Tekla Structures
Tekla Structures


You can export reinforcement geometry to BVBS (Bundesvereinigung Bausoftware) format. The result is a text file in ASCII format with a file name extension .abs.

The supported version of the BVBS format is 2.0 year 2000.

You can export bent reinforcing bars, reinforcing bar groups and reinforcement meshes, which can be rectangular, polygonal, non-bent or bent, and may include cuts. The export of hooks is also supported.

Reinforcing bars that have bendings with two or more variable radius values are exported fully conforming with the BVBS specification so that radius element and leg elements are written separately. If this causes compatibility issues within your own environment and other tools using the BVBS files, you can still go back to the older way of exporting by setting the advanced option XS_BVBS_EXPORT_ARC_COMPATIBLE_TO_OLDER_METHOD to TRUE in an .ini file, for example, in user.ini.

Export to the BVBS format

  1. Ensure that numbering is up to date.
  2. Go to the properties of the cast units and reinforcement that you plan to export, and edit the user-defined attributes on the BVBS tab as required. The user-defined attributes are environment specific.
  3. Select the cast units with the desired reinforcement content, or select the reinforcement.
  4. On the File menu, click Export > BVBS.

    The BVBS Export dialog box is displayed.

  5. Define the BVBS export settings:
    1. On the Parameters tab:
      • select which reinforcement to export

      • define how and where to export the BVBS file or files, and include the revision into the file name
      • select which BVBS elements to export
      • define class numbers for girders

      You can use saved selection filters to exclude reinforcement bars or meshes matching with the selected filter.

    2. On the Data content tab:
      • define how to export drawing data

      • give the reinforcement position source

      • give the project number

      • select whether you want to export the private data block and select the data items for this additional block

    3. On the Advanced tab:
      • round rebar lengths for 2D bent bars

      • define which bending radius is used to calculate the arc length

      • make meshes out of rebars, and give UDA name for grouping

      • include detailed data of mesh bars in the export

      • export tapered reinforcing bar groups as multiple separate reinforcing bar items

      • define the order of the items in the output file

      • define the export of reinforcement coupler data

      • define whether to combine single rebars or rebar groups by their position number, with the total bar quantity, or handle each single rebar or rebar group individually

      BVBS export uses arc geometry in two cases:

      • For circular rebars such as spirals or hoops.

      • When bent rebar has more than 1 bending radius, the bends with the larger radius are exported as arc sections.

    4. On the Checking tab, select whether you want to run additional checks for the reinforcing bars.
    5. On the UDAs tab, define the UDA fields to be used, and the content to write into reinforcement, part, cast unit and pour object UDAs.
  6. Click Export.
The BVBS file or files in .abs format are exported to the folder specified in the Output file area. You can check the export report by clicking the report link that appears at the bottom of the dialog box.

BVBS export settings

Use the BVBS Export dialog box to control the BVBS export settings.

Parameters tab



Model objects to be exported

Select which reinforcing bars or meshes are exported.

  • Reinforcement of all cast units in the model: Exports reinforcing bars or meshes in all cast units in the model. If there are cast units that do not have reinforcing bars or meshes, no empty files are created.

  • Reinforcement of selected cast units: Exports reinforcing bars or meshes in the cast units you have selected in the model.

  • Selected reinforcement only: Exports the reinforcing bars or meshes you have selected in the model or in the drawing. When you select this option, you can export only to a single file.

  • Reinforcement of selected cast units (totals by all positions): Exports reinforcing bars or meshes in all the cast units that have the same cast unit position as any of the selected cast unit positions.

    For example, if a cast unit with the cast unit position W-120 is selected, the reinforcing bars or meshes in all the cast units that have position W-120 are exported even though not all of them were selected.

  • Reinforcement of selected pours: Exports a set of reinforcement in the selected pour. Select the pour in the pour view. Ensure that you have used the Calculate pour units command to include the rebars in the pour.

Excluding reinforcement by filter

Exclude reinforcing bars or meshes by selecting any of the selection filters. Reinforcing bars or meshes that match the filter are excluded.

Output file - Single file

Export all BVBS information into one .abs file. Enter the file name in the box or click the ... button to browse for the file. If you do not enter a path, the file is saved in the model folder.

Output file - One file per each cast unit

Export each cast unit reinforcement content to its own file.

The files are created under the folder that you define in the Folder name box, or you can browse for the folder using the ... button.

Use the File naming template list to select how the created files are automatically named. You can use multiple assembly template properties in the file name. Type the template properties in the box and separate them with spaces. The combination will be separated by underscores in the exported file name.

Include revision into file name

Select to include revision into file name.

