ASTM C473-00

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: C 473 – 00
Standard Test Methods for
Physical Testing of Gypsum Panel Products
This standard is issued under the fixed designation C 473; 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 * with Terminology C 11.
3.2 Definitions of Terms Specific to This Standard:
1.1 These test methods cover the physical testing of gypsum
3.2.1 edge, n—the paper-bound edge, or long edge, as
panel products.
manufactured.
1.2 The test methods appear in the following order:
3.2.2 ends, n—the end perpendicular to the paper-bound
Section
edge or long edge.
Flexural Strength (Method A) 7
Core, End and Edge Hardness (Method A) 8
Nail Pull Resistance (Method A) 9
4. Sampling
Flexural Strength (Method B) 11
4.1 For use in these test methods, a sample shall consist of
Core, End and Edge Hardness (Method B) 12
Nail Pull Resistance (Method B) 13
not less than 0.25 % of the number of gypsum panel products
Humidified Deflection 14
in a shipment, but not less than three gypsum panel products.
End Squareness 15
Test specimens shall be taken from the sample lot as indicated
Nominal Thickness 16
Recessed- or Tapered Edge Depth 17
in each method.
Width 18
Length 19
5. Conditioning
Water Resistance of Core-Treated Water-Repellent
Gypsum Panel Products 20
5.1 Condition specimens to constant weight at a temperature
Surface Water Resistance of Gypsum Panel Products
of 85 6 15°F (29.5 6 8.5°C) and relative humidity of 50 6
with Water-Repellent Surfaces 21
2 % (Note 1). Test specimens individually after constant
1.3 The text of these test methods references notes and
weight is reached and within 10 min upon removal from the
footnotes that provide explanatory material. These notes and
conditioning chamber.
footnotes, excluding those in tables and figures, shall not be
NOTE 1—Laboratory test results indicated that conditioning tempera-
considered as requirements of these test methods.
tures may range from 70 to 100°F (21 to 38°C) without significantly
1.4 This standard does not purport to address all of the
affecting the results. However, relative humidity is critical. This is the
safety concerns, if any, associated with its use. It is the
reason for testing specimens within 10 min upon removal from the
responsibility of the user of this standard to establish appro-
conditioning chamber.
priate safety and health practices and determine the applica-
Method A—Constant Rate of Loading
bility of regulatory limitations prior to use.
INTRODUCTION
2. Referenced Documents
The following procedures are applicable to so-called “shot
2.1 ASTM Standards:
machines” that utilize lead or steel shot that applies a load to
C 11 Terminology Relating to Gypsum and Related Build-
the specimen at a constant stress rate or any other device that
ing Materials and Systems
applies the load at a constant stress rate.
D 3285 Test Method for Water Absorptiveness of Nonbibu-
lous Paper and Paperboard (Cobb Test)
6. Apparatus—Method A
E 4 Practices for Force Verification of Testing Machines
6.1 Testing Machine—Apply the test load at a uniform rate
3. Terminology
of 1 lbf/s (4.45 N/s) 610 %. Apply the load with a device
independent of manual control of the rate of loading during an
3.1 Definitions used in these test methods are in accordance
individual sample test (see Fig. 1). The deformation of the
1 specimen controls the cross head speed.
These test methods are under the jurisdiction of ASTM Committee C-11 on
Gypsum and Related Building Materials and Systems and are the direct responsi-
7. Flexural Strength (Method A)
bility of Subcommittee C11.01 on Specifications and Test Methods for Gypsum
Products.
7.1 Summary of Test Method—Flexural properties of gyp-
Current edition approved Jan. 10, 2000. Published March 2000. Originally
e1
sum panel products are evaluated by supporting the specimen
published as C 473 – 61. Last previous edition C 473 – 99 .
Annual Book of ASTM Standards, Vol 04.01.
near the ends and applying a transverse load midway between
Annual Book of ASTM Standards, Vol 15.09.
the supports.
Annual Book of ASTM Standards, Vol 03.01.
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C 473
edge, test one specimen from each gypsum panel product face
up and the other face down. For specimens with the long
dimension perpendicular to the edge, test one specimen from
each gypsum panel product face up and the other face down.
