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:
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 M.
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:
xmax = 0.53d
- for steel Fe 250
xmax = 0.48d
- for steel Fe 400
xmax = 0.46d
- for steel Fe 500
First, the program computes the ultimate shear strength of concrete Vuc.
where: τc is determined according to table 19 standard IS 456 : 2000.
If the ultimate shear strength of concrete is exceeded, the ultimate shear strength Vuc,max is checked.
where: τc,max is determined according to table 20 standard IS 456 : 2000.
Next, the necessary reinforcement area is given by: