ASTM C472-99(2014)

Standard Test Methods for Physical Testing of Gypsum, Gypsum Plasters and Gypsum Concrete

ABSTRACT
These test methods cover the physical testing of gypsum, gypsum plasters, and gypsum concrete. Test methods are detailed for the following: precautions for physical tests, reagents and materials, free water, fineness, normal consistency of gypsum plaster and gypsum concrete, setting time, setting time (temperature rise method), compressive strength, and density. Materials include distilled or deionized water and standard sand. For each test method, the following are specified: significance and use, apparatus, and procedure.
SCOPE
1.1 These test methods cover the physical testing of gypsum, gypsum plasters, and gypsum concrete.  
1.2 The test methods appear in the following sections:    
Sections  
Precautions for Physical Tests  
4  
Reagents and Materials  
5  
Free Water  
6  
Fineness  
7  
Normal Consistency of Gypsum Plaster  
8  
Normal Consistency of Gypsum Concrete  
9  
Setting Time  
10  
Setting Time (Temperature Rise Method)  
11  
Compressive Strength  
12  
Density  
13
1.3 The values regarded as the standard are either in inch-pound units or SI (metric). The values stated first shall be regarded as the standard. Values following in parentheses are approximate and are provided for information purposes only.  
1.4 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) are not requirements of the standard.  
1.5 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 and health practices and determine the applicability of regulatory limitations prior to use.For a specific precautionary statement, see X1.2.1.

General Information

• Status: Historical
• Publication Date: 31-Mar-2014
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: C11 - Gypsum and Related Building Materials and Systems
• Drafting Committee: C11.01 - Specifications and Test Methods for Gypsum Products

Relations

• Replaces: ASTM C472-99(2009) - Standard Test Methods for Physical Testing of Gypsum, Gypsum Plasters and Gypsum Concrete
• Effective Date: 01-Apr-2014
• Replaced By: ASTM C472-20 - Standard Test Methods for Physical Testing of Gypsum, Gypsum Plasters, and Gypsum Concrete
• Effective Date: 01-Apr-2020
• Referred By: ASTM E3355-23 - Standard Guide for Characterization of Coal Combustion Products (CCPs) in Storage Area(s) for Beneficial Use
• Effective Date: 01-Apr-2014
• Referred By: ASTM C59/C59M-00(2020) - Standard Specification for Gypsum Casting Plaster and Gypsum Molding Plaster
• Effective Date: 01-Apr-2014
• Referred By: ASTM C22/C22M-00(2021) - Standard Specification for Gypsum
• Effective Date: 01-Apr-2014
• Referred By: ASTM F2678-16(2021) - Standard Practice for Preparing Panel Underlayments, Thick Poured Gypsum Concrete Underlayments, Thick Poured Lightweight Cellular Concrete Underlayments, and Concrete Subfloors with Underlayment Patching Compounds to Receive Resilient Flooring
• Effective Date: 01-Apr-2014
• Referred By: ASTM C631-09(2020) - Standard Specification for Bonding Compounds for Interior Gypsum Plastering
• Effective Date: 01-Apr-2014
• Referred By: ASTM F710-22 - Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring
• Effective Date: 01-Apr-2014
• Referred By: ASTM C11-23 - Standard Terminology Relating to Gypsum and Related Building Materials and Systems
• Effective Date: 01-Apr-2014
• Referred By: ASTM C474-15(2020) - Standard Test Methods for Joint Treatment Materials for Gypsum Board Construction
• Effective Date: 01-Apr-2014
• Referred By: ASTM C110-20 - Standard Test Methods for Physical Testing of Quicklime, Hydrated Lime, and Limestone
• Effective Date: 01-Apr-2014
• Referred By: ASTM C617/C617M-15 - Standard Practice for Capping Cylindrical Concrete Specimens
• Effective Date: 01-Apr-2014
• Referred By: ASTM F2224-09(2020) - Standard Specification for High Purity Calcium Sulfate Hemihydrate or Dihydrate for Surgical Implants
• Effective Date: 01-Apr-2014
• Referred By: ASTM F2419-11(2021) - Standard Practice for Installation of Thick Poured Gypsum Concrete Underlayments and Preparation of the Surface to Receive Resilient Flooring
• Effective Date: 01-Apr-2014
• Referred By: ASTM C28/C28M-10(2020) - Standard Specification for Gypsum Plasters
• Effective Date: 01-Apr-2014

