• Make sure that the cracked area is clean of grease, oil, or any other substances. After, rise with water and let it dry. This will allow the caulk to set and bond properly when applied.
• Clear the crack of any loose fragments. Use steel brush or flat head screwdriver to clear out the crack and any loose pieces.
• You can use a regular concrete caulking, or more commonly used Sika Flex, found at your local hardware store with a caulking gun. Depending on the size of the crack, to reduce using a large amount of filler you can use Backer Rod Foam to fill a good portion of the crack before using the caulking. Backer Rod can be found at your local hardware store as well.
  Make sure when filling the crack that you try to get to the very bottom of the crack. In some cases, it is recommended to come back to the crack a few minutes later to see if that caulking has settled and if it is needed to add more. Once filled, using a sponge or towel, smooth the surface of the crack to obtain a flat surface.
• Allow the filler to set overnight or what is recommended per product details. Each product will vary. Once dry if additional repairs are needed repeat this process until filled.