Penetration Grade Bitumen
Penetration grade bitumen is classified based on its penetration degree, which indicates the adhesion and stiffness properties of the asphalt. The penetration grade is determined during the bitumen production process. In the bitumen production unit, a needle penetration test is performed on the bitumen. The degree of penetration of the needle determines the penetration grade of the bitumen. Harder bitumens have a lower penetration grade, while softer bitumens have a higher penetration grade.
The penetration test is conducted at a temperature of 25 to 70 degrees Celsius, which is close to the average temperature of asphalt. The advantages of the penetration test include its simplicity and low cost, making it easily feasible in a workshop setting. However, it is important to note that this test is purely empirical and does not measure any engineering parameters such as viscosity.
Applications of Penetration Grade Bitumen
The primary application of penetration grade bitumen is in road construction for paving surfaces. It also finds occasional use in certain industrial applications. In road construction, harder bitumens are used in hot climates, while softer bitumens are used in cold climates. In recent years, there has been a growing preference for using harder bitumens compared to softer bitumens in road construction.