ASTM C1922-23 PDF

SIGNIFICANCE AND USE 5.1 This test method provides a means for determining the ability of mortars and plasters to retain water when applied to specific substrates based on the intended use of the tested mortar. 5.2 The results obtained using this test method may be used to compare the relative ability of mortars and plasters to retain water when applied to different substrates or in comparison to other mortars or plasters applied to the same substrate. 5.2.1 If applied to the same substrate, water retention values of different mortar can be compared. 5.2.2 One mortar may be applied to different substrates to understand the impact of varying substrates on water retention of the mortar. 5.3 The results obtained using this test method do not necessarily indicate the degree of water retention when used with substrates found in the field. This is because the amount of water absorbed by the substrate depends not only on the ability of the mortar to retain water but also on the particular absorption of the substrate and environmental conditions. Environmental conditions are not taken into account in this test method. 5.4 The results obtained using this test method for plasters (stucco) do not necessarily indicate the degree of water retention when the plaster is applied as a second coat on the surface of a previously applied plaster base coat, since the amount of water absorbed from the second coat of plaster depends on the rate of absorption of the base coat. This is also true when a plaster is applied as a coating on masonry units. SCOPE 1.1 This test method provides for the determination of water retention of hydraulic cement based mortars and plasters. Water Retention is directly measured through the absorption of water from the mortar by the substrate. Various substrates may be chosen by the user based on the intended use of the tested mortar. This test method defines such substrates. Comparisons can be made between different mortars on the same substrate or the same mortar on different substrates. 1.2 This test method provides a water retention value via direct water loss, while Test Method C1506 provides a water retention value via mortar flow. 1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. When combined standards are cited, the selection of the measurement systems is at the user’s discretion subject to the requirements of the referenced standard. 1.4 The text of this test method references notes and footnotes that provide explanatory material. These notes and footnotes, excluding those in tables and figures, shall not be considered as requirements of this standard. 1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See the Safety Data Sheet for safety information regarding the materials being tested. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.