Paving grade bitumen manufactured to a tighter specification than prescribed in AS 2008 and is suitable for standard sealing and lightly trafficked asphalt applications. Bitumen used in road construction and maintenance are refined and blended to meet strict road engineering requirements and industry specifications. Paving grade bitumen’s are categorised according to viscosity (degree of fluidity) gradings.



Class 170 is widely used in sprayed sealing and light asphalt applications to provide durability and fatigue resistance. It is also used to manufacture cutback bitumen, bitumen emulsions and modified bitumen. Class 320 is most commonly used to manufacture asphalt mixes while Class 600 is primarily used to manufacture extra heavy-duty asphalt pavements that need to endure substantial traffic loadings.

Class 170 Class 320 Class 600
Viscosity at 60oC, pa.s 170 320 600
Viscosity  at 135oC Pa.s 0.40 0.53 0.80
Viscosity at 60oC after RTFO, Pa.s 300 640 1300
Penetration at 25oC, dmm 70 46 27
Flashpoint, oC 360 360 360
Viscosity of Residue at 60oC % of original 180 200 215
Density at 15oC, kg/m3 1.04 1.04 1.04

Bitumen Class 170,320 & 600
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