ASTM D7064-04
(Practice)Standard Practice for Open-Graded Friction Course (OGFC) Mix Design
Standard Practice for Open-Graded Friction Course (OGFC) Mix Design
SIGNIFICANCE AND USE
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 standard 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 D 6932 should be reviewed before starting the mix design. Where applicable, Specification D 3666 should be applied as a minimum for agencies testing and inspecting road and paving materials.
1.2 The values stated in SI units are to be regarded as standard. The inch-pound units in parentheses are for information only.
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
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
Designation: D 7064 – 04
Standard Practice for
Open-Graded Friction Course (OGFC) Mix Design
This standard is issued under the fixed designation D 7064; 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 Gravity and Density of Bituminous Paving Mixtures
D 2419 Test Method for Sand EquivalentValue of Soils and
1.1 This standard practice covers the mix design of open-
Fine Aggregate
graded friction course (OGFC) using the superpave gyratory
D 3203 Test Method for Percent Air Voids in Compacted
compactor (SGC) or other suitable forms of compaction. The
Dense and Open Bituminous Paving Mixtures
OGFC mix design is based on the volumetric properties of the
D 3381 Specification for Viscosity-Graded Asphalt Cement
mix in terms of air voids, and the presence of stone-on-stone
for Use in Pavement Construction
contact. Information found in Guide D 6932D 6932 should be
D 3666 SpecificationforMinimumRequirementsforAgen-
reviewed before starting the mix design. Where applicable,
cies testing and Inspecting Bituminous Paving Materials
Specification D 3666D 3666 should be applied as a minimum
D 4791 Test Method for Flat Particles, Elongated Particles,
for agencies testing and inspecting road and paving materials.
or Flat and Elongated Particles in Coarse Aggregate
1.2 The values stated in SI units are to be regarded as
D 5821 Test Method for Determining the Percentage of
standard. The inch-pound units in parentheses are for informa-
Fractured Particles in Coarse Aggregate
tion only.
D6114 Specification for Asphalt-Rubber Binder
1.3 This standard does not purport to address all of the
D 6373 Specification for Performance Graded Asphalt
safety concerns, if any, associated with its use. It is the
Binder
responsibility of the user of this standard to establish appro-
D 6390 Test Method for Determination of Draindown Char-
priate safety and health practices and determine the applica-
acteristics in Uncompacted Asphalt Mixtures
bility of regulatory limitations prior to use.
D 6752 Test Method for Bulk Specific Gravity and Density
2. Referenced Documents of Compacted Bituminous Mixtures Using Automatic
Vacuum Sealing Method
2.1 ASTM Standards:
D 6857 Test Method for Maximum Specific Gravity and
C 29/C 29M Test Method for Unit Weight and Voids in
Density of Bituminous Paving Mixtures Using Automatic
Aggregate
Vacuum Sealing Method
C 127 Test Method for Density, Relative Density (Specific
D 6932 Guide for Materials and Construction of Open
Gravity), and Absorption of Coarse Aggregate
Graded Friction Course Plant Mixtures
C 131 Test Method for Resistance to Degradation of Small-
2.2 AASHTO Standards:
Size CoarseAggregate byAbrasion and Impact in the Los
R 30 Mixture Conditioning of Hot Mix Asphalt (HMA)
Angeles Machine
T 283 Resistance of Compacted Bituminous Mixture to
C 136 Test Method for Sieve Analysis of Fine and Coarse
Moisture-Induced Damage
Aggregates
T 312 Preparing and Determining the Density of Hot-Mix
C 1252 Test Methods for Uncompacted Void Content of
Asphalt (HMA) Specimens by means of the Superpave
Fine Aggregate (as Influenced by Particle Shape, Surface
Gyratory Compactor
Texture, and Grading)
2.3 Other References:
D 946 Specification for Penetration-Graded Asphalt Ce-
TRB Synthesis 284
ment for Use in Pavement Construction
NCAT Report No. 2001-01 Design, Construction, and Per-
D 2041 Test Method for Theoretical Maximum Specific
formance of New-Generation Open-Graded Friction
Courses
This practice is under the jurisdiction of ASTM Committee D04 on Road and
3. Terminology
Paving Materials and is the direct responsibility of Subcommittee D04.23 on
Plant-Mixed Bituminous Surfaces and Bases. 3.1 Definitions of Terms Specific to This Standard:
Current edition approved Aug. 1, 2004. Published August 2004.