7.6.3 For gypsum panel products with surfacing material,
the load is determined at the time of transverse failure of the
surfacing material and core through the thickness of the
specimen. The specimens shall not show a break in the bond
between the surfacing and the core before transverse failure of
the gypsum panel product. If a single specimen fails, test two
FIG. 1 Apparatus Schematic for Core, End, and Edge Hardness
additional specimens from the same sample, and, if either one
Test
of the two specimen fail, the sample has failed. For gypsum
7.2 Significance and Use—This test method covers a pro-
panel products without surfacing material, the load is deter-
cedure for evaluating the ability of gypsum panel products to
mined at the time of transverse failure through the thickness of
withstand flexural stresses during handling or use of the
the specimen.
material. This test method is used to determine compliance
7.7 Report—Calculate and report the average breaking load
with gypsum panel product specifications. The degree of
in pound-force or newtons for each test condition, rounded to
correlation between this test and service performance has not
the nearest 1 lbf (N). The test conditions are: (1) parallel, face
been fully determined.
up; (2) parallel, face down; (3) perpendicular, face up; and, (4)
7.3 Apparatus—See Section 6.1.
perpendicular, face down.
7.3.1 Specimen Supports—All specimen bearing supports
7.8 Precision and Bias—The precision and bias for this test
and load surfaces shall be true, shall engage the full width of
method has not been determined.
the test specimen, shall be of such strength they will not
8. Core, End, and Edge Hardness (Method A)
deform under the test load, and shall be rounded to a radius of
0.125 in. (3.2 mm). The specimen supports shall be spaced 14 8.1 Summary of Test Method—The core, end, and edge
6 0.016 in. (356 6 0.41 mm) on centers measured at the points hardness of gypsum panel products is evaluated by determining
of surface contact with the specimen. The supports shall be the force required to push a steel punch into the area of test.
attached to a plate that shall be rigidly attached to the test 8.2 Significance and Use—This test method covers a pro-
apparatus. The supports shall be parallel to each other and cedure for evaluating the ability of the gypsum panel product
perpendicular to the long dimension of the test specimen. The core, ends, and edges to resist crushing during handling or use
bearing surface of the end supports shall be on the same plane of the material. This test method is used to determine compli-
to ensure contact along the entire bearing surfaces. Supports
ance with gypsum panel product specifications. The degree of
shall be not less than 12 in. (305 mm) in length. When a load correlation between these test methods and service perfor-
is being applied, the loading bar shall be in contact with the full mance has not been determined.
width of the specimen. The load-bearing surface shall be 8.3 Apparatus—See 6.1. Clamp or secure the specimen to
parallel to the bearing surface of the specimen supports. The the base of the test apparatus shown in Fig. 1 with the face of
specimen and supports shall be located so that the vertical axis the specimen perpendicular to the base of the test apparatus and
through the center of the load-bearing surface passes through parallel to the movement of the steel punch. Secure the steel
the specimen at one half of the specimen width and one half of punch to the moving head of the test apparatus, positioned so
the distance between the supports. that its center axis is parallel eith the line of travel and so that
7.4 Sampling—Sampling shall be in accordance with Sec- the punch is inserted into the core equidistant from the surfaces
tion 4. of the specimen. Use a steel punch 0.099 6 0.003 in. (2.515 6
7.5 Test Specimens: 0.076 mm) in diameter and more than ⁄2 in. (12.7 mm) long
7.5.1 Cut four specimens, each 12 in. (305 mm) by approxi- with the bearing surface machined to a 90° angle in reference
mately 16 in. (406 mm) from each gypsum panel product in the to the punch center line (see Fig. 1 for test setup schematic).
sample, two having the 16-in. dimension parallel to the edge 8.4 Sampling—Sampling shall be in accordance with Sec-
and two having the 16-in. dimension perpendicular to the edge. tion 4.
Cut the specimens not less than 4 in. (102 mm) away from the 8.5 Test Specimens:
ends and edges of the gypsum panel product except where the 8.5.1 Specimens for Core Hardness—Using a table or band
product is 24-in. or less in width, where it is impossible to do saw, cut one specimen from the center of each of the three
so.
gypsum panel product samples approximately 12 by not less
7.5.2 Condition specimens in accordance with Section 5. than 3 in. (305 by 76 mm), with the 12-in. dimension
7.6 Procedure: perpendicular to the edges of the products, for a total of not less
7.6.1 Use the apparatus in 7.3, supporting each specimen than three specimens. The smaller, not less than 3 in., dimen-
centrally on the fixed parallel bearings, 14-in. (356 mm) on sion will vary depending on the specific punch length and
centers, and apply the load on a similar bearing midway opening in the testing machines. Place the sample in the tester,
between the supports. Position perforated gypsum lath so the with the loading arm in a horizontal position and with the
load is not applied over perforations. punch resting on the specimen. Saw cuts along the 12-in.
