1.5 Rebar Constraints

By selecting the bar and clicking on the Edit Constraints icon, we move to the environment where we can set how the bar will behave in relation to the edges of the element in which it is placed, and in relation to other bars.  

The program automatically Constrain bars to a certain level, however, if we want to have more control over how the bar will behave when we change elements and in relation to other bars, it is necessary to set those parameters ourselves as it suits us. If we do this step correctly, in future changes that happen we will make our job easier and the program should automatically arrange all the bars in a certain element with minimal need to manually adjust each bar individually. 

Each bar segment has its own constraint for which we have several options. First, you need to choose which plane of the selected bar segment you want to constrain. Then, you pick and choose to which edge of the element or other bar you want to constrain that plane, and then insert a positive or negative value for the constraint. 

By pressing the Space bar, you can cycle between the bar segments that you want to constrain, or Shift+Space to cycle the opposite way. To finish editing, press Enter, and to discard all changes, press Esc. 

We can choose to constrain bar segments to the cover or to the edge of the element. 

When we add more bars, we get even more options. Now we have the option to constrain bars to other bars and to choose between two approaches that give the same result: clear spacing between bars and spacing between the center lines of the bars. But of course, we can also constrain those bars directly to the cover. 

We have one more option for constraints that directly affects the relation between two bar segments or series of bars. If we choose this option, then when we edit the selected bar series, we won't create any changes to the other bar series.

But if we choose the other option, then when we edit the selected bar series, we will affect the other bar series, and that series of bars will follow the constrained series. In this way, these two series of bars will be connected, and we can set their clear spacing or set a lap between them. 

When we set everything that we want with constraints, if we, for example, change the type of the column from 30x30 to 50x50 or the height of the column, all the bars inside that column will follow that change and adapt to the new dimensions of the column. 

Now that we have covered all the basics of the Rebar Constraint, I can give you some more tips related to this topic. 

If we select more bars or series of bars, we can constrain them all at once. 

But if we choose a new target for the constraint, then they will be constrained to the same target and will also have the same value for the constraint. 

Then, after we insert and confirm the new value of the constraint, the bars will be set exactly how we want. 

And one more interesting tip that is directly related to the previous one: if we, for example, select two series of stirrups and then pick Edit Constraint, when we pick the correct plane for the constraint, we can now drag or insert the value for the constraint for both series of stirrups together.