ABSTRACT
Chapter 9 is composed of questions and problems, which deal with the properties of asphalt binders including the Superpave properties and the specifications required for these properties. Despite that asphalt binder composes only about 5% of the asphalt mixture, but this material is considered an important part in the mixture due to the binding effect and the natural characteristics it has including durability, viscoelasticity, adhesion, and strength. Accordingly, the characterization of this material and the control of its properties are essential to optimize the properties of the asphalt mixture used for the construction of highway pavements. Although there have been lot of developments in the Superpave asphalt binder tests in the last decade including the Multiple Stress Creep Recovery (MSCR) test and the Linear Amplitude Sweep (LAS) test, but this chapter focuses on the main characterization tests required to evaluate the asphalt binder and its suitability for the use in asphalt paving mixtures based on the Superpave specifications and the well-known test methods. The Multiple Stress Creep Recovery (MSCR) test and the Linear Amplitude Sweep (LAS) test which are heavily used in research studies are conducted using the Dynamic Shear Rheometer (DSR) that is one of the devices used for the characterization methods in this chapter. The MSCR test evaluates the asphalt binder’s potential for permanent deformation, while, the LAS test evaluates the ability of asphalt binder to resist fatigue damage.
In Table 9.1, there are different asphalt binders classified either according to penetration, viscosity, or performance grade (PG) values. Compare the set in the first column with that in the third column of the table in terms of the property value in the fourth column (use >, <, or =).
Solution:
See Table 9.2.250
Write down the standard test conditions for each of the asphalt binder tests in Table 9.3.
Solution:
See Table 9.4.251
Write down the specification for each of the Superpave asphalt binder test parameters shown in Table 9.5.
Solution:
See Table 9.6.252
Write down the correct performance parameter and specification value in the proper place for each of the following Superpave asphalt binder tests (see Table 9.7).
Solution:
See Table 9.8.
Write down a check mark (√) in the appropriate space for each of the Superpave tests shown in Table 9.9 based on the temperature range at which each test is performed.253
Solution:
See Table 9.10.
Write down a check mark (√) in the appropriate space for each of the Superpave tests shown in Table 9.11 based on the aging condition of the asphalt binder that each test uses.
Solution:
See Table 9.12.254
In Table 9.13, match the standard asphalt binder test in the left column with the correct property in the right column that suits the test.
Solution:
See Table 9.14.255
In a standard Superpave rotational viscosity (RV) test of an asphalt binder sample, if the effective length of the spindle is 33.02 mm, the radius of the spindle is 9.525 mm, and the radius of the container is 11.76 mm, determine the shear strain rate (sec−1).
Solution:
The following formula is used to determine the shear strain rate (γ) of the asphalt binder:
γ = 2 ω R c 2 R s 2 x 2 ( R c 2 − R s 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0001.tif"/>
Where:
γ = shear rate (sec−1)
ω = rotational speed (rad/s)
Rc = radius of the container (m)
Rs = radius of the spindle (m)
x = radial distance from axis of the container to the point where shear rate is being calculated (m).
In this problem, Rc = 11.76 mm = 0.01176 m, Rs = 9.525 mm = 0.009525 m.
The standard rotational speed in a standard Superpave RV test is equal to:
ω = 20 rpm = 20 × 2 π 60 = 2.094 rad/s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0002.tif"/>
A typical value for the shear strain rate is calculated at the surface of the spindle; and therefore, x is equal to the radius of the spindle in this case; i.e., x = 9.525 mm = 0.009525 m.
⇒
γ = 2 ( 2.094 ) ( 0.01176 ) 2 ( 0.009525 ) 2 ( 0.009525 ) 2 [ ( 0.01176 ) 2 − ( 0.009525 ) 2 ] = 12.2 sec − 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0003.tif"/>
The MS Excel worksheet used to solve this problem is shown in Figure 9.1.256
In a rotational viscosity test, if the radius of the spindle is 9.525 mm and the radius of the container is 11.76 mm, determine the rotational viscosity (Pa.s) at a shear stress of 5 Pa and a standard rotational speed (ω) of 20 rpm.
Solution:
The same formula for the shear strain rate (γ) shown below is used:
γ = 2 ω R c 2 R s 2 x 2 ( R c 2 − R s 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0004.tif"/>
The standard rotational speed in a standard Superpave RV test is equal to:
ω = 20 rpm = 20 × 2 π 60 = 2.094 rad/s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0005.tif"/>
⇒
γ = 2 ( 2.094 ) ( 0.01176 ) 2 ( 0.009525 ) 2 ( 0.009525 ) 2 [ ( 0.01176 ) 2 − ( 0.009525 ) 2 ] = 12.2 sec − 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0006.tif"/>
The rotational viscosity is determined using the following formula:
η = τ γ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0007.tif"/>
Where:
η = rotational viscosity (Pa.s)
τ = applied shear stress (Pa)
γ = resulting shear strain rate (sec−1)
⇒
η = 5 12.2 = 0.411 Pa .s = 411 cPoise = 411 mPa .s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0008.tif"/>
Since 1 Pa.s = 10 Poise = 1000 cPoise = 1000 mPa.s
The MS Excel worksheet used to solve this problem is shown in Figure 9.2.257
Determine the shear stress applied on an asphalt binder sample having a rotational viscosity of 500 cPoise in a standard Superpave rotational viscosity (RV) test, if the radius of the spindle is 9.525 mm and the radius of the container is 11.76 mm.
