This practice is useful for producing uniform specimens of refractory plastics and ramming mixes for use in standard ASTM tests. Samples thus formed may be used for referee testing when setting specifications between producer and user. Forming parameters such as sample size, workability, and forming pressure should be agreed upon and specified in the report when referee testing.
This practice is applicable for preparing test specimens of various sizes. Note that 9 by 4½ by 2½ in. (228 by 114 by 64-mm) samples, because of their large cross-section, have a greater tendency to form flaws during pressing, handling, and drying than smaller cross-sectional samples.
Other tests for which these specimens may be used encompass, but are not limited to, the following ASTM standards: Method C 16, Test Methods C 20, Test Method C 113, Test Methods C 133, Test Method C 179, Test Method C 288, Test Method C 417, Test Method C 577, Test Method C 583, Test Method C 704, Test Methods C 830, Test Method C 832, Practice C 874, Test Method C 885, and Test Method C 914.
A purpose of this practice is to minimize flaws in pressed specimens. It is not intended to duplicate all field installation conditions.
Variations in workability as determined by Test Method C 181 can significantly affect the number of flaws contained in a specimen. For comparison testing between two laboratories, the workability level should be established by mutual agreement.
This practice is not intended for preparing specimens of basic ramming mixes, anhydrous tap-hole mixes, nor resin bonded mixes.