I agree with Charles, check the container for directions. In general,
I think the concrete should be clean and dry. An acid wash with
muriatic acid is sometimes suggested followed by washing it down with
water and letting it dry completely, but be careful with this as it
(acid) can be dangerous if used improperly.

If you want more information, just google search for "latex bondage"!

.....eep! no! I was just kidding about the search phrase!!!