OIL ROAD VISCOUS BITUMENS

Specifications

GOST
22245-90

STATE STANDARD OF THE USSR

1.1. Viscous petroleum road bitumen is produced by oxidation of products of direct distillation of oil and selective separation of petroleum products (deasphalting asphalts, selective purification extracts), as well as by compounding the indicated oxidized and non-oxidized products or in the form of a residue of direct distillation of oil in accordance with the requirements of this standard according to the technological regulations approved in in the prescribed manner. It is allowed to use the cracking residue as a component of the oxidation feedstock.

1.2. Characteristics

1.2.1. Depending on the depth of needle penetration at 25 °C, viscous road petroleum bitumen is produced in the following grades: BND 200/300, BND 130/200, BND 90/130, BND 60/90, BND 40/60, BN 200/300, BN 130 /200, BN 90/130, BN 60/90.
The scope of application of bitumen in road construction is in accordance with Appendix 1.

Name indicator	Standard for bitumen stamps
			OKP 02 5612 0113	OKP 02 5612 0112	OKP 02 5612 0111			OKP 02 5612 0203	OKP 02 5612 0202
Depth needle penetration, 0.1 mm:										According to GOST 11501
at 25 °C
at 0 °C, no less
Softening temperature along the ring and ball, °C, not lower										According to GOST 11506
Tensile strength, cm, not less										According to GOST 11505
at 25 °C
at 0 °C
Brittleness temperature, °C, not higher										According to GOST 11507
Flash point, °C, not lower										According to GOST 4333
Change in softening temperature after heating, °C, no more										According to GOST 18180 According to GOST 11506
Index penetration		-1.0 to +1.0				-1.5 to + 1.0				According to Appendix 2

1.2.2. In terms of physical and chemical parameters, bitumens must comply with the requirements and standards specified in table 1

1.2.3. Safety requirements

1.2.3.1. Viscous road petroleum bitumens are flammable substances with a flash point above 220 °C and a minimum auto-ignition temperature of 368 °C.

1.2.3.2. The maximum permissible concentration of bitumen hydrocarbon vapors in the air of the working area is 300 mg/m 3 - in accordance with GOST 12.1.005 . The content of hydrocarbon vapors in the air is determined according to GOST 12.1.014-84.

1.2.3.3. Bitumen are low-hazard substances and, in terms of the degree of impact on the human body, belong to the 4th hazard class according to GOST 12.1.007 .

1.2.3.4. When working with bitumen, personal protective equipment should be used in accordance with standard industry standards approved in accordance with the established procedure.

1.2.3.5. The room in which bitumen is worked must be equipped with supply and exhaust ventilation.

1.2.3.6. If small amounts of bitumen catch fire, it should be extinguished with sand, felt felt or a foam fire extinguisher. Developed bitumen fires should be extinguished with a foam jet.

1.3. Nature protection requirements

1.3.1. Effective measures to protect the natural environment include sealing equipment and preventing bitumen spills.

1.3.2. Waste from bitumen production (oxidation gases) is neutralized by combustion in an afterburner.

2. ACCEPTANCE

2.1. Viscous road petroleum bitumen is accepted in batches.

A batch is considered to be any quantity of bitumen that is uniform in terms of quality and accompanied by one quality document.

2.2. Sample size - according to GOST 2517.

2.3. If unsatisfactory test results are obtained for at least one of the indicators, repeated tests are carried out on a newly selected sample taken from the same batch.

The results of repeated tests apply to the entire batch.

2.4. The manufacturer determines the elongation at 0 °C and the change in softening temperature after heating periodically at least once every 10 days, and the flash point at least once a month.

2.5. If unsatisfactory results of periodic tests are received, the manufacturer transfers the tests for this indicator to the acceptance category until positive results are obtained for at least three batches in a row.

3. CONTROL METHODS

3.1. Samples of viscous road bitumen - according to GOST 2517. The mass of the combined sample of each grade of bitumen must be at least 0.5 kg.

3.2. The brittleness temperature of BN grade bitumen can be determined using a nomogram

3.3. The change in softening temperature after heating is calculated as the difference in softening temperatures determined according to GOST 11506 before and after the heating test according to GOST 18180 .

4. MARKING, TRANSPORTATION AND STORAGE

4.1. Labeling, transportation and storage of bitumen - in accordance with GOST 1510.

4.2. Viscous road bitumen belongs to the 9th transport hazard class according to GOST 19433-88 (subclass 9.1, category 9.13, classification code 9133).

5. MANUFACTURER WARRANTY

5.1. The manufacturer guarantees that the quality of bitumen meets the requirements of this standard subject to the conditions of transportation and storage.

The production technology guarantees the adhesion of bitumen grades BND with reference marble according to sample No. 2 according to GOST 11508-74 using method A.

5.2. The guaranteed shelf life of bitumen is one year from the date of manufacture.

Nomogram for determining the brittleness temperature of road surfaces
bitumen grades BN

Nomogram for determining the brittleness temperature of road surfaces
bitumen grades BN

Bitumen has been used for various purposes since ancient times and to this day is one of the most common materials for construction. Long before our era, such famous cities as Babylon and Assyria used it for construction purposes. It perfectly performs the function of both a cementitious and waterproof base.

Types of road bitumen

This building material can be divided into several separate groups according to properties and technical characteristics. All parameters can be determined only after studying the organic composition of the material. Tar bitumen acts as a separate group, since all varieties of pitch and tar can be classified into this broad group.

There are the following bitumen options:

1. Natural bitumen. This substance can be found in both liquid and solidified configurations, but all these varieties remain in the same group. GOST defines natural petroleum road bitumen as consisting of organic components, as well as their derivatives, which are classified as a non-metallic type of chemical compounds. Such a substance appears only after oil is treated with oxidizing polymers exclusively under natural conditions and after a large amount of time. Usually natural bitumen can be found in large quantities only in places where large oil deposits have been diagnosed and identified. This material can be compared to asphalt; it is stored in the form of specific small swamps. Typically, natural petroleum road bitumen, defined by GOST, is very rare, and is mainly found where there is a large amount of rock.
2. Asphalt powder. This is a substance that is buried only in rocks and has the appearance of limestone when found. When further processing of the substance occurs, it is extracted, and then the same actions are performed with it as with asphalt powder.

Other types of bitumen

1. Artificial bitumen. It is often called petroleum, since this material can only be obtained through oil refining. The technology that works in the production of bitumen involves several types of this type: oxidized, residual, cracked.
2. Tar bitumen. Its original location can be determined in fuel oil. This type can be obtained only by squeezing out some oil fractions from this substance. Tar oil road bitumen most often acts as an excellent binding element; it also helps to extract all other varieties of this building material.

Main types of bitumen

• BN-50/50. It can be softened only after reaching a temperature of 50 degrees, which is not an overestimated or difficult indicator. It has excellent adhesion, which is appreciated by all repair and construction teams involved in road laying. If you leave this material on a flat surface, it will gradually spread, that is, float, which makes it possible to guarantee an even and uniform layer.
• BN-70/30. In order for this substance to begin to soften, it is necessary to bring its temperature to 70-72 degrees, depending on the composition of the specific chemical compound. It adheres well to the surface, that is, it provides a high adhesion rate. Typically this material is used to create waterproofing, that is, as the bottom or top layer of the road. It should be remembered that this material is prone to chipping, but if it breaks, large pieces will form without additional dust or small elements.
• BN-90/10. A rather complex material that requires at least 90 degrees to melt. Provides excellent adhesion, and in finished form is practically insensitive even to relatively high temperatures. It is quite difficult to break it, but when applying a load similar to blows with a hammer, you can expect it to crumble into fragments, the surface of which has the ability to shine.

Areas of application

Viscous petroleum road bitumen is an almost universal building material, therefore, in addition to the hydraulic engineering and industrial spheres mixed with commerce, this substance is often used in road construction. Typically, bitumen is used not only for laying and building roads, but also for their repair, so the need for such material practically never dries up.

