ASTM C779/C779M-00
(Test Method)Standard Test Method for Abrasion Resistance of Horizontal Concrete Surfaces
Standard Test Method for Abrasion Resistance of Horizontal Concrete Surfaces
SCOPE
1.1 This test method covers three procedures for determining the relative abrasion resistance of horizontal concrete surfaces. The procedures differ in the type and degree of abrasive force they impart, and are intended for use in determining variations in surface properties of concrete affected by mixture proportions, finishing, and surface treatment. They are not intended to provide a quantitative measurement of the length of service that may be expected from a specific surface.
1.2 The values stated in SI units are to be regarded as the standard.
1.3 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. Note 1-Other procedures are available for measuring the abrasion resistance of concrete surfaces in addition to the three procedures contained in this test method. Consideration should be given to Test Methods C944 and C418. The test method most closely representing service conditions should be used.
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Designation:C779/C779M–00
Standard Test Method for
Abrasion Resistance of Horizontal Concrete Surfaces
This standard is issued under the fixed designation C 779/C 779M; 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 abrasion resistance of concrete, concrete materials, and curing
or finishing procedures. They may also be used for quality
1.1 This test method covers three procedures for determin-
acceptance of products and surface exposed to wear. They are
ing the relative abrasion resistance of horizontal concrete
notintendedtoprovideaquantitativemeasurementoflengthof
surfaces. The procedures differ in the type and degree of
service.
abrasive force they impart, and are intended for use in
3.2 The equipment used by each of these procedures is
determining variations in surface properties of concrete af-
portable and thus suitable for either laboratory or field testing.
fected by mixture proportions, finishing, and surface treatment.
The three procedures determine the relative wear of concrete
Theyarenotintendedtoprovideaquantitativemeasurementof
surfaces as follows:
the length of service that may be expected from a specific
3.2.1 Procedure A—The revolving-disk machine operates
surface.
by sliding and scuffing of steel disks in conjunction with
1.2 The values stated in SI units or inch-pound units are to
abrasive grit.
be regarded separately as standard. Within the text, the
3.2.2 Procedure B—The dressing-wheel machine operates
inch-pound units are shown in brackets. The values stated in
by impact and sliding friction of steel dressing wheels.
each system are not exact equivalents; therefore, each system
3.2.3 Procedure C—The ball-bearing machine operates by
shall be used independently of each other.
high-contact stresses, impact, and sliding friction from steel
1.3 This standard does not purport to address all of the
balls.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
NOTE 2—Diagrams of three machines meeting these specifications are
priate safety and health practices and determine the applica- shown in Fig. 1, Fig. 2, and Fig. 3.
bility of regulatory limitations prior to use.
PROCEDURE A—REVOLVING DISKS
NOTE 1—Other procedures are available for measuring the abrasion
resistance of concrete surfaces in addition to the three procedures
4. Apparatus
contained in this test method. Consideration should be given to Test
4.1 The function of the apparatus is dependent upon the
Methods C 944 and C 418. The test method most closely representing
abrasive action of the flat faces of three 60-mm (2 ⁄8-in.)
service conditions should be used.
diameter, cold-rolled steel revolving disks, each attached to
2. Referenced Documents
motor-driven vertical shafts which also revolve about a vertical
axis. The inside diameter of the resulting circular and abraded
2.1 ASTM Standards:
track shall be approximately 150 mm (6 in.) and the outside
C 418 Test Method for Abrasion Resistance of Concrete by
diameter 275 mm (11 in.). Crossed slots 90° to each other and
Sandblasting
3 1
cut5mm( ⁄16 in.) deep and 6 mm ( ⁄4 in.) wide are located
C 670 Practice for Preparing Precision and Bias Statements
symmetrically in the abrasive flat faces.
for Test Methods for Construction Materials
4.2 The disks are free floating inasmuch as they are self-
C 944 Test Method for Abrasion Resistance of Concrete or
supporting and are driven transversely along a circular path at
Mortar Surfaces by the Rotating-Cutter Method
12 rev/min (12 rpm) while being individually turned on their
3. Significance and Use
own axis at 280 rev/min (280 rpm). Cups attached at the top of
the shaft of each disk shall be loaded with lead shot to produce
3.1 The three test methods provide simulated abrasion
a uniform total load of 22 N (5 lbf) on each abrading disk face.
conditions, which can be used to evaluate the effects on
4.3 The abrasive grit shall consist of 250 µ [No. 60] silicon
carbide. This is fed from a storage cup mounted on the
This test method is under the jurisdiction of ASTM Committee C09 on
Concrete and ConcreteAggregates and is the direct responsibility of Subcommittee
C09.62 on Abrasion Testing of Concrete.
Current edition approved June 10, 2000. Published August 2000. Originally These machines are available from White Machine Co., 9591 York Alpha Dr.,
published as C 779 – 74. Last previous edition C 779 – 95. North Royalton, OH 44133; Spirit Fabricating, Ltd., 9260 Valley View Rd.,
Annual Book of ASTM Standards, Vol 04.02. Macedonia, OH 44056.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C779/C779M
FIG. 1 Revolving Disks Abrasion Test Machine
revolving circular plate through a 3-mm ( ⁄8-in.) orifice passing
through the plate. The flow of abrasive shall be controlled to a
rate of 4 to 6 g/min by an adjusting needle located in the
orifice. The abrasive falls at the midwidth of the circular
abraded track, and midway between two of the disks.
4.4 The micrometer bridge consists of a machine-finished
25-mm (1-in.) rectangular steel bar of at least 300-mm (12-in.),
clear span supported by a tripod and drilled along its centerline
1 1
with ten 3-mm ( ⁄8-in.) diameter holes spaced 6-mm ( ⁄4 in.) on
center. The measuring instrument is a depth micrometre with a
needle having an effective depth range of 25 to 50 mm (1 to 2
in.) and graduated to an accuracy of at least 0.025 mm (0.001
in.).
5. Test Specimen
5.1 For laboratory test purposes, the machine is designed to
accommodate approximately 300 by 300-mm (12 by 12-in.)
test specimens. The apparatus is equipped with an adjusting
handle linked by a sprocket and chain-drive assembly to the
four 25-mm (1-in.) diameter posts which support the entire
rotating abrasion element. This feature permits the abrasion of
test panels up to approximately 100-mm (4-in.) in thickness.A
zero adjustment in the height of the abrasion assembly also
permits the use of the apparatus as a portable device for
measuring the abrasion resistance on the surfaces in place as
FIG. 2 Dressing Wheel Abrasion Test Machine
well as on test specimens.
C779/C779M
depth of the slots to less than 1.5 mm ( ⁄16in.), they shall be
replaced.Newdiskfacesshallbesubjectedtoabreak-inperiod
of at least 15 min.
7. Interpretation of Results
7.1 The comparison of measurements of average depth of
wear of representative surfaces at 30 and 60-min exposure to
abrasion will indicate the relative abrasion resistance of these
surfaces.
8. Report
8.1 Report the depth of wear of each surface tested as well
as the average obtained on replicate surfaces.
8.2 Record mixture proportions (including cement content
and water-cement ratio), specific gravities, grading of fine and
coarse aggregates, Los Angeles abrasion test results, type and
amount of material added to freshly placed concrete surface,
typeandextentoftroweling,curingdetails,andageofconcrete
when tested.
PROCEDURE B—DRESSING WHEELS
9. Apparatus
9.1 The function of the apparatus is dependent upon the
FIG. 3 Ball Bearing Abrasion Test Machine
abrasive action of three sets of steel dressing wheels riding in
a circular path over a horizontal concrete surface. The dressing
wheels in each of the three sets of wheels turn freely on a
6. Procedure
horizontal axle at the bottom of a free-floating, weighted,
vertical steel shaft.
6.1 Prior to the test period, precondition the sample to
9.2 Each of the three sets of seven dressing wheels are
remove curing compound and surface irregularities by running
spaced so that each set cuts approximately a 40-mm (1 ⁄2-in.)
the abrasion machine for 5 min, after which the initial
wide path. The machine produces a circular abrasion path of
measurements shall be taken. Obtain initial measurements to
1 1
about 140-mm (5 ⁄2-in.) inside diameter and 220-mm (8 ⁄2-in.)
an accuracy of at least 0.025 mm (0.001 in.) of the test area by
outside diameter.
takingtwoseriesof20measurementseach.Placethemicrome-
9.3 The apparatus shall consist of a motor-driven spider
ter bridge so that the line of the second series of readings
arrangementturningat56rev/min(56rpm).Themotorshallbe
bisects at right angles to the first series of measurements. In
mounted on a horizontal plate supported by four screw jacks
making measurements subsequent to the abrasion period, take
allowing the motor to be raised and lowered. The spider shall
care that the micrometer bridge is placed in precisely the same
be hung from the vertical motor shaft. The three vertical shafts
position in which the reference measurements were obtained.
shall be mounted in the spider arrangement so that they rotate
To ensure this, outline the ends of the positioned micrometer
with the spider and are free to move up and down in
bridge on the surface prior to making the initial measurements.
independent thrust-bearing sockets.