7.6.2 For specimens with the long dimension parallel to the dimension shall be smooth and square with the smaller (not
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
C 473
less than 3-in.) dimension, as well as with the specimen. force a standard nail head through the product. This test
8.5.2 Specimens for End Hardness—Cut specimens the method is used to determine compliance with gypsum panel
same size and method as described in 8.5.1 from one mill-cut product specifications. The degree of correlation between these
end of the gypsum panel product, with the 12-in. (305-mm) test methods and service performance has not been determined.
dimension perpendicular to the edges, for a total of not less 9.3 Apparatus—See 6.1. This apparatus shall be used with
than three specimens, and run tests only on the mill-cut end of either of the specimen support plates in 9.3.1 or 9.3.2.
the specimens. 9.3.1 Fig. 2 shows a schematic of a nail pull resistance
8.5.3 Specimens for Edge Hardness—Cut specimens the apparatus adaptable to a typical flexural strength apparatus
same size and method as described in 8.5.1 from the opposite commonly used in the gypsum industry. The specimen support
edges of each gypsum panel product, with the 12 in. (305 mm) plate shall have a 3-in. (76-mm) diameter hole in the center.
dimension of the specimens parallel with the edges, for a total The support plate shall be not less than 6 by 6 in. (152 by 152
of not less than six specimens. For gypsum panel products with mm). It shall be attached to the apparatus as necessary to
1 1
surfacing material, cut a ⁄4 to ⁄2-in. (6 to 13-mm) strip of maintain the surface of the plate perpendicular to the travel of
surfacing material from the edge of the test specimens expos- the test nail. The support plate must also be located so that the
ing the core for test. Remove as little of the core as possible vertical axis through the center of the nail shank passes through
when removing the surfacing material. Prepare the first test the center of the hole in the support plate. The test nail shank
area 2 6 ⁄2 in. (51 6 13 mm) from one edge of the specimen, shall be 0.099 6 0.003 in. (2.515 6 0.076 mm) in diameter and
with the next two test areas approximately 4 in. (102 mm) the nail head shall be 0.2506 0.005 in. (6.350 6 0.127 mm) in
apart. diameter. The nail shall be attached at the head to the movable
8.5.4 Condition specimens in accordance with Section 5. cross head of the test apparatus. This attachment shall not
8.6 Procedure—Using the apparatus in 8.3, clamp or secure exceed the diameter of the nail head and shall be placed
the specimen in a fixed vertical position on its 12 in. (305 mm) directly over the head. It shall also be attached so that the
dimension edge (see Fig. 1 for test setup schematic. If vertical axis through the nail shank is parallel with the travel.
necessary, modify the flexural strength test equipment to 9.3.2 Fig. 3 shows a schematic of an alternate nail pull
conduct the core, end, and edge hardness test). Place this test resistance apparatus adaptable to a typical flexural strength
surface not less than 1 in. (25 mm) above the grip of the apparatus commonly used in the gypsum industry. This appa-
specimen holder. Conduct three tests spaced approximately 4 ratus mirrors all of the requirements of 9.3.1, except that the
in. (102 mm) apart on each specimen, with the first test area 2 nail is not attached at the head to the movable cross head of the
6 ⁄2 in. (51 6 13 mm) from one edge of the specimen. test apparatus. The alternate apparatus utilizes a machined
Position the steel punch over the test area and apply the load. plunger with the nail head and shank incorporated as an
Report as the core, end, or edge hardness the load required to integral part of the plunger. The plunger fits into a bushing that
push the steel punch a distance of ⁄2 in. (13 mm) into the core keeps the nail aligned perpendicular to the test specimen.
of the specimen. 9.4 Sampling—Sampling shall be in accordance with Sec-
8.6.1 Procedure for Core Hardness—Test either of the tion 4.
12-in. (305-mm) saw cut edges, for a total of not less than nine 9.5 Test Specimen
...