ASTM C198-91(1996)e1

e1
Designation: C 198 – 91 (Reapproved 1996)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Cold Bonding Strength of Refractory Mortar
This standard is issued under the fixed designation C 198; 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.
e NOTE—Keywords were added editorially in September 1996.
1. Scope tions known or intended to be compatible for a particular use
should be tested.
1.1 This test method covers the determination of the bond-
3.3 Properties of the brick, including its strength, apparent
ing strength of air-setting refractory mortar by determining the
porosity, and pore size distribution, can affect the measurement
flexural strength (modulus of rupture) at room temperature of
of both the bonding strength of the brick-mortar composite and
oven-dried brick-mortar joints.
the intrinsic strength of the mortar. The average modulus of
1.2 The values stated in inch-pound units are to be regarded
rupture of the test brick, as determined by Test Method C 133,
as the standard. The values stated in SI units are for informa-
should exceed that expected for the mortar being tested. The
tion only.
testing of specific brands or lots of brick and mortar is
1.3 This standard does not purport to address all of the
preferred.
safety concerns, if any, associated with its use. It is the
3.4 Three modes of failure are available: the break may
responsibility of the user of this standard to establish appro-
occur within the brick itself, at the brick-mortar interface, or
priate safety and health practices and determine the applica-
within the mortar itself. The latter provides a practical mea-
bility of regulatory limitations prior to use.
surement of the strength of the mortar itself and is the
2. Referenced Documents
predominant mode of failure with the four-point flexure test
2.1 ASTM Standards:
described. The three-point flexure test measures the failure
C 78 Test Method for Flexural Strength of Concrete (Using strength of the brick-mortar composite. Failure within the brick
Simple Beam With Third-Point Loading)
itself suggests that either the particular brick contained a
C 133 Test Methods for Cold Crushing Strength and Modu- serious flaw, or that the mortar joint strength is of the same
lus of Rupture of Refractories
magnitude or greater than that of the refractory brick. The
C 651 Test Method for Flexural Strength of Manufactured mode of failure should always be reported in the final report.
Carbon and Graphite Articles Using Four-Point Loading at
3.5 A ruggedness test for this test method performed in
Room Temperature
1985 found the following variables to be rugged: specimen size
E 4 Practices for Force Verification of Testing Machines
(2.5 to 3.0 in.), mortared surface (cut versus uncut), joint
1 1
thickness ( ⁄16to ⁄8 in.), pulling of rods (fast versus slow), the
3. Significance and Use
loading rate (500 to 1000 lbf/min), the method of load
3.1 The data developed by this test method show the
application (3- versus 4-point), and the operator.
bonding strength and intrinsic strength of different qualities of
3.6 The cold bonding strengths of refractory mortars ob-
air-setting mortar. The procedures described in this test method
tained by this test method are suitable for use in research and
measure the bonding strength and intrinsic strength of air-
development, quality control, and for establishing and evalu-
setting mortars when used with specific brands or lots of
ating compliance with specifications between producers and
refractory brick.
consumers.
3.2 Note that it is possible to obtain results with these
methods for brick and mortar combinations which are incom-
4. Apparatus
patible for use at high operating temperatures. The user must
1 1
4.1 Brick—At least five 9 by 4 ⁄4 by 2 ⁄2-in. (230 by 114 by
determine this compatibility. Only brick and mortar combina-
65-mm) straight brick having plane surfaces and true rectan-
gular shape and an average modulus of rupture higher than that
expected from the mortar under test, when determined in
This test method is under the jurisdiction of ASTM Committee C-8 on
Refractories and is the direct responsibility of Subcommittee C08.09 on Monolithic
accordance with Test Methods C 133, compose a sample.
Refractories.
4.2 Spacing Rods—Two joint-thickness spacing rods made
Current edition approved Jan. 25, 1991. Published August 1991. Originally
published as C 198 – 45 T. Last previous edition C 198 – 83.
Annual Book of ASTM Standards, Vol 04.02.
3 5
Annual Book of ASTM Standards, Vol 15.01. Supporting data on ruggedness testing is available from ASTM. Request
Annual Book of ASTM Standards, Vol 03.01. RR:C-8-1008.
C 198
of ⁄16-in. (2-mm) diameter drill rod cut into 4-in. (102-mm) such as a 50 or 100-lb (23 or 45-kg) bag from which a 10-lb
lengths. (4.5 kg) sample may be obtained using acceptable sampling
4.3 Oven—A drying oven to accommodate at least five 9-in.
procedures. The 10-lb (4.5 kg) sample should be thoroughly
(230-mm) straight brick standing on end, and for use at 220 to mixed with water to a uniform, troweling consistency and
230°F (105 to 110°C).
stored in a covered container (resistant to possible corrosive
4.4 Testing Machine—A standard mechanical or hydraulic
action by the mortar) for at least 16 h prior to the test.
compression testing machine conforming to the requirements
NOTE 1—Reaction of phosphoric acid or aluminum phosphate with
of Practices E 4 and having a sensitivity of 20 lbf or less in the
metallics may cause the development of hydrogen gas in some mortars.
range from 0 to 4000 lbf (17.8 kN) may be used.
Therefore, the container should be covered only to minimize moisture
4.5 Loading Fixture—The fixtures shall provide load bear-
loss, not tightly sealed.
ing blocks which ensure that the forces are applied normal to
the beam without eccentricity. The directions of loads and
6. Procedure
reactions may be maintained parallel by judicious use of
6.1 Cut each of the bricks of the sample (see Note 2) into
linkages, roller bearings, and flexure plates. Eccentricity of
1 1
two equal parts on a plane parallel to the 2 ⁄2 by 4 ⁄4-in. (65 by
loading can be avoided by the use of spheri
...