For over forty years, asbestos has been used in cementitious mortar formulations to improve workability and water retention. Asbestos fibers have the ability to absorb more moisture and to hold it longer than any other known natural or synthetic fillers. In addition to asbestos' ability to retain moisture, asbestos fibers also provide great plasticity and workability for cementitious mortars. Specifically, these properties allowed mortars to be easily moved through mechanical pumps and further to easily achieve a variety of finishes after application.
However, because of the dangers caused when asbestos fibers are inhaled, governing agencies in the United States and other countries have banned asbestos for many usages. The asbestos ban has left a void to be filled by a product to replace asbestos in use in cementitious mortars.