ASTM C642-13 pdf free download.Standard Test Method for Density, Absorption, and Voids in Hardened Concrete.
1 . 1 This test method covers the determinations of denisty, percent absorption, and percent voids in hardened concrete.
1.2 The text of this test method references notes and footnotes which provide explanatory information. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of this standard.
1.3 The values stated in SI units are to be regarded as the Standard.
1 .4 This standard does not purport to a(ldress 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. Significance and Use
2.1 This test method is useful in developing the data required for conversions between mass and volume for concrete. It can be used to determine conformance with specifications for concrete and to show differences from place to place within a mass of concrete.
3. Apparatus
3.1 Balance, sensitive to 0.025 % of the mass of the specimen.
3.2 Container, suitable for immersing the specimen and suitable wire for suspending the specimen in water.
4. Test Specimen
4.1 Whenever possible. the sample shall consist of several individual portions of concrete, each to be tested separately. The individual portions may he pieces of cylinders, cores, or beams of any desired shape or size, except that the volume of each portion shall he not less than 350 cm3 (or for normal weight concrete, approximately 800 g); and each portion shall be free from observable cracks, fissures, or shattered edges.
5. Procedure
5.1 Oven-Drv Mass—Determine the mass of the portions, and dry in an oven at a temperature of 110 ± 5 °C for not less than 24 h. After removing each specimen from the oven, allow it to cool in dry air (preferably in a desiccator) to a temperature of 20 to 25 °C and determine the mass. If the specimen was comparatively dry when its mass was first determined, and the second mass closely agrees with the first, consider it dry. If the specimen was wet when its mass was first determined, place it in the oven for a second drying treatment of 24 h and again determine the mass. If the third value checks the second, consider the specimen dry. In case of any doubt, redry the specimen for 24-h periods until check values of mass are obtained. If the difference between values obtained from two successive values of mass exceeds 0.5 % of the lesser value, return the specimens to the oven for an additional 24-h drying period, and repeat the procedure until the difference between any two successive values is less than 0.5 % of the lowest value obtained. Designate this last value A.
5.2 Saturated Mass After Immersion—Immerse the specimen. after final drying, cooling, and determination of mass, in water at approximately 21 °C for not less than 48 h and until two successive values of mass of the surface-dried sample at intervals of 24 h show an increase in mass of less than 0.5 % of the larger value. Surface-dry the specimen by removing surface moisture with a towel, and determine the mass. Designate the final surface-dry mass after immersion B.
ASTM C642 pdf download.