Solution:
The same formula for the shear strain rate (γ) shown below is used:
γ = 2 ω R c 2 R s 2 x 2 ( R c 2 − R s 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0009.tif"/>
The standard rotational speed in a standard Superpave RV test is equal to:
ω = 20 rpm = 20 × 2 π 60 = 2.094 rad/s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0010.tif"/>
⇒
γ = 2 ( 2.094 ) ( 0.01176 ) 2 ( 0.009525 ) 2 ( 0.009525 ) 2 [ ( 0.01176 ) 2 − ( 0.009525 ) 2 ] = 12.2 sec − 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0011.tif"/>
Using the formula shown below, the shear stress can be determined (see Figure 9.3):
η = τ γ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0012.tif"/>
η = 500 cPoise = 0.500 Pa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0013.tif"/> 258
⇒
0.500 = τ 12.2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0014.tif"/>
⇒
τ = 0.500 × 12.2 = 6.1 Pa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0015.tif"/>
Determine the torque applied to an asphalt binder sample having a rotational viscosity of 800 cPoise in a standard Superpave rotational viscosity (RV) test if the effective length of the spindle is 33.02 mm, the radius of the spindle is 9.525 mm, and the radius of the container is 11.76 mm.
Solution:
The same formula for the shear strain rate (γ) shown below is used:
γ = 2 ω R c 2 R s 2 x 2 ( R c 2 − R s 2 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0016.tif"/>
The standard rotational speed in a standard Superpave RV test is equal to:
ω = 20 rpm = 20 × 2 π 60 = 2.094 rad/s https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0017.tif"/>
⇒
γ = 2 ( 2.094 ) ( 0.01176 ) 2 ( 0.009525 ) 2 ( 0.009525 ) 2 [ ( 0.01176 ) 2 − ( 0.009525 ) 2 ] = 12.2 sec − 1 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0018.tif"/>
Using the formula shown below, the shear stress can be determined:259
η = τ γ https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0019.tif"/>
η = 800 cPoise = 0.800 Pa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0020.tif"/>
⇒
0.800 = τ 12.2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0021.tif"/>
⇒
τ = 0.800 × 12.2 = 9.7 Pa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0022.tif"/>
Using the following formula, the torque applied to the asphalt binder sample is calculated:
τ = T 2 π R s 2 L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0023.tif"/>
Where:
τ = applied shear stress (Pa)
T = torque applied to the asphalt binder sample (N.m)
Rs = radius of the spindle (m)
L = effective length of the spindle (m)
⇒
τ = T 2 π R s 2 L https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0024.tif"/>
9.7 = T 2 π ( 0.009525 ) 2 ( 0.03302 ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0025.tif"/>
⇒
T = 0.000183 N .m = 0.183 N .mm https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0026.tif"/>
The computations of the results of this problem are performed using the MS Excel worksheet shown in Figure 9.4.260
If the relationship between an asphalt binder’s shear stress, τ (Pa) and shear strain rate, γ (sec−1) at a specific temperature is given by: τ = 1.2γ, determine the viscosity of the asphalt binder and describe the behavior of the asphalt binder based on this relationship.
Solution:
Since the relationship between the shear stress and the shear strain rate of the asphalt binder is linear and the viscosity is defined as the shear stress divided by the shear strain rate, the viscosity in this case is constant and equal to the slope of this relationship; i.e., the viscosity = 1.2 Pa.s. Consequently, the behavior of the asphalt binder is Newtonian behavior.
The relationship between a polymer-modified asphalt binder’s rotational viscosity, RV (cP) and shear strain rate, γ (sec−1) at a specific temperature is given by: RV = 226.6 − 50.3 ln γ, describe the behavior of the modified asphalt binder in this case.
Solution:
From the relationship between the rotational viscosity and the shear strain rate; as the shear strain rate increases, the rotational viscosity decreases. This behavior is called a non-Newtonian behavior (shear-softening or thinning behavior).
By plotting this relationship over a rotational speed range of 1 to 100 rpm (shear strain rate range between 0.609 and 60.9 rad/s) using an arithmetic scale, the following figure is obtained (see Figure 9.5).261
Using a semi-log scale, the relationship is plotted as in Figure 9.6.
The data used to plot the above relationship in both figures is summarized in Table 9.15.262
If the time lag between the maximum applied shear stress and the maximum resulting shear strain in a standard DSR test for an asphalt binder is 0.135 seconds, compute the phase angle for this asphalt binder.
