Improved casing strings, and methods of using improved casing strings in subterranean operations, are provided. An example of a method is a method of cementing a pipe string in a subterranean formation. Another example of a method is a method of cementing a pipe string in a well bore. An example of an apparatus is an improved pipe string comprising at least one pipe section; and a delivery system of an activator; wherein the delivery system of an activator is disposed adjacent an outer surface of the at least one pipe section.