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Standard Test Method for Determining the Apparent Chloride Diffusion Coefficient of Cementitious Mixtures by Bulk Diffusion
Přeložit název
NORMA vydána dne 1.10.2022
Označení normy: ASTM C1556-22
Datum vydání normy: 1.10.2022
Kód zboží: NS-1090559
Počet stran: 7
Přibližná hmotnost: 21 g (0.05 liber)
Země: Americká technická norma
Kategorie: Technické normy ASTM
Keywords:
chloride, concrete, corrosion, diffusion, ion transport, service life,, ICS Number Code 71.060.99 (Other inorganic chemicals)
Significance and Use | ||||||||||||||||
5.1?This test method is applicable to cementitious mixtures that have not been exposed to external chloride ions, other than the negligible quantity of chloride ion exposure from sample preparation using potable water, prior to the test. 5.2?The calculation procedure described in this test method is applicable only to laboratory test specimens exposed to a sodium chloride solution as described in this test method. This calculation procedure is not applicable to specimens exposed to chloride ions during cyclic wetting and drying. Note 1:?The diffusion of ionic species in concrete occurs
within the fluid-filled pores, cracks and void spaces. The
concentration and valence of other ionic species in the pore fluid
also influence the rate of chloride diffusion, and therefore, the
apparent diffusion coefficient as determined by this test
procedure.
5.3?In most cases, the value of the apparent chloride diffusion coefficient for cementitious mixtures changes over time (see Note 2). Therefore, apparent diffusion coefficients obtained at early ages may not be representative of performance in service. Note 2:?The rate of change of the apparent diffusion
coefficient for cementitious mixtures containing pozzolans or
blast-furnace slag is typically different than that for mixtures
containing only portland cement.
5.4?The apparent chloride diffusion coefficient is used in Fick's second law of diffusion to estimate chloride penetration into cementitious mixtures that are in a saturated condition. 5.5?The apparent chloride diffusion coefficient is commonly used in chloride ingress models based on Fick's second law of diffusion. The apparent diffusion coefficient determined by this method includes bound chloride, so proper use of the apparent chloride diffusion coefficient to predict chloride ingress requires consideration of chloride binding. 5.6?The resistance to chloride penetration is affected by such factors as the environment, finishing, mixture composition, workmanship, curing, and age. |
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1. Scope | ||||||||||||||||
1.1?This test method covers the laboratory determination of the apparent chloride diffusion coefficient for hardened cementitious mixtures. 1.2?The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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. 1.4?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. |
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2. Referenced Documents | ||||||||||||||||
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