The first layer of the concrete subfloor of the makerspace is getting poured today. The black goo at the left edge of the photo is sand-impregnated epoxy that acts as a moisture barrier and gives the concrete something rough to adhere to. The white sheets are fiberglass mesh that will increase fracture toughness, i.e. it will allow the floor to flex more before it cracks.
The floor for the whole space will require around 32,000 lbs of fiberglass-impregnated cement, plus around 1600 gallons of water that will evaporate over the next few weeks. About half of this will get pumped in through the window today; the second half will get pumped in Friday.
Next week, framing begins!
Below, the concrete mixer and what should be ~800 bags of concrete.