Important differences from other materials

Petroleum road bitumen consists of an organic binder and rubber, which can be replaced by a certain polymer. This composition makes it possible to improve the quality and wear resistance of products made from bitumen or items with its addition, as well as ensure compliance with the standards of modern technologies in construction.

Bitumen composition

Typically, petroleum road bitumen has a simple composition, since it contains approximately the same components, mixed in slightly different proportions. The largest part is occupied by carbons, since there are about 75-80% of them in this substance. Hydrogen occupies a significant, but still not the first position, since its volume is about 10-15% of the total composition. This is how the share of the volatile part of oil road bitumen is determined. Sulfur is usually present, but its amount never exceeds 10% if the composition of the bitumen complies with basic standards. Oxygen takes up only 5%, but is an important element. If you compare the structure of bitumen with the colloidal system, you can find many common features. Asphaltenes are completely dispersed in a specially created medium consisting of a mixture of oil and water.

Features of the composition

The elements listed above are always included in the composition of liquid petroleum road bitumen. GOST defines several important properties and characteristics of this building material. To increase the hardness of bitumen, it is enough to add more asphaltenes to the mixture together with the resin. It should be remembered that an increase in these parameters entails an increase in density and an increase in temperature at which even minimal melting of a particular material is possible.

Features of bitumen

When petroleum road bitumens are considered, the technical characteristics provide for a high content of various substances of an oily nature. This element liquefies more strongly and becomes soft in all respects. It can be easily melted using even a lower temperature than indicated in the characteristics of a particular brand, which includes petroleum road bitumen. GOST 22245-90 determines that the oil content together with resin in bitumen must be adjusted to an average level. If this parameter is neglected or correction is not possible, one should expect that the material will become less durable and will melt better.

Determination of technical characteristics

It should be remembered that the degree of viscosity can be determined by the minimum temperature at which bitumen melts. If you increase the temperature, the viscosity will increase almost immediately. When the degrees decrease, the material hardens noticeably and becomes less plastic. If the temperature drops to zero or sub-zero levels are observed, GOST defines viscous petroleum road bitumen as having possible fragility, therefore, when choosing a material for road production, special care should be taken.

Main advantages

Bitumen has one important and largely positive property. It is not able to dissolve in water. It should be taken into account that GOST defines petroleum road liquid bitumens as subject to complete or partial dissolution in substances of an acidic nature. Also, bitumen does not have a high heat capacity, so it is not suitable for insulation. As an insulating material, it is used only to isolate the structure from moisture. If we take into account the certificate of conformity, petroleum road bitumen must have a consistency with a density of at least 1.5 g/cm3. When the total mass of bitumen is calculated, per 1 liter of the substance a density value of 1 kg/m3 is acceptable. This fact predetermines the characteristics of viscous petroleum road bitumens.

GOST stipulates that bitumen has a wide range of positive features and important properties. High-quality bitumen must be hydrophobic, not dissolve in liquid if there are no chemical reagents in it, soften and become more viscous when the ambient temperature changes. Among binding materials in the construction industry, petroleum road bitumen occupies an undeniable first place. If you choose a high-quality type, you can use it with maximum efficiency for the construction of massive roads, as well as their repair, providing a long-lasting positive result.

Federal Agency for Education Moscow State Academy of Fine Chemicals

technology named after M.V. Lomonosov

Department of Technology of Petrochemical Synthesis and Artificial Liquid Fuel named after. A.N. Bashkirova

Likhterova N.M., Nikolaev A.I.

PROPERTIES AND METHODS FOR DETERMINING THEIR CHARACTERISTICS.

Guidelines for performing laboratory work

Moscow, 2008

BBK 35.514ya73 UDC 541,127:665.642

Likhterova N.M., Nikolaev A.I.

BITUMEN. PROPERTIES AND METHODS FOR DETERMINING THEIR CHARACTERISTICS.

Guidelines for performing laboratory work M, MITHT im. M.V. Lomonosova, 2008, 35 p.

