ASTM C20-00(2010)

    Historical Standard: Стандартные методы испытания для определения кажущейся пористости, влагопоглощения, кажущейся плотности и объемной плотности обожженного огнеупорного кирпича и фасонных изделий посредством кипящей воды

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    Significance and Use

    Apparent porosity, water absorption, apparent specific gravity, and bulk density are primary properties of burned refractory brick and shapes. These properties are widely used in the evaluation and comparison of product quality and as part of the criteria for selection and use of refractory products in a variety of industrial applications. These test methods are used for determining any or all of these properties.

    These test methods are primary standard methods which are suitable for use in quality control, research and development, establishing criteria for and evaluating compliance with specifications, and providing data for design purposes.

    Fundamental assumptions inherent in these test methods are that the test specimens are not attacked by water, the test specimens conform to the requirements for size, configuration, and original faces, the open pores of the test specimens are fully impregnated with water during the boiling treatment, and the blotting of the saturated test specimens is performed as specified in a consistent and uniform manner to avoid withdrawing water from the pores. Deviation from any of these assumptions adversely affects the test results.

    In laboratory studies involving castable specimen, a bias was noted between formed 2 by 2 by 2in. (50 by 50 by 50mm) and specimens that were quartered from larger 9 by 4.5 by 2.5 (228 by 114 by 64 mm) cast specimens. Additionally, an error in the apparent porosity determination on castables was found whenever the specimens were heated to 1500°F (816°C) and then exposed to water as a saturation media (Test Method C830). The error was attributed to reactivity of cement with water and subsequent re-hydration of cement phases. The higher the cement level of the castable, the greater the error noted. It was concluded that an error in porosity values could occur for refractory materials having a potential to form hydrated species with water.

    Certain precautions must be exercised in interpreting and using results from these test methods. All four property values are interrelated by at least two of the three base data values generated during testing. Thus, an error in any base data value will cause an error in at least three of the property values for a given test specimen. Certain of the properties, that is, apparent specific gravity and bulk density, are functions of other factors such as product composition, compositional variability within the same product, impervious porosity, and total porosity. Generalizations on or comparisons of property values should only be judiciously made between like products tested by these test methods or with full recognition of potentially inherent differences between the products being compared or the test method used.

    1. Область применения

    1.1 Настоящий метод испытаний охватывает методики определения следующих свойств обожженного огнеупорного кирпича:

    1.1.1 Кажущейся пористости,

    1.1.2 Влагопоглощения,

    1.1.3 Кажущейся плотности и

    1.1.4 Объемной плотности.

    1.2 Настоящие методы испытания не применимы к огнеупорам, не подвергавшимся ранее воздействию воды.

    1.3 Значения, указанные в системе дюйм-фунт, должны рассматриваться в качестве стандартных. Значения, приведенные в скобках, представляются исключительно в информационных целях.

    1.4 Настоящий стандарт не ставит целью описание всех проблем безопасности, если они имеются, связанных с его использованием. В обязанности пользователя настоящего стандарта входит определение надлежащих методов техники безопасности и охраны труда, а также определение применимости нормативных ограничений перед его использованием.

    2. Ссылочные документы

    C134 Test Methods for Size, Dimensional Measurements, and Bulk Density of Refractory Brick and Insulating Firebrick

    C830 Test Methods for Apparent Porosity, Liquid Absorption, Apparent Specific Gravity, and Bulk Density of Refractory Shapes by Vacuum Pressure

    E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method