After the concrete floor was poured we could frame the interior loadbearing partitions and the 2nd floor framing. I am now able to get a feel for my floor plan as the inside takes shape. We used a wood i-joist product for a stronger, sturdier floor, as well as being able to design a 4'-0" cantilever to support the loft stairs. 

I was extremely impressed and happy with my choice of concrete contractor on this job. The finish was very shiny and smooth. Due to the heavy machinery that will be parked inside, we decided after recommendations from the contractor to go with 6-7" of concrete through-out. The concrete contractor came back after the floor cured and saw cut to control cracking due to shrinkage. 
On a completely unrelated topic, I was completely fascinated by the light in this early morning photo. ​

Rough-in plumbing and electrical are placed in the ground below the concrete floor.
Our HVAC contractors laid 2" of rigid foam and plastic tubing for the radiant floor heat. We will be installing an indoor wood boiler. Our hope is to primarily heat the building with wood but we are required to have a back-up propane forced air furnace, which we will also use for air-conditioning.
We installed 6 x 6 wire mesh on top, and are now ready for the concrete floor.