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
Standards volume information, refer to the standard’s Document Summary page on Available from American Association of State Highway and Transportation
the ASTM website. Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D7064–04
3.1.1 open-graded friction course (OGFC), n—special type 5. Significance and Use
of hot mix asphalt surface mixture used for reducing hydro-
5.1 The procedure described in this practice is used to
planing and potential for skidding, where the function of the
design OGFC mixtures that will provide good performance in
mixture is to provide a free-draining layer that permits surface
terms of permeability (tending to reduce hydroplaning and
watertomigratelaterallythroughthemixturetotheedgeofthe
potential for skidding), and durability when subjected to high
pavement.
volumes of traffic.
3.1.2 air voids (V ), n—the total volume of the small
a
pockets of air between the coated aggregate particles through-
6. Material Selection
out a compacted paving mixture, expressed as a percent of the
6.1 The first step in the mix design process is to select
total volume of the compacted specimen.
materials suitable for the OGFC. Materials include aggregates,
3.1.3 voids in coarse aggregate (VCA), n—the volume in
asphalt, and additives.
between the coarse aggregate particles, where this volume
includes filler, fine aggregate, air voids, asphalt, and fiber, if 6.1.1 Selection of Coarse Aggregate—Coarse aggregate
used. should have abrasion values of less than 30 % in accordance
3.1.4 nominal maximum size of aggregate, n—in specifica- with Test Method C 131C 131. Crushed gravel (if used) must
tions for, or descriptions of aggregate, the smallest sieve
have at least 90 % particles with two faces and 95 % particles
opening through which the entire amount of aggregate is with one face resulting from crushing in accordance with Test
permitted to pass.
Method D 5821D 5821. The percentage of flat and elongated
3.1.4.1 Discussion—Specifications on aggregates usually particles should not exceed 10 %, with a ratio of 5:1 in
stipulate a sieve opening through which all of the aggregate
maximum to minimum dimension, respectively in accordance
may, but need not, pass so that a stated maximum proportion of with Test Method D 4791D 4791.
the aggregate may be retained on that sieve.Asieve opening so
6.1.2 Selection of Fine Aggregate—The fine aggregate
designated is the nominal maximum aggregate size.
should have an uncompacted voids content of least 40 % when
3.1.5 maximum aggregate size, n—in specifications for, or
tested in accordance with Test Methods C 1252C 1252,
descriptions of aggregate, the smallest sieve opening through
Method C. It is important that the aggregate be clean.The sand
which the entire amount of aggregate is required to pass.
equivalent value of the fine aggregate passing the No. 8 (2.36
3.1.6 stabilizing additive, n—polymer, crumb rubber, or
mm) sieve, according to Test Method D 2419D 2419, should
fibers, or both, used to minimize draindown of the asphalt
be at least 45 % or greater. It is recommended that the material
during transport and placement of the OGFC.
to be tested be separated on the No. 8 (2.36 mm) sieve because
of the coarse grading of the aggregate. It is also very important
4. Summary of Practice
toremoveanycoatingsorfinesadheringtothecoarsematerial.
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
4.2 Select Optimum Grading—At least three trial aggregate
performance of the OGFC. The preferred specified asphalt
gradings from the selected aggregate stockpiles are blended. grade should meet Specification D 6373D 6373, however other
Gradings for OGFC are based on volume. The dry-rodded unit
grades of asphalt, such as viscosity-graded Specification
weight for the coarse aggregate for each trial grading is D 3381D 3381 or penetration graded Specification
determined in accordance with Test Method C 29/C 29MC 29/
D 946D 946 may be suitable. A pg-grade, one or two grades
C 29M. For each trial grading, an initial trial asphalt content stiffer (at high temperature) than normally used at the location
between 6.0 and 6.5 % (generally higher for asphalt-rubber
of the pavement, has been shown to perform successfully.
Specification D 6114D6114) is selected and at least two Mixes with modified asphalt cements have shown significant
specimens are compacted using 50 gyrations of the SGC
improvement in performance. The use of modified asphalt
(AASHTO T 312) or other suitable compactor. An optimum cements is permitted provided that the selected asphalt grade
grading is selected to ensure stone-on-stone contact.
has a PG temperature range exceeding 95°C. This is deter-
mined by subtracting the low from the high specification
NOTE 1—If a standard aggregate grading and asphalt content has been
temperature grade [for example, PG 70-28 = 70-(-28) = 98].A
successfully used, three trial gradings may not be necessary. Examples of
value less than 95°C may be used if satisfactory performance
commonly used gradings and asphalt contents are shown inAppendix X1.
has been noted with the selected PG grade.
