ASTM D7064/D7064M-08(2013)
(Practice)Standard Practice for Open-Graded Friction Course (OGFC) Mix Design
Standard Practice for Open-Graded Friction Course (OGFC) Mix Design
SIGNIFICANCE AND USE
5.1 The procedure described in this practice is used to design OGFC mixtures that will provide good performance in terms of permeability (tending to reduce hydroplaning and potential for skidding), and durability when subjected to high volumes of traffic.
SCOPE
1.1 This practice covers the mix design of open-graded friction course (OGFC) using the superpave gyratory compactor (SGC) or other suitable forms of compaction. The OGFC mix design is based on the volumetric properties of the mix in terms of air voids, and the presence of stone-on-stone contact. Information found in Guide D6932 should be reviewed before starting the mix design. Where applicable, Specification D3666 should be applied as a minimum for agencies testing and inspecting road and paving materials.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with 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.
General Information
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D7064/D7064M − 08 (Reapproved 2013)
Standard Practice for
Open-Graded Friction Course (OGFC) Mix Design
This standard is issued under the fixed designation D7064/D7064M; 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.
1. Scope C1252 Test Methods for Uncompacted Void Content of Fine
Aggregate (as Influenced by Particle Shape, Surface
1.1 This practice covers the mix design of open-graded
Texture, and Grading)
friction course (OGFC) using the superpave gyratory compac-
D946 Specification for Penetration-Graded Asphalt Cement
tor (SGC) or other suitable forms of compaction. The OGFC
for Use in Pavement Construction
mix design is based on the volumetric properties of the mix in
D2041 Test Method for Theoretical Maximum Specific
terms of air voids, and the presence of stone-on-stone contact.
Gravity and Density of Bituminous Paving Mixtures
Information found in Guide D6932 should be reviewed before
D2419 Test Method for Sand Equivalent Value of Soils and
startingthemixdesign.Whereapplicable,SpecificationD3666
Fine Aggregate
should be applied as a minimum for agencies testing and
D3203 Test Method for Percent Air Voids in Compacted
inspecting road and paving materials.
Dense and Open Bituminous Paving Mixtures
1.2 The values stated in either SI units or inch-pound units
D3381 Specification for Viscosity-Graded Asphalt Cement
are to be regarded separately as standard. The values stated in
for Use in Pavement Construction
each system may not be exact equivalents; therefore, each
D3666 Specification for Minimum Requirements for Agen-
system shall be used independently of the other. Combining
cies Testing and Inspecting Road and Paving Materials
values from the two systems may result in non-conformance
D4791 Test Method for Flat Particles, Elongated Particles,
with the standard.
or Flat and Elongated Particles in Coarse Aggregate
1.3 This standard does not purport to address all of the D5821 Test Method for Determining the Percentage of
safety concerns, if any, associated with its use. It is the
Fractured Particles in Coarse Aggregate
responsibility of the user of this standard to establish appro- D6114 Specification for Asphalt-Rubber Binder
priate safety and health practices and determine the applica-
D6373 Specification for Performance Graded Asphalt
bility of regulatory limitations prior to use. Binder
D6390 Test Method for Determination of Draindown Char-
2. Referenced Documents
acteristics in Uncompacted Asphalt Mixtures
D6752 Test Method for Bulk Specific Gravity and Density
2.1 ASTM Standards:
of Compacted Bituminous Mixtures Using Automatic
C29/C29M Test Method for Bulk Density (“Unit Weight”)
Vacuum Sealing Method
and Voids in Aggregate
D6857 Test Method for Maximum Specific Gravity and
C127 Test Method for Relative Density (Specific Gravity)
Density of Bituminous Paving Mixtures Using Automatic
and Absorption of Coarse Aggregate
Vacuum Sealing Method
C131 Test Method for Resistance to Degradation of Small-
D6925 Test Method for Preparation and Determination of
Size CoarseAggregate byAbrasion and Impact in the Los
the Relative Density ofAsphalt Mix Specimens by Means
Angeles Machine
of the Superpave Gyratory Compactor
C136 Test Method for Sieve Analysis of Fine and Coarse
D6926 Practice for Preparation of Asphalt Mixture Speci-
Aggregates
mens Using Marshall Apparatus
D6932 Guide for Materials and Construction of Open-
Graded Friction Course Plant Mixtures
This practice is under the jurisdiction of ASTM Committee D04 on Road and
Paving Materials and is the direct responsibility of Subcommittee D04.23 on
2.2 AASHTO Standards:
Plant-Mixed Asphalt Surfaces and Bases.
R30 Mixture Conditioning of Hot Mix Asphalt (HMA)
Current edition approved Dec. 1, 2013. Published February 2014. Originally
T 283 Resistance of Compacted Bituminous Mixture to
approved in 2004. Last previous edition approved in 2008 as D7064/
ε1
D7064M – 08 . DOI: 10.1520/D7064_D7064M-08R13.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from American Association of State Highway and Transportation
Standards volume information, refer to the standard’s Document Summary page on Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,
the ASTM website. http://www.transportation.org.
