Cast-in-place concrete

"Cast-in-place concrete" means making a sidewalk (or floor, or building) right where it will stay, without moving it.

It starts with a hole dug into the ground. A wooden box called a "form" is put into the hole to make the shape of the sidewalk.

Then, big trucks bring concrete that's been mixed up with water and sand and rocks. The concrete is poured into the form and smoothed out.

After a day or two, the concrete hardens and becomes really strong, like a rock. The form is taken off, and the brand new sidewalk is ready to use!