4.3 Design Asphalt Content Selection—Replicate speci-
6.1.4 Selection of Additives—Either a cellulose fiber or a
mens are compacted using 50 gyrations of a SGC or other
mineral fiber may be used to minimize draindown. Typically a
suitable compactor at three asphalt contents. The design
dosage rate of 0.3 % by mixture mass (or weight of total mix)
asphalt content is selected on the basis of satisfactory confor-
is used but the draindown target of 0.3 % maximum should be
mance with the requirements of Section 12.
the acceptance guideline for the dosage rate of the fiber
4.4 Evaluating Moisture Susceptibility—The moisture sus-
stabilized additive. The dosage rate of fiber stabilizer additive
ceptibility of the designed mixture shall be evaluated using the
used should be in the range listed in 12.8.
AASHTO T 283 test method. If the mixture fails the selected
moisture susceptibility requirement, it is suggested that appro-
NOTE 2—For some mixes which use polymer-modified asphalt or
priate modifiers such as liquid anti-strip, or hydrated lime, or
asphalt rubber, fiber additives may not be required or necessary to obtain
both are evaluated to meet the requirement. good performance or control draindown.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
D7064–04
7. Test Specimens 7.4.4 Form a crater in the dry blended aggregate and to this
add stabilizing fiber additive if used, and then add the weighed
7.1 Numbers of Samples—Twelve samples are initially
preheated required amount of asphalt into the crater formed in
required: four samples at each of the three trial gradings. Each
the aggregate blend. Exercise care to prevent loss of the mix
sample is mixed with the trial asphalt content (typically
during subsequent handling. At this point, the temperature of
between 6.0 and 6.5 % for neat liquid asphalts), and three of
the aggregate and asphalt shall be within the limits of the
the four samples for each trial grading are compacted. The
mixing temperature established in 7.3. Mix the aggregate and
remaining sample of each trial grading is then used to
asphalt rapidly until thoroughly coated.
determine the theoretical maximum density according to Test
7.5 Size and Shape of Compacted Specimens—Specimen
Method D 2041D 2041 or Test Method D 6857D 6857.
diameter shall be 100 mm (4 in.) and nominal height shall be
NOTE 3—For some polymer modified asphalt and asphalt-rubber, the
63.5 mm (2.5 in.).
typical asphalt content may be higher; see Appendix X1.
7.6 Compaction of Specimens—The compaction tempera-
7.2 Preparation of Aggregates—Dry aggregates to a con-
ture is determined in accordance with 7.3. Laboratory samples
stant mass at 105 to 110°C (220 to 230°F) and separate the
of OGFC are short-term aged in accordance with AASHTO
aggregates by dry-sieving into the desired size fractions (Test
PP2 and then compacted using 50 gyrations of the SGC or
Method C 136C 136).
other compactor providing equivalent compacted density.
7.3 Determination of Mixing and Compaction Tempera-
8. Selection of Trial Gradings
tures:
7.3.1 The temperature to which an asphalt must be heated to
8.1 Three trial gradings should be selected to be within the
produce a viscosity of 170 6 20 cSt shall be the mixing
recommended master range of grading shown in Table 1,ora
temperature.
grading shown in Appendix X1 or a grading that has demon-
7.3.2 The temperature to which the asphalt must be heated
strated good performance. The three trial gradings should
to produce a viscosity 280 6 30 cSt shall be the compaction
generally fall along the coarse and fine limits of the grading
temperature.
range,alongwithonefallinginthemiddle.Thesetrialgradings
7.3.3 However, while the temperatures shown in 7.3.1 and
are obtained by adjusting the amount of fine and coarse
7.3.2 will work for most unmodified asphalt, the selected
aggregate in each blend.
temperatures may need to be changed for polymer modified
NOTE 5—If a satisfactory grading has been successfully used on
asphalt or asphalt-rubber. For polymer modified asphalt and
previous projects or a grading shown in Appendix X1 is selected by the
asphalt-rubber, the manufacturer or supplier guidelines for
designer, Sections 8 through 11 may be disregarded.
mixing and compaction temperatures should be followed.
7.4 Preparation of Mixtures:
9. Selection of Trial Asphalt Content
7.4.1 A mechanical mixing apparatus shall be used.
9.1 For each trial aggregate grading, an asphalt content
7.4.2 An initial batch shall be mixed for the purpose of
between 6.0 and 6.5 % should be initially selected based on the
coating (buttering) the mixture bowl and stirrers. This batch
aggregates’ bulk specific gravity. Higher asphalt contents
shall be wasted after mixing and the sides of the bowl and
should be selected for polymer modified asphalt or asphalt-
stirrers shall be cleaned of mixture residue by scraping with a
rubber, as noted i
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