Bitumen Definition
Bitumen is a viscous, black and thick substance that is better known as bitumen and is obtained from petroleum products. Due to its adhesion and waterproof properties, this material is used in various industries, especially in construction, road construction and asphalting industries.
Asphalt , dense, highly viscous, petroleum-based hydrocarbon that is found in deposits such as oil sands and pitch lakes (natural bitumen) or is obtained as a residue of the distillation of crude oil (refined bitumen).
It’s a crucial component in asphalt for paving roads and sealing roofs due to its adhesive and waterproofing properties.
Asphalt is an oil based substance. It is a semi-solid hydrocarbon product produced by removing the lighter fractions (such as liquid petroleum gas, petrol and diesel) from heavy crude oil during the refining process. As such, it is correctly known as refined bitumen. In North America, Asphalt is commonly known as “asphalt cement” or “asphalt”. While elsewhere, “asphalt” is the term used for a mixture of small stones, sand, filler and bitumen, which is used as a road paving material. The asphalt mixture contains approximately 5% bitumen. At ambient temperatures Asphalt is a stable, semi-solid substance.
Other names: Asphalt Cement, Asphalt, Blacktop
Bitumen is viscous, nonvolatile liquid or solid. Bitumen is a complex colloid system the chemical properties of which are dependent on the properties of crude oil from which it is produced. Pure bitumen is a colloid dispersion of microscopic asphalt particles (dispersion phase). The chemical composition of bitumen is a mixture of various hydrocarbons with molecules of oxygen, sulfur, and nitrogen. Hydrocarbons present in bitumen are mostly condensed naphthene and aromatic rings with the small number of side paraffin chains. Mass fraction of hydrocarbons is 75-85%, hydrogen 9-10%, oxygen 2-8%, sulphur 5-7%, and nitrogen 0.1-0.5%. Bitumen is partially or completely soluble in various organic solvents. Dissolved fractions of bitumen insolvent are called maltenes or petrolenes, and undissolved fractions are called asphaltenes. The maltenes are a mixture of resins and oil, and they are a dispersing agent. For the most part, the physical properties of bitumen depend on the dispersion degree of asphaltenes in maltenes.
Understanding Bitumen
Understanding bitumen involves knowing its properties, uses, production process, and environmental impact.
- Properties: Blacktop is highly viscous, black or dark brown, and waterproof. It’s composed of complex hydrocarbons and has excellent adhesive properties, making it ideal for various applications.
- Uses: Bitumen is primarily used in road construction for asphalt paving, but it’s also used in waterproofing, industrial coatings, roofing materials, adhesives, soundproofing, and more.
- Production Process: Blacktop is typically obtained through the distillation of crude oil in refineries. It can also be extracted from natural Blacktop deposits through mining or in-situ methods like steam-assisted gravity drainage.
- Environmental Impact: The extraction, processing, and use of bitumen can have environmental implications, including habitat disruption, air and water pollution, and greenhouse gas emissions. However, efforts are underway to develop more sustainable extraction methods and improve the environmental footprint of Asphalt Cement-based products.
Asphalt Applications
Asphalt Cement has a wide range of applications:
- Road Construction: It’s a key component in asphalt for paving roads, highways, and airport runways due to its binding and waterproofing properties.
- Waterproofing: Asphalt is used to waterproof various surfaces like roofs, foundations, and basements, protecting them from water damage.
- Industrial Coatings: It’s used in coatings for pipelines, tanks, and other industrial structures to provide corrosion resistance and waterproofing.
- Pavement Maintenance: Asphalt Cement is also used in maintenance activities such as crack sealing and surface rejuvenation to extend the life of asphalt pavements.
- Roofing Materials: It’s a common ingredient in roofing materials like shingles and membranes, providing durability and weather resistance.
- Adhesives: Bitumen-based adhesives are used in the manufacturing of various products, including carpet tiles, flooring materials, and roofing membranes.
- Soundproofing: Asphalt sheets or mats are used for soundproofing in buildings, vehicles, and machinery due to their ability to dampen sound vibrations.
- Emulsions: Asphalt emulsions are used for surface treatments, tack coats, and dust control in road construction and maintenance.
Properties of Asphalt
Asphalt, which is commonly referred to as bitumen, possesses several key properties:
- Viscosity: Asphalt is highly viscous at normal temperatures, allowing it to flow and adhere to surfaces during paving.
- Adhesion: Asphalt has excellent adhesive properties, allowing it to bond strongly with aggregates and surfaces, creating a durable pavement.
