ASTM D7906-14
(Practice)Standard Practice for Recovery of Asphalt from Solution Using Toluene and the Rotary Evaporator
Standard Practice for Recovery of Asphalt from Solution Using Toluene and the Rotary Evaporator
SIGNIFICANCE AND USE
4.1 To determine the characteristics of the asphalt in an asphalt paving mixture, it is necessary to extract the asphalt from the aggregate by means of a suitable solvent and then to recover the asphalt from the solvent without significantly changing the asphalt’s properties. The asphalt recovered from the solvent by this practice can be tested using the same methods as for the original asphalt cement, and comparisons between the properties of the original and recovered asphalt can be made.
4.2 Users are cautioned that the recovered binder properties from an asphalt mixture sample may not exactly represent the properties of the original asphalt binder due to factors outside of laboratory control such as aging, contamination, and molecular changes caused by exposure to heat and solvents. Consequently, recovered asphalt binder properties should not be used as a basis for acceptance.Note 1—The quality of the results produced by this is dependent on the competence of the personnel performing the procedure and the capability, calibration, and maintenance of the equipment used. Agencies that meet the criteria of Specification D3666 are generally considered capable of competent and objective testing, sampling, inspection, and so forth. Users of this practice are cautioned that compliance with Specification D3666 alone does not completely assure reliable results. Reliable results depend on many factors; following the suggestions of Specification D3666 or some similar acceptable guideline provides a means of evaluating and controlling some of those factors.
SCOPE
1.1 This practice is intended to be used to recover asphalt from a solvent using the rotary evaporator to ensure that changes in the asphalt properties during the recovery process are minimized.
1.2 Units—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 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: D7906 − 14
Standard Practice for
Recovery of Asphalt from Solution Using Toluene and the
1
Rotary Evaporator
This standard is issued under the fixed designation D7906; 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 4. Significance and Use
1.1 This practice is intended to be used to recover asphalt
4.1 To determine the characteristics of the asphalt in an
from a solvent using the rotary evaporator to ensure that
asphalt paving mixture, it is necessary to extract the asphalt
changes in the asphalt properties during the recovery process
from the aggregate by means of a suitable solvent and then to
are minimized.
recover the asphalt from the solvent without significantly
changing the asphalt’s properties. The asphalt recovered from
1.2 Units—The values stated in SI units are to be regarded
the solvent by this practice can be tested using the same
as standard. No other units of measurement are included in this
methods as for the original asphalt cement, and comparisons
standard.
between the properties of the original and recovered asphalt
1.3 This standard does not purport to address all of the
can be made.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 4.2 Users are cautioned that the recovered binder properties
priate safety and health practices and determine the applica- from an asphalt mixture sample may not exactly represent the
bility of regulatory limitations prior to use. properties of the original asphalt binder due to factors outside
of laboratory control such as aging, contamination, and mo-
2. Referenced Documents
lecular changes caused by exposure to heat and solvents.
2
Consequently, recovered asphalt binder properties should not
2.1 ASTM Standards:
be used as a basis for acceptance.
D92 Test Method for Flash and Fire Points by Cleveland
Open Cup Tester
NOTE 1—The quality of the results produced by this is dependent on the
D2172/D2172M TestMethodsforQuantitativeExtractionof
competence of the personnel performing the procedure and the capability,
Bitumen From Bituminous Paving Mixtures calibration, and maintenance of the equipment used. Agencies that meet
the criteria of Specification D3666 are generally considered capable of
D3666 Specification for Minimum Requirements for Agen-
competent and objective testing, sampling, inspection, and so forth. Users
cies Testing and Inspecting Road and Paving Materials
of this practice are cautioned that compliance with Specification D3666
alone does not completely assure reliable results. Reliable results depend
3. Summary of Practice
on many factors; following the suggestions of Specification D3666 or
some similar acceptable guideline provides a means of evaluating and
3.1 The solution of solvent and asphalt from a prior extrac-
controlling some of those factors.
tion is first distilled by partially immersing the rotating
distillation flask of the rotary evaporator in a heated oil bath
5. Apparatus
while the solution is subjected to a partial vacuum. During the
5.1 Rotary Evaporator (see Fig. 1), equipped with distilla-
final stage of the process, vacuum is increased and nitrogen or
tion flask, variable speed motor capable of rotating the distil-
carbon dioxide gas is introduced to the solution to remove
lation flask at a rate of at least 40 rpm, condenser (Note 2),
remaining toluene and prevent further aging of the asphalt.The
solvent recovery flask, and heated oil bath. The angle of the
recovered asphalt can then be tested as required.
distillation flask from the horizontal to the bath is set at
approximately 30 6 10°. The distillation flask when fully
1 immersed in the oil bath should be at a depth of approximately
This practice is under the jurisdiction of ASTM Committee D04 on Road and
Paving Materials and is the direct responsibility of Subcommittee D04.25 on 40 mm.
Analysis of Bituminous Mixtures.
5.2 Distillation and Receiving Flasks, a distillation flask
Current edition approved Jan. 1, 2014. Published February 2014. DOI: 10.1520/
D7906-14.
with a minimum capacity of 1 L is required for the sufficient
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
recovery of asphalt binder. It is recommended for the receiving
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
flask to have a minimum capacity of 1-L to maximize the
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. amount of solvent recovery.
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