Precast Concrete Wall Height Increase

[Brad805]

A client of ours is planning to supply and install new precast wall panels for a building project that was partially damaged by a fire. During my review I noted an odd detail. I am not the EOR, and I have not had a chance to speak with him yet. I am concerned about the detail used to increase the wall height. In the attached sketch you can see how they would like to increase the ceiling height from 16'-7" to approximately 24'-0". The handwritten details and rudimentary calculations are mine. The elevation detail is my best guess at how I believe the contractor would have implemented the work. The existing panels are insulated panels and not solid. This detail was applied to 164'-0" of existing walls that were not damaged by the fire, so it seems a rather critical detail in my view. At this point I am interested to hear other opinions if they think the detail is reasonable, or if it would be advisable that the responsible parties review this detail further.

Thanks

 

[CELinOttawa]

I would be more concerned about the ability of the panel connections to take the additional loads...

The detail seems reasonable for extending the walls, but there would be a good deal of calculations required to show this. By making this change the End is responsible for the performance of the existing panel going forward, and I'm not sire I'd be keen to do this on an insulated panel at all without stripping the insulatelion and making the affected area solid.

 

[hokie66]

Looks dodgy to me. I don't know much about insulated panels, but I assume the panels were braced at or near the top, and now they aren't.

 

[CELinOttawa]

How can my phone's spell check change "Eng" to "End", "suure" to "sire" and NOT catch "insulatelion" as being "insulation". *sigh*

 

[Brad805]

Dodgy was my thought also. It is not a method I would have used to extend the panels. When I was first told of this I assumed that the columns extended to the foundation. Needless to say that I was a little surprised when I started to examine the drawings and discovered this.

This panel type has a solid region around the perimeter of the panel, so the column connections should be at least 4" from the insulation zones.

Thanks to both of you. I will have to ponder this a little further.

 

[ztengguy]

Do the panels still work for the new height/span of about 24', seems the moment would increase quite a bit.

 

[Brad805]

The increase in the moment will not be a significant problem due to the wall height increase. The handling stresses during de-moulding and erection typically governs the design wrt to bending moments. This particular panel is offered in heights greater than 24'-0", and the reinforcing is similar between a 16'-0" and 24'-0" panel.