- Water Resistance: Asphalt is impermeable to water, providing effective waterproofing when used in road surfaces or roofing materials.
- Flexibility: Asphalt pavements are flexible, which helps them withstand traffic loads, temperature changes, and ground movement without cracking or breaking.
- Durability: Asphalt pavements are known for their longevity and ability to withstand heavy traffic and environmental conditions.
- Rheological Properties: Asphalt exhibits viscoelastic behavior, meaning it behaves like both a viscous liquid and an elastic solid under different conditions, enabling it to deform under load and recover its shape.
- Temperature Sensitivity: Asphalt’s properties change with temperature; it becomes softer and more workable when heated and harder when cooled, allowing for easy construction and maintenance.
The difference between natural bitumen and petroleum Asphalt
The main differences between natural bitumen and petroleum bitumen lie in their origins and compositions:
- Origins:
-Natural Bitumen: Also known as asphaltite or tar sands, natural bitumen forms through geological processes over millions of years. It occurs naturally in deposits near the Earth’s surface and requires mining or extraction.
– Petroleum Bitumen: Petroleum bitumen, commonly referred to as asphalt or bitumen, is a byproduct of the refining process of crude oil. It’s derived from the distillation of heavier fractions of crude oil. - Composition:
– Natural Bitumen: Natural bitumen typically contains higher levels of impurities, such as sulfur, nitrogen, and heavy metals, compared to petroleum bitumen. Its composition can vary depending on the geological source.
– Petroleum Bitumen: Petroleum bitumen is composed primarily of hydrocarbons, with fewer impurities compared to natural bitumen. Its composition can be controlled more precisely during the refining process. - Properties:
– Natural Bitumen: Natural Asphalt tends to be harder and more brittle than petroleum bitumen. It may require additional processing to achieve desired properties for specific applications.
– Petroleum Bitumen: Petroleum bitumen is more commonly used in various applications due to its consistent quality, versatility, and ability to be modified for specific purposes. It’s often softer and more flexible than natural bitumen. - Availability:
– Natural Bitumen: Natural bitumen deposits are found in specific geological formations in various regions around the world, including Canada, Venezuela, and the Middle East.
– Petroleum Bitumen: Petroleum bitumen is widely available as a byproduct of the oil refining industry and is produced in large quantities globally.
Pipe Coating
Coating systems advanced and at the same time modified polymers on the basis of economic the result is a wide research and long-lasting oil companies shell and Phoenix are Denmark. the characteristics of the coating causing severe epidemics can be high adhesion and resistant top of that soil degradation and stresses cathodic. Has your unique restorative properties. An article for corrosion protection of steel pipes buried in soil for a long period of time, with an appropriate yield. This coating due to being economical and safe for the environment continues to be an option in the transmission lines projects.
Roll Sheet
Water Proofing Asphalt Membrane Sheet (Here referred to as WPBS) are the best industrial outcome in the area of waterproofing ever attained by scientific and technological advancement. These products enable us to prevent the adverse effects of rain and snow water penetration into structures from their foundation up to roof. Employing different polymers and synthetic fibers, WPBS pass through well-equipped labs to be amended for attaining resistance against, high and low temperatures, tearing tension, and penetration of water
In addition to low weight and resistance against cold, heat, expansion and contraction, ZUMRUT Co WPBS show high endurance being produced in two aluminum-covered and polyethylene film-covered versions. There two types of base products: single layered (nonwoven Spun bond polyester), and double layered (stringed fiber gloss tissue and 110 gr polyester) giving the product higher tensile strength against vibrations of the structure. WPBS is used in waterproofing of roofs, water canals, the foundation of tunnels, dams, pools, sloped surfaces, and the like.
Also, ZUMRUT Co Bitumen membrane sheet reinforced by two layers of fiberglass and non-woven tissues with “needdle type” polyester. Azargum humidity polyester in spite of economic point of view possesses perfect utility qualities, therefore, resolves additional directional stability and ordinary surface replacements.
Types of Bitumen By Grade
There are different types of asphalt cement available with different properties, specifications and uses based on requirements of consuming industry.
Oxidized Grade
Blown bitumen grades or Oxidized Bitumen are produced by passing air through the penetration grades. This process gives the bitumen more rubbery properties than its original formula and they are simply harder bitumen. Hard asphalt under controlled temperature conditions is widely used as an anti-slip layer compound in the piling industry, for manufacture of roofing felts, the roofing and waterproofing industries, for sound dampening felts and under carriage sealant in the automotive industry, electric cable joint protection, joint filling compound, sealant compound and many others. Also used in sealing saw cuts and joints where expected movements are minimum. It is also used in the manufacturing of bituminous marine mastic for the oil & gas pipeline joints.
