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Standard Specification for

Performance-Graded Asphalt
Binder Using Multiple Stress
Creep Recovery (MSCR) Test

AASHTO Designation: M 332-191

Technical Subcommittee: 2b, Liquid Asphalt
Release: Group 3 (July)

American Association of State Highway and Transportation Officials

444 North Capitol Street N.W., Suite 249
Washington, D.C. 20001
 Copyrighted material licensed to Adrianna Salamanca on 2019-10-31 for licensee's use only.
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Standard Specification for

Performance-Graded Asphalt Binder Using

Multiple Stress Creep Recovery (MSCR) Test

AASHTO Designation: M 332-191

Technical Subcommittee: 2b, Liquid Asphalt
Release: Group 3 (July)

1. SCOPE
1.1. This specification covers asphalt binders graded by performance using the multiple stress creep
recovery (MSCR) test. Grading designations are related to the average seven-day maximum
pavement design temperature, minimum pavement design temperature, and traffic loading.

1.2. This specification incorporates T 350 for determining non-recoverable creep compliance, Jnr. “S,”
“H,” “V,” or “E” designations must be specified for standard, high, very high, or extremely high
traffic loading, respectively.
Note 1—For asphalt cements graded by viscosity at 60°C, see M 226.
Note 2—For performance-graded asphalt binder, see M 320.

1.3. To ensure that the asphalt binder exhibits elastic response, the specifying agency may require
compliance with R 92.

2. REFERENCED DOCUMENTS
2.1. AASHTO Standards:
 M 226, Viscosity-Graded Asphalt Cement
 M 320, Performance-Graded Asphalt Binder
 M 323, Superpave Volumetric Mix Design
 R 28, Accelerated Aging of Asphalt Binder Using a Pressurized Aging Vessel (PAV)
 R 35, Superpave Volumetric Design for Asphalt Mixtures
 R 66, Sampling Asphalt Materials
 R 92, Evaluating the Elastic Behavior of Asphalt Binders Using the Multiple Stress Creep
Recovery (MSCR) Test
 T 44, Solubility of Bituminous Materials
 T 48, Flash and Fire Points by Cleveland Open Cup
 T 240, Effect of Heat and Air on a Moving Film of Asphalt Binder (Rolling Thin-Film
Oven Test)
 T 313, Determining the Flexural Creep Stiffness of Asphalt Binder Using the Bending Beam
Rheometer (BBR)
 T 314, Determining the Fracture Properties of Asphalt Binder in Direct Tension (DT)
 T 315, Determining the Rheological Properties of Asphalt Binder Using a Dynamic Shear
Rheometer (DSR)

TS-2b M 332-1 AASHTO

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 T 316, Viscosity Determination of Asphalt Binder Using Rotational Viscometer
 T 350, Multiple Stress Creep Recovery (MSCR) Test of Asphalt Binder Using a Dynamic
Shear Rheometer (DSR)

2.2. ASTM Standards:

 D8, Standard Terminology Relating to Materials for Roads and Pavements
 D5546, Standard Test Method for Solubility of Asphalt Binders in Toluene by Centrifuge
(withdrawn 2017)

3. TERMINOLOGY
3.1. Definitions:

3.1.1. Definitions for many terms common to asphalt binder are found in ASTM D8.

3.1.2. asphalt binder—an asphalt-based cement that is produced from petroleum residue either with or
without the addition of nonparticulate organic modifiers.

4. ORDERING INFORMATION
4.1. When ordering under this specification, include in the purchase order the performance grade (PG)
of asphalt binder required including the designation for traffic loading (e.g., M 332, PG 64V-22).

4.1.1. If required to comply with the elastic response requirements in R 92, include reference to R 92 in
the purchase order (e.g., M 332, PG 64V-22, R 92, Percent Recovery of X).

4.2. The required environmental asphalt binder grades may be selected by following the procedures
described in M 323 and R 35, except do not use the “grade bumping” procedure in M 323. Select
the environmentally appropriate high- and low-temperature grades and the appropriate “S,” “H,”
“V,” or “E” grade for the expected traffic level and traffic load rate.

