What do I use to fill in the space between slabs in my concrete driveway?

The original felt (?) material is coming out, leaving about 1/2 inch space. Weeds are growing.

What can I do to brighten up a concrete driveway?

I was thinking of laying over a brand new thin layer of concrete maybe mixed with something to give some slight colour and texture? Is this possible or can’t you lay brand new cement over old? Any other options that wont involve pulling the drive up …

when you pour a driveway to a existing garage should you put rebar into the concrete floor or just use an?

expansion joint