1. Scope
1.1 This test method describes procedures for microscopical determinations of the air content of hardened concrete and of the specific surface, void frequency, spacing factor, and paste-air ratio of the air-void system in hardened concrete (1). Two procedures are described:
1.1.1 Procedure A, the linear-traverse method (2,3 ).
1.1.2 Procedure B, the modified point-count method (3,4 5,6, ).
1.2 This test method is based on prescribed procedures that are applied to sawed and lapped sections of specimens of concrete from the field or laboratory.
1.3 It is intended to outline the principles of this test method and to establish standards for its adequate performance but not to describe in detail all the possible variations that might be used to accomplish the objectives of this test method.
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.
This standard does not purport to address all of the safety concerns 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. For specific hazard statements see 8.3 and 10.1.
2. Referenced Documents
C138/C138M Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
C173/C173M Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method
C231 Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
C42/C42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
C823 Practice for Examination and Sampling of Hardened Concrete in Constructions
C856 Practice for Petrographic Examination of Hardened Concrete
D92 Test Method for Flash and Fire Points by Cleveland Open Cup Tester
201.2R Guide to Durable Concrete
211.1 Recommended Practice for Selecting Proportions for Normal, Heavyweight, and Mass Concrete
Index Terms
air content; air void parameters of hardened concrete; area-prepared surface required; average chord-length of voids; determination of air-void parameters; entrained void; entrapped void; grits for lapping hardened concrete; index point; lapping; length of traverse required; linear-traverse method; microscopical; number of points required; paste-air ratio; paste-air ratio modification; paste content; point-count method (modified); sample preparation for microscopical analysis; spacing factor; specific surface; void frequency; water void
Citing ASTM Standards
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