Solution:
The phase angle is computed using the formula shown below:
δ = time lag × f × 360 ° https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0027.tif"/>
Where:
δ = phase angle (degrees)
f = standard loading frequency used in the DSR test (1.59 Hz = 10 rad/s).
The standard loading frequency in a Superpave DSR test = 1.59 Hz (10 rad/s)
⇒
δ = 0 .135 × 1.59 × 360 ° = 77.3 ° https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0028.tif"/>
Figure 9.7 shows an image of the MS Excel worksheet computations for this problem.
What is the Superpave performance grade (PG) of an asphalt binder that is passing the Superpave DSR test at a maximum temperature of 54°C and the BBR test at a minimum temperature of −14°C assuming that it passes the intermediate temperature DSR test?
Solution:
Since the asphalt binder passes the DSR test at a maximum temperature of 54°C, the Superpave high PG grade is 52. And since the asphalt binder passes the BBR test at a minimum temperature of −14°C, it will pass a minimum temperature of −14−10 = −24°C in the field. There is a −10°C-shift between the lab and the field for low-temperature specifications. Therefore, the Superpave low PG grade is −22. In conclusion, the performance grade of this asphalt binder is PG 52-22.263
What is the Superpave performance grade (PG) of an asphalt binder that is passing the Superpave DSR test at a maximum temperature of 62°C and the BBR test at a minimum temperature of −8°C assuming that it passes the intermediate temperature DSR test?
Solution:
Since the asphalt binder passes the DSR test at a maximum temperature of 62°C, the Superpave high PG grade is 58. And since the asphalt binder passes the BBR test at a minimum temperature of −12°C, it will pass a minimum temperature of −8−10 = −18°C in the field. There is a −10°C-shift between the lab and the field for low-temperature specifications. Therefore, the Superpave low PG grade is −16. In conclusion, the performance grade of this asphalt binder is PG 58-16.
What would be the Superpave performance grade (PG) of an asphalt binder that is passing the Superpave asphalt binder grading tests in the laboratory at a maximum temperature of 66°C and at a minimum temperature of −7°C?
Solution:
Since the asphalt binder passes the Superpave asphalt binder grading tests at a maximum temperature of 66°C, the Superpave high PG grade is 64. And since the asphalt binder passes the Superpave asphalt binder grading tests at a minimum temperature of −7°C, it will pass a minimum temperature of −7−10 = −17°C in the field. There is a −10°C-shift between the lab and the field for low-temperature specifications. Therefore, the Superpave low PG grade is −16. In conclusion, the performance grade of this asphalt binder is PG 64-16.
What is the high PG grade of an asphalt binder that passes the Superpave DSR test for both unaged and RTFO-aged conditions at a maximum test temperature of 67°C?
Solution:
Since the asphalt binder passes the DSR test at a maximum temperature of 67°C, the Superpave high PG grade is 64.
What is the low PG grade of an asphalt binder that passes the Superpave BBR test for PAV conditions at a minimum test temperature of −9°C?
Solution:
Since the asphalt binder passes the BBR test at a minimum temperature of −9°C, it will pass a minimum temperature of −9−10 = −19°C in the field due to the −10°C-shift between the lab and the field specifications. Therefore, the Superpave low PG grade is −16.
Rank the following five Superpave asphalt binders: PG 76-10, PG 64-10, PG 58-16, and PG 70-16, PG 52-10 according to viscosity (or stiffness) from highest to lowest.
Solution:
The viscosity (or stiffness) of the asphalt binder is correlated to the high PG grade of the binder. As the high PG grade increases, the viscosity (or stiffness) increases as well, and vice versa. Therefore, the ranking of these five asphalt binders from highest to lowest would be as follows:
PG 76-10, PG 70-16, PG 64-10, PG 58-16, PG 52-10
If the BBR creep stiffness of an asphalt binder, S (MPa) with time, t (s) is given by the relationship log S ( t ) = 2.23 − 0.85 log ( t ) + 0.15 ( log ( t ) ) 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0029.tif"/> , determine the creep stiffness and the m-value at 60 seconds. Does this asphalt binder pass the Superpave specifications? And why?264
Solution:
Substituting in the formula for S(t) using t = 60 s, the stiffness is obtained as shown below:
log S ( t ) = 2.23 − 0.85 log ( t ) + 0.15 ( log ( t ) ) 2 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0030.tif"/>
⇒
log S ( t ) = 2.23 − 0.85 log ( 60 ) + 0.15 ( log ( 60 ) ) 2 = 1.193 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0031.tif"/>
⇒
S ( t ) = 10 1.193 = 15.6 MPa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0032.tif"/>
The m-value is the slope of the relationship between log(S) and log(t). The slope is equal to the absolute value of the first derivative of the relationship with respect to log(t). Therefore:
Slope = | d d log ( t ) ( log S ( t ) ) | https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0033.tif"/>
⇒
Slope = | d d log ( t ) [ 2.23 − 0.85 log ( t ) + 0.15 ( log ( t ) ) 2 ] | https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0034.tif"/>
⇒
m-Value = | − 0.85 + 2 ( 0.15 ) log ( t ) | https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0035.tif"/>
At t = 60 seconds,
m-Value = | − 0.85 + 2 ( 0.15 ) log ( 60 ) | = 0.32 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0036.tif"/>
The MS Excel worksheet used to solve this problem is shown in Figure 9.8.265
Yes, the asphalt binder passes the Superpave specifications because the stiffness S at 60 seconds = 15.6 MPa ≤ 300 MPa (the maximum requirement for S in the Superpave criteria), and the m-value = 0.32 ≥ 0.300 (the minimum requirement for the m-value in the Superpave criteria).
