Significance and Use
One of the factors affecting the performance provided by a cementitious treatment is how readily water vapor passes through it. Hence, the water vapor transmission characteristics of treatments are important in assessing their performance in practical use.
The purpose of this test method is to obtain values of water vapor transfer through treatments that range in permeability from high to low. These values are for use in design, manufacture, and marketing.
Water vapor transmission is not a linear function of film thickness, temperature or relative humidity.
Values of water vapor transmission rate (WVT) and water vapor permeance (WVP) can be used in the relative rating of treatments only if the treatments are tested under the same closely controlled conditions of temperature and relative humidity.
1. Scope
1.1 This test method covers the determination of the rate at which water vapor passes through non film forming treatments, such as silanes, siloxanes and blends of silanes/siloxanes applied to cementitious substrates.
1.2 This test method covers the use of the wet cup technique, which most closely approaches the exterior conditions for use for these materials. Other conditions can be used if agreed upon between purchaser and supplier. Agreement should not be expected between results obtained by different methods or test conditions.
1.3 The values stated in SI units of measurement are designated as the standard. Factors for conversion to inch-pound units are given in 9.2.1.1 and 9.2.2.1.
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.
ASTM Standards
D823 Practices for Producing Films of Uniform Thickness of Paint, Varnish, and Related Products on Test Panels
D1193 Specification for Reagent Water
D1734 Practice for Making Cementitious Panels for Testing Coatings
D3924 Specification for Environment for Conditioning and Testing Paint, Varnish, Lacquer, and Related Materials
E104 Practice for Maintaining Constant Relative Humidity by Means of Aqueous Solutions
Keywords
permeability; permeance; perms; water vapor permeance; water vapor transmission;
ICS Code
ICS Number Code 87.040 (Paints and varnishes)
DOI: 10.1520/D6490-99R06
ASTM International is a member of CrossRef.
Citing ASTM Standards
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