100mm thick architectural cladding(4x3.2m) is possible?

[precast123]

Hello all,

The project is in tender stage. Client is asking for a 100mm cladding, which will be supported on Cip beams top and bottom on each floor. I am afraid about Demoulding the panel which can be solved by using a tilting table. Embeds like Halfen channel might not be possible as the panel thickness is small.

What problems(design,connections, production, demoulding, transportation and erection) I might be facing if I keep the panel thickness 100 mm ? Please suggest.

 

[KootK]

The trite answer is that your 4" panels would need to pass all of the same design checks that an 8" panel would need to pass. 4" panels have certainly been done before (Link). That being said, a span to thickness ratio of 52 is getting up there. And the parapet cantilever and roof connection won't benefit any from that 22 mm reveal that will leave you with only 80mm panel thickness where you may need it most.

I would call some local precasters to get a better sense of feasibility. They may come to you with issues first as part of the tendering process. A tender addendum may be in order. I also imagine that the panels will want to hang from the top and float at the bottom so, at minimum, the connection detailing probably needs some revision. Precasters usually find a way when it comes to connections however.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[precast123]

Yes, connections is not a big problem there. But I am a bit worried about the recess which is leaving the panel thickness to 80 mm as you said. I would like to increase the thickness to at least 120 mm to accommodate any recess in panel (20 mm) but no one is giving ears to it.

 

[Brad805]

I assume these are pre-stressed. Have you looked at the elevations to see if there are any narrow ribs between windows or doors? Once the wall elevations get broken into 3 - 4m wide pieces for shipping, that's where you will find the problems.

 

[precast123]

No its not prestressed. Windows might have some projections around perimeter.

 

[hokie66]

Not thick enough. No competent precaster will do this.

 

[precast123]

@kookt: I will increase the height of the corbel, which will solve the recess problem.. and I will still have 100mm thickness there for cantilever.

 

[KootK]

Can you sketch up what you've got in mind Khaleel? The way that I'm envisioning it, I don't think that a deeper corbel would help.

I'm actually somewhat doubtful that the panels will end up having corbels in the conventional sense. The detailing would be tough to make work in the space available I'd think. My guess is that your connections will be two embedded hardware connections at each end of the panels. Others participating in this thread are more knowledgeable about precast than I, however, so I'm prepared to stand corrected in my assessment.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[jwilki]

5th level of a car park and a panel size of ≅ 6.8m high x (6m - 3m) wide x 100mm thick? I'd like to see them lift that in place safely... you may be able to design a 100mm thick panel for "in place" conditions, but surely the precaster will need something thicker for his lifting requirements. Also is the roof deck serviceable and used as a car park? => will they want to attach a guard rail to the precast panel?

 

[Ron]

While the detail might not show everything, I hope there is some auxilliary barrier for stopping the cars other than the wheel stops and the 100mm wall.

Also, the sketches imply the slabs are not cast integrally with the spandrel (unless spandrel is precast/prestressed)

 

[precast123]

@ KootK, Please see the attachment.

This is how I will divide the parapet. But there is extra load from the Mono rail. In that case i have to increase the parapet thickness.

 

[precast123]

Connection I will make similar to this.

I have done a 120mm thick cladding before.

 

[precast123]

@jwilki : I wont be going beyond 4x3m panel. Demoulding is done by tilting table and lifting is always almost vertical. So it wont be a problem. Yes there is rail attached to the parapet running all around the perimeter of the building. I have to increase the parapet thickness in that case. Yes roof deck is a car park with some shade above them.

@Ron : Cladding can take somewhat lateral load as the connections are designed according to wind load. I think it is sufficient to take some minor collisions with the cladding. Yes slabs are Hollowcore with structural screed of 75mm and some connections which will ensure the structural integrity.

 

[hokie66]

If your panels are only 4m x 3m, how do you span 5m floor to floor? This whole scheme doesn't pass the smell test.