The steel cages of rebar are being assembled in the lower and mid grade beam forms.  This steel will be tied into the tops of the caissons and will reinforce the concrete which will form the grade beam structure.  Just a little steel so far.....

Underneath the steel cages are cardboard void forms.  Yes they are cardboard and the cement for the grade beams will be poured right over it.  The forms have a honeycomb structure inside to hold up the concrete while the concrete sets.  The idea for the void forms is that the cardboard deteriorates leaving a void between the grade beam and the ground so if and when the ground shifts, it doesn’t cause the grade beam to crack or buckle.