I was convinced the repair was made using a premixed concrete patching compound. These are commodity items found at any home center or hardware store. They come in small buckets. The label says ...

“Concrete patching compound can repair minor cracks and chips in concrete," Barnard says, "while epoxy crack fillers can be used for slightly larger cracks for a stronger, more durable repair ...

Fill any cracks with a concrete sealant, which you'll apply like caulk, or a concrete patching compound. Then, you'll have to ...