4.2.1. Standard Designation “S” in most typical situations will be for traffic levels fewer than 10 million
Equivalent Single Axle Loads (ESALs) and more than the standard traffic speed (>70 km/h).

4.2.2. High Designation “H” in most situations will be for traffic levels of 10 to 30 million ESALs or
slow-moving traffic (20 to 70 km/h).

4.2.3. Very High Designation “V” in most situations will be for traffic levels of greater than 30 million
ESALs or standing traffic (< 20 km/h).

4.2.4. Extremely High Designation “E” in most situations will be for traffic levels of greater than
30 million ESALs and standing traffic (< 20 km/h) such as toll plazas or port facilities.
Note 3—“Grade bumping” is accomplished by using “H,” “V,” or “E” designations and not by
increasing the PG high-temperature grade as recommended in M 323.

5. MATERIALS AND MANUFACTURE

5.1. Asphalt binder shall be prepared by the refining of crude petroleum by suitable methods, with or
without the addition of modifiers.

TS-2b M 332-2 AASHTO

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5.2. Modifiers may be any organic material of suitable manufacture that is used in virgin or
recycled condition and that is dissolved, dispersed, or reacted in asphalt binder to enhance
its performance.

5.3. The asphalt binder shall be homogeneous, free from water and deleterious materials, and shall not
foam when heated to 175°C.

5.4. The asphalt binder shall be at least 99.0 percent soluble as determined by T 44 or ASTM D5546.

5.5. This specification is not applicable for asphalt binders in which fibers or other discrete particles
are larger than 250 μm in size.

5.6. The grades of asphalt binder shall conform to the requirements given in Table 1.

5.7. If required to exhibit an elastic response, the asphalt binder shall conform to the requirements of
R 92.

6. SAMPLING
6.1. The material shall be sampled in accordance with R 66.

7. TEST METHODS
7.1. The properties outlined in Sections 5.3, 5.4, and 5.6 shall be determined in accordance with R 28,
T 44, or ASTM D5546, T 48, T 240, T 313, T 314, T 315, T316, and T 350.

8. INSPECTION AND CERTIFICATION

8.1. Inspection and certification of the material shall be agreed on between the purchaser and the seller.
Specific requirements shall be part of the purchase contract. The seller shall provide material
handling and storage procedures to the purchaser for each asphalt binder grade certified.

9. REJECTION AND RETESTING

9.1. If the results of any test do not conform to the requirements of this specification, retesting to
determine conformity is performed as indicated in the purchase order or as otherwise agreed on
between the purchaser and the seller.

10. KEYWORDS
10.1. Asphalt binder; asphalt cement; direct tension; flash point; modifier; multiple stress creep recovery
(MSCR); performance specifications; pressure aging; rheology.

TS-2b M 332-3 AASHTO

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Table 1—Performance-Graded Asphalt Binder Specificationa
PG 46 PG 52 PG 58
Performance Grade
34 40 46 10 16 22 28 34 40 46 16 22 28 34 40
Average 7-day max pavement design temp,
<46 <52 <58
°Cb
Min pavement design temp, °Cb >–34 >–40 >–46 >–10 >–16 >–22 >–28 >–34 >–40 >–46 >–16 >–22 >–28 >–34 >–40
Original Binder
Flash point temp, T 48, min °C 230
Viscosity, T 316:c
135
max 3 Pa•s, test temp, °C
Dynamic shear, T 315:d
G*/sinδ, min 1.00 kPa e 46 52 58
test temp @ 10 rad/s, °C
Rolling Thin-Film Oven Residue (T 240)
Mass change, max, percent f 1.00
MSCR, T 350:
Standard Traffic “S”
Jnr3.2, max 4.5 kPa–1 46 52 58
Jnrdiff , max 75% g
test temp, °C
MSCR, T 350:
Heavy Traffic “H”
Jnr3.2, max 2.0 kPa–1 46 52 58
Jnrdiff , max 75% g
test temp, °C
MSCR, T 350:
Very Heavy Traffic “V”
Jnr3.2, max 1.0 kPa–1 46 52 58
Jnrdiff , max 75% g
test temp, °C
MSCR, T 350:
Extremely Heavy Traffic “E”
Jnr3.2, max 0.5 kPa–1 46 52 58

