ASTM C457/C457M-12
Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete

Standard No.

ASTM C457/C457M-12

Release Date

2012

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM C457/C457M-16

Latest

ASTM C457/C457M-23a

Scope

5. Significance and UseTop Bottom

5.1 The parameters of the air-void system of hardened concrete determined by the procedures described in this test method are related to the susceptibility of the cement paste portion of the concrete to damage by freezing and thawing. Hence, this test method can be used to develop data to estimate the likelihood of damage due to cyclic freezing and thawing or to explain why it has occurred. The test method can also be used as an adjunct to the development of products or procedures intended to enhance the resistance of concrete to cyclic freezing and thawing (1).

5.2 Values for parameters of the air-void system can be obtained by either of the procedures described in this test method.

5.3 No provision is made for distinguishing among entrapped air voids, entrained air voids, and water voids. Any such distinction is arbitrary, because the various types of voids intergrade in size, shape, and other characteristics. Reports that do make such a distinction typically define entrapped air voids as being larger than 1 mm in at least one dimension being irregular in shape, or both. The honey-combing that is a consequence of the failure to compact the concrete properly is one type of entrapped air void (9, 10).

5.4 Water voids are cavities that were filled with water at the time of setting of the concrete. They are significant only in mixtures that contained excessive mixing water or in which pronounced bleeding and settlement occurred. They are most common beneath horizontal reinforcing bars, pieces of coarse aggregate and as channelways along their sides. They occur also immediately below surfaces that were compacted by finishing operations before the completion of bleeding.

5.5 Application of the paste-air ratio procedure is necessary when the concrete includes large nominal maximum size aggregate, such as 50 mm [2 in.] or more. Prepared sections of such concrete should include a maximum of the mortar fraction, so as to increase the number of counts on air voids or traverse across them. The ratio of the volume of aggregate to the volume of paste in the original mix must be accurately known or estimated to permit the calculation of the air-void systems parameters from the microscopically determined paste-air ratio.

Note 1???The air-void content determined in accordance with this test method usually agrees closely with the value determined on the fresh concrete in accordance with Test Methods C138/C138M, C173/C173M, or C231 (

ASTM C457/C457M-12 Referenced Document

• ASTM C125 Standard Terminology Relating to Concrete and Concrete Aggregates
• ASTM C138/C138M Standard Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
• ASTM C173/C173M Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method
• ASTM C231 Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
• ASTM C42/C42M Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
• ASTM C666/C666M Standard Test Method for Resistance of Concrete to Rapid Freezing and Thawing*， 2024-04-20 Update
• ASTM C670 Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
• ASTM C672/C672M Standard Test Method for Scaling Resistance of Concrete Surfaces Exposed to Deicing Chemicals
• ASTM C823 Standard Practice for Examination and Sampling of Hardened Concrete in Constructions
• ASTM C856 Standard Practice for Petrographic Examination of Hardened Concrete
• ASTM D92 Standard Test Method for Flash and Fire Points by Cleveland Open Cup

ASTM C457/C457M-12 history

• 2024 ASTM C457/C457M-23a Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2023 ASTM C457/C457M-23 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2016 ASTM C457/C457M-16 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2012 ASTM C457/C457M-12 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2011 ASTM C457/C457M-11 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2010 ASTM C457/C457M-10a Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2010 ASTM C457/C457M-10 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2009 ASTM C457-09 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2008 ASTM C457-08d Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2008 ASTM C457-08c Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2008 ASTM C457-08b Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2008 ASTM C457-08a Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2008 ASTM C457-08 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 2006 ASTM C457-06 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete
• 1998 ASTM C457-98 Standard Test Method for Microscopical Determination of Parameters of the Air-Void System in Hardened Concrete