Penetration Grade Bitumen

Penetration Grade Bitumen

Bitumen is produced from heavier components of crude oil which is also called the “residue” of distillation process. It’s composed of complex hydrocarbons and contains elements such as calcium, iron, sulfur, and oxygen. There is also a kind of naturally occurring bitumen which is the remaining of migrated crude oil with very huge molecules of hydrocarbon.

Alike other petroleum products, bitumen is characterized by bulk physical properties. There are different standards that define the behavior of bitumen in different conditions.

One of the oldest standards (since 1900s) in defining characteristics of petroleum bitumen is “Penetration Test Method” which observers the penetration depth of a specific needle with specific weight in standard condition.

The penetration index was define based on the assumption that thermal sensitivity of the bitumen used in road construction was zero. Bitumen is a thermoplastic material, meaning that is becomes pliable or moldable above a specific temperature and return to solid state upon cooling.

Penetration graded bitumen is widely used in road and motorway construction. Different grades of this type are categorized according to designed temperature of the pavement. Bitumen 40/50 is the hardest grade and is used in high temperature areas while bitumen 200/300 is the softest one and used in cold climates such as northern Canada.

We are capable of providing different grades of road surfacing bitumen in compliance all international standards. Penetration rate bitumen is graded based on penetration and softening point tests. This table describes the physical properties of penetration-grade bitumen based on European standards. During the last two decades of the 20th century, most road construction projects showed inclination for solid bitumen which results in more effective asphalt.

Test	Methodology	30-40	40-50	60-70	85-100	100-120
Density	ASTM D‐7	1.01-1.06	1.01-1.06	1.01-1.06	1.01-1.05	1.01-1.04
Penetration Rate at 25ºC	ASTM D‐5	30-40	40-50	60-70	85-100	100-120
Softening Point ºC	ASTM D‐36	55-63	52-60	49-56	45-52	42-49
Ductility at 25 ºC (cm)-min	ASTM D‐113	100	100	100	100	100
Flash Point ºC-min	ASTM D‐92	250	250	250	250	250
Solubility in Disulfide %wt-min	ASTM D‐4	99.5	99.5	99.5	99.5	99.5
Stain Test	AASHTO T 102	Negative	Negative	Negative	Negative	Negative
Weight Loss by Heating %wt-max	ASTM D‐6	0.2	0.2	0.2	0.2	0.2
Penetration Loss by Heating %-max	ASTM D‐6-D-5	20	20	20	20	20