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ASTM C1777-20
Standard Test Method for Rapid Determination of the Methylene Blue Value for Fine Aggregate or Mineral Filler Using a Colorimeter
Přeložit název
NORMA vydána dne 1.6.2020
Informace o normě:
Označení normy: ASTM C1777-20
Datum vydání normy: 1.6.2020
Kód zboží: NS-997824
Počet stran: 4
Přibližná hmotnost: 12 g (0.03 liber)
Země: Americká technická norma
Kategorie: Technické normy ASTM
Kategorie - podobné normy:
Anotace textu normy ASTM C1777-20 :
Keywords:
clay, fine aggregate, limestone filler, methylene blue, mineral filler,, ICS Number Code 91.100.15 (Mineral materials and products)
Doplňující informace
| Significance and Use | ||||||||
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5.1 This test method is used to determine rapidly the amount of methylene blue adsorbed by a specimen of fine aggregate or mineral filler. The result is reported as a methylene blue value in units of mg of methylene blue adsorbed per g of fine aggregate or mineral filler. The methylene blue value is a function of the amount and characteristics of clay minerals present in the test specimen. High methylene blue values indicate increased potential for diminished fine aggregate or mineral filler performance in a cementitious mixture due to the presence of clays. Note 1: Results from this test method are not expected to be
correlated with those obtained using AASHTO T 330 or EN 933-9.
These three test methods are likely to give very different
numerical values even though the units are the same. The AASHTO T
330 test is performed only on the fraction of an aggregate passing
the 75 μm sieve, the EN 933-9 test is performed only on the
fraction finer than 2 mm, and this test is performed on the
fraction finer than the 4.75 mm sieve. Therefore, when testing the
same fine aggregate source, the AASHTO test method would give the
highest methylene blue value because any clay present in the
specimen would be concentrated in the fraction finer than the 75 μm
sieve. The AASHTO and EN test methods do not take into account the
amount of material passing the 75 μm sieve or 2 mm sieve,
respectively. For example, a fine aggregate with high methylene
blue value measured by the AASHTO method but low percentage passing
the 75 μm sieve may have less effect on concrete performance than a
fine aggregate with low methylene blue value measured by the AASHTO
method but a high percentage passing the 75 μm sieve. In contrast,
this test method expresses methylene blue value based on the entire
fine aggregate or mineral filler specimen. Additionally, the AASHTO
and EN test methods use titration to determine the amount of
methylene blue of known concentration that is adsorbed by a
specimen and require the operator to visually determine the end
point of the test. In contrast, this test method uses a colorimeter
to detect the change in concentration of methylene blue solution
before and after being mixed with the fine aggregate or mineral
filler specimen.
Note 2: Recommendations for maximum methylene blue values for
specific applications are not provided in this test method. Maximum
methylene blue values should be established based on successful
performance of fine aggregate or mineral filler in the applications
under consideration.
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| 1. Scope | ||||||||
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1.1 This test method provides a rapid test to determine the amount of methylene blue adsorbed by a specimen of fine aggregate or mineral filler and can be used both in the laboratory and in the field. 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 The text of this standard refers to 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. 1.4 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. 1.5 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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