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D7064/D7064M − 08 (2013)
Moisture-Induced Damage 4.3 DesignAsphalt Content Selection—Replicate specimens
are compacted using 50 gyrations of a SGC or other suitable
2.3 Other References:
compactor at three asphalt contents.The design asphalt content
TRB Synthesis 284
is selected on the basis of satisfactory conformance with the
NCAT Report No. 2001-01 Design, Construction, and Per-
requirements of Section 12.
formance of New-Generation Open-Graded Friction
Courses 4.4 Evaluating Moisture Susceptibility—The moisture sus-
ceptibility of the designed mixture shall be evaluated using the
3. Terminology AASHTO T 283 test method. If the mixture fails the selected
moisture susceptibility requirement, it is suggested that appro-
3.1 Definitions of Terms Specific to This Standard:
priate modifiers such as liquid anti-strip, or hydrated lime, or
3.1.1 open-graded friction course (OGFC), n—special type
both are evaluated to meet the requirement.
of hot mix asphalt surface mixture used for reducing hydro-
planing and potential for skidding, where the function of the
5. Significance and Use
mixture is to provide a free-draining layer that permits surface
5.1 The procedure described in this practice is used to
watertomigratelaterallythroughthemixturetotheedgeofthe
design OGFC mixtures that will provide good performance in
pavement.
terms of permeability (tending to reduce hydroplaning and
3.1.2 air voids (V ), n—the total volume of the small
a
potential for skidding), and durability when subjected to high
pockets of air between the coated aggregate particles through-
volumes of traffic.
out a compacted paving mixture, expressed as a percent of the
total volume of the compacted specimen.
6. Material Selection
3.1.3 voids in coarse aggregate (VCA), n—the volume in
6.1 The first step in the mix design process is to select
between the coarse aggregate particles, where this volume
materials suitable for the OGFC. Materials include aggregates,
includes filler, fine aggregate, air voids, asphalt, and fiber, if
asphalt, and additives.
used.
6.1.1 Selection of Coarse Aggregate—Coarse aggregate
3.1.4 nominal maximum size of aggregate, n—in specifica-
should have abrasion values of less than 30 % in accordance
tions for, or descriptions of aggregate, the smallest sieve
with Test Method C131. Crushed gravel (if used) must have at
opening through which the entire amount of aggregate is
least 90 % particles with two faces and 95 % particles with one
permitted to pass.
face resulting from crushing in accordance with Test Method
3.1.4.1 Discussion—Specifications on aggregates usually
D5821. The percentage of flat and elongated particles should
stipulate a sieve opening through which all of the aggregate
not exceed 10 %, with a ratio of 5:1 in maximum to minimum
may, but need not, pass so that a stated maximum proportion of
dimension, respectively in accordance with Test Method
the aggregate may be retained on that sieve.Asieve opening so
D4791.
designated is the nominal maximum aggregate size.
6.1.2 Selection of Fine Aggregate—The fine aggregate
should have an uncompacted voids content of least 40 % when
3.1.5 maximum aggregate size, n—in specifications for, or
tested in accordance withTest Methods C1252, Method C. It is
descriptions of aggregate, the smallest sieve opening through
important that the aggregate be clean. The sand equivalent
which the entire amount of aggregate is required to pass.
value of the fine aggregate passing the 2.36 mm [No. 8] sieve,
3.1.6 stabilizing additive, n—polymer, crumb rubber, or
according to Test Method D2419, should be at least 45 % or
fibers, or both, used to minimize draindown of the asphalt
greater. It is recommended that the material to be tested be
during transport and placement of the OGFC.
separated on the 2.36 mm [No. 8] sieve because of the coarse
grading of the aggregate. It is also very important to remove
4. Summary of Practice
any coatings or fines adhering to the coarse material.
4.1 Materials Selection—Aggregates, asphalt, and additives 6.1.3 Asphalt Grade Selection—The asphalt grade selection
that meet specification are selected. is based on environment, traffic, and expected functional
performance of the OGFC. The preferred specified asphalt
4.2 Select Optimum Grading—At least three trial aggregate
grade should meet Specification D6373, however other grades
gradings from the selected aggregate stockpiles are blended.