Penetration Grade
Graded Bitumen is classified by the depth to which a standard needle will penetrate under specified test conditions. This “pen” test classification is used to indicate the hardness of bitumen, lower penetration indicating a harder bitumen. Specifications for penetration graded bitumen’s normally state the penetration range for a grade, e.g. 50/70. Other tests are used to classify the bitumen for specification purposes, such as softening point, solubility, flash point etc.
Performance Grade
Performance Grade (PG) bitumen is Asphalt which is graded based on its performance at different temperatures. The Long-Term Pavement Performance(LTPP) has given certain algorithm to calculate the temperature of the pavement based on the temperature of the air above. From this, the highest and the lowest temperatures of the pavement is calculated and the Asphalt that performs well in that temperature range is selected.
Viscosity Grade
Viscosity Grade Bitumen (Asphalt) is a standard grade Asphalt usually used as a Paving Grade Bitumen suitable for road construction and for the production of asphalt pavements with superior properties. This grade of Asphalt is mainly used in the manufacture of hot mix asphalt for bases and wearing courses, and possesses characteristics and qualities unique sand quite different from other agents. They achieve very flexible and tenacious connections with other materials due mainly to viscoelastic response of Asphalt, which behavior depends on how fast charges are applied.
Polymer Modified
Polymer modified Asphalt (PMB) is one of the specially designed and engineered Asphalt grades that are used in making pavement, roads for heavy duty traffic and home roofing solutions to withstand extreme weather conditions. PMB is a normal Asphalt with the added polymer, which gives it extra strength, high cohesiveness and resistance to fatigue, stripping and deformations, making it a favorable material for infrastructure.
Other Types of Bitumen
Cutback Bitumen
Cutback or Liquid Bitumen is Asphalt that is dissolved in a solvent. Typical solvents include Naphtha, gasoline and kerosene, white spirit etc. The type of solvent controls the curing time while the amount determines the viscosity of the Cutback Asphalt . Asphalt is ‘cutback’ by adding controlled amounts of petroleum distillates such as kerosene. This is done to reduce the viscosity of the Asphalt temporarily so it can penetrate pavements more effectively or to allow spraying at temperatures that are too cold for successful sprayed sealing with neat Asphalt. The materials used to cutback bitumen will evaporate after application to leave the remaining material similar in hardness to the original Asphalt.
Blown Bitumen
It comes from hot air blown to pure Asphalt in the last stage of refining. In this process, hot air having 200-300 degree centigrade temperature is blown to Asphalt container with porous tubes. In this process, hydrogen atoms in Asphalt hydrocarbon are combined with oxygen in the air and by forming water, polymerization happens. Compared with pure Asphalt, blown asphalt has a low penetration rate and a high softness point. This kind is used in making roof sheets, automobile battery, and coating.
Natural Bitumen
Natural Asphalt or native asphalts are a class of Asphalt which have been naturally produced due to climate conditions in the course of time, and are used without the need to be processed in distillation ways; they are very varied regarding their composition and properties.
Coating Bitumen
Asphalt coating compositions having substantially improved application and drying properties and producing coatings of improved properties including resistance to ultraviolet rays and alligatoring resulting therefrom said coating compositions comprising volatile solvent solutions of a Asphalt coating material having softening point between 110 F To 250 F. The Asphalt coating are also characteristically non-viscous materials which are not thixotropic and are therefore ordinarily applied as thin films. It’s compositions may also contain filler materials which tend to settle from the non-thixotropic compositions after storage for only a short time. It has been proposed in the past to add inert colloidal fillers such as silica to obtain thixotropic properties and thicker films on the application of the compositions. However, even such inert fillers tend to affect only solution properties and generally exist in the finished coating as an expensive additive which does not benefit other properties of the coating.
Bitumen Emulsion
This is a mixture of water & Asphalt. Hey wait, we know that Asphalt is a oil product and it cannot be mixed with water. That is why we add an emulsifier (a surface active agent) with water before adding Asphalt. Addition of emulsifier with water facilitates breaking of Asphalt into minute particles and keeps it dispersed in suspension. Therefore we can say that a bitumen emulsion is a liquid product consisting of three things, (i.e. water + Emulsion + Asphalt) where droplets of Asphalt are suspended in water.