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:C472 −99 (Reapproved 2014)
Standard Test Methods for
Physical Testing of Gypsum, Gypsum Plasters and Gypsum
Concrete
This standard is issued under the fixed designation C472; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
1.1 These test methods cover the physical testing of 2.1 ASTM Standards:
gypsum, gypsum plasters, and gypsum concrete. C11 Terminology Relating to Gypsum and Related Building
Materials and Systems
1.2 The test methods appear in the following sections:
C778 Specification for Standard Sand
Sections
E11 Specification for Woven Wire Test Sieve Cloth and Test
Precautions for Physical Tests 4 Sieves
Reagents and Materials 5
Free Water 6
3. Terminology
Fineness 7
Normal Consistency of Gypsum Plaster 8
3.1 Definitions:
Normal Consistency of Gypsum Concrete 9
3.1.1 For useful definitions refer to Terminology C11.
Setting Time 10
Setting Time (Temperature Rise Method) 11
4. Precautions for Physical Tests
Compressive Strength 12
Density 13
4.1 Gypsum products are greatly affected by small amounts
1.3 The values regarded as the standard are either in
of impurities introduced by careless laboratory manipulation.
inch-pound units or SI (metric). The values stated first shall be
In order to obtain accurate results, it is absolutely essential to
regarded as the standard. Values following in parentheses are
observe the following precautions:
approximate and are provided for information purposes only.
4.1.1 Keep all apparatus thoroughly clean. Remove all
traces of set plaster.
1.4 The text of this standard references notes and footnotes
which provide explanatory material. These notes and footnotes
NOTE 1—For mixing pastes and mortars, a 500-ml rubber dental bowl
(excluding those in tables and figures) are not requirements of
is a convenience.
NOTE 2—Use care when drying gypsum, gypsum plasters, or gypsum
the standard.
concrete. Exceeding the specified drying temperatures may calcine the
1.5 This standard does not purport to address all of the
specimens, which will cause inaccurate test results.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 5. Reagents and Materials
priate safety and health practices and determine the applica-
5.1 Distilled or Deionized Water—free of chlorides and
bility of regulatory limitations prior to use. For a specific
sulfates at a temperature of 21 6 1°C (70 6 2°F).
precautionary statement, see X1.2.1.
5.2 Standard Sand— Specification C778, 20–30 sand.
1.6 This international standard was developed in accor-
dance with internationally recognized principles on standard-
6. Free Water
ization established in the Decision on Principles for the
6.1 Significance and Use—This test method determines the
Development of International Standards, Guides and Recom-
free water contained in gypsum, gypsum plasters, and gypsum
mendations issued by the World Trade Organization Technical
concrete samples, and prepares the sample for subsequent
Barriers to Trade (TBT) Committee.
testing.
These test methods are under the jurisdiction of ASTM Committee C11 on 6.2 Apparatus:
Gypsum and Related Building Materials and Systems and are the direct responsi-
bility of Subcommittee C11.01 on Specifications and Test Methods for Gypsum
Products. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2014. Published April 2014. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1961. Last previous edition approved in 2009 as C472 – 99 (2009). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/C0472-99R14. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C472−99 (2014)
sheet of paper on the table and tap it sharply against the table. Then
6.2.1 Balance, capable of weighing not less than 500 g at
transfer all the retained material back into the sieve and continue sieving.
a precision of 0.1 g.
6.2.2 Drying Oven, set at 45 6 3°C. 7.4 Report—Report the percent by weight retained on each
6.2.3 Desiccator, containing calcium chloride or equiva- sieve or passing particular sieves in accordance with the
lent desiccant. material specification to the nearest full percentage point.
6.3 Procedure: 7.5 Precision and Bias—The precision and bias of the
6.3.1 Weigh a sample of not less than 500 g of the material fineness test method have not been determined.
as received to the nearest 0.1 g and spread it to a thin layer in
8. Normal Consistency of Gypsum Plaster
a suitable-vessel. Place in an oven (6.2.2) and dry for 2 h; then
cool in a desiccator (6.2.3) and weigh again.
8.1 Significance and Use—This test method is used to
6.3.2 Retain the dried sample in an airtight container until
determine the volume of water required for mixing gypsum
