ASTM C948-81(2001)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:C948–81 (Reapproved 2001)
Standard Test Method for
Dry and Wet Bulk Density, Water Absorption, and Apparent
Porosity of Thin Sections of Glass-Fiber Reinforced
Concrete
This standard is issued under the fixed designation C 948; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 Container, suitable for immersing the specimen and
suitable wire for suspending the specimen in water.
1.1 This test method covers the determinations of dry and
wet bulk density, water absorption, and apparent porosity of
4. Sampling
thin sections of glass-fiber reinforced concrete.
4.1 Sampling method shall be in accordance with govern-
NOTE 1—This test method does not involve a determination of absolute
ing specifications.
specific gravity. Therefore, such pore space as may be present in the
specimen that is not emptied during the specified drying or is not filled
5. Test Specimen
with water during the specified immersion is considered “impermeable”
5.1 Whenever possible, the sample shall consist of indi-
and is not differentiated from the solid portion of the specimen for the
vidual portions of glass-fiber reinforced concrete, each to be
calculations, especially those for percent voids.
Depending upon the pore size distribution and the pore entry radii of the tested separately. The individual portions may be pieces of any
specimen and on the purposes for which the test results are desired, the
desired shape or size, except that the volume of each portion
procedures of this method may be adequate, or they may be insufficiently
shallbenotlessthan25cm (or50gnominalmassglass-fiber
rigorous. In the event that it is desired to fill more of the pores than will
reinforced concrete, approximately 1.7 oz, and shall not be
be filled by immersion, various techniques involving the use of vacuum
greater than 650 cm or 1300 g nominal glass-fiber reinforced
treatment or increased pressure may be used. If a rigorous measure of total
concrete, approximately 46 oz); and each portion shall be free
pore space is desired, this can only be obtained by determining absolute
of observable cracks, fissures, or shattered edges.
specific gravity by first reducing the sample to discrete particles, each of
which is sufficiently small so that no impermeable space can exist within
6. Procedure
any of the particles.
6.1 ImmersedMassandSaturatedSurface—DryMassAfter
1.2 This standard does not purport to address all of the
Immersion:
safety concerns, if any, associated with its use. It is the
6.1.1 Immerse the specimen in water at approximately 21°C
responsibility of the user of this standard to establish appro-
(70°F) for not less than 24 h and until two successive
priate safety and health practices and determine the applica-
determinations of mass of the surface-dried specimens at
bility of regulatory limitations prior to use.
intervals of 2 h show an increase in mass of less than 0.5 % of
2. Significance and Use
the heavier mass. Determine the mass of the specimen sus-
pended in water to the nearest 0.01 g (0.00034 oz). Designate
2.1 Material properties determined by this test method are
this mass as A.
useful for quality control of glass-fiber reinforced concrete,
ascertaining compliance with governing specifications, and
NOTE 2—Take care during this operation to ensure that air bubbles do
research and development.
not adhere to the surface of the specimen.
6.1.2 Remove the specimen from t
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