ASTM C673-97(2003)

1.1 This classification covers fireclay and high-alumina plastic refractories and ramming mixes that can be pounded or rammed into place to form a monolithic structure. The terms "plastic" and" ramming mix" are generally intended to describe the workability of the material. In this regard, plastics are considered to be materials having a workability index of more than 15 % in accordance with Test Method C 181, while ramming mixes generally have less than 15 % workability by the same procedure.