The manual contains a section devoted to the properties of bitumen, as well as a section that presents methods for determining the physical and mechanical characteristics that determine these properties.

Intended for 4th - 6th year students studying in the areas of higher engineering school 072000 “Standardization and Certification”, 250400 - “Chemical technology of natural energy carriers and carbon materials”, as well as in the master’s degree 550808 - “Chemical technology of natural energy carriers and carbon materials”.

Reviewer: senior researcher TsKP MITHT im. M.V. Lomonosova, Ph.D. Gorodsky S.N.

© MITHT im. M.V. Lomonosova, 2008

1. Petroleum bitumens
1.1. Properties of bitumen
1.2. Raw materials for the production of petroleum bitumen
2. Modern domestic petroleum bitumens
3. Experimental methods for determining physical
chemical characteristics of petroleum bitumen
3.1. Method for determining needle penetration depth
according to GOST 11501-78
3.2. Method for determining softening temperature by
ring and ball according to GOST 11506-73
3.3. Fraas brittleness temperature method
according to GOST 11507-78
3.4. Method for determining the change in mass after heating
according to GOST 18180-72
3.5. Method for determining elongation according to GOST 111505-75
4. Calculation methods for determining physical and mechanical properties
characteristics of bitumen

1. Petroleum bitumens.

Natural bitumen has been known to mankind for many thousands of years. In addition to their natural origin, bitumen can be obtained from the processing of oil, shale, peat and coal. In the 20th century, with the development of the oil production and oil refining industry, the production and consumption of bitumen produced from petroleum feedstock increased. The scope of their application is quite wide. So they are used as construction and waterproofing materials in the construction of building foundations and roofs (insulating and roofing bitumen), a binder when laying roads (road bitumen), etc. It should be noted that for the successful use of bitumen they must have a certain set of properties.

1.1. Properties of bitumen. 1.1.1. Viscosity.

At high temperatures, bitumens approach the properties of a liquid, and at low temperatures they acquire the properties of a solid. For road bitumens, viscosity as an indicator of performance properties is important in two cases. During the period of mixing bitumen with mineral materials, they must have a sufficiently low viscosity to ensure ease and efficiency of mixing and laying the mixture into the pavement. During the operation of the road surface, bitumen must have a very high viscosity at elevated temperatures, providing it with the necessary strength. Therefore, viscosity is one of the main characteristics of the structural and mechanical properties of bitumen. The viscosity of bitumen varies widely depending on the chemical composition and temperature. The quantitative ratio of asphaltenes and oils has a significant influence on the viscosity of bitumen. As the amount of asphaltenes increases, the viscosity increases. To increase the durability of the road surface, it is important that the viscosity of the bitumen changes to a lesser extent in the temperature range at which the surface is operated.

A marking feature of viscous road bitumen, which indirectly determines their viscosity, is the depth of needle penetration (penetration) into the bitumen at temperatures of 25 and 0°C. The higher the asphaltene content in the bitumen, the lower the needle penetration depth. The depth of penetration of the needle indirectly characterizes the performance qualities of bitumen such as hardness, strength and heat resistance.

The marking feature of liquid road bitumen is the indicator of conditional viscosity, characterized by the expiration time in

seconds 50 ml of bitumen through a 5 mm hole at a temperature of 60°C and determined using a standard viscometer.

1.1.2. Softening temperature.

The temperature at which bitumens turn from a relatively solid state into a liquid state is conventionally called the softening temperature. The softening point is also a conditional indicator of the viscosity of bitumen at higher temperatures. More viscous bitumens have a higher softening point. At the same needle penetration depth, bitumens with a higher softening temperature are also more heat-resistant. Bitumen with a low softening point have low strength at elevated temperatures.

The softening temperature depends on the composition of the bitumen. The higher the ratio of asphaltenes to the content of liquid components of bitumen - resins and oils - it is higher.