test temp, °C
Pressurized Aging Vessel Residue (R 28)
PAV aging temp, °C h 90 90 100
Dynamic shear, T 315:
“S”
10 7 4 25 22 19 16 13 10 7 25 22 19 16 13
G* sinδ, max 5000 kPae
test temp @ 10 rad/s, °C
Dynamic shear, T 315:
“H,” “V,” “E”
10 7 4 25 22 19 16 13 10 7 25 22 19 16 13
G* sinδ, max 6000 kPae
test temp @ 10 rad/s, °C
Creep stiffness, T 313:i
S, max 300 MPa
–24 –30 –36 0 –6 –12 –18 –24 –30 –36 –6 –12 –18 –24 –30
m-value, min 0.300
test temp @ 60 s, °C
Direct tension, T 314:i
Failure strain, min 1.0% –24 –30 –36 0 –6 –12 –18 –24 –30 –36 –6 –12 –18 –24 –30
test temp @ 1.0 mm/min, °C
a
MSCR testing on RTFO residue should be performed at the PG grade based on the environmental high pavement temperature. Grade bumping is accomplished by requiring a lower Jnr
value while testing at the environmental temperature.
b
Pavement temperatures are estimated from air temperatures using an algorithm contained in the LTPP Bind program, may be provided by the specifying agency, or by following the
procedures as outlined in M 323 and R 35, excluding the provisions for “grade bumping.”
c
This requirement may be waived at the discretion of the specifying agency if the supplier warrants that the asphalt binder can be adequately pumped and mixed at temperatures that meet all
applicable safety standards.
d
For quality control of unmodified asphalt binder production, measurement of the viscosity of the original asphalt binder may be used to supplement dynamic shear measurements of G*/sinδ
at test temperatures where the asphalt is a Newtonian fluid.
e
G*/sinδ = high temperature stiffness and G* sinδ = intermediate temperature stiffness.
f
The mass change shall be less than 1.00 percent for either a positive (mass gain) or a negative (mass loss) change.
g
The Jnrdiff requirement shall not apply to asphalt binders having a Jnr3.2 value of 0.5 kPa–1 or lower at the selected test temperature. For each grade, the Jnr is a maximum value. A binder that
has a Jnr of 0.4 may be supplied as an E grade, and may also be supplied as a V, H, or S grade as well.
h
The PAV aging temperature is based on simulated climatic conditions and is one of three temperatures, 90°C, 100°C, or 110°C. Normally the PAV aging temperature is 100°C for PG 58-
xx and above. However, in desert climates, the PAV aging temperature for PG 70-xx and above may be specified as 110°C.
i
If the creep stiffness is below 300 MPa, the direct tension test is not required. If the creep stiffness is between 300 and 600 MPa, the direct tension failure strain requirement can be used in
lieu of the creep stiffness requirement. The m-value requirement must be satisfied in both cases.
Continued on next page.

TS-2b M 332-4 AASHTO

© 2019 by the American Association of State Highway and Transportation Officials.
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 Copyrighted material licensed to Adrianna Salamanca on 2019-10-31 for licensee's use only.
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Table 1—Performance-Graded Asphalt Binder Specificationa (Continued)
PG 64 PG 70
Performance Grade
10 16 22 28 34 40 10 16 22 28 34 40
Average 7-day max
<64 <70
pavement design temp, °Cb
Min pavement design
>–10 >–16 >–22 >–28 >–34 >–40 >–10 >–16 >–22 >–28 >–34 >–40
temp, °Cb
Original Binder
Flash point temp, T 48, min °C 230
Viscosity, T 316:c
135
max 3 Pa•s, test temp, °C
Dynamic shear, T 315: d

