Bitumen is a viscous mixture in black color having hydrocarbons. Bitumen is typically extracted naturally or in the form of residue from distillation of petroleum. Bitumen is supplied by asphalt plant mixture manufacture in China and is utilized in roofing and road surfacing.
Below are six critical properties of bitumen:
The adhesive characteristic of bitumen holds together all the components without any changes in their natural features. Asphalt is able to adhere to a solid surface while in a fluid state depending upon surface nature. The presence of water on the surface will affect adhesion.
Bitumen under bitumen storage silo can work as a capable sealant. Bitumen is insoluble if put in water.
To gauge the bitumen’s hardness, a test is conducted called penetration test. The test measures the penetration depth in tenths of a millimeter of a weighted needle in bitumen at a noted temperature. Commonly, a 100 grams weight is applied for five seconds at a 77 degree Fahrenheit temperature. The penetration is the hardness measurement. Results are generally 10 for asphalt which are hard coating – 15 to 40 for roofing asphalt and >100 for waterproofing asphalt.
The flow of viscous characteristics of bitumen are of significance both:
The flow attributes of asphalt vary substantially with stress conditions and temperature. Loss of properties and deterioration concerning bitumen encapsulates the state of hardening. As a result, a decrease in flow and adhesive attributes occurs alongside the rising in the coefficient of thermal expansion.
Test of ductility is taken for determination of the amount the bitumen will stretch at a temperature below the softening point. A briquette with a cross-sectional area of 1 square inch in the tester at 77 degrees Fahrenheit. Values of ductility range from zero to above 150 depending upon bitumen type. Existence of ductility depicts the formation of film and proper coating would be done.
The durability of bitumen tells about the long-term resistance towards material’s oxidative hardening in the field. In service, every asphalt hardens with the passage of time via reaction. With oxygen present in the air, outrageous rate of hardening (poor durability) can cause surface failure and premature binder embrittlement in chip and cracking loss. Bitumen’s lifespan is twenty years if implied with proper maintenance throughout the pavement life.