ASTM D7428-08
(Test Method)Standard Test Method for Resistance of Fine Aggregate to Degradation by Abrasion in the Micro-Deval Apparatus
Standard Test Method for Resistance of Fine Aggregate to Degradation by Abrasion in the Micro-Deval Apparatus
SIGNIFICANCE AND USE
The Micro-Deval abrasion test is a test of fine aggregate to determine abrasion loss in the presence of water and an abrasive charge. Many aggregates are more susceptible to abrasion when wet than dry, and the use of water in this test incorporates this reduction in resistance to degradation. The test results are helpful in evaluating the toughness/abrasion resistance of fine aggregate subject to abrasion when adequate information is not available from service records. This test is suitable for measuring the amount of weak, soft material such as shale or shaley carbonate in fine aggregate. Materials that give a low loss in this test are unlikely to exhibit significant degradation during handling, mixing or placing. There is a relationship between drying shrinkage of cement mortar and Micro-Deval abrasion loss of fine aggregate, with higher loss materials resulting in higher drying shrinkage. Descriptions of the development of the test and the relationship with other properties have been published. , ,
The Micro-Deval abrasion test on fine aggregate is useful for detecting changes in properties of aggregate produced from an aggregate source as part of a quality control or quality assurance process.
The Micro-Deval abrasion test on fine aggregate, in contrast to the version on coarse aggregate, has a significant correlation with the Magnesium Sulfate soundness loss of fine aggregate. The Micro-Deval test on fine aggregate has better precision than the sulfate soundness test, is quicker, and may be used in place of that test. Advice on specific values for selection of aggregate will be found in the appendix.
SCOPE
1.1 This test method covers a procedure for testing fine aggregate for resistance to abrasion using the Micro-Deval apparatus.
1.2 The values stated in SI units are to be regarded as the standard.
1.3 The text of this method references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the test method.
1.4 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.
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Standards Content (Sample)
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Designation:D7428–08
Standard Test Method for
Resistance of Fine Aggregate to Degradation by Abrasion in
the Micro-Deval Apparatus
This standard is issued under the fixed designation D 7428; 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 3.1.1 constant mass, n—the condition of a test sample dried
at a temperature of 110 6 5°C such that it will not lose more
1.1 This test method covers a procedure for testing fine
than 0.1 % moisture after2hof drying.
aggregate for resistance to abrasion using the Micro-Deval
3.1.1.1 Discussion—Such a condition of dryness can be
apparatus.
verified by determining the mass of the sample before and after
1.2 The values stated in SI units are to be regarded as the
successive 2-h drying periods. In lieu of such a determination,
standard.
samples may be considered to have reached constant mass
1.3 The text of this method references notes and footnotes
when they have been dried at a temperature of 110 6 5°C for
which provide explanatory material. These notes and footnotes
an equal or longer period than that previously found adequate
(excluding those in tables and figures) shall not be considered
for producing the desired constant mass condition under equal
as requirements of the test method.
or heavier loading conditions of the oven.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
responsibility of the user of this standard to establish appro-
4.1 The Micro-Deval Test is a measure of abrasion resis-
priate safety and health practices and determine the applica-
tance and durability of mineral aggregates resulting from a
bility of regulatory limitations prior to use.
combination of actions including abrasion and grinding with
2. Referenced Documents steel balls in the presence of water. A 500 g sample with
standard grading is initially soaked in water for not less than
2.1 ASTM Standards:
one hour.The sample is then placed in a jar mill with 0.75 Lof
C88 Test Method for Soundness of Aggregates by Use of
water and an abrasive charge consisting of 1250 g of 9.5-mm
Sodium Sulfate or Magnesium Sulfate
diameter steel balls. The jar, aggregate, water, and charge are
C117 Test Method for Materials Finer than 75-µm (No.
revolvedat100rpmfor15minutes.Thesampleisthenwashed
200) Sieve in Mineral Aggregates by Washing
and oven dried. The loss is the amount of material passing the
C 136 Test Method for Sieve Analysis of Fine and Coarse
75 µm sieve expressed as a percent by mass of the original
Aggregates
sample.
C 670 Practice for Preparing Precision and Bias Statements
for Test Methods for Construction Materials
5. Significance and Use
D 6928 Test Method for Resistance of CoarseAggregate to
5.1 The Micro-Deval abrasion test is a test of fine aggregate
Degradation by Abrasion in the Micro-Deval Apparatus
to determine abrasion loss in the presence of water and an
E11 Specification for Wire Cloth and Sieves for Testing
abrasive charge. Many aggregates are more susceptible to
Purposes
abrasion when wet than dry, and the use of water in this test
3. Terminology incorporates this reduction in resistance to degradation. The
test results are helpful in evaluating the toughness/abrasion
3.1 Definitions:
resistance of fine aggregate subject to abrasion when adequate
information is not available from service records. This test is
This test method is under the jurisdiction of ASTM Committee D04 on Road
suitable for measuring the amount of weak, soft material such
and Paving Materials and is the direct responsibility of Subcommittee D04.51 on
as shale or shaley carbonate in fine aggregate. Materials that
Aggregate Tests.
