Cut HC Plank

[dik]

On an earlier project a contractor cot a 12" HC Plank in half. The HC Plank is supported and the remaining two parts have about 4x the reinforcing needed and are over reinforced.

Is it necessary to core drill to cut the added strands at 4' centres is so?

I'm trying to reach out to the precaster.

I can't get away for a bit.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[jhnblgr]

Could you provide a few sketches?
What is sounds like is the cut the plank in 1/2 thus the reason it is considered over reinforced for the span. Just trying to understand the concern driving the need to cut the reinforcement.

 

[JAE]

If you cut a HC plank down in span you run the risk of the eccentric tendons, and their resulting flexural bending, causing the plank to explode upward since the span and dead weight don't naturally resist the upward prestress forces.

A core drill will only cut the tendons at discreet spots - there will still be tension in the tendons between the cores (with reduced development of course) but the distance may preclude overall prestressing effects - kind of a weird scenario to core like that so I would have to think through the implications.