G*/sinδ, min 1.00 kPae 64 70

test temp @ 10 rad/s, °C
Rolling Thin-Film Oven Residue (T 240)
Mass change, max, percent f 1.00
MSCR, T 350:
Standard Traffic “S”
Jnr3.2, max 4.5 kPa–1 64 70
Jnrdiff, max 75% g
test temp, °C
MSCR, T 350:
Heavy Traffic “H”
Jnr3.2, max 2.0 kPa–1 64 70
Jnrdiff, max 75% g
test temp, °C
MSCR, T 350:
Very Heavy Traffic “V”
Jnr3.2, max 1.0 kPa–1 64 70
Jnrdiff, max 75%g
test temp, °C
MSCR, T 350:
Extremely Heavy Traffic “E”
64 70
Jnr3.2, max 0.5 kPa–1
test temp, °C
Pressurized Aging Vessel Residue (R 28)
PAV aging temp, °Ch 100 100 (110)
Dynamic shear, T 315:
“S”
31 28 25 22 19 16 34 31 28 25 22 19
G* sinδ, max 5000 kPae
test temp @ 10 rad/s, °C
Dynamic shear, T 315:
“H,” “V,” “E”
31 28 25 22 19 16 34 31 28 25 22 19
G* sinδ, max 6000 kPae
test temp @ 10 rad/s, °C
Creep stiffness, T 313:i
S, max 300 MPa
0 –6 –12 –18 –24 –30 0 –6 –12 –18 –24 –30
m-value, min 0.300
test temp @ 60 s, °C
Direct tension, T 314:i
Failure strain, min 1.0% 0 –6 –12 –18 –24 –30 0 –6 –12 –18 –24 –30
test temp @ 1.0 mm/min, °C
a
MSCR test on RTFO residue should be performed at the PG grade based on the environmental high pavement temperature. Grade bumping is accomplished by requiring a lower Jnr value
while testing at the environmental temperature.
b
Pavement temperatures are estimated from air temperatures using an algorithm contained in the LTPP Bind program, may be provided by the specifying agency, or by following the
procedures as outlined in M 323 and R 35, excluding the provisions for “grade bumping.”
c
This requirement may be waived at the discretion of the specifying agency if the supplier warrants that the asphalt binder can be adequately pumped and mixed at temperatures that meet all
applicable safety standards.
d
For quality control of unmodified asphalt binder production, measurement of the viscosity of the original asphalt binder may be used to supplement dynamic shear measurements of G*/sinδ
at test temperatures where the asphalt is a Newtonian fluid.
e
G*/sinδ = high temperature stiffness and G* sinδ = intermediate temperature stiffness.
f
The mass change shall be less than 1.00 percent for either a positive (mass gain) or a negative (mass loss) change.
g
The Jnrdiff requirement shall not apply to asphalt binders having a Jnr3.2 value of 0.5 kPa–1 or lower at the selected test temperature. For each grade, the Jnr is a maximum value. A binder that
has a Jnr of 0.4 may be supplied as an E grade, and may also be supplied as a V, H, or S grade as well.
h
The PAV aging temperature is based on simulated climatic conditions and is one of three temperatures, 90°C, 100°C, or 110°C. Normally the PAV aging temperature is 100°C for PG 58-
xx and above. However, in desert climates, the PAV aging temperature for PG 70-xx and above may be specified as 110°C.
i
If the creep stiffness is below 300 MPa, the direct tension test is not required. If the creep stiffness is between 300 and 600 MPa, the direct tension failure strain requirement can be used in
lieu of the creep stiffness requirement. The m-value requirement must be satisfied in both cases.
Continued on next page.

