penetration grade bitumen
Bitumen includes varieties and different classifications. The base oil of the bitumen and the producing process are crucial in the end bitumen. Experts have classified bitumen in several grading systems such as penetration grade, viscosity grade and Superpave performance. Penetration grade is the most common method, and it shows how much the penetrates the surface.
In 1888, the penetration test was invented and measured by a penetrometer for the first time.
Depending on the level of penetration, bitumen has various grades, including 40/50, 60/70, 80/100.
The higher the penetration , the softer the bitumen. Accordingly, 80/100 is way much softer than 40/50.
In refineries, the crude oil turns into vacuum residue in the bottom of the distillation tower. Vacuum residue is the raw material of bitumen units.
After entering the aeration tower, the vacuum bottom is exposed to oxygen and nitrogen and loses its hydrogen as much as possible and becomes heavier.
The final product is different types of grade bitumen.
The longer the aeration process takes, the heavier the final bitumen gets.
Accordingly, to have heavier bitumen, vacuum residue is more exposed to the air in the aeration process. The 50/40 grade bitumen is the hardest type, and the 80/100 is the softest.
Important question Penetration Grade Bitumen
Therefore , Road construction is the major use of grade bitumen. To choose the suitable penetration grade, you need to consider the type of soil, climate and traffic loads of the road you want to pave.
Soft bitumen is more suitable for soils with high particle density such as clay. On the other hand, high penetration graded bitumen works better for soils with low particle density.
If the bitumen is too soft or hard in the environment temperature, cracking or deformation possibility increase. Therefore, soft bitumen performs better in cold climates and harder bitumen works better in hot climates.
The traffic load of the road affects the paving considerably. If the road holds a high amount of traffic loads, softer grades such as 60/70 show more durability as the pavement.
Similarly, Softer grades like 60/70 show more durability exposing to heavy traffic loads. Accordingly, lower grades are used for paving roads with high traffic loads. On the contrary, high penetration grade is suitable for the roads with low traffic loads.