Concrete Beam ( Modeling > F2 >   Concrete > select " Concrete Beam ")

Tool summary :

  • Adds a concrete beam that is positioned by the two points that you locate.
  • The Concrete Beam Edit window opens when you add the beam.

Also see :

VIDEO A Concrete Beam member is added between two concrete columns. The chosen template adds horizontal rebar without further user intervention, and the beam is automatically set back from the columns.

  To add a concrete beam :

Before adding a concrete beam , you should confirm that the " Template " that you want to use for the beam has been properly set up in Concrete Setup > Beam Templates . The template sets, for example, whether the profile of the beam is rectangular or an irregular shape.

A concrete beam can be added in Modeling by pressing F2 to open the Member Type Selection window, then double-clicking " Concrete Beam ."

Two work points are required to add a beam. The order in which you locate these points does not matter since the work point that is closest to the global axes 0, 0, 0 point is recorded as the " Left end " work point. This is exactly the same way that the left end is determined for steel beams. Click here for more information on the topic of how a member's left end relates to global coordinates.

Concrete beams can be sloping or non-sloping. The member line of a concrete beam will adjust to a change in that member's " End elevation ."

For more information related to locating the work points for a concrete beam member, familiarize yourself with the following help topics: Offset Controls for point location , Locators , Locate menu, point location target ( ), status line , X-Y-Z display , global coordinate system .

Concrete beam properties

------ Rebar settings ------

Include top/bottom bars from template: or . This applies to concrete beams when dowels have been defined in the selected " Template ." These are the reinforcing bars that run along the length of the concrete beam.

If this box is checked ( ), longitudinal reinforcing bars that are defined in the " Template " are included in the concrete beam. Ties can be added to the bars using " Tie Zone ."

If the box is not checked ( ), the rebar defined in the beam template ( Beam Templates ) is not included in the beam. If you so choose, you can add a system of longitudinal reinforcing bars using a Rebar Area Layout .

Max bar length: AUTO or AUTO . This applies when the option to " Include dowels from template " is checked.

' AUTO (checked) ' instructs the Concrete Beam program to determine the " Max bar length ."

' AUTO (not checked) ' lets you enter a distance in the primary dimension " Units " or other units .

Max length >= length of run: If the " Max bar length " that is entered is greater than or equal to the length of the rebar run, the rebar run will consist of a single rebar that is the required length. Assuming that there is no " Material setback ," that required length is the distance between the left- and right-end work points minus two times the " End cover " distance that is defined in the Concrete Beam Template Editor .

Max length < length of run: If the " Max bar length " that is entered is less than the length of run that is required and the concrete beam program does not override your entry due to " Min bar length " being set to ' AUTO ', the rebar run is broken two or more rebar lengths, the first of which is (or are) the " Max bar length ."

Example: " Max bar length " results in each rebar run in the concrete beam being divided into three rebar segments. The first two segments are the " Max bar length ." The third segment is the length that is required to complete the run.

Note: A " Max bar length " that is less than the " Min bar length " is an invalid entry. You need to change that setting, or you will not be able to close the Concrete Beam Edit window using " OK ".

Min bar length: AUTO or AUTO . This applies when the option to " Include dowels from template " is checked.

' AUTO (checked) ' instructs the concrete beam program to determine the " Min bar length ." Be aware that when ' AUTO ' is checked, a distance that you enter for " Max bar length " may be overridden.

' AUTO (not checked) ' lets you enter a distance in the primary dimension " Units " or other units . Be aware that this distance may not be applied when a specific " Max bar length " has been entered.

------ Bar division ------

Bar division: None or Lap splice (bars inline) or Lap splice (bars offset) or Crank splice . These options determine if or how bars are spliced.

Bar division options affect the length of rebar shape material.

' None ' prevents splices from being modeled. The rebar is modeled as a single length.

' Lap splice (bars inline) ' models splices that accommodate the " Max bar length " and the " Overlap "; however, the splices are within the same rebar run and are modeled as clashing material.

' Lap splice (bars offset) ' models splices that accommodate the " Max bar length " and the " Overlap ". The bars are offset so that their material does not clash.

' Crank splice ' models splices that accommodate the " Max bar length " and the " Overlap ". The bars are within the same rebar run, but cranks are provided that conform to the " Crank length " options to prevent the bars from clashing.