6.2 A test period of 30 min generally produces significant
9.4 The three shafts shall be fitted with a yoke inside, upon
wear on most concrete surfaces, but it is recommended to
which a series of seven dressing wheels are placed on a
extend the test period to 60 min, if information on the longtime
horizontal axle. The mass of each complete dressing wheel
abrasion resistance is desired.
assembly as it bears on the concrete surface shall be 7.5 kg
6.3 In using the device as a portable apparatus, take care in
(16.5 lb).
the selection of the areas to be tested.Although the base of the
9.5 The dressing wheels shall have an outside diameter of
apparatus is equipped with rubber pads, not only to prevent the
3 1
60 mm (2 ⁄8 in.) and a thickness of 3 mm ( ⁄8 in.) and shall be
apparatus from creeping during the abrasion operation but also
provided with 18 flattened points, each having dimensions of
to minimize the effect of slight variations in the level of the test
3.0 by 2.0-mm (0.125 by 0.075 in.). The dressing wheels shall
areas. Select test areas with a minimum of variation in level so
be assembled on the shaft alternated with steel washers. The
as to eliminate the creeping effect.
total width of seven dressing wheels and eight washers shall be
6.4 Take measurements of depth wear with a micrometer
approximately 40 mm (1 ⁄2in.). The dressing wheels must be
bridge as described in 4.4 to an accuracy of at least 0.025 mm
loose enough to turn freely and independently.
(0.001 in.). Prior to each set of measurements, clean the
specimen surface carefully by removing loose particles.
6.5 Make three tests on surfaces representative of the
Dressing wheels of a suitable type may be purchased from sources, such as
concrete to be evaluated. When wear of the disks reduces the Desmond-Stefan Manufacturing Co., 713 South Walnut, Urbana, OH.
C779/C779M
9.6 The measuring instrument shall be a dial micrometer, 13.2 Record the mixture proportions including cement con-
reading to an accuracy of at least 0.025 mm (0.001 in.) with a tent and water-cement ratio, specific gravities, grading of fine
range of at least 10 mm (0.4 in.). The contact end of the and coarse aggregates, Los Angeles abrasion test results, type
micrometer spindle shall have a spherical surface of 9.5-mm and amount of material added to freshly placed concrete
( ⁄8-in.) diameter. A jig located on the underside of the spider surface, type and extent of troweling, curing details, and age of
holdsthemicrometremagneticallyintheapproximatecenterof concrete when tested.
the path of the dressing wheels.
PROCEDURE C—BALL BEARINGS
10. Test Specimen
14. Apparatus
10.1 Place a sample approximately 300 by 300 by 100-mm
(12 by 12 by 4-in.) thick into the machine and lock it in place
14.1 The function of the apparatus is dependent upon the
with vises provided. Do not remove the sample until the test is
abrasive action of a rapidly rotating ball bearing under load on
completed. Test three identical samples.
a wet concrete test surface. Water is used to flush out loose
particles from the test path, bringing the ball bearing in contact
11. Procedure
with sand and stone particles still bonded to the concrete
11.1 Position the abrasion apparatus over surface to be
surface, thus providing impact as well as sliding friction.
tested. Rubber pads on the bottom of machine will hold the
14.2 The apparatus shall consist of a motordriven, hollow,
machine in place. Turn the screw crank until the full weight of
vertical shaft resting on and turning ball bearings which rest on
each dressing-wheel shaft is resting on the concrete surface.
the concrete surface. As the ball bearings cut into the concrete
Lower the spider as far as possible without exerting any
surface, depth-of-wear readings can be taken continuously
pressure from the spider itself onto these three shafts. Allow a
without stopping the test.
spacing of 15 mm (0.5 in.) for vertical travel of the dressing
14.3 A digital clock shall be electrically connected to the
wheels. Lock the screw crank to prevent any change in vertical
drive motor so that both the drive motor and the clock can be
movement of the spider during testing.
started simultaneously. The clock shall read in seconds up to
11.2 Take an initial measurement to the nearest 0.025 mm
9999 s.
(0.001 in.) on the test area with the dial micrometer in place
14.4 The abrasion tool shall be composed of eight 18-mm
while revolving the spider two revolutions by hand. Record
( ⁄32-in.) diameter steel balls equally spaced in a retainer ring.
this initial reading as a reference reading and then remove the
The diameter of the ball circle shall be 60 mm (2 ⁄2 in.). The
micrometer. Start the machine and let it run for 30 min, brush
abrasion tool shall be given a breaking-in period of 300 s. The
offtheloosematerial,insertthedialmicrometer,andrecordthe
abrasion tool shall be discarded when the diameter of the steel
average reading again. If the readings are not reasonably
ball has been reduced to 17.8 mm (0.7 in.).
uniform, record several readings taken around the circumfer-
NOTE 3—During this period the steel balls will become slightly
ence of the abraded surface from which the average reading
textured, leaving an apparent larger diameter.
may be computed. The difference between the reference
14.5 The hollow vertical drive shaft shall be provided with
reading and the 30-min reading is indicative of the depth of
a flanged bearing plate at its lower end, grooved to match the
wear
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