Select one of the following options to include it in the output file name:

  • Revision mark: REVISION.MARK, default value

  • Revision number: REVISION.NUMBER

  • Rev<Revision mark>: same as Revision mark but the text Rev comes first

  • Rev<Revision number>: same as Revision number but the text Rev comes first

BVBS elements to be exported

Select which item types are exported. The options are:
  • 2D reinforcement bars (BF2D)

  • 3D reinforcement bars (BF3D)

  • Spiral reinforcement coils (BFWE)

  • Reinforcement meshes (BFMA)

  • Lattice girders (BFGT)

    If you select Lattice girders (BFGT), enter the class numbers used in the model for the lattice girder bars in the Class numbers for girder box. The lattice girder may contain two or three chord bars and one or two diagonal zig-zag bars. The lattice girder length and other attributes are taken from the main chord (usually top chord).

Class numbers for girder

Enter the class attribute for recognizing lattice girders. The class should be same for all rebars within a girder.

Data content tab

Option Description

Drawing name source

In BVBS file each row/rebar has a data field for Drawing number of the respective drawing (drawing name) and Index of the respective drawing (drawing revision). With the option Drawing name source you can control how the values for these data fields will be set.

Cast unit position

Drawing Name

Drawing Mark

Drawing Title1

Drawing Title2

Drawing Title3

Fixed text: If you select this, enter the text in User-defined drawing name.

Reinforcement UDA

Reinforcement template

Assembly template

By selecting the option Fixed text you can enter the values in the dialog box and same ("fixed") values will be written for every exported rebar.

If any of the other options is selected, the drawing name and revision will be taken from the cast unit or cast unit drawing of the rebar.

Note that it depends on the receiving system of the BVBS file how important and for what purpose this data will be used. From Tekla Structures perspective, using this data field is not obligatory.

User-defined drawing name

Enter a text string to be used for the drawing in the export.

This option is available only when you have selected the Fixed text option in Drawing name source.


Drawing revision (index).

This option is available only when you have selected the option Fixed text in Drawing name source.

Position source

Define the source of the position. The options are Reinforcement position, Reinforcement UDA, Reinforcement template and Fixed text.

User-defined reinforcement position

Define the reinforcement UDA position number. Exported item with the same position number but different UDA position number will be exported to different rows.
Project number

Define the project number. The options are:

Project Properties: The export fetches the project number information from the project properties set in Tekla Structures.

Project properties UDA: The export uses the UDA name entered in the User-defined project number box.

Fixed text: The export uses the text entered in theUser-defined project number box.

User-defined project number

Define the UDA project number or a text string to be used as the project number.

Private data block

With Private data block you can control whether the private data block is exported (Export private data block) and select the data items for this additional block. The following data types are available:

- Reinforcement report property (integer, float or text)

- User-defined attribute (integer, float or text)

- Open API object property

- Assembly report property (integer, float or text)

Click the New... button to add new predefined private data fields to the list. Enter information about the data item.

  • Name in list

    The text shown in the Private data block list.

  • Field identifier (one lower case letter)

    The field code which separates the individual data fields in the private data block. It can be any lower case letter. Typically, it is a good practice to use a different value for each data item but this is not required. The receiving system may also be able to read only certain data fields.

  • Property or UDA name

    The value defines which data will be inquired from the reinforcement object. Note that a non-existing property will be not exported.

  • Property data type

    The value has to match the actual selected property. The options are:

    • Reinforcement report property Integer/Reinforcement report property Float/Reinforcement report property Text

    • User defined attribute - Integer/User defined attribute - Float/User defined attribute - Text

    • Open API object property

    • Assembly report property Integer/Assembly report property Float/Assembly report property Text

You can also edit and remove data fields, and change their order.

Advanced tab




Round lengths to

Round leg lengths to

Round rebar lengths for 2D bent bars. Mesh and 3D rebars are not affected.

To round the lengths, first select an option for the Round setting. The options are:

Yes - Uses the nearest rounding value.

Up - Rounds the lengths up.

Down - Rounds the lengths down.

For the Round options Up and Down, there is a preliminary tolerance for small length differences up to 0.2 mm before performing the rounding. This ensures that values very close to exact increment are not rounded when it is not necessary.

Round lengths to rounds the total rebar lengths in the corresponding BVBS field in the header block, and the available values are 1 (default), 5, 10, and 25.

Round leg lengths to rounds the leg lengths in the geometry block, and the available values are 1 (default), 5, and 10.

Bent leg arc radius

This setting defines which bending radius is used to calculate the arc length: Bending radius to the rebar center line (Center line), which is the default for most interfaces, or to the rebar inner edge (Inner edge). If you select Inner edge, the bending radius is shortened with half of the rebar nominal diameter.

The BVBS export uses arc geometry in two cases:

  • For circular rebars such as spirals or hoops.

  • When bent rebar has more than 1 bending radius, the bends with the larger radius are exported as arc sections.

Try to make meshes of rebars

Select whether the export tries to automatically form meshes of a single reinforcing bar or of a group reinforcing bars and export them as a mesh instead of separate 2D bars. The options are:

Yes, group rebars by class

Yes, group rebars by name

Yes, group rebars by grade

Yes, group rebars by UDA

In order to form a mesh the reinforcing bars need to belong to the same part, be straight, be on the same plane, and have equal filtering attribute values.

