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Repost...TC Bolts

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This is a repost from several weeks ago. I did not see any responses. Forgive me if I missed them.

I have a project where all the beam connections are designed with bolts in bearing. The wind bracing is designed with slip critical bolts. 

The erector would like to use TC bolts for the entire project. This is a hospital and from what I understand the TC bolts are quiter than torquing conventional bolts (for the slip critical connections). The entire building is going to be fireproofed (so the steel will have no paint).

It seems to me that we should use conventional bolts for the bearing connections and TC bolts for the slip critical connections, and not TC bolts for the entire project. I would rather have the conventional bolts, installed finger tight, and therefore able to slip into bearing at lower levels of load (like when the building is under construction) rather then TC bolts highly torqued that then are required to slip at higher load levels (like after the building is occupied). I don't really know if using TC bolts for bearing connections can contribute to bolt banging (after occupancy), but I certainly want to avoid any possibility of this.

In addition, we have some shear tab connections with short slotted holes, that are designed for higher loads (than those shear tabs with standard holes). It seems that it may be possible to overstress some welds and plates if those connections were installed with highly torqued slip critical bolts instead of bearing bolts. Also, we have some connections to the existing building where we have slotted connections for expansion where we definitely do not want TC bolts (because of the unintended restraint that could be provided). 

Any thoughts or comments would be appreciated.

Jim K.


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