Before the Slab Pour: ABC Aggregate

Before we can pour a slab, we have to have “ABC” aggregate material to fill most of the cavity formed by the stem walls. The slab will sit or float on the materials. I asked someone why it is called “ABC” aggregate and the letters merely refer to three different sizes of material (rock/gravel). So, you basically just fill up the space with aggregate and allow it to settle and then pour the slab. Below are some photos of the aggegate in place.