For the quality of bitumen, the relationship between the depth of penetration of the needle and the softening temperature is of great importance. More valuable are bitumens that, at a given softening temperature, have a higher needle penetration depth. This means that bitumens are relatively less susceptible to temperature changes.

Thus, the viscosity of bitumens has a significant impact on the properties of the asphalt concrete mixture during mixing, laying and compaction, as well as on construction and technical properties of asphalt concrete. The high viscosity of bitumens increases the strength, water resistance and heat resistance of asphalt concrete, but bitumens with increased viscosity cover the surface of mineral materials worse, therefore bitumens should be used with a certain viscosity and at certain heating temperatures, taking into account the climatic conditions of the construction area, the type, brand and type of asphalt concrete, the automobile category roads.

This indicator serves for the operational assessment of bitumen and relates the softening temperature and needle penetration depth. The penetration index (I.P.) is expressed as an abstract number determined by the formula:

AND . P .= 1 + 30 50 A − 10

A = 2.9031− logP

T − 25

where P is the depth of penetration of the needle at 25°C, 0.1 mm;

T - softening temperature, °C.

The penetration index characterizes the colloidal properties of bitumen, their plastic properties and their dependence on temperature.

According to the penetration index, bitumens are divided into three groups:

1. bitumens and IP 2 (sol), which do not have a dispersed phase or contain highly pentized asphaltenes (bitumens from cracking residues or coal tar pitches). The elasticity of such bitumen (ductility at 25° C) is close to zero;

2. bitumen and IP from -2 to +2 (sol-gel) there are elements for the formation of a spatial coagulation framework with layers of dispersed medium that prevents the aging of bitumen (bitumens for road construction);

3. bitumens with IP 2 are gels and are prone to aging. Requirements of modern GOST 22245-90 for viscous road

bitumen provides for a change in IP from -1 to +1.

1.1.4. Extensibility.

The extensibility of bitumens is assessed by their ability to stretch into a thread of a certain length under the influence of load.

The extensibility of bitumens depends on their temperature, group composition and structure. Bitumen with a high content of resins with an optimal content of oils and asphaltenes have greater plasticity. With increasing temperature, the extensibility of bitumen increases. Bitumen with a greater needle penetration depth also have greater extensibility. With an increase in the content of solid paraffins in bitumen, the extensibility of bitumen decreases.

The extensibility of bitumen indirectly characterizes their adhesion to mineral materials. With increasing extensibility, the adhesion of bitumen to mineral materials increases, which is explained by the significant content of aromatic compounds and resins in bitumen. The extensibility of bitumen at 25° C also characterizes the degree of structuring of the bitumen and the type of its dispersed structure.

One of the most important properties of asphalt concrete is closely related to the extensibility of bitumen at low temperatures - its deformability at low operating temperatures. Insufficient deformability leads to rapid destruction of asphalt concrete and cracks appear in the coatings. Increasing the extensibility of bitumen at subzero temperatures is the most important task for researchers and engineers.

1.1.5. Brittleness temperature.

The lowest temperature at which bitumen, under given test conditions, loses its viscoplastic properties and becomes brittle is called the brittleness temperature.

The brittleness temperature is one of the most important indicators of the quality of road, roofing and a number of other bitumens, characterizing the performance of bitumen-containing materials at low temperatures. A possibly lower brittleness temperature of bitumen is desirable, since such bitumen has better plastic properties, and road or roofing coatings work better in harsh climates and cold weather. Bitumen coatings with a high brittleness temperature at low temperatures chip, crack and quickly collapse.

The presence of paraffin-naphthenic and monocyclic aromatic compounds determines the low brittleness temperature of bitumen.

The temperature interval between the softening temperature and the brittleness temperature is called the plasticity interval. Bitumen with a wide range of plasticity (more than 70°C) have increased deformability, resistance to cracking at low temperatures and resistance to shear at elevated summer temperatures. The larger the temperature range in which bitumen is in an elastic-viscous state, the better its performance properties. Such bitumen usually also exhibits good adhesion to the surface of the mineral material.

1.1.6. Adhesion to the surface of mineral materials

(adhesion).

