Design of Longitudinal Reinforcement for Slabs
The design of reinforcement is performed for load caused by the bending moment MEd. The program provides the required area of tensile and compressive (if needed) reinforcement. It takes into account conditions for the minimum and maximum degree of reinforcement in a given cross-section. First, the program determines the location of the neutral axis as (Art. 3.1.7, Art. 6.1):
Providing the location of the neutral axis is less than the allowable one (x < xmax), the program determines the area of tensile reinforcement Ast from the expression:
Providing the location of the neutral axis is greater than the allowable one (x > xmax), the program determines the areas of both compressive Asc and tensile Ast reinforcement from the expressions:
The limit location of the neutral axis is found from (Art. 5.6.3(2)):
xmax = 0.45d
for concrete C40/45 and lower
xmax = 0.35d
for concrete C45/50 and higher
The computed degree of reinforcement is checked using the following expressions (Art. 188.8.131.52):
Standard values of coefficients ρmin, ρmax are built-in the program - these values can also be input by the user depending on the selected National annex.
If the maximum degree of total reinforcement ρmax is exceeded, the program informs the user that the longitudinal reinforcement cannot be designed for a given cross-section.