ASTM D7402-09(2017)
(Practice)Standard Practice for Identifying Cationic Emulsified Asphalts
Standard Practice for Identifying Cationic Emulsified Asphalts
SIGNIFICANCE AND USE
3.1 Cationic emulsified asphalts are identified by the migration of the particles to a negatively charged electrode (cathode) by means of a direct current. Aggregates and sands used in conjunction with emulsified asphalts are often predominantly either negatively or positively charged. Emulsified asphalts should be selected to be compatible with the available aggregate or sand. This practice will aid in identifying a cationic type of emulsified asphalt as defined by Specification D2397.
SCOPE
1.1 This practice is used to identify cationic emulsified asphalts. Positively charged particles are classified as cationic. Emulsified asphalts that don’t register a positive charge may also be classified as cationic slow-setting if they coat a specific type of negatively charged silica sand.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7402 −09 (Reapproved 2017)
Standard Practice for
Identifying Cationic Emulsified Asphalts
This standard is issued under the fixed designation D7402; 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 should be selected to be compatible with the available aggre-
gateorsand.Thispracticewillaidinidentifyingacationictype
1.1 This practice is used to identify cationic emulsified
of emulsified asphalt as defined by Specification D2397.
asphalts. Positively charged particles are classified as cationic.
Emulsified asphalts that don’t register a positive charge may
4. Sample Conditioning for Testing
also be classified as cationic slow-setting if they coat a specific
4.1 All emulsified asphalts shall be properly stirred to
type of negatively charged silica sand.
achieve homogeneity before testing.
1.2 The values stated in SI units are to be regarded as
4.2 All emulsified asphalts with viscosity testing require-
standard. No other units of measurement are included in this
ments of 50 °C shall be heated to 50 6 3 °C in the original
standard.
sample container in a water bath or oven.The container should
1.3 This standard does not purport to address all of the
be vented to relieve pressure. After the sample reaches 50 6
safety concerns, if any, associated with its use. It is the
3 °C, stir the sample to achieve homogeneity.
responsibility of the user of this standard to establish appro-
4.3 Emulsified asphalts with viscosity testing requirements
priate safety, health, and environmental practices and deter-
of25 °Cshouldbemixedorstirredat25 63 °Cintheoriginal
mine the applicability of regulatory limitations prior to use.
sample container to achieve homogeneity.
1.4 This international standard was developed in accor-
NOTE 1—Emulsified asphalts with viscosity testing requirements of
dance with internationally recognized principles on standard-
25 °C may be heated and stirred as specified in 4.2 if necessary. In the
ization established in the Decision on Principles for the
event the 4.2 method is used, the sample should be cooled to 25 63°C
Development of International Standards, Guides and Recom- before testing.
mendations issued by the World Trade Organization Technical
METHOD A
Barriers to Trade (TBT) Committee.
5. Apparatus
2. Referenced Documents
5.1 Current Source, of 12-V DC, a milliammeter, and a
2.1 ASTM Standards:
variable resistor (see Figs. 1 and 2).
C778 Specification for Standard Sand
5.2 Electrodes—Two stainless steel plates, approximately
D2397 Specification for Cationic Emulsified Asphalt
25 mm by 100 mm insulated from each other and rigidly held
E1 Specification for ASTM Liquid-in-Glass Thermometers
parallel 12.5 6 0.5 mm apart (see Fig. 3).
3. Significance and Use
5.3 Insulator—Polytetrafluoroethylene resin square rod, vir-
gin electrical grade, 12.5 6 0.5 mm thick (see Fig. 3).
3.1 Cationic emulsified asphalts are identified by the migra-
tion of the particles to a negatively charged electrode (cathode)
5.4 Glass Beaker, 250-mL.
by means of a direct current. Aggregates and sands used in
5.5 GlassRod, approximately 100 mm long and 6 mm thick
conjunction with emulsified asphalts are often predominantly
or other suitable material or device that is capable of insulating
either negatively or positively charged. Emulsified asphalts
and suspending the electrode assembly in emulsified asphalt.
5.6 Water Bath, capable of maintaining the required testing
temperature within the limits specified in this test method.
This practice is under the jurisdiction of ASTM Committee D04 on Road and
Paving Materials and is the direct responsibility of Subcommittee D04.42 on
5.7 Thermometer, ASTM 19C or 19F conforming to the
Emulsified Asphalt Test.
requirements of Specification E1 or equivalent thermometric
Current edition approved Oct. 1, 2017. Published October 2017. Originally
approved in 2009. Last previous edition approved in 2009 as D7402 – 09. DOI:
device.
10.1520/D7402-09R17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or 6. Hazards
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
6.1 Warning—Mercury has been designated by the United
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. States Environmental ProtectionAgency (EPA) and many state
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7402 − 09 (2017)
7.6 Observe the asphalt deposit on the electrodes.Acationic
emulsified asphalt will deposit a discernible amount of asphalt
on the cathode (negative electrode) while the anode (positive
electrode)willberelativelyclean.Anyevidenceofadepositof
asphalt on the cathode which is clearly discernible when
compared to the anode is to be considered passing.
8. Report
8.1 Report the following information:
8.1.1 Level of current used, and
8.1.2 Whether the tested emulsified asphalt passes or is
non-conclusive as defined in 7.6.
8.2 If the emulsified asphalt does not produce conclusive
results using Method A and it is purported to be a cationic
slow-setting grade, then proceed with Method B shown below
for identification of cationic slow-set emulsified asphalt.
FIG. 1 Particle Charge Tester
METHOD B
agencies as a hazardous material that can cause central nervous
9. Summary of Practice
system, kidney, and liver damage. Mercury, or its vapor, may
9.1 A weighed amount of washed and dried silica sand is
be hazardous to health and corrosive to materials. Caution
hand mixed with a weighed amount of emulsified asphalt.
should be taken when handling mercury and mercury-
Mixing time should extend until aggregate is completely
containing products. See the applicable product Material
coated. The amount of cationic slow-setting grade emulsified
Safety Data Sheet (MSDS) for details and the EPA’s website
asphalt in the mix should give a total mix asphalt content of
(www.epa.gov/mercury/faq.htm) for additional information.
about 5.0 %. The sample is spread out and allowed to air cure
Users should be aware that selling mercury and/or mercury-
for 24 h. The retained coating, after boiling, is determined.
containing products in yo
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