The results of a DSR test conducted on an asphalt binder under three conditions (fresh before RTFO aging, after RTFO aging, and after PAV aging) are summarized in Table 9.16.
Where:
G* = complex shear modulus
δ = phase angle
Determine the fatigue parameter (|G*| sin δ) and the rutting parameter (|G*|/sin δ) for this asphalt binder.
Solution:
The fatigue parameter (|G*| sin δ) is determined for the asphalt binder after PAV aging. Therefore, the results for the PAV-aged asphalt binder are used as shown below:
| G * | sin δ = 532.9 × sin ( 46 ° ) = 383.3 kPa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0037.tif"/>
On the other hand, the rutting parameter (|G*|/sin δ) is determined for the fresh asphalt binder (before RTFO aging) and for the RTFO-aged asphalt binder as follows:
For the fresh asphalt binder:
| G * | sin δ = 2.77 sin ( 71 ° ) = 2.93 kPa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0038.tif"/>
And for the RTFO-aged asphalt binder:
| G * | sin δ = 5.87 sin ( 66 ° ) = 6.43 kPa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0039.tif"/>
The computations of the results in this problem are performed using the MS Excel worksheet shown in Figure 9.9.266
An asphalt binder having a performance grade of PG 70-16 is tested in the DSR test to verify the high PG grade. The test results are shown in Table 9.17.
Based on these results, verify that this asphalt binder complies with the Superpave specifications for the high PG 70.
Solution:
The rutting parameter (|G*|/sin δ) is determined for the fresh asphalt binder (before RTFO aging) and for the RTFO-aged asphalt binder as follows:
For the fresh asphalt binder:
| G * | sin δ = 1.10 sin ( 71 ° ) = 1.16 kPa ≥ 1.0 kPa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0040.tif"/>
⇒ OK because the Superpave minimum requirement = 1.0 kPa for fresh asphalt binders.267
For the RTFO-aged asphalt binder:
| G * | sin δ = 2.40 sin ( 66 ° ) = 2.63 kPa ≥ 2.20 kPa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0041.tif"/>
⇒ OK because the Superpave minimum requirement = 2.20 kPa for RTFO-aged asphalt binders.
For PG 70-16, according to the Superpave, the intermediate temperature for fatigue cracking is equal to:
T intermediate = High PG + Low PG 2 + 4 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0042.tif"/>
Where:
Tintermediate = the intermediate temperature (°C) at which PAV-asphalt binder is tested in the DSR to check the fatigue cracking parameter (|G*| sin δ).
High PG = high temperature in the PG grade
Low PG = low temperature in the PG grade
⇒
T intermediate = 70 − 16 2 + 4 = 31 ° C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0043.tif"/>
Therefore, the |G*| sin δ for the PAV-aged asphalt binder is calculated as below:
| G * | sin δ = 480.0 × sin ( 46 ° ) = 345.3 kPa ≤ 5000 kPa https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0044.tif"/>
⇒ OK because the Superpave maximum requirement = 5000 kPa for PAV-aged asphalt binders.
In conclusion, the asphalt binder complies with the Superpave specifications for the high PG of the performance grade PG 70-16.
The computations of the results in this problem are performed using the MS Excel worksheet shown in Figure 9.10.268
In a standard Superpave Bending Beam Rheometer (BBR) test for an asphalt binder, the following test results are obtained at time = 60 seconds (see Table 9.18).
Based on these results, what is the lowest temperature at which the asphalt binder passes the Superpave criteria for low-temperature cracking?
Solution:
The Superpave criteria state that the BBR creep stiffness (S) ≤ 300 MPa and the m-value ≥ 0.300 at time = 60 seconds (see Table 9.19).269
Based on the above results, the BBR creep stiffness (S) for the three test temperatures are all lower than 300 MPa. However, the lowest temperature at which the m-value is higher than 0.300 is −6°C. Consequently, the lowest temperature in the lab at which this asphalt binder passes the Superpave criteria for low-temperature cracking is −6°C. In the field, the lowest temperature at which this asphalt binder will pass the Superpave criteria for low-temperature cracking is −16°C since there is a −10°C-shift between the lab and the field for low-temperature specifications.
