Asphalt Cement Grade (AC)

Bitumen Asphalt Cement Grade (AC)

Asphalt cement grade of bitumen is one of the main categories of viscosity grade bitumen. The American Association of State Highway Official (AASHTO) has classified viscosity grade bitumen into two categories as follow.

First one is AC, which stands for Asphalt Cement, and the second one is AR, which is the abbreviated form of Aged Residue. The difference between AR and AC grade is in the meaning of the numbers following them in written form. AC grade is followed by a number which indicates the viscosity at 60 c while AR grade is followed by a number which indicates the viscosity at 60 c after the bitumen has been aged.

The viscosity grading system is more comprehensive compared to the penetration grading system. Viscosity is the conversion of fluidity. It’s a general concept for the texture of substances. Chemically speaking, viscosity is applied as a consistency measurement. Viscosity test is conducted at 60 c (the maximum pavement temperature). Good to know that the measurement unit of viscosity grading system is Poise.

The viscosity grading can be done on both original (as-supplied) asphalt binder which is called AC grading and aged residue binder which is called AR grading.

The AC grading is related to absolute viscosity at 60 c in 100 poises.

Here are six asphalt cement (AC) viscosity grades: AC-2.5 (which is the softest grade), AC-5, AC-20, AC-30, and AC-40(which is the hardest grade).

As a brief explanation, AC-2.5 is asphalt cement with a target viscosity of 250 poises at 60c. (250 are divided by 100).

As mentioned above, for other grades, the divided number for each grade stands for the target viscosity poises.

Low viscosity grades are AC-2.5 and AC-5. They are recommended for cold climate whereas other grades AC10 to AC40 are suitable for hot climate.

 

Absolute Minimum Grades Viscosity Poises at 60 C

 

Equivalent Penetration Grades
VG-10 800 C 85/100
VG-20 1600 C —-
VG-30 2400 C 60/70
VG-40 3200 C 30/40

 

40/50

 

 

Penetration Grade Viscosity

 

Performance Grade
Bitumen Bitumen Residue
Bitumen 40/50 AC-2.5 AR 10 PG-46/22

PG-52/28

Bitumen 60/70 AC-5 AR 20 PG-58/16

 

Bitumen 85/100 AC-10 AR 40 PG-64/22

 

Bitumen 120/150 AC-20 AR 80 PG-70/10
Bitumen 200/300 AC-40 AR 160 PG-76/10

PG-82/10

Bitumen AC-2.5
Viscosity Grade AC-2.5 Bitumen Specifications
Properties Units Specifications Test Method
Viscosity, 140°F (60°C) P 250± 50 ASTM D-2171
Viscosity, 275°F (135°C), Min cSt 80 ASTM D-2171
Penetration, 77°F (25°C), 100g, 5sec, Min 0.1 MM 200 ASTM D-5
Flash point, Cleveland open cup, Min °C 163 ASTM D-92
Solubility in trichloroethylene, Min %Wt. 99 ASTM D-2042
Tests on residue from thin-film oven test:
Viscosity, 140°F (60°C), Max P 1250 ASTM D-2171
Ductility, 77°F (25°C), 5cm/min, Min CM (1)100 ASTM – D113
Bitumen AC-5
Viscosity Grade AC-5 Bitumen Specifications
Properties Units Specifications Test Method
Viscosity, 140°F (60°C) P 500± 100 ASTM D-2171
Viscosity, 275°F (135°C), Min cSt 110 ASTM D-2171
Penetration, 77°F (25°C), 100g, 5sec, Min 0.1 MM 120 ASTM D-5
Flash point, Cleveland open cup, Min °C 177 ASTM D-92
Solubility in trichloroethylene, Min %Wt. 99 ASTM D-2042
Tests on residue from thin-film oven test:
Viscosity, 140°F (60°C), Max P 2500 ASTM D-2171
Ductility, 77°F (25°C), 5cm/min, Min CM 100 ASTM – D113
Bitumen AC-20

Bitumen AC grade is one of the famous grades among the countries. AC grade disproportionately has application in Sudan country. Infinity Galaxy excels in monthly exporting bitumen AC 20 to a great number of customers in Sudan. Good to know that, in order to export bitumen AC 20 to the Port Sudan , the inspector company should check the drum marking and the importer information and Port Sudan customs in the destination. Drums must have the specific marking, batch number, producer number, date of production and expiration of the bitumen. The sample of GEOchem inspection of exported bitumen by Infinity Galaxy to Sudan can be seen in a photo below.
Besides, the sample of drum marking is shown below.

Download PDF

Viscosity Grade AC-20 Bitumen Specifications
Properties Units Specifications Test Method
Viscosity, 140°F (60°C) P 2000± 400 ASTM D-2171
Viscosity, 275°F (135°C), Min cSt 210 ASTM D-2171
Penetration, 77°F (25°C), 100g, 5sec, Min 0.1 MM 40 ASTM D-5
Flash point, Cleveland open cup, Min °C 232 ASTM D-92
Solubility in trichloroethylene, Min %Wt. 99 ASTM D-2042
Tests on residue from thin-film oven test:
Viscosity, 140°F (60°C), Max P 10000 ASTM D-2171
Ductility, 77°F (25°C), 5cm/min, Min CM 20 ASTM – D113
Bitumen AC-30
Viscosity Grade AC-30 Bitumen Specifications
Properties Units Specifications Test Method
Viscosity, 140°F (60°C) P 3000± 600 ASTM D-2171
Viscosity, 275°F (135°C), Min cSt 250 ASTM D-2171
Penetration, 77°F (25°C), 100g, 5sec, Min 0.1 MM 30 ASTM D-5
Flash point, Cleveland open cup, Min °C 232 ASTM D-92
Solubility in trichloroethylene, Min %Wt. 99 ASTM D-2042

Tests on residue from thin-film oven test:

Viscosity, 140°F (60°C), Max P 15000 ASTM D-2171
Ductility, 77°F (25°C), 5cm/min, Min CM 15 ASTM – D113
Bitumen AC-40
Viscosity Grade AC-40 Bitumen Specifications
Properties Units Specifications Test Method
Viscosity, 140°F (60°C) P 4000± 800 ASTM D-2171
Viscosity, 275°F (135°C), Min cSt 300 ASTM D-2171
Penetration, 77°F (25°C), 100g, 5sec, Min 0.1 MM 20 ASTM D-5
Flash point, Cleveland open cup, Min °C 232 ASTM D-92
Solubility in trichloroethylene, Min %Wt. 99 ASTM D-2042

Tests on residue from thin-film oven test:

Viscosity, 140°F (60°C), Max P 20000 ASTM D-2171
Ductility, 77°F (25°C), 5cm/min, Min CM 10 ASTM – D113