Section 4137.  Asphalt Binder

 

4137.01     general requirements.

 

A.    Meet the requirements for the type and grade specified in the contract documents.

 

B.    Determine performance grade according to AASHTO R 29.

 

C.    Do not add acids to modify asphalt binders.

 

D.    For asphalt binder grades with a temperature spread of 92° or greater1, use binders that meet the PG+ requirements established by of the Combined State Binder Group as follows:

 

Table 4137.01-1: PG+ Requirements

Temperature Spread1, 2

92

98

104

Elastic Recovery: AASHTO T 301 at 77° F.

(RTFO Aged AASHTO T 240)

65% min.

65% min.

65% min.

DSR Phase Angle; degrees (original binder)

77.0 max.

75.0max.

73.0 max.

1      Temperature spread is determined by subtracting low temperature from high temperature; for example PG 64-28: 64 - (-28) = 92

 

2      When a grade change is required to compensate for binder in recycled materials, the virgin binder provided shall meet the above requirements for the original grade specified in the contract documents.

 

AASHTO R 29

Grade

AASHTO T 350

Minimum Percent Recovery (R3.2)

DSR Phase Angle; degrees (original binder)

Test Temperature2

58°C

64°C

58-34P

30

25

77

64-28P

30

25

77

64-34P

55

45

75

70-22P

55

45

77

70-28P

55

45

75

70-34P

75

75

73

76-28P

75

75

73

76-34P

75

75

73

82-22P

75

75

73

1      Temperature spread is determined by subtracting low temperature from high temperature; for example PG 64-28: 64 - (-28) = 92.

2      See Figure 4137.01-01 for test temperatures.

 

Figure 4137.01-01: AASHTO T 350 Test Temperature by County (°C)