ASTM C1815-17 (R2021) pdf free download.Standard Practice for Periodically Measuring and Monitoring Sealant Dimensions to Stability Following a Period of Compression or Tension.
1.1 This practice covers a procedure for measuring and monitoring the physical dimensions of an elastomeric joint sealant in a test specimen configuration described in Test Method C719 following a period of compression or tension. These sealant materials are typically highly filled elastic materials. The dimensional change of these sealant materials is determined by measuring the dimensions at specific intervals over a period ot’ time.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.
3. Terminology
3. 1 Definitions:
3.1.1 For definitions of terms used in this practice. refer to Terminologies E631 and C717.
4. Summary of Practice
4.1 This practice consists of monitoring the dimensional change of a sealant for a period of time required to establish dimensional stability.
4.2 The motivation for this practice is to monitor the dimensions of a sealant at any time, hut especially after a period of extended tension or compression to establish the stable dimensions of that sealant. The latter is used in applicat ion of a standard, such as Test Method C 1735, by using the accurate dimensions determined by this practice after dimensional stability is attained.
4.3 This practice will enable determination of the stable dimensions of a sealant. It will also allow the reporting of the time scale over which the sealant dimensions are changing.
5. Significance and Use
5.1 Many sealants have been observed to dimensionally change following a period of compression or tension, such as occurs during exposure in accordance with Practice C 1589. It has been shown that for some sealants, increasing exposure to weathering increases the time required for dimensional stability and decreases the magnitude of dimensional change. Dimensional stability and knowledge of the stable sealant dimensions are critical to the accurate measurement of the sealant’s modulus by a test such as Test Method C 1735.
5.2 This practice will find application in improving the accuracy of the modulus determined by a standard such as Test Method C1735 by using the accurate dimensions determined by this practice after stability is attained.
6. Apparatus
6. 1 Dimensional Measuring Tool—A micrometer, such as digital calipers, capable of measuring the dimensions of aluminum substrate and sealant to an accuracy of at least ±0.05 mm (±0.002 in.), is required. An accurate measurement of the geometry is critical.ASTM C1815 pdf download.