Construction Joints for post tensioned continous beams

[istruct1980]

Where Can I see references regarding construction joints for post tensioned reinforced concrete beams?

As stated in ACI, its description excludes prestressed concrete:

Thank you!

 

[KootK]

Where Can I see references regarding construction joints for post tensioned reinforced concrete beams?

I know of no such references. But I'll be thrilled if someone else manages to post some.

I suspect that prestressed concrete is excluded from that clause simply because prestressed concrete adds enough complexity to the situation that it's probably best left to the EOR to establish -- or at least review -- the joint locations.

A couple of those complexities:

a) Any prestressing strand crossing the joint is likely to be draped. The EOR may have preferences as to what the angle of the tendons are as they cross the joint.

b) The prestressing crossing the joint may be intermediately stressed at the joint. This can create a situation where balancing loads kind of create a temporary, upwards cantilever.

It's not the case that the joints can't or shouldn't be placed in the middle third I feel. It's just that the situation is potentially too complex for the usually rule of thumb to be a slam dunk.