Overlap: AUTO or AUTO . This applies when the runs of horizontal rebar have been divided into multiple rebar lengths to accommodate the " Max bar length ." A lap splice is a common way of splicing two reinforcing bars. Lap splices that are within the same rebar run are modeled as a material clash between the two lengths of rebar that are being spliced. The length that the rebar clashes in the model is the " Overlap " that has been entered.

' AUTO (checked) ' instructs the concrete beam program to determine the " Overlap ." If the program applies splices, the overlap will be the " Horz. in concrete " distance entered in the Reinforcing Bar Definitions window.

' AUTO (not checked) ' lets you enter a distance in the primary dimension " Units " or other units . That user-entered lap length applies when the " Max bar length " results in each run of longitudinal rebar being divided into multiple rebar lengths. The diagram below shows a single rebar run. Since rebar 2 requires two lap splices, the " Overlap " (marked lap in the diagram) is applied twice.

Entering an appropriate " Overlap " ensures that sufficient lengths of rebar are ordered to achieve a lap splice. As shown in this diagram, a lap splice that is within the same rebar run is modeled as a material clash.

Crank length: ratio or dimension . This option applies when " Bar division type " is ' Crank splice '.

' ratio ' specifies the ratio (expressed as a decimal number) of the crank length to bar size; that is, the crank length divided by the bar size. It follows that if you multiply the ratio by the bar size, you can calculate the resulting crank length:

Example using imperial units :
ratio = ' 6.0 '
bar size = #6 (i.e. 3/4", or 0.75 )
crank length = C

C ÷ 0.75 = 6.0
C = 6.0 × 0.75
C = 4.5 , or 4 1/2"

Example using metric units :
ratio = ' 6.0 '
bar size = #19 (i.e. 19 mm)
crank length = C

C ÷ 19 = 6.0
C = 6.0 × 19
C = 114 mm

' dimension ' specifies the crank length as a distance in the primary dimension " Units " or other units . This option allows the crank length to be entered directly.

Left end settings
Right end settings

  origin symbol identifies a member's left end when you hover its member line .

------ Member ------

End elevation: The elevation (in the primary dimension " Units " or other units ) of the work point at the top of this end of the concrete beam. For a non-sloping concrete beam, both the left and right end elevations will be the same.

A concrete beam has two exact points , whose elevation you can change by changing the member's left- and/or right-end " End elevation ."

To determine the end elevation on a concrete beam in the 3D model, use Construction Line Add or a similar tool, select EXPT as the Locate option, then snap the point location target to the work point at the end of the beam. The Z coordinate reported in the X-Y-Z display tells you the elevation at the snapped-to exact point.

Material setback: AUTO or AUTO .

' AUTO (checked) ' instructs the concrete beam program to automatically calculate the left-end " Material setback " and right-end " Material setback " for beam-to-column framing situations such as that shown below.

In the above example, the concrete beam's left-end " Material setback " ( lsb ) and the right-end " Material setback " ( rsb ) is the half-depth of the concrete column.

The " Material setback " adjusts the length of the concrete beam. It also affects the " Volume (yards) " and " Total length " that is reported for the concrete beam.

' AUTO (not checked) ' lets you enter a distance in the primary dimension " Units " or other units .

Notch end: or . The example shown below depicts the left end of a concrete beam. " Notch end " under " Right end settings " works in a similar way.

If this box is checked ( ), a notch will be generated (after you press " OK ") based on the " Notch depth " and " Notch length " that you enter for this end of the beam.

If the box is not checked ( ), the beam's end will not be notched.

Notch depth: The distance (in the primary dimension " Units " or other units ) from the bottom of the concrete beam to the top of the notch. This distance is measured parallel with the depth of the concrete beam.

For a left-end notch like that which is shown, " Notch depth " is measured from the bottom, left end edge of the member. For a right-end notch, its measured from the bottom, right end edge.

Notch length: The distance (in the primary dimension " Units " or other units ) from the end of the concrete beam to the interior of the notch. This distance is measured parallel with the length of the concrete beam.

For a left-end notch like that which is shown, " Notch length " is measured from the left end of the member. For a right-end notch, it is measured from the right end.