The ability of bitumen to firmly adhere to the surface of mineral particles prevents spalling of the mineral material from the road surface monolith and ensures its frost and water resistance.

The adhesion of bitumen to mineral material depends on the properties of bitumen and mineral materials, as well as on the external conditions in which mixing is carried out and the road surface is operating.

The adhesion of bitumen is determined by the polarity of the molecules of the mixture components. In bitumen, the molecules of asphaltenes and asphaltotenic acids and their anhydrides have significant polarity.

Bitumen adheres well to the surface of mineral materials of carbonate and basic rocks and poorly to the surface of mineral materials of acidic (SiO2 content more than 65%) rocks (granite).

The adhesion of bitumen increases with increasing temperature, and the presence of moisture on the surface of the mineral material sharply reduces the adhesion of bitumen.

Water-soluble compounds include compounds that are extracted with water in the form of a solution or released from bitumen in the form of emulsions. As a rule, these are low-molecular compounds (acids or alkalis) and some salts of organic acids.

The presence of water-soluble compounds in bitumen leads to the fact that when bitumen comes into contact with water, extraction of these substances occurs. The process of washing out individual components from the composition of the bitumen binder contributes to the formation of microcracks (voids) in the road surface, which in turn leads to its destruction in winter due to the wedging effect of water in a crystalline state. This may expose mineral material and then crumble out of the road surface.

1.1.8. Aging.

Aging is usually called a set of irreversible changes in the chemical composition, structure and properties of bitumen that occur when bitumen is exposed to various factors - temperature, light, air, water, mineral materials and mechanical loads.

As a result of aging, bitumens increase their viscosity and fragility. An increase in viscosity occurs due to a change in the group composition of bitumen - resins transform into asphaltenes, asphaltenes partially transform into carbenes and carboids, and the content of aromatic compounds decreases. When bitumen is stored in the open air for a long time, cracks and peeling appear on its surface as a result of oxidation, and adhesion to mineral materials deteriorates. Such changes in the physical properties and chemical composition of bitumen are associated primarily with the processes of oxidation and polymerization occurring in bitumen and to a lesser extent depend on the evaporation of light fractions.

A characteristic of bitumen's resistance to aging (stability) under conditions of long-term storage at elevated temperatures is an increase in the softening temperature after heating.

Bitumen with a higher initial viscosity are subject to less changes from atmospheric factors than bitumen with a lower initial viscosity. The intensity of aging increases in bitumen when heated in the presence of mineral materials that act as catalysts. Also, the intensity of aging of bitumen in an asphalt concrete pavement is significantly influenced by the volume and structure of the pores of asphalt concrete. Large volume of open

9 (communicating) pores, promoting increased circulation of air and water, intensifies the aging processes of bitumen. In dense asphalt concretes, characterized by closed pores, bitumen aging is less intense. The thinner the asphalt concrete layer, the greater the intensity of bitumen aging.

1.1.9. Fire safety of bitumen.

When bitumens are heated, gaseous products are released, which can ignite in the presence of an open flame. To protect bitumens from fire during their manufacture and use, it is necessary to take into account the flash and self-ignition temperatures.

The flash point is the temperature at which the gaseous products of heated bitumen form a mixture with the surrounding air that ignites when a flame is applied to it.

The auto-ignition temperature is the temperature of gaseous products released from heated bitumen, which, when mixed with air after ignition, burn for at least 5 s.

In practice, the flash point and self-ignition temperature are used to judge the fire hazard and expected losses from the evaporation of bitumen.

1.2. Raw materials for the production of petroleum bitumen.

The main raw materials for the production of bitumen are the residues of vacuum distillation of oil - tars, as well as by-products of oil production - deasphalting asphalts, that is, asphalt-resinous substances deposited from tars, usually with liquid propane. They are also called precipitated bitumen. In some cases, cracked residues from a thermal cracking unit are used to produce bitumen.