Current edition approved Feb. 1, 2008. Published March 2008. give a low loss in this test are unlikely to exhibit significant
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
degradation during handling, mixing or placing. There is a
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
relationship between drying shrinkage of cement mortar and
Standards volume information, refer to the standard’s Document Summary page on
Micro-Deval abrasion loss of fine aggregate, with higher loss
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7428–08
materials resulting in higher drying shrinkage. Descriptions of 7. Supplies
the development of the test and the relationship with other
7.1 Laboratory Reference Aggregate—Asupply of standard
, ,
3 4 5
properties have been published.
“Standard Sutherland Micro-Deval Fine Aggregate” available
5.2 The Micro-Deval abrasion test on fine aggregate is
from the Soils and Aggregates Section, Materials Engineering
useful for detecting changes in properties of aggregate pro-
Materials Office, Ministry of Transportation, 1201 Wilson
duced from an aggregate source as part of a quality control or
Avenue, Downsview, Ontario, Canada M3M1J8. Fax: 1-416-
quality assurance process.
235-4101. The material shall be prepared as follows:
5.3 The Micro-Deval abrasion test on fine aggregate, in
Passing Retained Mass
4.75-mm 2.36-mm 40 g
contrast to the version on coarse aggregate, has a significant
2.36-mm 1.18-mm 115 g
correlation with the Magnesium Sulfate soundness loss of fine
1.18-mm 0.600-µm 180 g
aggregate. The Micro-Deval test on fine aggregate has better
0.600-µm 0.300-µm 120 g
0.300-µm 150-µm 38 g
precision than the sulfate soundness test, is quicker, and may
150-µm 75-µm 7 g
be used in place of that test. Advice on specific values for
7.2 Calibration Aggregate—An adequate supply of aggre-
selection of aggregate will be found in the appendix.
gate, established by the Laboratory to use for calibration of the
test method (see 11.1).
6. Apparatus
6.1 Micro-Deval Abrasion Machine, a jar rolling mill as 8. Test Sample
specified in Test Method D 6928.
8.1 The test sample shall be washed over a 75-µm sieve
6.2 Containers, stainless steel Micro-Deval abrasion jars as
following Test MethodC117 and oven-dried at 110 6 5°C to
specified in Test Method D 6928.
constant mass, separated into individual size fractions in
accordance with Test Method C 136, and recombined to meet
6.3 Abrasive Charge—Magnetic stainless steel balls are
required. These shall have a diameter of 9.5 6 0.5 mm. Each the grading shown in 8.2.
jar requires a charge of 1250 6 5 g of balls. 8.2 Aggregate for the test sample shall consist of material
passing the 4.75-mm sieve, retained on the 75-µm sieve with a
NOTE 1—Prior to use, new containers and new steel balls should be
Fineness Modulus of 2.8 (Note 2). An oven dried sample of
conditioned. Conditioning is accomplished by running the equipment with
500 6 5 g shall be prepared as follows:
a charge of 500 g of silica sand with 750 ml of water for a period of four
Passing Retained Mass
hours. From time to time it may be necessary to recondition the containers
4.75-mm 2.36-mm 50 g
and steel balls. The need for this will be indicated by significant reduction
2.36-mm 1.18-mm 125 g
in loss with the calibration material. It has been found that reconditioning
1.18-mm 0.600-µm 125 g
is usually needed when the equipment has been used for testing carbonate
0.600-µm 0.300-µm 100 g
coarse aggregate in the coarse aggregate version of the test (Test Method
0.300-µm 150-µm 75 g
D 6928), which may lead to polishing of the inside of the container and
150-µm 75-µm 25 g
ball surfaces. The conditioning process gives the containers and balls a
NOTE 2—Fine aggregates that have a fine grading give a slightly higher
“frosted” surface, which promotes tumbling of the balls and aggregate
Micro-Deval Abrasion loss than those with a coarser grading from the
inside the container, rather than sliding when the containers are rotated.
samesource.Theeffectofgradingissmallwhenthemeanlossislessthan
When silica rich fine aggregates are tested, the need for reconditioning
about 20 %. For materials of low loss, which easily meet applicable
may be reduced or eliminated provided the calibration aggregate gives
specification requirements, it may be practical to test material without
satisfactory results. For this reason, it is good practice to not use
preparing to the grading given above for routine quality control purposes.
containers used for testing coarse aggregate in the fine aggregate version
When desired, other grading may be used but the use of such grading
of the test.
should be reported.
6.4 Sieves, with square openings, and of the following sizes
9. Test Procedure
conformingtoSpecificationE11specifications:6.7or6.3mm,
9.1 Prepare a representative 500 6 5 g test sample in
4.75 mm, 2.36 mm, 1.18 mm, 0.600 µm, 300 µm, 150 µm, 75
accordance with Section 8. Weigh the test sample and record
µm.
the Mass, A, to the nearest 0.1 g.
6.5 Oven, capable of maintaining a temperature of 110 6
9.2 Immerse the test sample in 0.75 6 0.05 L of tap water
5°C.
at a temperature 20 6 5°C for a minimum of 1 h either in the
6.6 Balance, or scale accurate to 0.1 g.
Micro-Deval container or some other suitable container.
9.3 Add 1250 6 5 g steel balls to the prepared test sample
andthewa
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