topic Re: Volume Quantities Results Difference - Concrete Structure in Revit Structure Forum

Volume Quantities Results Difference - Concrete Structure

Anonymous — Mon, 07 Jan 2019 14:27:43 GMT

Hi All,

I made a simple Revit model to check how Revit 2018 calculates the volume of concrete elements modelled into 2 different ways:

Dimensions:

Columns 60x60 cm

Beams 20x60 cm

Slab 20 cm thickness

Walls 20 cm thickness

Model 1 - "Tradicional":

In this model:

- The slab is modeled from corner to corner (Square).

- Columns have no offset at the top (not avoiding slab).

- Beams (height = 60 cm) don't have "Z" offset to avoid the slab.

- Walls have no offset at the top (not avoiding slab).

Model 2 - "Norma Cubicaciones":

In this model:

- The slab is modeled according to the column and beam edges.

- Columns have no offset at the top.

- Beams (height = 60 cm) don't have "Z" offset. Directly related to the corresponding level.

- Walls have "-20 cm" offset at the top to avoid the slab.

Now, if I compute the volume calculations I get the following results (Schedule). There are some differences between the 2 models:

Does anyone know how Revit 2018 is calculating the volume for the 1st model (when different elements are colliding eachother)? Does it have a certain hierarchy?

Any tip of advice will be very well received.

Thanks in advace!

Re: Volume Quantities Results Difference - Concrete Structure

A_MAQ — Mon, 07 Jan 2019 16:48:06 GMT

Hi jvillaroel,

Can you upload your simple project so I can have a look on it

Re: Volume Quantities Results Difference - Concrete Structure

ToanDN — Mon, 07 Jan 2019 16:52:05 GMT

Walls have no offset at top versus -20 cm offset.

Re: Volume Quantities Results Difference - Concrete Structure

Anonymous — Mon, 07 Jan 2019 17:05:00 GMT

Hi All,

After some tests, I got to get the expected result. The difference was that the slab, automatically understands when a column and a beam is placed "inside it" so this volume is not taken into account. With the walls, it relies on this message:

If it is set to "Yes", the constraints are satisfied according to the model (top and base constraint with no offset) but for volume calculation, the slab understands the portion of the wall that is placed inside the slab.

Maybe this is a straight-forward thing for most of you, but in my office was a common thing to use the "No" option of this message.

Hope it helps someone.

Regads!

Re: Volume Quantities Results Difference - Concrete Structure

ToanDN — Mon, 07 Jan 2019 17:06:54 GMT

Yes. If you don't attach then the walls and the slab overlap, as shown clearly in your 1st picture.

Re: Volume Quantities Results Difference - Concrete Structure

A_MAQ — Mon, 07 Jan 2019 17:07:33 GMT

Great,

That's what I was going to tell you,

good to hear that you got it