The test results for an asphalt binder tested using the standard Superpave Bending Beam Rheometer (BBR) test at four low temperatures are summarized in Table 9.20.
Based on these results, determine the low performance grade (PG) for this asphalt binder assuming that the binder passes the Superpave specifications for intermediate temperatures.
Solution:
The Superpave criteria for low temperatures are: the BBR creep stiffness (S) ≤ 300 MPa and the m-value ≥ 0.300 at time = 60 seconds (see Table 9.21).
Based on the above results, the asphalt binder passes the Superpave specifications for creep stiffness (S) at the four test temperatures. However, for m-value, the asphalt binder passes the Superpave specifications at a lowest temperature of −12°C. In the field, the lowest temperature at which this asphalt binder will pass the Superpave criteria for low-temperature cracking is −22°C since there is a −10°C-shift between the lab and the field for low-temperature specifications. Hence, the low PG grade for this asphalt binder would be PG-22.270
Five asphalt binders have been tested in the BBR creep test at −6°C. The test results for creep stiffness (S) and m-value at 60 seconds are provided for the five asphalt binders in the table below, respectively (see Table 9.22).
In this case and according to the Superpave requirements, which asphalt binder should be tested using the Superpave Direct Tension Test (DTT) to ensure that the asphalt binder meets the Superpave specifications at −6°C?
Solution:
According to the Superpave requirements, the asphalt binder should be tested using the DTT as a complementary test after it has been tested in the BBR creep test for low temperature cracking under the following condition:
300 MPa < BBR creep stiffness, S (MPa) at 60 seconds ≤ 600 MPa, and m-value ≥ 0.300
In other words, the asphalt binder must pass the Superpave criteria for m-value (m-value must be ≥ 0.300); and when the creep stiffness, S fails the Superpave specifications (S > 300 MPa), it must not exceed 600 MPa so that the asphalt binder could be tested in the DTT to ensure that it meets the Superpave criteria for low temperature cracking. In case the asphalt binder’s creep stiffness (S) exceeds 600 MPa, the asphalt binder is considered failing the Superpave specifications and there is no need to perform the DTT for the asphalt binder.
In this case, the following results are obtained (see Table 9.23). Therefore, asphalt binder #4 requires further testing in the Superpave DTT.271
In a Superpave DTT for an asphalt binder, the elongation at failure was obtained to be 450 microns. If the effective gage length is 33.8 mm, determine the tensile strain at failure for this asphalt binder. Does the asphalt binder pass the Superpave specifications?
Solution:
ε f = Δ L f G L × 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0045.tif"/>
Where:
εf = tensile strain of asphalt binder sample at failure (%)
ΔLf = elongation of asphalt binder sample at failure (mm)
GL = effective gage length (mm)
ΔLf = 450 microns = 0.450 mm
GL = 33.8 mm
⇒
ε f = 0.450 33.8 × 100 % = 1 .33% https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0046.tif"/>
The MS Excel worksheet used to perform the computations of this problem is shown in Figure 9.11.
In a Superpave DTT for an asphalt binder, the tensile strain at failure for this asphalt binder is 0.80%, determine the elongation at failure for the asphalt binder if the effective gage length is 33.8 mm.
Solution:
ε f = Δ L f G L × 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0047.tif"/>
εf = 0.80%
GL = 33.8 mm
⇒272
0.80 % = Δ L f 33.8 × 100 % https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0048.tif"/>
⇒
Δ L f = 0.80 × 33.8 100 = 0.270 mm = 270 microns https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0049.tif"/>
The MS Excel worksheet used to perform the computations of this problem is shown in Figure 9.12.
A modified asphalt binder to be classified (graded) using the Superpave Asphalt Binder Performance Grading (PG) System has been tested in the laboratory for a series of Superpave tests. The Dynamic Shear Rheometer (DSR) test has been conducted for the original asphalt binder and the RTFO-aged asphalt binder at five different high temperatures (58, 64, 70, 76, and 82°C), and for the Pressure Aging Vessel (PAV)-aged asphalt binder at four intermediate temperatures (28, 31, 34, and 37°C). The Bending Beam Rheometer (BBR) test has been also performed on the PAV-aged asphalt binder at four different low temperatures (−6, −12, −18, and −24°C). All the Superpave test results are shown in Tables 9.24, 9.25, and 9.26. Based on these results, required is to grade (classify) the asphalt binder using the Superpave asphalt binder PG System (see Tables 9.24, 9.25, and 9.26).273
Solution:
For rutting, the DSR |G*|/sin δ is calculated for the original asphalt binder and for the RTFO-aged asphalt binder at the high temperatures as shown in Tables 9.27 and 9.28.274
Based on the above results, the highest temperature at which the asphalt binder passes the Superpave specifications for rutting is 76°C. In other words, the maximum temperature at which both the original asphalt binder’s |G*|/sin δ must be higher than 1.00 kPa and the RTFO-aged asphalt binder’s |G*|/sin δ must be higher than 2.20 kPa is 76°C. Therefore, the high-performance grade is PG 76.