used for the fineness test (Section 7).
plaster when performing the setting time and compressive
strength tests.
6.4 Report—Report the loss in weight as a percentage of the
original weight of the sample as received to a precision of
8.2 Apparatus:
0.1%.
8.2.1 Modified Vicat Apparatus—The modified Vicat appa-
ratus (Fig. 1) shall consist of a bracket, A, bearing a movable
6.5 Precision and Bias—The precision and bias of the free
brassrod,B,6.3mmindiameterandofsuitablelengthtofitthe
water test method have not been determined.
Vicat Bracket. A conical plunger made of aluminum with an
7. Fineness apex angle of 53° 08 min and a height of 45 mm shall be
attachedtothelowerendoftherod.Thetotalweightoftherod
7.1 Significance and Use—This test method covers a proce-
andplungershallbe35g.Ameansshallbeprovidedforadding
dure for determining the fineness of gypsum and gypsum
plasters and is used to determine compliance with gypsum and
gypsum plaster specifications. The degree of correlation be-
This method is described by Kuntze, R. A., “An Improved Method for the
tween the results of this test method and service performance
Normal Consistency of Gypsum Plasters,” ASTM Bulletin No. 246, ASTM, May
has not been determined.
1960, p. 35.
7.2 Apparatus:
7.2.1 Sieves, as required by a particular gypsum or gypsum
plaster specification, in accordance with Specification E11.
7.2.2 Balance, capable of weighing not less than 1000 g at
a precision of 0.1 g.
7.2.3 Mechanical Sieving Machine
7.3 Procedure:
7.3.1 Determine fineness by sieving a known weight of the
dried sample through sieves of the specified sizes (Note 3 and
Note 4). The size of the sample to be used in determining
fineness depends upon the particle size of the material. If the
material will pass a 6.3-mm ( ⁄4-in.) sieve, a 100-g sample will
besufficient;ifthelargestparticlesaremorethan25mm(1in.)
in diameter, use not less than a 1000-g sample. With these
limitations the size of sample to be used is left to the discretion
of the operator. Shake the sample through each sieve with as
little abrasion as possible (Note 5). Weigh the amount of
material retained on each sieve and calculate the fineness,
expressed as a percentage of the weight of the original sample.
7.3.2 If a mechanical sieving machine is used, make a series
of tests at one minute intervals, with each type of material and
sieve size combination to be used. When not more than 0.5 g
passes each sieve in a one minute interval, use that time as the
standard sieving time for that test procedure on that machine.
NOTE 3—For suggested method of sieving gypsum through a 45-µm
(No. 325) sieve, see Appendix X1.
NOTE 4—The sizes of the sieves to be used are given in the specifica-
tions of ASTM covering the particular product in question.
A—Hinged support bracket D—Graduation mark
NOTE 5—When sieving by hand through a 150-µm (No. 100) sieve, use
B—Plunger support rod E—Lock screw
a lateral motion, and tap the side of the sieve with the palm of the hand.
C—Conical plunger F—Modified scale
Continuewithoutbrushinguntilnotmorethan0.5gpassesthroughduring
G—Weight
1 min of sieving. If the sieve openings become clogged, transfer the
retained material temporarily to another vessel, invert the sieve over a FIG. 1 Modified Vicat Apparatus (Conical Plunger Method)
C472−99 (2014)
a weight, G, to the rod, increasing the total weight to 50 g. The 9.2 Apparatus:
rod shall be capable of being held in any position by a screw, 9.2.1 Consistometer (Fig. 2)—The consistometer consists of
E. The rod shall have a mark, D, midway between the ends a conical vessel made of noncorroding, nonabsorbent material,
which moves under a scale, F, graduated in millimetres, and having an inside diameter of 9 in. (229 mm) at the top and
3 1
attached to the bracket, A. 1 ⁄4 in. (44.5 mm) at the bottom, and a height of 5 ⁄2 in. (139.7
8.2.2 Mold—The conical ring mold shall be made of a mm). It shall be provided with a sliding gate at the bottom and
noncorroding, nonabsorbent material, and shall have an inside supported so that the bottom is 4 in. (102 mm) above the base
diameter of 60 mm at the base and 70 mm at the top and a plate. The base plate shall be of plate glass, free of scratches
height of 40 mm. and about 18 in. (457 mm) square.
8.2.3 Base Plate—The base plate for supporting the ring 9.2.2 Balance, capable of weighing not less than 2000 g at
a precision of 1 g.
mold shall be of plate glass and about 100 mm square.
8.2.4 Balance, capable of weighing not less than 500 g at a
9.3 Procedure:
precision of 0.1 g.
9.3.1 Cleananddrytheconsistometerandthebaseplateand
8.2.5 Graduated Cylinder, shall be made to deliver the
close the sliding gate.
