"Expansion joint" gone from concrete drive

I don't know all the right words for this, but here goes:

Mother-in-law's concrete driveway is relatively new, and the black "filler" that goes between the different sections is gone for whatever reason. The gap is about a half inch wide, and she's concerned ice will break the driveway next winter.

What's the right way to handle this? Can I get more of that black filler, or is there some kind of caulk or filler goo?

Thanks

 

You can get some more expansion joint and put it back in, but it could be difficult. You'd have to make sure that EVERYTHING was cleaned out of the joint so the new stuff would fit in. To make it easier, forget about the black fiber expansion and look for some foam expansion joint. It comes on a roll and is 4 inches tall, 1/2 inch thick, and 50 feet long. You could stuff it into the joint much more easily. You will find it at a concrete contractor's supply place, some ready-mix concrete plants, or if you have a Menard's close by, they carry it too. It doesn't rot out quickly like the fiber stuff does.
Another option is to buy a roll of foam backer rod, stuff it into the joints until they are full to about 1/2 inch from the top, then caulk over it. This will keep water out and keep the backer rod in place. good luck.

Pecos

 

The one joint I looked at was very clean. If we go the foam and caulk route, what kind of caulk goes in there?