Reinforcement

The Reinforcement tab, selected in the New Reinforcement Parameters dialog, defines reinforcement parameters.

The dialog defines the reinforcing bar diameter and a cover.

• Diameter d1. The diameter of reinforcing bars of the bottom main reinforcement
• Diameter d1'. The diameter of reinforcing bars of the top main reinforcement
• Diameter d2. The diameter of reinforcing bars of the bottom reinforcement perpendicular to the main reinforcement.
• Diameter d2'. The diameter of reinforcing bars of the top reinforcement perpendicular to the main reinforcement
• Cover c1. Bottom reinforcement cover
• Cover c2. Top reinforcement cover
• Values c1' and c2'. Distances of the bottom and top reinforcements, respectively, from the slab reinforcement in the other direction (by default, they are not available until they are selected).

Note: Cover is taken from the plate edge to the exterior surface of the main reinforcing bars.

Note: Reinforcing bars located on the main reinforcement direction are exterior bars. In bottom reinforcement they appear on the lower layer and in top reinforcement, in the top layer.

The lower part of the dialog defines the following:

• Unidirectional reinforcement. When selected, only the main direction reinforcement will be calculated (forces acting in the perpendicular direction are ignored). This offers two-fold acceleration of calculations. Note that a simplification is adopted here, which is based on negligible influence (or lack of influence at all) of forces acting in the perpendicular direction. On the main reinforcement verification of user defined settings is not made. Improper use of the option may result in wrong results. Codes for RC element design often require that distributed reinforcement be provided for the direction perpendicular to the main reinforcement direction. The area of distributed reinforcement is not calculated.
• Membrane reinforcement in one layer (in axis). Compression/tension type must be selected on the General tab for this option to be available. When selected, reinforcement is positioned in axis of an RC element (reinforcement will be subjected to compression / tension due to membrane forces).

The following table shows the required parameters for Unidirectional reinforcement and Membrane reinforcement in one layer (in axis) when they are selected or deselected.

Reinforcement Option		Required Parameters
Unidirectional	In one layer (in axis)	d1	d2	d1'	d2'	c1	c2
Yes	No	Yes	Yes	Yes	Yes	Yes	Yes
No	Yes	Yes	Yes	No	No	No	No
Yes	No	Yes	No	Yes	No	Yes	Yes
Yes	Yes	Yes	No	No	No	No	No

Options at the bottom of the dialog determine the criteria of generating the minimum reinforcement in RC panels. These include the following.

• None. The minimum reinforcement will not be generated in a panel
• For FE for which reinforcement As > 0. The minimum reinforcement will be generated only in those panels for which the calculated reinforcement is less than the minimum reinforcement and greater than zero. If the calculated reinforcement area for a (triangular) finite element equals zero, then the minimum reinforcement will not be generated.
  
• For the whole panel. The minimum reinforcement will be generated for a whole panel.
  

Minimum reinforcement considers all code combinations and all load cases. Reinforcement may be calculated for one side of a section, both sides, and for a whole section (separately for each instance) depending on code requirements.

Verification starts with checking the total minimum reinforcement. If there is such a condition, it checks if the sum of the bottom and top reinforcements is less than the total amount. If it is greater, then conditions are satisfied and calculations are stopped.

If the sum is less, then:

• The maximum value of the bottom reinforcement and the minimum bottom reinforcement areas are assumed.
• The maximum value of the top reinforcement and the minimum top reinforcement areas are assumed.

The minimum total reinforcement is divided by the sum of the maximum values. The coefficient obtained is denoted by m. Next, the coefficient is multiplied by the maximum values of the bottom and top reinforcements. Their sum will equal the area of the minimum total reinforcement.

Data:

AsTotmin

AsUppmin

AsLowmin

AsUpp

AsLow

AsUpp'=max(AsUppmin; AsUpp)

AsLow'=max(AsLowmin; AsLow)

m= AsTotmin/(AsUpp'+AsLow')

m*AsUpp'+m*AsLow'=AsTotmin.