Active Standard ASTM C135 | Developed by Subcommittee: C08.03
Book of Standards Volume: 15.01
Historical (view previous versions of standard)
Significance and Use
The true specific gravity of a material is the ratio of its true density, determined at a specific temperature, to the true density of water, determined at a specific temperature. Thus, the true specific gravity of a material is a primary property which is related to chemical and mineralogical composition.
For refractory raw materials and products the true specific gravity is a useful value for: classification, detecting differences in chemical composition between supposedly like samples, indicating mineralogical phases or phase changes, calculating total porosity when the bulk density is known, and for any other test method which requires this value for the calculation of results.
This test method is a primary standard method which is suitable for use in specifications, quality control, and research and development. It can also serve as a referee test method in purchasing contracts or agreements.
Fundamental assumptions inherent in this test method are the following:
The sample is representative of the material in general,
The total sample has been reduced to the particle size specified,
No impurity has been introduced during processing of the sample,
The sample itself is not magnetic and all magnetic material introduced during processing of the sample has been removed,
The material is not hydratable or reactive with water, and
The test method has been conducted in a meticulous manner.
Deviation from any of these assumptions negates the usefulness of the results.
In interpreting the results of this test method it must be recognized that the specified sample particle size does not guarantee that all closed pores have been eliminated. The amount of residual closed pores may vary between materials or even between samples of the same or like materials, and the specified sample particle size is not the same as that specified for Test Method C 604
1.1 This test method covers the determination of true specific gravity of refractory materials under prescribed conditions. It is not applicable to materials attacked by water.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.2.1 Exception—The equipment used in this standard for weights and volumes is only available in SI units.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
C604 Test Method for True Specific Gravity of Refractory Materials by Gas-Comparison Pycnometer
D153 Test Methods for Specific Gravity of Pigments
E11 Specification for Woven Wire Test Sieve Cloth and Test Sieves
ICS Number Code 81.080 (Refractories)