Why do sidewalks have blocks, instead of being solid?

Question

Why do sidewalks have blocks, instead of being solid?

In: 205

Answer 1

Ground shifts, freezing water has a place to expand, pouring concrete in smaller sections is easier than doing long continuous sections, and you can replace a block without having to redo a huge section or patching and trying to get it to match.

Also, keeping large amounts of concrete from hardening is a hell of a lot more work than mixing it in a bucket or wheelbarrow when you need it.