Subbase

Have you ever played with building blocks? The ones that you put on top of each other to make a tower or a house? Well, imagine you want to build a road or a parking lot. You can't just put the pavement on top of the dirt - that's too squishy! The pavement needs a strong foundation to sit on, just like a building block tower needs a strong base to sit on.

The "subbase" is what we call the foundation that goes underneath the pavement. It's like a layer of big, strong building blocks that are put down before the pavement is installed. These building blocks are made of bigger pieces of rocks and gravel than the ones used for the pavement itself. They are put down in layers and sometimes even compacted (squished down tight) to make sure they are really strong and won't move.

So, just like your building block tower needs a strong base to stay up, a road or parking lot needs a strong subbase to stay flat and not break apart. Without a good subbase, the pavement could sink, crack, or even become dangerous to drive or walk on!