Natural Asphalt
Natural asphalt is produced in natural conditions and in open environments through the evaporation and conversion of crude oil existing in nature over long periods of time (millions of years). This type of asphalt, called natural or mineral asphalt, has specific applications.
As mentioned, the percolation of crude oil over long periods is one of the reasons for the production of natural asphalt. Natural asphalt is a natural hydrocarbon resin, also known as bitumen or asphaltum. Its durability exceeds that of petroleum-derived asphalt. It is sometimes referred to as lake asphalt, such as the asphalt of Lake Behbahan or the Trinidad Lake Asphalt in the United States.
In our country, Iran, natural asphalt is commonly known as gilsonite. In fact, it is hardened crude oil due to pressure. To determine the specifications of natural asphalts, parameters such as color, odor, softening point, moisture content, ash content, carbon content, and solubility are measured and considered.
In Iran, there are abundant mines of natural asphalt, especially in western regions such as Kermanshah, Ilam, and Kurdistan, which are currently being exploited. The ash content in natural asphalt is of particular importance; the lower the ash content, the higher the quality of the asphalt. The softening point of asphalt is another important parameter in assessing the quality of natural asphalt.
The sulfur content present in asphalt and the oxygen in natural asphalt are also significant. Compared to petroleum asphalts, natural asphalts contain more sulfur and have some ash content, while petroleum asphalts are ash-free. Natural asphalt is used in drilling mud to control wellbore stability, mixing in asphalt, mixing in formwork for casting, and in printer ink.
Since natural asphalt is water-resistant and resistant to acids and bases, it is used in the production of roofing asphalt, isogam, and moisture barriers. Natural asphalt is in a lump form, glossy, black in color, and in a powdery micronized state, it is dark brown. It can be obtained using mechanical shovel and compressor and has high solubility in organic solvents.
Although visually coal and natural asphalt may appear similar, coal is formed from the remains of plants and trees over time, while natural asphalt is derived from the evaporation of crude oil from plankton remains.
The most common use of natural asphalt is in isogam, where adding it to petroleum asphalt reduces penetration and increases viscosity and softening point, reducing the thermal sensitivity of the asphalt and improving its performance at high temperatures, thus reducing damage from low temperatures.
Although it is said that using natural asphalt in hot asphalt mixes increases the strength and durability of pavements against traffic, and prevents cracking at low temperatures, it is not recommended to add it to petroleum asphalt for asphalt production and road construction due to the presence of ash.
The percentage of ash in natural asphalt is the most important indicator in its analysis, which is determined by ASTM 3174 standard.
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Natural Asphalt Applications
- Road Construction and Pavement: Natural asphalt is utilized as a primary material in the preparation of asphalt for road construction and maintenance.
- Moisture Barriers: Due to its water resistance, natural asphalt is used in the production of moisture barriers for buildings and other structures.
- Isogam: By adding natural asphalt to isogam materials, their resistance and waterproofing properties are enhanced.
- Drilling and Oil Extraction: In the drilling industry, natural asphalt is used to control pressure and strengthen the walls of wells.
- Printing Industry: Natural asphalt is used in the production of printing inks.
- Materials: Adding natural asphalt to construction materials such as concrete and bricks enhances their strength and resistance to environmental factors including heat and moisture.
بیشتر بخوانید:
- عصب کشی دندان
- سه مقصد اروپایی برای استارتاپ
- بهترین پوزیشن جنسی برای دیسک کمر
- بهترین پوزیشن جنسی برای باردار شدن
- پوزیشن اولین رابطه جنسی
Properties of Natural Asphalt
- Water Resistance: Natural asphalt exhibits high resistance to water and is favored for use in waterproofing materials.
- Chemical Resistance: This type of asphalt is resistant to acids and bases, making it a suitable choice for various industrial applications.
- Thermal Stability: Natural asphalt exhibits high thermal stability, making it suitable for use in various temperature conditions, including high temperatures.
- Solubility: Natural asphalt has high solubility in organic solvents, making it suitable for mixing in various industries such as printing and road construction.
- Mechanical Strength: Natural asphalt exhibits high mechanical strength, making it a suitable choice for use in structures requiring high strength.
Source:
The Difference Between Petroleum Bitumen and Natural Bitumen