I would reject the ever living shiz out of that slab, post tensioned or not.

Post tensioning is not supposed to be a method that takes chunks of concrete and holds them together. You still need proper subgrade prep (which you decidedly do not have here) and proper placement and curing (again, which you do not have here). Post tensioning sucks in general IMO, but I can guarantee you with 100% accuracy that the design parameters are not to squeeze cracks together but rather to provide compression on properly placed concrete to prevent structural failure.

Even of your concrete reaches design fc (doubtful given the failure here), you will still have settlement issues due to the failure and crappy subgrade prep and placement that led to it.

Any engineer or builder that tells you cracks that transverse the thickness of the slab and grade beam are of no concern and will be held together by the cables are full of crap.

Any updates from the OP?

Have the eyes of a LOCAL structural engineer (find one licensed at state engineering board website) come visit and tell you what to do. This is not layman opinion fare. It takes years of education then practice/training then local conditions nuances all come into play. Pay for one hour = $120-170, take notes.

Who's this builder?

Even TAMU will all its power/money gave up on post-tensioned for our area, last visited doing pavement for the East Gate circle drive, replaced by conventional rebar practice.

The typical suspect for local foundation cracks is water being in the wrong place, giving too much support/rise or being absent due to drought, giving no support. Think kitchen sink sponge that can expand 1-6"ht with over 2 tons/SF force.

https://engineers.texas.gov/search.php

More free advice @ tgivaughn@juno.com .. for a limited time ...

I am a semi-retired builder with 20k+ houses in my past. You need to hire an engineer. Your slab appears to have more than a hairline crack.

I'm a builder, that's one of the larger cracks I've seen. Definitely get an engineer to see it. If I was the builder, I would be concerned and probably call my own engineer out to cya.

Sorry, if I missed it, but what city is the home in?

DO NOT ACCEPT THIS!!!!!!!!

Water,ants, termites, mold, you name it can and will come thru that crack... That slab is post tension which means it will hold the slab together but that rebar will bend like hot butter!!!!!!!!

No freaking way!!! Redo it and make them add piers are get your money back and move on!!!!!!!!!!!!!!!!

I have first hand experience with this, take my advice!!!!

Would love to hear what the outcome of this situation.

We have a situation going on with a slab poured in early August, house was dried in, sheetrock delivered and install began in late sept. As of now (sept 29), cables have not been tensioned. Crack developed in the last week or so (so after slab had been poured 6+ weeks). City put a stop work order on the house. Builder's engineer is going to have to write a letter to appease the city. I have engineers on standby to do an eval from me, but I'm not sure if we should do it pre-tension or post tension.

Link to photos: https://photos.app.goo.gl/YBaxkjUgewhqtPTA9

I would not allow a framing contractor client of mine to frame on this slab without a complete release of liability from SOMEONE -- an engineer, the GC, whoever.