Best way to model CMU/Masonry?

[Anonymous]

Hello,

I'm trying to find out what the best way to model a concrete masonry unit (CMU) wall in Revit Structure is. I'm intersted in modelling in order to obtain wall area, so it's not really relevant to me whether I'm able to model the individual CMUs or just do a solid wall. 

For the moment I've been using regular old walls, and to distinguish them in my schedules I simply create a family type that suits my needs, e.g. 150mm CMU wall, 200mm CMU wall, etc. The annoying part is that most of these walls have a beam that rides on top. When I put the beam on top, using the top floor level as a guide, the walls cut the beam and the beam disappears. And my schedule gets messed up because the beam volume isn't reported, and instead I get more masonry area reported.

I have to go to a 3D view, and change the join order beam by beam so the beam cuts the wall. In large projects where there's a lot of intersecting walls, that takes a bit of time. 

Is that how you do CMU walls, or is there a better way that doesn't require so much correcting? Is there a way that you can change the default join order, so that beams by default cut the walls and not the other way around?

[Anonymous]

Hi,

Can you please send me your sample file for reference?

Thanks & regards,

Subhradeep Sen

Kolkata

India

[Anonymous]

Sure, see attached file.

On the 3D view, you can see the idea. A cast-in-place concrete frame, and the spaces inside the frame are filled with CMU walls. So the beam "rides" on top of the CMU wall.

When I'm scheduling quantities, the CMU walls are scheduled by m2 (the standard here), since CMU's are sold just like tile, by units or area. And the columns/beam are scheduled by m3 since your concrete is sold by m3. 

First case. When you draw them using Revit's defaults, the beam "disappears" inside the wall, which means the wall cut the beam. In the schedule for walls, you can see the walls are 8 m2. Which is wrong, since the area we'd build is actually 2.5 x 2.7m = 6.75 m2. If you look at the framing schedule, there's only 0.02 m3 of beam, which confirms the case.

Second case. Switch the join order. The beam now cuts the wall. The quantities are right. Only problem is, when you have one of those really dense buildings, where walls intersect each other all over the place, you'd have to do the "change join order" operation 20 or 30 times per floor. 

Third case. Unjoin the beam and the wall. Unconstrain the wall, and manually set the height. Works just as well as case 2, except you have to manually set your height for every wall segment. Same thing, imagine doing that 10 or 20 times per level.

Fourth case. Let's say you have one of those property line walls that's on an inclined axis. So you make your wall, adjust your alignments, and it turns out you missed the beam and it's a fraction of a degree off. Now since the beam isn't perfectly aligned, it doesn't cut 100% of the CMU wall. If you look at the schedule, you're back to case 1: Revit schedules the CMU wall as 8.10 m2, and the beam as 0.83 m3. So I'm not missing concrete, but I've got excess CMU area.

So that's where my question comes in. What's the easiest way to model something like this? Is it the second case, third case, or some other strategy I'm not aware of? How can you prevent accidental misalignments, like the one in the fourth case? Is there any way to constrain the beam to the wall,so they both rotate in unison?

[Anonymous · Accepted solution]

Hi,

Thanks for your reply. I am sending 2 nos. image files. Please see the attached files.

1. First Image:- This image is indicating about wall height. When you create an wall under a beam then wall height should be excluding beam depth. As for example, if your floor to floor height is 3000mm. and beam depth is 500mm. then wall height would be (3000-500) = 2500mm. See the Red Marking how to reduce the wall height in the model. This is the exact process to create a structural model. I think you know that practically on site this process follow to create a structure.

2. Second Image:- This image is indicating about Beam Analytical Line. If you dont need the Analytical Line in model just turn off that from Properties Bar. See the Red Marking.

After the above process just go to your Schedule and see the "Wall Schedule" & "Structural Framing Schedule". Now you will get the exact quantity (both Volume & Surface Area).

Where are you from and what is full name?

If there is any other queries then please write to me.

Thanks & regards,

Subhradeep Sen

Kolkata

India

[Anonymous]

Another thing is that dont create a beam continuously. Create a beam one column face to another column face. It will helpful for your quantity extraction. Try it.

I am resending you your Revit Sample file with rectification so that you can understand what I have done in this file. Please tally this file with your previous file.