Its the tropics. They usually free in sections and then powder dust the top. They skip the mesh and rebar because high rain levels and soak into the slab and rust the metal in no time. Occasionally they use it if they need to preform a harden shape, but they will usually use that as a base to free pour around and then they will remove the rebar and metal.
It was pretty wierd the first time i saw it as well.
GMC Price at posting:
1.5¢ Sentiment: Hold Disclosure: Held