Longitudinal Reinforcement

In the Longitudinal Reinforcement tab, you can define the reinforcement that should be applied in the bending design and the internal force design of the member.

Items

This section allows you to define reinforcement items of the longitudinal reinforcement. There is only one item preset, which represents a kind of "basic reinforcement". You can adjust this default setting and add further items (see the image Defining Longitudinal Reinforcement), for example, to arrange the reinforcement in sections with additions. Use the button at the end of the list to create new items. You can also use the button to copy the selected item and then adjust the copy.

In the case of ribs, you have the option to generate the longitudinal reinforcement in a chord from the surface reinforcement. To do this, click the button at the end of the list. The program creates the longitudinal reinforcement of the rib member from the surface reinforcement that is provided in the connected surface. These items are displayed in the list, but cannot be changed. You can also deactivate the surface reinforcement again by using the button.

Parameters

In this section, you can define the longitudinal reinforcement properties. The parameters always refer to the item selected in the "Items" list.

Base Data

Select the "rebar type" from the list. There are several options for the reinforcement layout.

The options result in the following distribution scheme:

The entries in the Rebar Parameters category correspond to the rebar type.

A "basic reinforcement" is preset. It has an "symmetrical" layout with three rebars of 20 mm each on the top and bottom. This reinforcement is used to enable the design without a specific reinforcement definition. However, you usually have to adjust the reinforcement to ensure the design checks correspond to the real conditions! Otherwise, the program would use the presented basic reinforcement for all design checks.

If you do not want to adjust the reinforcement and want to keep the basic reinforcement for the moment, you should evaluate the "distribution of the required or uncovered reinforcement" after the design. Please note that the distribution of the required or uncovered reinforcement only takes into account the ultimate limit state. The serviceability limit state and fire resistance¹ design checks require the reinforcement to be defined as realistically as possible.

Assign material to the longitudinal reinforcement. If you have already defined the suitable reinforcement steel in the model, you can select it in the list.

You can also use the button in the text box to create a new material by opening the New Material dialog box, where you can access the material library.

The "Reinforcement placed in the bent corner of the stirrup" option allows you to control whether to arrange the rebars at the top or bottom edge of the stirrup, or exactly in the radius or the center of the bent corner.

This option is especially useful for columns. In contrast, for the beams mainly subjected to moment loading around the y-axis of the member, you can arrange the reinforcement on the top or bottom edge of the stirrup.

Rebar Parameters

The options in this category correspond to the rebar type.

Define the "number of bars" n_s and the "bar diameter" d_s of the longitudinal reinforcement. For the "Line" and "Single" rebar types, you can also define the rebar offset. This value can refer to the stirrup, the concrete cover, or the section surfaces (see also the Additional Reinforcement Offset). The graphic provides a perfect control option here.

Reinforcement Areas

This category provides the information about the sectional areas of the inserted reinforcement (see the image Reibar Parameters). These are useful if you discover, after an initial calculation, that the individual design checks are not complied with, with the provided reinforcement. You can then check the distribution of the required or uncovered reinforcement, compare it to the information in this dialog box, then adjust the diameter or the number of rebars accordingly.

Span Location

In this category, you specify where in the member the longitudinal reinforcement "item" is located. You can define this position with a "reference" to the start, the end, or the x-location. Select the corresponding option in the list to define the reference point for the span location.

With a "span", you have the option to arrange additional reinforcement in a member section and thus provide the required longitudinal reinforcement that is not covered locally.

In the case of the reference to the "start" of the current member, it is necessary to enter the span distance with a positive sign, and in the case of the reference to the "end" of the member, with a negative sign.

If the member is divided by a node of the "On Member" type (which does not divide the member in contrast to a standard node), you can also define the span with a reference to this internal node.

Furthermore, you can use the "definition format" to control whether to define the distances absolutely in length units or relatively in percentage.

Enter the "start" x₁ and the "end" x₂ of the span. The "span length" ls represents the length of the longitudinal reinforcement in the member.

Additional Reinforcement Offset

This category is available for the "Symmetrical", "Unsymmetrical", and "Uniformly Surrounding" rebar types. It allows you to individually place the longitudinal reinforcement in the member.

Select the "offset type" from the list, which controls the reference of the distances. You can select one of the following options:

• "From Stirrup": The distances e_z and e_y refer to the inner edge of the defined stirrups.
• "From Concrete Cover": The offset of the longitudinal reinforcement results from the distance from the cross-section outside, minus the concrete cover, minus the distances e_z and e_y.
• "From Section Surfaces": The offset of the longitudinal reinforcement results from the distance from the cross-section outside, minus the distances e_z and e_y.

Anchorage Start / Anchorage End

The design of anchorage length requires the longitudinal reinforcement anchorage entry. The list provides you with different options for the "Anchorage Start" and the "Anchorage End".

Enter the "anchor length" l_bd and, if applicable, the "bending diameter" d_br for both ends.

Information

Finally, here is the following information about the stirrup reinforcement of the current item:

• Length of one rebar L_lr,1
• Length of all rebars L_lr as a sum
• Weight of one rebar W_lr,1
• Weight of all rebars W_lr as a sum

Graphic

You can see the member section on the right, and the longitudinal section below. The functions of both graphic areas are described in Chapter Shear Reinforcement .

¹ The fire resistance design is not yet available in the current state (spring 2023).