compression force. The program verifies a reinforced concrete section using the method of limit deformation. The maximum allowable strain of concrete in compression is 0,002 - 0,0035. Compression reinforcement is not taken into account. Minimum eccentricity is applied:
The computed degree of reinforcement is checked using the following expressions:
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where: |
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| - for fy = 460 N/mm2 | |
| - for fy = 250 N/mm2 | |
Interaction diagram N-M
Usage ratio of concrete cross-section subject to the combination of bending moment and normal force is determined as |0L| / |0R|. Where L is load and R is strength with prescribed excentricity.
Bending without normal force
The cross-section is rectangular, reinforced on one side and loaded by the bending moment Mu.
The permissible moment for a given area of reinforcements As reads:
The program further checks whether the location of neutral axis x is less than the limit location of neutral axis xmax given by:
Shear
First, the program computes the ultimate shear strength of concrete Vc.
where:
The νc values are for fcu above 25 N/mm2 multiplied by (fcu / 25)1/3
If the ultimate shear strength of concrete is exceeded, the ultimate shear strength Vmax is checked.
Next, the necessary reinforcement area is given by:
where:
