ASTM D6995-21

Standard Test Method for Determining Field VMA Based on the Maximum Specific Gravity of an Asphalt Mixture (G<inf>mm</inf>)

SIGNIFICANCE AND USE
4.1 Various users desire indication of compliance with VMA specifications for hot mix asphalt (HMA) during production.  
4.2 The standard practice for determining VMA requires that the bulk specific gravity of the aggregate components be determined. This is a very time-consuming test, which is not suitable for routine QC procedures.  
4.3 When an aggregate source used in the mix has a highly variable bulk specific gravity and a reference average bulk specific gravity (Gsb) (for example, as established in the mix design) is used to calculate VMA during HMA production, erroneous values may occur.  
4.4 The test for maximum specific gravity of the mix (Gmm) is a routine QC test at HMA plants. The effective specific gravity of the aggregate components (Gse) can be easily calculated from this test. However the Gse does not take into account the amount of asphalt absorbed, which is required for accurate VMA determination. This method provides a means to correct the Gse to account for the average absorbed asphalt. This procedure should not be used if the percent water absorption of the total (combined) aggregates varies between four tests, randomly obtained over a 30 day period, by more than 0.4 %.
SCOPE
1.1 This test method is intended to be used for a rapid field determination of voids in mineral aggregate (VMA) of asphalt mixture. It provides equations for calculating the VMA based on the asphalt content of the mix and its maximum specific gravity (Gmm). It is intended that this should be used for the rapid “field” determination of VMA during quality control (QC) operations at HMA plants, particularly where the specific gravity of the aggregate is highly variable.
Note 1: VMA determined using the rapid field method is VMA that has been corrected for aggregate absorption.  
1.2 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.  
1.3 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

• Status: Published
• Publication Date: 30-Apr-2021
• ICS: 93.080.20 - Road construction materials
• Technical Committee: D04 - Road and Paving Materials
• Drafting Committee: D04.21 - Specific Gravity and Density of Asphalt Mixtures

Relations

• Refers: ASTM D854-23 - Standard Test Methods for Specific Gravity of Soil Solids by the Water Displacement Method
• Effective Date: 01-Nov-2023
• Refers: ASTM D6857/D6857M-23 - Standard Test Method for Maximum Specific Gravity and Density of Asphalt Mixtures Using Automatic Vacuum Sealing Method
• Effective Date: 01-Nov-2023
• Refers: ASTM D2041/D2041M-19 - Standard Test Method for Theoretical Maximum Specific Gravity and Density of Asphalt Mixtures
• Effective Date: 01-Jun-2019
• Refers: ASTM D6307-19 - Standard Test Method for Asphalt Content of Asphalt Mixture by Ignition Method
• Effective Date: 01-Jan-2019
• Refers: ASTM D6857/D6857M-18 - Standard Test Method for Maximum Specific Gravity and Density of Asphalt Mixtures Using Automatic Vacuum Sealing Method
• Effective Date: 15-Aug-2018
• Refers: ASTM D2726/D2726M-17 - Standard Test Method for Bulk Specific Gravity and Density of Non-Absorptive Compacted Asphalt Mixtures
• Effective Date: 01-Jun-2017
• Refers: ASTM D6857/D6857M-17 - Standard Test Method for Maximum Specific Gravity and Density of Asphalt Mixtures Using Automatic Vacuum Sealing Method
• Effective Date: 01-Jun-2017
• Refers: ASTM D2172/D2172M-17 - Standard Test Methods for Quantitative Extraction of Asphalt Binder from Asphalt Mixtures
• Effective Date: 01-Apr-2017
• Refers: ASTM D2172/D2172M-17e1 - Standard Test Methods for Quantitative Extraction of Asphalt Binder from Asphalt Mixtures
• Effective Date: 01-Apr-2017
• Refers: ASTM D6307-16 - Standard Test Method for Asphalt Content of Asphalt Mixture by Ignition Method
• Effective Date: 01-May-2016
• Refers: ASTM D2726/D2726M-13 - Standard Test Method for Bulk Specific Gravity and Density of Non-Absorptive Compacted Bituminous Mixtures
• Effective Date: 01-Jul-2013
• Refers: ASTM C128-12 - Standard Test Method for Density, Relative Density (Specific Gravity), and Absorption of Fine Aggregate
• Effective Date: 01-Apr-2012
• Refers: ASTM C127-12 - Standard Test Method for Density, Relative Density (Specific Gravity), and Absorption of Coarse Aggregate
• Effective Date: 01-Apr-2012
• Refers: ASTM D6857/D6857M-11 - Standard Test Method for Maximum Specific Gravity and Density of Bituminous Paving Mixtures Using Automatic Vacuum Sealing Method
• Effective Date: 01-Jun-2011
• Refers: ASTM D2172/D2172M-11 - Standard Test Methods for Quantitative Extraction of Bitumen From Bituminous Paving Mixtures
• Effective Date: 01-Feb-2011

Overview

ASTM D6995-21, Standard Test Method for Determining Field VMA Based on the Maximum Specific Gravity of an Asphalt Mixture (Gmm), provides a rapid and practical procedure for determining the voids in mineral aggregate (VMA) of hot mix asphalt (HMA) in the field. This method utilizes measured values such as the maximum specific gravity of the asphalt mixture (Gmm), asphalt content, and the specific gravity values of the asphalt and aggregates to calculate VMA efficiently during quality control (QC) operations. It is particularly useful for situations where the aggregate bulk specific gravity exhibits significant variability and traditional laboratory methods are not feasible for routine plant QC.

Key Topics

• Field VMA Determination: The standard offers a rapid calculation for voids in mineral aggregate by correcting for aggregate asphalt absorption, ensuring more accurate field VMA values.
• Maximum Specific Gravity (Gmm): Utilization of Gmm allows for streamlined procedures in the plant environment, enhancing QC productivity.
• Quality Control in HMA Production: Supports ongoing compliant monitoring of asphalt mixtures during plant operations, especially when aggregate properties are subject to change.
• Correction Factor for Asphalt Absorption: The method incorporates a lab-established correction factor to account for the amount of asphalt absorbed by aggregates, which is essential for precise VMA calculation.

Applications

ASTM D6995-21 is widely applicable in scenarios requiring efficient, real-time assessment of VMA for HMA, making it integral for:

• Asphalt Plant Quality Control: Used by QC technicians and plant managers to monitor and adjust mix properties during HMA production, supporting compliance with VMA specifications.
• Mix Design Verification: Facilitates comparison of field VMA with mix design values, identifying discrepancies due to material source variability.
• Routine Production Testing: Enables frequent, repeatable VMA measurements without the time and labor intensity of traditional aggregate-specific gravity determination, ideal for settings where aggregate bulk specific gravity fluctuates.
• Regulatory and Performance Compliance: Aids organizations in meeting local, national, or international hot mix asphalt specifications by ensuring accurate VMA measurements for performance-based acceptance.

Related Standards

This test method references several other ASTM standards that support and complement its procedures:

• ASTM C127: Test Method for Relative Density and Absorption of Coarse Aggregate
• ASTM C128: Test Method for Relative Density and Absorption of Fine Aggregate
• ASTM D70/D70M: Test Method for Specific Gravity and Density of Semi-Solid Asphalt Binder
• ASTM D2041/D2041M: Test Method for Theoretical Maximum Specific Gravity and Density of Asphalt Mixtures
• ASTM D2172/D2172M: Test Methods for Quantitative Extraction of Asphalt Binder from Asphalt Mixtures
• ASTM D2726/D2726M: Test Method for Bulk Specific Gravity and Density of Compacted Asphalt Mixtures
• ASTM D6307: Test Method for Asphalt Content of Asphalt Mixture by Ignition Method
• ASTM D6857/D6857M: Test Method for Maximum Specific Gravity and Density Using Automatic Vacuum Sealing

These interconnected test methods establish a comprehensive approach for determining critical HMA properties, ensuring consistency and reliability in road construction and maintenance projects.

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Keywords: ASTM D6995-21, field VMA, hot mix asphalt, maximum specific gravity, Gmm, asphalt mixture QC, HMA production, aggregate absorption, VMA test method, asphalt plant quality control.

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:D6995 −21
Standard Test Method for
Determining Field VMA Based on the Maximum Specific
Gravity of an Asphalt Mixture (G )
mm
This standard is issued under the fixed designation D6995; 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 D2041/D2041M Test Method for Theoretical Maximum
Specific Gravity and Density of Asphalt Mixtures
1.1 This test method is intended to be used for a rapid field
D2172/D2172M TestMethodsforQuantitativeExtractionof
determination of voids in mineral aggregate (VMA) of asphalt
Asphalt Binder from Asphalt Mixtures
mixture. It provides equations for calculating the VMA based
D2726/D2726M Test Method for Bulk Specific Gravity and
on the asphalt content of the mix and its maximum specific
Density of Non-Absorptive Compacted Asphalt Mixtures
gravity (G ). It is intended that this should be used for the
mm
D6307 Test Method forAsphalt Content ofAsphalt Mixture
rapid “field” determination of VMA during quality control
by Ignition Method
(QC) operations at HMAplants, particularly where the specific
D6857/D6857M Test Method for Maximum Specific Grav-
gravity of the aggregate is highly variable.
ity and Density of Asphalt Mixtures Using Automatic
NOTE 1—VMA determined using the rapid field method is VMA that
Vacuum Sealing Method
has been corrected for aggregate absorption.
1.2 This standard does not purport to address all of the
3. Summary of Test Method
safety concerns, if any, associated with its use. It is the
3.1 The percent of (field)VMAin the mix can be calculated
responsibility of the user of this standard to establish appro-
by means of equations in which measured values for the
priate safety, health, and environmental practices and deter-
theoretical maximum specific gravity, the asphalt content, the
mine the applicability of regulatory limitations prior to use.
specific gravity of the asphalt, and the average bulk specific
1.3 This international standard was developed in accor-
gravity of the total aggregate and the compacted mix are
dance with internationally recognized principles on standard-
known.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
4. Significance and Use
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 4.1 Various users desire indication of compliance with
VMA specifications for hot mix asphalt (HMA) during pro-
2. Referenced Documents
duction.
2.1 ASTM Standards:
4.2 The standard practice for determining VMA requires
C127 Test Method for Relative Density (Specific Gravity)
that the bulk specific gravity of the aggregate components be
and Absorption of Coarse Aggregate
determined. This is a very time-consuming test, which is not
C128 Test Method for Relative Density (Specific Gravity)
suitable for routine QC procedures.
and Absorption of Fine Aggregate
4.3 When an aggregate source used in the mix has a highly
D70/D70M Test Method for Specific Gravity and Density of
variable bulk specific gravity and a reference average bulk
Semi-Solid Asphalt Binder (Pycnometer Method)
specific gravity (G ) (for example, as established in the mix
D854 Test Methods for Specific Gravity of Soil Solids by sb
design) is used to calculate VMA during HMA production,
Water Pycnometer
erroneous values may occur.
This test method is under the jurisdiction of ASTM Committee D04 on Road
4.4 The test for maximum specific gravity of the mix (G )
mm
and Paving Materials and is the direct responsibility of Subcommittee D04.21 on
is a routine QC test at HMA plants. The effective specific
Specific Gravity and Density of Asphalt Mixtures.
gravity of the aggregate components (G ) can be easily
se
Current edition approved May 1, 2021. Published May 2021. Originally
calculated from this test. However the G does not take into
approved in 2005. Last previous edition approved in 2013 as D6995 – 05 (2013).
se
DOI: 10.1520/D6995-21.
account the amount of asphalt absorbed, which is required for
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
accurateVMAdetermination.Thismethodprovidesameansto
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
correct the G to account for the average absorbed asphalt.
Standards volume information, refer to the standard’s Document Summary page on se
the ASTM website. This procedure should not be used if the percent water
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6995−21
absorption of the total (combined) aggregates varies between need periodic adjustment based on plant production (see 5.2.2
four tests, randomly obtained over a 30 day period, by more and Note 2). If the (C ) varies by more than 10 %, it should be
f
than 0.4 %. re-verified in accordance with 5.2.7.
NOTE2—VerificationTesting:Sincethismethoddependsontheasphalt
5. Procedure
absorption remaining constant, it is recommended that the bulk specific
5.1 DeterminethepercentoffieldVMAinacompactedmix gravity of each aggregate be tested approximately once per month during
productionandtheG (comb)revisedifthereisachangeof>0.015inany
sb
sample by first obtaining the following information and then
aggregate G .Acorresponding sample of plant mix should be obtained in
sb
calculating the value.
conjunction with this testing and the C verified.
f
5.2 Tests Run During the HMA Mix Design Procedure:
5.3.6 DeterminethefieldVMAinaccordancewith6.2using
5.2.1 Test Methods C127, C128, and D854—Determin
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D6995 − 05 (Reapproved 2013) D6995 − 21
Standard Test Method for
Determining Field VMA basedBased on the Maximum
Specific Gravity of the Mix an Asphalt Mixture (G )
mm
This standard is issued under the fixed designation D6995; 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
1.1 This test method is intended to be used for a rapid field determination of voids in mineral aggregate (VMA) of hot mix asphalt
(HMA).mixture. It provides equations for calculating the VMA based on the asphalt content of the mix and its maximum specific
gravity (G ). It is intended that this should be used for the rapid “field” determination of VMA during Quality Controlquality
mm
control (QC) operations at HMA plants, particularly where the specific gravity of the aggregate is highly variable.
NOTE 1—VMA determined using the rapid field method is VMA that has been corrected for aggregate absorption.
1.2 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.3 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.
2. Referenced Documents
2.1 ASTM Standards:
C127 Test Method for Relative Density (Specific Gravity) and Absorption of Coarse Aggregate
C128 Test Method for Relative Density (Specific Gravity) and Absorption of Fine Aggregate
D70D70/D70M Test Method for Specific Gravity and Density of Semi-Solid Asphalt Binder (Pycnometer Method)
D854 Test Methods for Specific Gravity of Soil Solids by Water Pycnometer
D2041D2041/D2041M Test Method for Theoretical Maximum Specific Gravity and Density of Asphalt Mixtures
D2172D2172/D2172M Test Methods for Quantitative Extraction of Asphalt Binder from Asphalt Mixtures
D2726D2726/D2726M Test Method for Bulk Specific Gravity and Density of Non-Absorptive Compacted Asphalt Mixtures
D6307 Test Method for Asphalt Content of Asphalt Mixture by Ignition Method
D6857/D6857M Test Method for Maximum Specific Gravity and Density of Asphalt Mixtures Using Automatic Vacuum Sealing
Method
3. Summary of Test Method
3.1 The percent of (field) VMA in the mix can be calculated by means of equations in which measured values for the theoretical
This test method is under the jurisdiction of ASTM Committee D04 on Road and Paving Materials and is the direct responsibility of Subcommittee D04.21 on Specific
Gravity and Density of BituminousAsphalt Mixtures.
Current edition approved June 1, 2013May 1, 2021. Published September 2013May 2021. Originally approved in 2005. Last previous edition approved in 20052013 as
D6995 – 05.D6995 – 05 (2013). DOI: 10.1520/D6995-05R13.10.1520/D6995-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6995 − 21
maximum specific gravity, the asphalt content, the specific gravity of the asphalt, and the average bulk specific gravity of the total
aggregate and the compacted mix are known.
4. Significance and Use
4.1 Various users desire indication of compliance with VMA specifications for hot mix asphalt (HMA) during production.
4.2 The standard practice for determining VMA requires that the bulk specific gravity of the aggregate components be determined.
This is a very time consuming time-consuming test, which is not suitable for routine QC procedures.
4.3 When an aggregate source used in the mix has a highly variable bulk specific gravity and a reference average bulk specific
gravity (G ) (for example, as established in the mix design) is used to calculate VMA during HMA production, erroneous values
sb
may occur.
4.4 The test for maximum specific gravity of the mix (G ) is a routine QC test at HMA plants. The effective specific gravity of
mm
the aggregate components (G ) can be easily calculated from this test. However the G does not take into account the amount
se se
of asphalt absorbed, which is required for accurate VMA determination. This method provides a means to correct the G to account
se
for the average absorbed asphalt. This procedure should not be used if the percent water absorption of the total (combined)
aggregates varies between four tests, randomly obtained over a 30 day period, by more than 0.4 %.
5. Procedure
5.1 Determine the percent of field VMA in a compacted mix sample by first obtaining the following information and then
calculating the value.
5.2 Tests Run During the HMA Mix Design ProcedureTests Run During the HMA Mix Design Procedure:
5.2.1 Test MethodMethods C127, C128, and D854—Determine the average bulk specific gravity (G ) of the three (3) samples of
sb
each fine and coarse aggregates,aggregate, and mineral filler, if applicable. Once this value is determined it should be used in the
calculations in section 6.1.1 until a change in the plant produced mix occurs.
NOTE 1—It is recommended that a minimum of three sets of tests (one for each aggregate) should be averaged to establish this bulk specific gravity.
5.2.2 Use the percent by weight of each aggregate established in the mix design in the calculation in section 6.1.1. If the percent
of individual aggregates in the mix is changed during production, a new G (comb) should be calculated per section 6.1.1, using
sb
the new percentages.
5.2.3 Test Method D70D70/D70M—Determine the specific gravity of the asphalt binder (G )).
b
5.2.4 Determine the bulk specific gravity of the combined aggregates in the mix (Gmix, G (comb)(comb), in accordance with the
sb
formula in section 6.1.1, using the values established above.
5.2.5 Test Method D2041/D2041M or D6857/D6857M—Determine the maximum specific gravity of the mix (G ) according to
mm
the mix design at optimum asphalt content.
5.2.5.1 If there is a short-term aging protocol for the plant mix by an agency, it
...