Column-PT slab joint

[Enhineyero]

I understand that the joint on a concrete wall and PT slab/beam should allow for horizontal movement during the stressing of the tendons. I haven't seen this done in columns. Are columns flexible enough to neglect their potential to restraint the slab/beam from movement during stressing? or have I missed out an important detail?

 

[KootK]

That's generally the idea. It tends to be more truthy for slabs where each floor has the same column layout and each floor contracts similarly; less truthy at levels such as the first level above the foundation where the columns bottoms are restrained laterally.

We probably would have slip joints in columns if there were a practical way to detail that without making a dog's breakfast of the finished connection.

 

[KootK]

You'll enjoy this thread initiated by Inginuity: Link

 

[Enhineyero]

KootK, now that I thought more about it, the spacing of column reinforcement and ligs will probably make it difficult to make this happen.

You'll enjoy this thread initiated by Inginuity: Link

I find this particularly interesting, never seen one before. I could only imagine what the guys on-site were thinking when they were building this.

Does anyone have any experience in blade columns (or any column) cracking as a result of PT restraint? is there any way to know if 100% of the PT force went to the slab/beam instead of the possible restraints (i.e. columns, walls)?

 

[jimstructures]

Enhineyero,

What is meant by the term "ligs"???

Jim H

 

[KootK]

Stirrups and ties in the English speaking SE Pacific. Ligatures?

 

[jimstructures]

Thanks KootK, would I be correct in assuming it is left over from the French?

Jim H

 

[KootK]

I'm really not sure Jim. The etymology googles from latin into either old English or old french. I encounter the term in speaking with AU/NZ folks so I've been assuming British origins. Obviously, there were french colonies in the southeast Pacific too but I'm afraid I don't know what the french call their ties. I probably should given that my county includes Quebec.

 

[Agent666]

I'd like to say it's only those damn aussies that use ligs and cogs and other silly words, never heard any other nation using that terminology. Maybe it has its roots in the fact that they are all descendants of criminals?

It's not something that they stole from NZ for a change....