TS-2b M 332-5 AASHTO

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Table 1—Performance-Graded Asphalt Binder Specificationa (Continued)
PG 76 PG 82
Performance Grade
10 16 22 28 34 10 16 22 28 34
Average 7-day max
<76 <82
pavement design temp, °Cb
Min pavement design
>–10 >–16 >–22 >–28 >–34 >–10 >–16 >–22 >–28 >–34
temp, °Cb
Original Binder
Flash point temp, T 48, min°C 230
Viscosity, T 316:c
135
max 3 Pa•s, test temp, °C
Dynamic shear, T 315: d

G*/sin δ, min 1.00 kPae 76 82

test temp @ 10 rad/s, °C
Rolling Thin-Film Oven Residue (T 240)
Mass change, max, percent f 1.00
MSCR, T 350:
Standard Traffic “S”
Jnr3.2, max 4.5 kPa–1 76 82
Jnrdiff, max 75% g
test temp, °C
MSCR, T 350:
Heavy Traffic “H”
Jnr3.2, max 2.0 kPa–1 76 82
Jnrdiff, max 75% g
test temp, °C
MSCR, T 350:
Very Heavy Traffic “V”
Jnr3.2, max 1.0 kPa–1 76 82
Jnrdiff, max 75%g
test temp, °C
MSCR, T 350:
Extremely Heavy Traffic “E”
76 82
Jnr3.2, max 0.5 kPa–1
test temp, °C
Pressurized Aging Vessel Residue (R 28)
PAV aging temp, °Ch 100 (110) 100 (110)
Dynamic shear, T 315:
“S”
37 34 31 28 25 40 37 34 31 28
G* sinδ, max 5000 kPae
test temp @ 10 rad/s, °C
Dynamic shear, T 315:
“H,” “V,” “E”
37 34 31 28 25 40 37 34 31 28
G* sinδ, max 6000 kPae
test temp @ 10 rad/s, °C
Creep stiffness, T 313:i
S, max 300 MPa
0 –6 –12 –18 –24 0 –6 –12 –18 –24
m-value, min 0.300
test temp @ 60 s, °C
Direct tension, T 314:i
Failure strain, min 1.0% 0 –6 –12 –18 –24 0 –6 –12 –18 –24
test temp @ 1.0 mm/min, °C
a
MSCR test on RTFO residue should be performed at the PG grade based on the environmental high pavement temperature. Grade bumping is accomplished by requiring a lower Jnr value
while testing at the environmental temperature.
b
Pavement temperatures are estimated from air temperatures using an algorithm contained in the LTPP Bind program, may be provided by the specifying agency, or by following the
procedures as outlined in M 323 and R 35, excluding the provisions for “grade bumping.”
c
This requirement may be waived at the discretion of the specifying agency if the supplier warrants that the asphalt binder can be adequately pumped and mixed at temperatures that meet all
applicable safety standards.
d
For quality control of unmodified asphalt binder production, measurement of the viscosity of the original asphalt binder may be used to supplement dynamic shear measurements of G*/sinδ
at test temperatures where the asphalt is a Newtonian fluid.
e
G*/sinδ = high temperature stiffness and G* sinδ = intermediate temperature stiffness.
f
The mass change shall be less than 1.00 percent for either a positive (mass gain) or a negative (mass loss) change.
g
The Jnrdiff requirement shall not apply to asphalt binders having a Jnr3.2 value of 0.5 kPa–1 or lower at the selected test temperature. For each grade, the Jnr is a maximum value. A binder that
has a Jnr of 0.4 may be supplied as an E grade, and may also be supplied as a V, H, or S grade as well.
h
The PAV aging temperature is based on simulated climatic conditions and is one of three temperatures, 90°C, 100°C, or 110°C. Normally the PAV aging temperature is 100°C for PG 58-
xx and above. However, in desert climates, the PAV aging temperature for PG 70-xx and above may be specified as 110°C.
i
If the creep stiffness is below 300 MPa, the direct tension test is not required. If the creep stiffness is between 300 and 600 MPa, the direct tension failure strain requirement can be used in
lieu of the creep stiffness requirement. The m-value requirement must be satisfied in both cases.

1
Formerly AASHTO Provisional Standard MP 19. First published as a full standard in 2014.

TS-2b M 332-6 AASHTO

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