indicated volume at 20°C (68°F) and shall be subdivided to not
9.3.2 Sift 2000 g of the sample into a known volume of
less than 1 mL.
water (see 5.1) to which 1.0 g of sodium citrate has previously
been added. After allowing the sample to soak for 1 min, stir
8.3 Procedure:
the mixture for 3 min to an even fluidity. Pour the mixture into
8.3.1 Clean the plunger, mold, and base plate of the modi-
the consistometer until level with the top. Then rapidly and
fied Vicat apparatus. Apply a thin coat of petroleum jelly or
completely open the sliding gate, allowing the mixture to run
other suitable lubricant to the upper surface of the base plate in
out onto the base plate. When the sliding gate is opened, take
order to prevent leaks during the test.
care to avoid jarring the consistometer.
8.3.2 Sift a weighed quantity of the sample (200 to 300 g as
9.3.3 Measure the resulting patty along its major and minor
required to fill the mold) into a known volume of water (See
axes and determine the average diameter.
5.1). If the plaster is unretarded, add to the mixing water 0.2 g
9.3.4 Test gypsum concrete with different amounts of water
of sodium citrate per 100 g of sample. After allowing the
until a patty diameter of 380 6 13 mm (15 6 ⁄2 in.) is
sample to soak for 2 min, stir the mixture for 1 min to an even
obtained.
fluidity. Pour this sample into the ring mold, work slightly to
remove air bubbles, and then strike off flush with the top of the
9.4 Report—Report the normal consistency as the number
mold. Wet the plunger of the modified Vicat apparatus and
of millilitres of water to the nearest whole millilitre required to
lowerittothesurfaceofthesampleatapproximatelythecenter
be added to 100 g of the gypsum concrete.
of the mold. Read the scale and release the plunger immedi-
9.5 Precision and Bias—The precision and bias of the test
ately.After the rod has settled, read the scale again. Make three
method for normal consistency of gypsum concrete have not
determinations on each mix, care being taken to have the mold
been determined.
completely filled and the plunger clean and wet.
8.3.3 Test gypsum molding plaster and gypsum gauging
10. Setting Time
plasterwithdifferentamountsofwateruntilapenetrationof30
10.1 Significance and Use—This test method is used to
6 2 mm is obtained. Use the rod and plunger for this
determine the setting time of gypsum plaster and gypsum
determination weighing 35 g.
concrete, and is used to determine compliance with gypsum
8.3.4 Test all gypsum mixtures containing aggregates with
plaster and gypsum concrete specifications. Since variable job
different amounts of water until a penetration of 20 62mmis
conditions influence the setting time, the degree of correlation
obtained. Add weight to the rod and plunger to bring the total
between this test method and service performance has not been
weight to 50 g for these determinations.
determined.
8.3.5 Mix gypsum neat plaster with standard sand (see 5.2)
10.1.1 This test method does not determine the time of
in the ratio of 200 g of sand to 100 g of plaster before testing
complete hydration of gypsum plaster or gypsum concrete. To
for normal consistency.
determine the time of complete hydration see Setting Time,
8.4 Report: Report the normal consistency as the average
(Temperature Rise Method,) Section 11.
number of millilitres of water required to be added to 100 g of
10.2 Apparatus:
the dry mixture to the nearest whole millilitre.
10.2.1 Vicat Apparatus—The Vicat apparatus (Fig. 3) shall
8.5 Precision and Bias—The precision and bias of the test
consist of a frame, A, bearing a movable rod, B, weighing 300
method for normal consistency of gypsum plaster have not
g, one end, C, the plunger end, being 10 mm in diameter for a
been determined.
distance of not less than 50 mm, the other end having a
removable needle, D, 1 mm in diameter and 50 mm in length.
9. Normal Consistency of Gypsum Concrete
The rod, B, shall be reversible, shall be able to be held in any
9.1 Significance and Use—This test method is used to position by a screw, E, and shall have an adjustable indicator,
determine the volume of water required for mixing gypsum F, that moves over a scale (graduated in millimetres) attached
concrete when performing the setting time and compressive to the frame, A. The paste shall be held in a rigid conical ring,
strength tests. G, resting on a glass plate, H, about 100 mm square. The ring
C472−99 (2014)
FIG. 2 Consistometer
shall be made of a noncorroding, nonabsorbent material and 10.3 Procedure:
shall have an inside diameter of 70 mm at the base and 60 mm
10.3.1 Gypsum Concrete and All Gypsum Plasters, Except
at the top, and a height of 40 mm.
Gypsum Neat Plast
...