Concrete recommendation?

[Red Arrow]

OSU Civil Engineering, BS Construction Management & 7-yrs. with an interior concrete company concreterevolution.com

Relevant credentials are not allowed on this forum.   

[MyDogHunts]

Not sure on who's side this goes, but control-joints control for cracking, which again, usually will occur; expansion-joints control for expansion & contraction... such as buckling.  Control joints are only partially cut and so really don't help with buckling.

And the big suprise:  steel needs to be placed in the right portion of the concrete or it adds nothing (bottom side of a beam serving as tension).

[MyDogHunts]

One of my friends had a hangar built on a post-stressed slab but it still got some cracks.  To be honest, the cracks may have developed before the cables were tensioned.  I don't remember.  What is the supposed advantage of post-stressed vs. rebar?  It seems like anchoring a cable at each end of the slab would invite buckling.

Positioning the cable correctly is important.  A cable in the center of the slab height adds little to nothing to the flex-strength of a slab. Post-tensioning adds a tremendous amout of tension (check-out the bow-ness of post-tensioned beams) & with the added tension you can add more compression in the upper portion of the beams concrete which means it will support more load.

One of the coolest classes was Mechanics where mathmatical solutions can be drawn graphically.  Simple things like a²+b²=c² seem truthier when viewed graphically.