For low-temperature cracking, the BBR creep stiffness (S) and m-value are summarized for the PAV-aged asphalt binder at the low temperatures as shown in Table 9.29.275
Based on these results, the minimum temperature at which the asphalt binder passes the Superpave specifications for low-temperature cracking is −18°C. Since there is a −10°C-shift between the lab and the field for low-temperature specifications, the low performance grade is PG-28.
Now, the criteria for fatigue cracking must be checked. The DSR |G*| sin δ is calculated for the PAV-aged asphalt binder at the intermediate temperatures as shown in Table 9.30.
Since the performance grade is PG 76-28, the fatigue cracking parameter, |G*| sin δ is verified at an intermediate temperature equal to:
T intermediate = 76 − 28 2 + 4 = 28 ° C https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/TNF-CH009_eqn_0050.tif"/>
The |G*| sin δ at 28°C = 543.9 ≤ 5000 kPa; and therefore, the performance grade of this asphalt binder is PG 76-28 (see Table 9.31).
Select the appropriate performance grade (PG) asphalt binder among the following asphalt binders that will suit a Superpave highway pavement project located in an area with a high pavement temperature of 54°C and a low pavement temperature of −14°C.
PG 64-16; PG 64-10; PG 58-16; PG 58-10; PG 52-16; PG 52-10
Solution:
Since the high pavement temperature is 54°C, the selected asphalt binder must have a high-performance grade (PG) of 54 or higher to cover the high pavement temperature range in the area. In addition, since the low pavement temperature is −14°C, the selected asphalt binder must have a low performance grade (PG) of −14 or lower to cover the low pavement 276temperature range in the area. In Superpave, the high-performance grades are following the trend:
And the low performance grades also follow the trend:
Therefore, the appropriate asphalt binder for this project in this area is PG 58-16.
A highway pavement is to be constructed in an area having high pavement temperature of 72°C and low pavement temperature of −12°C, which asphalt binder among the following Superpave asphalt binders—PG 82-22, PG 76-10, PG 76-16, PG 70-10, PG 70-16, PG 64-10, PG 64-16—would be most suitable for this highway pavement according to the Superpave asphalt binder grading system?
Solution:
Since the high pavement temperature is 72°C, the selected asphalt binder must have a high-performance grade (PG) of 72 or higher to cover the high pavement temperature range in the area. In addition, since the low pavement temperature is −12°C, the selected asphalt binder must have a low performance grade (PG) of −12 or lower to cover the low pavement temperature range in the area. Therefore, the appropriate asphalt binder among the given asphalt binders for this project in this area is PG 76-16.
Asphalt Binders with Penetration, Viscosity, and PG Classifications Asphalt Binder >, <, = Asphalt Binder Property AC-40 AC-5 Penetration AC-40 AC-5 Viscosity AC-10 AC-5 High PG 60/70 85/100 Penetration 60/70 85/100 Viscosity 85/100 40/50 High PG PG 64-10 PG 70-10 Penetration PG 64-10 PG 70-10 Viscosity Ranking of Asphalt Binders Based on Penetration, Viscosity, and PG Classifications Asphalt Binder >, <, = Asphalt Binder Property AC-40 < AC-5 Penetration AC-40 > AC-5 Viscosity AC-10 > AC-5 High PG 60/70 < 85/100 Penetration 60/70 > 85/100 Viscosity 85/100 < 40/50 High PG PG 64-10 > PG 70-10 Penetration PG 64-10 < PG 70-10 Viscosity Asphalt Binder Tests Test Test Conditions Penetration Ductility Rotational Viscosity (RV) Rolling Thin-Film Oven (RTFO) Pressure Aging Vessel (PAV) Test Conditions for Asphalt Binder Tests Test Test Conditions Penetration 25°C; 100 g; 5 s Ductility 25°C; 5 cm/min Rotational Viscosity (RV) 135°C; 20 rpm Rolling Thin-Film Oven (RTFO) 163°C; 75 min Pressure Aging Vessel (PAV) 90, 100, or 110; 300 psi (2.1 MPa); 20 hr Asphalt Binder Tests Test Specification Flash Point Rotational Viscosity (RV) Rolling Thin-Film Oven (RTFO) Mass Loss Dynamic Shear Rheometer (DSR) G*/sin δ at high temperatures for original binder Dynamic Shear Rheometer (DSR) G*/sin