Why do sidewalks have blocks, instead of being solid?

Question

Why do sidewalks have blocks, instead of being solid?

In: 205

Answer 1

Most of these ‘blocks’ are not separate blocks. What you’re seeing is a solid concrete sidewalk with grooves on the surface.

I believe these are to allow thermal expansion/contraction with the outside temperature. The temperature at the surface of the concrete can get much hotter than points deeper underneath. So it’s only the surface that needs these grooves. It doesn’t need to go all the way down to create separate ‘blocks’