Asphalt cement, referred to as AC grade bitumen within the realm of viscosity grade bitumen, stands as a cornerstone in pavement engineering. Classified by the American Association of State Highway Officials (AASHTO), viscosity grade bitumen comprises two principal groups:
Asphalt Cement (AC) Grade Bitumen
Aged Residue (AR) Grade Bitumen
Within the domain of AC bitumen, a nuanced gradation system exists, tailored to accommodate diverse environmental conditions and vehicular loads.
Further Insight into AC Grade Bitumen:
Distinguishing AC Grade Bitumen from AR Grade Bitumen:
The alphanumeric sequences appended to AR and AC grades serve distinct functional roles. While the numerical suffix following the AC designation delineates viscosity at 60°C, those accompanying AR grades denote viscosity at 60°C as determined by the thin film oven test.
In-Depth Analysis of AC 10, AC 20, and AC 30 Bitumen:
AC10, AC20, and AC30 emerge as pivotal designations within the taxonomy of AC bitumen. Their classification hinges upon the absolute viscosity measured at 60°C in 100 poises. By extension, the viscosity of bitumen designated as AC10 is rendered as 10*100, equating to 1000 poise (100 Pa.s).
Delving into Bitumen AC10:
Bitumen AC10 epitomizes a low-viscosity variant within the spectrum of AC bitumen formulations. Characterized by elevated penetration and ductility indices, Bitumen AC10 is often harnessed in locales beset by cooler temperatures or in the development of thoroughfares predisposed to lighter traffic loads.
The tables below contains the specifications of bitumen:
Bitumen AC10 Specification |
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Specification |
Test Method |
Unit |
Value |
|
Viscosity, @ 60 ◦C |
ASTM D2171 |
Poise |
1000±200 |
|
Viscosity, @ 135 ◦C |
ASTM D2170 |
CST |
Min 150 |
|
Flash Point (Cleveland Open Cup) |
ASTM D92 |
◦C |
Min 219 |
|
Solubility in Trichloroethylene |
ASTM D2042 |
%WT |
Min 99 |
|
Penetration, 100g, 5s, @ 25 ◦C |
ASTM D5 |
0.1mm |
Min 70 |
|
Thin-Film Oven Test (TFOT) |
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Viscosity, @ 60 ◦C |
ASTM D2171 |
Poise |
Max 5000 |
|
Ductility, 5 cm/min, @ 25 ◦C |
ASTM D113 |
cm |
Min 50 |
Bitumen AC20 Specification |
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Specification |
Test Method |
Unit |
Value |
Viscosity, @ 60 ◦C |
ASTM D2171 |
Poise |
2000±400 |
Viscosity, @ 135 ◦C |
ASTM D2170 |
CST |
Min 210 |
Flash Point (Cleveland Open Cup) |
ASTM D92 |
◦C |
Min 232 |
Solubility in Trichloroethylene |
ASTM D2042 |
%WT |
Min 99 |
Penetration, 100g, 5s, @ 25 ◦C |
ASTM D5 |
0.1mm |
Min 40 |
Thin-Film Oven Test (TFOT) |
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Viscosity, @ 60 ◦C |
ASTM D2171 |
Poise |
Max 10000 |
Ductility, 5 cm/min, @ 25 ◦C |
ASTM D113 |
cm |
Min 20 |
Bitumen AC30 Specification |
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Specification |
Test Method |
Unit |
Value |
Viscosity, @ 60 ◦C |
ASTM D2171 |
Poise |
3000±600 |
Viscosity, @ 135 ◦C |
ASTM D2170 |
CST |
Min 250 |
Flash Point (Cleveland Open Cup) |
ASTM D92 |
◦C |
Min 232 |
Solubility in Trichloroethylene |
ASTM D2042 |
%WT |
Min 99 |
Penetration, 100g, 5s, @ 25 ◦C |
ASTM D5 |
0.1mm |
Min 30 |
Thin-Film Oven Test (TFOT) |
|||
Viscosity, @ 60 ◦C |
ASTM D2171 |
Poise |
Max 15000 |
Ductility, 5 cm/min, @ 25 ◦C |
ASTM D113 |
cm |
Min 15 |