δ at high temperatures for RTFO binder Dynamic Shear Rheometer (DSR) G*sin δ intermediate temperatures for PAV binder Bending Beam Rheometer (BBR) Stiffness (S) at 60 seconds Bending Beam Rheometer (BBR) m-Value at 60 seconds Direct Tension Test (DTT) Failure Strain (εf) Specifications for Asphalt Binder Tests Test Specification* Flash Point ≥ 230°C Rotational Viscosity (RV) ≤ 3 Pa.s Rolling Thin-Film Oven (RTFO) Mass Loss ≤ 1.00% Dynamic Shear Rheometer (DSR) G*/sin δ at high temperatures for original binder ≥ 1.00 kPa Dynamic Shear Rheometer (DSR) G*/sin δ at high temperatures for RTFO binder ≥ 2.20 kPa Dynamic Shear Rheometer (DSR) G*sin δ intermediate temperatures for PAV binder ≤ 5000 kPa Bending Beam Rheometer (BBR) Stiffness (S) at 60 seconds ≤ 300 MPa Bending Beam Rheometer (BBR) m-Value at 60 seconds ≥ 0.300 Direct Tension Test (DTT) Failure Strain (εf) ≥ 1.00% *Reference: Superpave Performance Graded Asphalt Binder Specifications and Testing, Asphalt Institute Superpave Series No. 1 (SP-1), 2003 Superpave Asphalt Binder Tests Test Parameter/Specification Rutting Fatigue Low-Temperature Workability RV DSR BBR DT Performance Parameters and Specifications for Superpave Asphalt Binder Tests Test Parameter/Specification Rutting Fatigue Low-Temperature Workability RV RV ≤ 3 Pa.s DSR G*/sinδ ≥ 1.0 kPa G*sinδ ≤ 5,000 kPa G*/sinδ ≥ 2.2 kPa BBR S ≤ 300 MPa m-Value ≥ 0.300 DT εf ≥ 1.0% Superpave Asphalt Binder Tests Test Temperature Range Mixing and Laydown High Intermediate Low RV DSR BBR DT Temperature Range for Superpave Asphalt Binder Tests Test Temperature Range Mixing and Laydown High Intermediate Low RV √ DSR √ √ BBR √ DT √ Superpave Asphalt Binder Tests Test Aging Original RTFO PAV RV DSR BBR DT Proper Aging Condition for Superpave Asphalt Binder Tests Test Aging Original RTFO PAV RV √ DSR √ √ √ BBR √ DT √ Asphalt Binder Tests and Properties Test Name Property No. Absolute Viscosity Elastic and viscous properties at intermediate and high temperatures 1 Penetration Aging due to hot mixing and construction 2 Flash Point Workability at mixing and laydown temperatures 3 Ductility Consistency at maximum surface temperature 4 Rolling Thin-Film Oven (RTFO) Test The temperature at which the asphalt binder sparks 5 Pressure Aging Vessel (PAV) Test for Cold Climate Low-temperature behavior for PAV-aged asphalt binder 6 Rotational Viscosity (RV) Consistency at the average service temperature 7 Dynamic Shear Rheometer (DSR) Test Tensile properties 8 Bending Beam Rheometer (BBR) Test Long-term aging 9 Matching of Asphalt Binder Tests with the Right Properties https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/table9_14_B.tif"/> MS Excel worksheet image for the computations of Problem 9.8. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_1_B.tif"/> MS Excel worksheet image for the computations of Problem 9.9. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_2_B.tif"/> MS Excel worksheet image for the computations of Problem 9.10. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_3_B.tif"/> MS Excel worksheet image for the computations of Problem 9.11. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_4_B.tif"/> Relationship between shear strain rate and rotational viscosity for a polymer-modified asphalt binder. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_5_B.tif"/> Shear strain rate versus rotational viscosity for a polymer-modified asphalt binder (on a semi-log scale). https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_6_B.tif"/> Superpave Rotational Viscosity Test Data at Different Shear Strain Rates for a Polymer-Modified Asphalt Binder ω (rpm) γ (rad/s) RV (mPa.s) 1 0.609 251.5 2 1.218 216.7 3 1.827 196.3 4 2.435 181.8 5 3.044 170.6 10 6.089 135.7 12 7.306 126.6 20 12.18 100.9 30 18.27 80.5 50 30.44 54.8 60 36.53 45.6 100 60.89 19.9 MS Excel worksheet image for the computations of Problem 9.14. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_7_B.tif"/> MS Excel worksheet image for the computations of Problem 9.21. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_8_B.tif"/> Superpave DSR Test Data for an Asphalt Binder Under Three Aging Conditions Temperature (°C) G* Value (kPa) δ (degrees) Before RTFO 70 2.77 71 After RTFO 70 5.87 66 After PAV 31 532.9 46 MS Excel worksheet image for the computations of Problem 9.22. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_9_B.tif"/> Superpave DSR Test Data for a PG70-16 Asphalt Binder Temperature (°C) G* Value (kPa) δ (degrees) Before RTFO 70 1.10 71 After RTFO 70 2.40 66 After PAV 31 480.0 46 MS Excel worksheet image for the computations of Problem 9.23. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_10_B.tif"/> Superpave BBR Test Data for an Asphalt Binder Test Temperature (°C) Creep Stiffness, S (MPa) m-Value 0 10.6 0.341 −6 15.8 0.322 −12 20.4 0.271 Superpave BBR Test Criteria Compared to the BBR Test Data for the Given Asphalt Binder Test Temperature (°C) Creep Stiffness, S (MPa) Superpave Criteria Passes Criteria? m-Value Superpave Criteria Passes Criteria? 0 10.6 ≤ 300 MPa OK 0.341 ≥ 0.300 OK −6 15.8 OK 0.322 OK −12 20.4 OK 0.271 Not OK Superpave BBR Test Data for an Asphalt Binder at Four Low Temperatures Test Temperature (°C) Creep Stiffness, S (MPa) m-Value 0 12.4 0.412 −6 16.5 0.360 −12 24.2 0.311 −18 36.8 0.263 Superpave BBR Test Criteria Compared to the BBR Test Data for the Given Asphalt Binder at Four Low Temperatures Test Temperature (°C) Creep Stiffness, S (MPa) Superpave Criteria Passes Criteria? m-Value Superpave Criteria Passes Criteria? 0 12.4 ≤ 300 MPa OK 0.412 ≥ 0.300 OK −6 16.5 OK 0.360 OK −12 24.2 OK 0.311 OK −18 36.8 OK 0.263 Not OK Superpave BBR Test Results (Stiffness and m-Value) for Five Asphalt Binders Asphalt Binder # [S (MPa), m-Value] 1 [280, 0.316] 2 [650, 0.330] 3 [340, 0.284] 4 [395, 0.314] 5 [650, 0.242] Checking the Superpave BBR Test Criteria and Whether the DTT is Needed for Five Asphalt Binders Asphalt Binder # [S (MPa), m-Value] m-Value Stiffness, S DTT Needed? 1 [280, 0.316] Pass Pass No 2 [650, 0.330] Pass Not; S > 600 MPa No 3 [340, 0.284] Not Not; 300 < S ≤ 600 MPa No 4 [395, 0.314] Pass Not; 300 < S ≤ 600 MPa Yes 5 [650, 0.242] Not Not; S > 600 MPa No MS Excel worksheet image for the computations of Problem 9.27. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_11_B.tif"/> MS Excel worksheet image for the computations of Problem 9.28. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429054297/5885f92e-b0a3-419d-837a-bad4e02024b0/content/fig9_12_B.tif"/> Superpave DSR Test Results for a Modified Asphalt Binder (Original and RTFO-Aged Samples) Temperature (°C) Fresh Asphalt Binder RTFO Asphalt Binder G* (Pa) δ (degrees) G* (Pa) δ (degrees) 58 6378 59.2 10534 58.1 64 3356 59.8 5859 59.0 70 1995 60.6 3361 59.6 76 1204 61.9 1959 60.5 82 1066 62.3 1108 61.2 Superpave DSR Test Results for a Modified Asphalt Binder (PAV-Aged Sample) Temperature (°C) PAV Asphalt Binder G* (kPa) δ (degrees) 28 781.6 44.1 31 539.1 45.6 34 421.1 46.2 37 335.2 47.9 Superpave BBR Test Results for a Modified Asphalt Binder (PAV-Aged Sample) Temperature (°C) Stiffness, S (MPa) m-Value −6 33.2 0.482 −12 45.6 0.364 −18 66.5 0.302 −24 80.5 0.256 Superpave DSR |G*|/sin δ for a Modified Asphalt Binder (Unaged Sample) Temperature (°C) G*/sin δ (kPa) Superpave Specification Pass 58 7.4 ≥ 1.0 kPa Yes 64 3.9 Yes 70 2.3 Yes 76 1.4 Yes 82 1.2 Yes Superpave DSR |G*|/sin δ for a Modified Asphalt Binder (RTFO-Aged Sample) Temperature (°C) G*/sin δ (kPa) Superpave Specification Pass 58 12.4 ≥ 2.20 kPa Yes 64 6.8 Yes 70 3.9 Yes 76 2.3 Yes 82 1.3 No Superpave BBR Test Results for a Modified Asphalt Binder (PAV-Aged Sample) Temperature (°C) Stiffness, S (MPa) Superpave Specification m-Value Superpave Specification Pass −6 33.2 ≤ 300 MPa 0.482 ≥ 0.300 Yes −12 45.6 0.364 Yes −18 66.5 0.302 Yes −24 80.5 0.256 No Checking the DSR Test Results against the Superpave Criteria (PAV-Aged Sample) Temperature (°C) G*sin δ (kPa) Superpave Specification 28 543.9 ≤ 5000 kPa 31 385.2 34 303.9 37 248.7 Superpave High and Low Performance Grades for a Modified Asphalt Binder High PG 76 Low PG −28 Performance Grade PG 76-28 PG 52 PG 58 PG 64 PG 70 PG 76 PG 82 PG −10 PG −16 PG −22 PG −28 PG −34