Control (Concrete Column)

Last modified by Fredrik Lagerström on 2021/05/27 14:15

When the Control program mode is active one or several Ultimate- or Serviceability Limit States can be analyzed for sections with a defined distribution of reinforcement. A reinforcement distribution calculated in the Design program mode can e.g. be copied to a Serviceability Limit State load case to be analyzed in the Control program mode.

The input data field

The input data field contains a number of tabs in which the example is being defined. Many of these are identical in the Design and Control program modes.
The field contains initially the tabs Section information and Load case.

Section information

Section information is the same as in Design.

Load case

Current section forces, initial bow imperfection, limit states and type are stated in the Load case dialog box. Calculations for loads in Ultimate- and Serviceability Limit State are being performed in the Control program mode. Ordinary Ultimate Limit load cases as well as accidental load cases can be defined for the Ultimate Limit State. The type’s short term and long term can be stated for a Serviceability Limit Load case. A special marking for any defined shear force for load cases in Serviceability Limit State indicates that these forces are not a part of the calculation. When the cross-section and load cases have been defined Creep data, Buckling data, Material, Reinforcement input and Calculation settings tabs will be added to the input data field.

Creep data

Creep data is the same as in Design.

Buckling data

Buckling data is the same as in Design.


Material is the same as in Design.

Reinforcement input

With the Reinforcement input option current distribution of reinforcement is stated or copied from another load case.


Main reinforcement

The distribution of reinforcement can be stated in a number of different ways or as a combination of these as described below. The best way to use depends on how complicated the reinforcement distribution is. Coordinates, diameters and quality of reinforcement are shown gradually in the table above, in which also bars can be defined directly.

Defined stirrup reinforcements are displayed on the continuously updated drawing area.

  • Manage Reinforcement
    With the Manage Reinforcement button a dialog box in which the user can state a distribution of reinforcement graphically will be displayed. This is the most advanced way and gives the user a very powerful tool to quickly and simply state even very irregular reinforcement patterns with mixed diameters if wished.


    The Show coordinates option is activated as default, which is why the coordinates for the cursor are shown every time it is being moved across the section. If the right mouse button is pressed the Undo, Redo, Settings and Guides options as seen below will be available.

    With the Undo option copy, insert, move and delete performed according to the instruction below can be undone. These can be restored with the Redo option. This means that every Undo is a step back and Redo is a step forward, e.g. the latest Delete is being restored again.

    Under Settings the following options are available:
    Show bar ID which means that the ID-number and diameter of active bars are being shown
    Show coordinates which means that the position of the cursor is shown all the time, and
    Show Guides which means that the created support lines (see below) are being shown or hidden.

    Under Guides we have the options
    Set snap distance: It means that the user can change the 10 mm default distance, i.e. the distance within which a moved bar will automatically end up on a support line.
    Delete every guide: This means that any earlier defined support lines disappear.

    Support lines
    These support lines are intended as an aid for swiftly moving a bar or a group of bars to any position. Horizontal support lines are being created by moving the cursor to the gauge in the upper edge of the picture, pressing the left mouse button down and keep it pressed down until the right coordinate position in the vertical direction has been reached. Pointing at it and then pressing down the left mouse button can then move a support line. Vertical support lines are being retrieved in a similar way via the gauge in the left part of the picture. An arbitrary number of support lines can with this be defined as shown above.

    Define reinforcement
    In order to state an arbitrary distribution of reinforcement, at least one bar of each wanted diameter and strength class has to be predefined using one of the other options described in this section. Four bars have been chosen in the above shown picture; two with 20 mm diameter in the bottom corners and two with 16 mm diameter in the top corners. The first step will be to activate one or more bars by pointing at them and press down the left mouse button. It is also possible to activate a group of bars with a square by pressing down the left mouse button and at the same time drag the mouse over the current bars. Activated bars will be marked in red. Double clicking in an arbitrary point of the section will deactivate all bars. If the right mouse button is pressed when a bar has been activated, the following options will be displayed.
    • Copy
      A copy of all active bars will be created by clicking on the Copy button. These will be placed near each original bar for a later removal.
      The copy procedure can be undone as described above.
    • Insert
      A new bar is created between two activated bars (or, as an alternative, to the right of or below the current bar if only one bar is active) by clicking on the Insert button. Insert can be made undone as described above.
    • Move
      One or more bars can be moved to an optional position by using Move and then grab one of the bars by pressing the left mouse button. If a group of bars are being moved these will keep their reciprocal distance. Move can be made undone as described above.
    • Delete
      The currently active bars will disappear by clicking on the Delete button. Delete can be made undone as described above.

      Example: We want to define a bar with a 16 mm diameter on the coordinate x = 200 mm, y = 300 mm. Two support lines that intersect in this point should be defined in order to make the placing easier. Then a bar with this diameter will be activated after which Copy is chosen as shown below.


      A new bar is created and placed near the original bar. The next step is to choose Move as shown below.


      Keeping the left mouse button pressed while moving it to an optional position then moves the bar. The chosen snap distance (see above) affects the placing itself. The higher the value, the earlier the bar will be pulled into the right point. The new bar is now in the right position as shown below.


      By using these commands it is easy to create a totally arbitrary reinforcement distribution.
  • Copy reinforcement from load cases
    With the Copy reinforcement from load cases option a dialog box will be displayed in which distribution of reinforcement can be copied from a load case to another.

    Example: A section has been calculated for an Ultimate Limit Load case in the Design program mode. The user now wants to perform a control in Serviceability Limit State for the current distribution of reinforcement. A Serviceability Limit Load case is then created in the Control program mode after which the distribution of reinforcement is copied from the Ultimate Limit Load case with this option.


    Five load combinations have been stated in the example. The distribution of reinforcement for load combination 1 shall be copied to load combination 2. Load combination 2 has therefore been activated which is shown in the status bar in the top right of the program window.
    The current dialog box shows the remaining load cases where Load combination 1 is currently active. The distribution of reinforcement for the active load combination is shown in the dialog box, and Load combination 3 will get the same reinforcement as Load combination 1 by clicking on the Copy button.
  • Layer of reinforcement
    The most common way to define reinforcement is with the Layer of reinforcement button. A dialog box in which the user quickly can state one or several layers of reinforcement in the lower and/or upper edge will be displayed. Current covers of reinforcement can be defined here too.

  • Standard reinforcement
    With the Standard reinforcement button a dialog box appears from which a number of pre-selected reinforcement suggestions can be chosen, maybe as a start for further editing. Here, current covers of reinforcement can also be defined.

  • Material
    Strength classes for bars in the table are defined for each bar in the Material column. By clicking on the button with three small dots in the Material column the Material dialog is activated and makes it possible to change material. Active bars have a blue number.

  • Copy
    The properties of an active bar can be copied with the Copy command so that a new bar with the same position, diameter and strength class will be created in the list.
  • Delete
    The currently active bar in the list will disappear with the delete command.
  • Secondary reinforcement
    Stirrups are stated as secondary reinforcement with current spacing, diameter and strength class. If the defined spacing is larger than the minimum requirements the spacing will changed to this maximum allowed value. Defined stirrup reinforcements are displayed on the continuously updated drawing area. The stirrup reinforcement is removed (see section picture) if spacing is defined as zero.


Calculation settings

Calculation settings is the same as in Design.