How to repair cracking garage floor?

[stovepipe]

There is a section on the garage floor that has been cracking for well over 15 years. It has slowly spread over the years. Looking to help out a family member fix this but don't know the correct way to repair it. As seen in the pic there is plastic under the layer of concrete. Any help on how to repair this properly would be greatly appreciated.

 

[Shea]

If the crack has slowly been getting wider, all you can do is temporarily patch it up. It can't be properly repaired until the source of the problem that is causing the concrete to crack has been addressed. The repair is only going to break apart (just as the concrete has) due to the dissimilar movement in areas of the slab that has obviously been continuing through the years.

 

[stovepipe]

Thanks for the info. I thought there might be some kind of material or something like an epoxy that's flexible in hot n cold weather. Their house has slowly sinking in the past 20 years. I'm guessing thats the reason for the cracking.

 

[Armorpoxy]

Agree, unfortunately there is nothing to 'glue together' the slabs...