Looks great! Need more details and pictures! What is you main application? Automotive, woodworking, etc. Looks like you have some upper level space as well, man cave?
Here are some photos of a recent underlayment install over the radiant heat tubing on the second floor. Why? 12 block to support the weight of the ceiling/ second floor 120,000 lbs. The walls were constructed with vertical reinforcement every four feet. Rebar attached in the footing all the way up and out the walls. We were able to tie the ceiling directly into the footings. There are two bond beams one showin in a photo. One on top of the windows and the top course which ties the ceiling in with rebar and grout. The reason for the concrete plank is 32' toal freespan with no supports and full use of the second floor. No Labor. Four hours installed the ceiling and stairs. The pre stressed concrete plank is only 7.5 inches tall which meshes in with a course of block. No finishing or paint usless you choose to do so. Strength. The safest place in South jersey is in that stairwell under that steel I beam. I had the stairs made with intergral plates. The beam was welded to rebar in the wall and the stairs are welded to the beam. The garage plan originally was to have a basement in it. The same concrete plank could easily support a truck shop. But the budget was getting out of control so I nixed the basement. Needed 14" poured walls to support the upstairs.
Wow, that's some awesome above ground 'air-raid shelter'; talk about bomb proof! How the heck do you insulate all that block surface? I've heard that a "A man's home is his castle", all that's missing on yours is a moat and a drawbridge. lol
It must have gone WAY over budget because you're stuck buying that cheap, generic T.P.!