of asphalt, such as viscosity-graded Specification D3381 or
Gradings for OGFC are based on volume. The dry-rodded unit
penetration graded Specification D946 may be suitable. A
weight for the coarse aggregate for each trial grading is
PG-grade, one or two grades stiffer (at high temperature) than
determined in accordance with Test Method C29/C29M. For
normally used at the location of the pavement, has been shown
each trial grading, an initial trial asphalt content between 6.0
to perform successfully. Mixes with modified asphalt cements
and 6.5 % (generally higher for asphalt-rubber Specification
have shown significant improvement in performance. The use
D6114) is selected and at least two specimens are compacted
of modified asphalt cements is permitted provided that the
using 50 gyrations of the Superpave Gyratory Compactor
selected asphalt grade has a PG temperature range exceeding
(SGC) (Test Method D6925) or other suitable compactor. An
95. This is determined by subtracting the low from the high
optimum grading is selected to ensure stone-on-stone contact.
specification temperature grade (for example, PG 70 – 28 = 70
NOTE 1—If a standard aggregate grading and asphalt content has been
– (–28) = 98).Avalue less than 95 may be used if satisfactory
successfully used, three trial gradings may not be necessary. Examples of
commonly used gradings and asphalt contents are shown in Appendix X1. performance has been noted with the selected PG grade.
D7064/D7064M − 08 (2013)
6.1.4 Selection of Additives—Either a cellulose fiber or a stabilizing additive should be dry-mixed thoroughly with the
mineral fiber may be used to minimize draindown. Typically a heated aggregate. This procedure is needed to ensure an even
dosage rate of 0.3 % by mixture mass (or weight of total mix) distribution of the stabilizing additive during the laboratory
is used but the draindown target of 0.3 % maximum should be mixing process. Slightly longer mixing times may be required
the acceptance guideline for the dosage rate of the fiber due to the increased surface area added by the fiber, compared
stabilized additive. The dosage rate of fiber stabilizer additive to mixes without fibers. The supplier recommended mixing
used should be in the range listed in 12.8. temperature should compensate for this stiffening.
NOTE 2—For some mixes which use polymer-modified asphalt or NOTE 4—For polymer modified asphalt and asphalt-rubber, the addi-
asphalt rubber, fiber additives may not be required or necessary to obtain tives should be incorporated into the liquid asphalt and thoroughly
good performance or control draindown. interacted according to the procedure recommended by the manufacturer
or supplier of the additives before the asphalt is mixed with the aggregate.
7. Test Specimens
7.4.4 Form a crater in the dry blended aggregate and to this
7.1 Numbers of Samples—Twelve samples are initially re- add stabilizing fiber additive if used, and then add the weighed
quired: four samples at each of the three trial gradings. Each
preheated required amount of asphalt into the crater formed in
sample is mixed with the trial asphalt content (typically the aggregate blend. Exercise care to prevent loss of the mix
between 6.0 and 6.5 % for neat liquid asphalts), and three of during subsequent handling. At this point, the temperature of
the four samples for each trial grading are compacted. The the aggregate and asphalt shall be within the limits of the
remaining sample of each trial grading is then used to mixing temperature established in 7.3. Mix the aggregate and
determine the theoretical maximum density according to Test asphalt rapidly until thoroughly coated.
Method D2041 or Test Method D6857.
7.5 Size and Shape of Compacted Specimens—Specimen
NOTE 3—For some polymer modified asphalt and asphalt-rubber, the
diameter shall be 100 mm [4 in.] and nominal height shall be
typical asphalt content may be higher; see Appendix X1.
63.5 mm [2.5 in.].
7.2 Preparation of Aggregates—Dry aggregates to a con-
7.6 Compaction of Specimens—The compaction tempera-
stant mass at 105 to 110°C [220 to 230°F] and separate the
ture is determined in accordance with 7.3. Laboratory samples
aggregates by dry-sieving into the desired size fractions (Test
of OGFC are short-term aged in accordance with AASHTO R
Method C136).
30 and then compacted using 50 gyrations of the SGC or other
7.3 Determination of Mixing and Compaction Tempera-
compactor providing equivalent compacted density.
tures:
7.3.1 The temperature to which an asphalt must be heated to
8. Selection of Trial Gradings
produce a viscosity of 0.00017 6 0.00002 m /s [170 6 20 cSt]
8.1 Three trial gradings should be selected to be within the
shall be the mixing temperature.
recommended master range of grading shown in Table 1,ora
7.3.2 The temperature to which the asphalt must be heated
2 grading shown in Appendix X1 or a grading that has demon-
to produce a viscosity 0.00028 6 0.00003 m /s [280 6 30 cSt]
strated good performance. The three trial gradings should
shall be the compaction temperature.
generally fall along the coarse and fine limits of the grading
7.3.3 However, while the temperatures shown in 7.3.1 and
range,alongwithonefallinginthemiddle.Thesetrialgradings
7.3.2 will work for most unmodified asphalt, the selected
are obtained by adjusting the amount of fine and coarse
temperatures may need to be changed for polymer modified
aggregate in each blend.
asphalt or asphalt-rubber. For polymer modified asphalt and
NOTE 5—If a satisfactory grading has been successfully used on
asphalt-rubber, the manufactur
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