UDA name for grouping

If you selected the value Yes, group rebars by UDA for Try to make meshes of rebars, enter the UDA name for grouping.

Exporting of mesh bar data (@X..@Y..)

Use this setting to control whether the detailed data on mesh bars is included in the exported data of the mesh. The appropriate option depends on the needs and capabilities of the receiving system. The data is needed if it will be used, for example, for mesh fabrication.

  • Custom and cut catalog meshes only: Detailed bar data is included only for custom meshes and catalog meshes that have additional cuts, openings or skewed edges.

  • All meshes: Detailed bar data is written for all meshes.

  • None meshes: Detailed bar data is not written to any of the meshes.

Export stepped bars as separate items

By default a stepped group is exported as a single string with the stepping length defined in a certain data block.

If you select the value Yes for Exporting of mesh bar data (@X..@Y..), all tapered reinforcing bar groups are exported as multiple separate reinforcing bar items even if they have regular spacing and could be exported as one single stepped reinforcing bar item.

If all the tapered bars within the group have the same geometry and length, they will be exported within a single BVBS string as a regular group would, regardless of this setting.

Sort items

Use this setting to define the order of the items in the output files. The options are:

No sorting

By diameter, smaller size first

By diameter, bigger size first

By position number


You can export coupler and thread data.

Set Export reinforcement coupler data to Yes to export coupler or thread data.

Enter the UDAs for connection method, product/supplier and product code for the rebar start and rebar end separately, METHOD_START, PRODUCT_START, CODE_START and METHOD_END, PRODUCT_END and CODE_END, for example.

Note that the UDAs depend on the creation tool and may differ from the examples. The UDA representing the method must be of type INTEGER, and the UDAs representing product and code must be of type STRING.

Single rebar and rebar groups

Select either of the following options:

  • Yes: Single rebars or rebar groups are combined by their position number, with the total bar quantity. This is the default option.

  • No: Each single rebar or rebar group is handled individually and exported. This leads to a larger BVBS file, but the advantage is that each single rebar and rebar group can be identified and handled by its own GUID, and the BVBS file will reflect the model objects or IFC exported rebars.

Checking tab



Check reinforcement

Select whether you want to run additional checks for the following:

Reinforcement diameters (separated with spaces)

Minimum cutting length of reinforcing bars

Maximum cutting length of the reinforcing bars

Minimum leg length for straight sections between the bends

Maximum weight of individual bars

When you select the Check reinforcement check box, and the values of the exported reinforcing bar are less than the minimum or greater than the maximum, a warning is written to the export log file.

The log file entry contains the ID of the reinforcing bar. You can locate the reinforcing bar in the model by selecting the appropriate row in the log file. Note that the reinforcing bar is still exported normally and only the additional warning is given.

Note that when the check is activated, the length of lattice girders is also checked. A warning is added in the log when the check fails. The length of the main chord defines the exported length of the lattice girder.

UDAs tab

On this tab you can define the UDA fields to be used (UDA), and the content to write into reinforcement, part, cast unit and pour object UDAs (UDA content). You can tag UDAs based on release code, release status, release date and released by information. You can also select whether existing UDAs are checked and handled by using the setting Check existing UDAs. The options are No, Prevent export, Report to log, Report to log and overwrite, and Overwrite only.

BVBS export file description (.abs)

The content of the BVBS export file .abs is described below. The example data structure here represents a 2D bar, which is either straight, or bent on one plane at most. Section H is the header section (identification and general information), and section G is the geometry section (production geometry).

(1) BVBS element (product type)

(2) Project number

(3) Drawing number (in this example, cast unit position number)

(4) Drawing revision number (not in use in this example)

(5) Rebar position number

(6) Single rebar length

(7) Product quantity

(8) Single rebar weight

(9) Rebar diameter

(10) Material grade

(11) Bending diameter (a straight bar)

(12) Rebar layer (not in use the BVBS export)

(13) Step tapering for a tapered rebar series if grouping tapered enabled in export settings (no tapering in this example)

(14) Leg length (only 1 leg in this example)

(15) Bending angle after the leg

(16) Checksum for correct data transfer

Reinforcing bar length calculation in BVBS export

The length of the reinforcing bar is calculated according to the BVBS specification. The length also depends on the bending angle. Lengths L1 and L2 are exported.

If you set the advanced option XS_​USE_​USER_​DEFINED_​REBAR_​LENGTH_​AND_​WEIGHT to TRUE, the user-defined length value is exported as the overall length for the reinforcing bar.

Note that the BVBS format specifications define that the overall length of the bar is ignored if the data contains actual geometry data. Some other software applications may still use the overall length values in the BVBS file for calculating quantities. The exported overall length in Tekla Structures is the same length as shown in reports.

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