【国外标准】 Standard Test Method for Water Retention of Hydraulic Cement-Based Mortars and Plasters

4.1 This test method provides a means for determining the ability of mortars and plasters to retain water under suction. Test results may be used to determine compliance with specifications.4.2 The results obtained using this test method can be used to compare the relative ability of mortars and plasters to retain water under suction.4.3 The results obtained using this test method for masonry mortars do not necessarily indicate the degree of water retention when used with masonry units, since the amount of water absorbed by the unit depends on the rate of absorption of the masonry unit.4.4 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.1.1 This test method provides for the determination of water retention of hydraulic cement-based mortars and plasters.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. When this test method refers to combined-unit standards, the selection of the measurement systems is at the user’s discretion.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, health and environmental practices and determine the applicability of regulatory limitations prior to use. (Warning—Fresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure.)21.4 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.