It should be noted that to obtain high-quality bitumen with high thermal stability and good binding properties, it is advisable to use tars of heavy oils with a naphthenoaromatic base, containing a lot of asphalt-resinous substances. However, to produce bitumen on a large scale, it is necessary to use mass-produced oils. For example, the possibility of obtaining bitumen from oils, the characteristics of which are presented in Table 1, was studied for 22 fields in Turkmenistan.

Table 1 Composition of oils from Turkmenistan fields.

Oil fields

Kotur - Tepe

Kotur - Tepe

Komsomol

Zap. Cheleken

Dagadzhik

Western

Central

Eastern

Oval-Toval

Barca-Gelmes

West

Central

Paraffin

Asphaltene

Continuation of Table 1

Oil fields

Kotur - Tepe

Pribalkhansky

Gograndag -

West

Oriental

Buruns-kaya

Monjucly

Reed ski

Is it Karadash?

Paraffin

asphaltenes

Using the classification of oils developed by the BashNIINP Institute (classification 1), according to the content of asphaltenes (A), resins (C) and paraffins (P), the results presented in

Definition of bitumen, properties of bitumen, application of bitumen

Information on the definition of bitumen, properties of bitumen, applications of bitumen

1. Properties

2. Test methods and corresponding types of classifications

Penetration

Softening point

Brittle point

Ductility

Viscosity

Rheology of bitumen

Solubility

3.

- Road

- Building

Roofing

- Insulating

- fragile

Bitumen for filling battery mastics

4. Industrial production

Methods

Technology

5. Petroleum bitumens, composition, structure and properties

6. Solid fossil fuel bitumen

7. Natural bitumens

8. Bituminous varnishes

9. How and with what to remove bitumen from the paintwork of a car body

10. Bitumen in the environment

Bitumen is(from lat. bitumen - mountain resin) - solid or resin-like products, which are a mixture of hydrocarbons and their nitrogenous, oxygenous, sulfur and metal-containing derivatives. Bitumen is insoluble in water, completely or partially soluble in benzene, chloroform, carbon disulfide and other organic solvents; density 0.95-1.50 g/cm³.

Properties

The properties of bitumen depend on the production methods, the quality of the raw material (the nature of the oil being processed), as well as on the parameters of the thermolysis process - temperature, pressure, duration. The production of high-quality bitumen from oils of different natures (component composition) is possible with the correct determination of not only the contribution of a particular process to the overall production flow chart, but also the sequence of their implementation.

Bitumen is a black product with a density of about one, with low thermal and electrical conductivity. It perfectly resists the effects of various chemical reagents, is water- and gas-proof, resistant to various types of radiation and prolonged thermal exposure. It is precisely these valuable qualities of bitumen, combined with low cost and mass production, that have made them indispensable in many areas of the economy.

Being an amorphous substance, bitumen does not have a melting point. The transition from solid to liquid is characterized by a softening point, which is usually determined by the “ring and ball” method. The hardness of bitumens is assessed by measuring penetration, and ductility is assessed by elongation (ductility).

Bitumen is insoluble in water, completely or partially soluble in benzene, chloroform, carbon disulfide and other organic solvents; density 0.95-1.50 g/cm3.

As will be discussed in detail below, petroleum bitumen, according to the production method, is divided into residual, oxidized and compounded. Residual bitumens are soft, fusible products, oxidized ones are elastic and heat-stable. Bitumen obtained by oxidation of cracking residues contain a large amount of carbenes and carboids, which disrupt the homogeneity of bitumen and impair their cementing properties.

Test methods and corresponding types of classifications

To classify commercial bitumen into grades depending on their quality, various test methods have been developed and used. These methods are approved by the standards of different countries.

The purpose of generally accepted methods for testing the quality of bitumens is to determine their consistency, purity and heat resistance. To determine consistency, many methods have been proposed to establish its dependence on viscosity. Bitumen is characterized and compared by the degree of fluidity at a certain temperature or by the temperature at which certain properties are determined.

Such indicators characterizing the properties of solid bitumen include the penetration depth of a standard needle (penetration), softening temperature, elongation into a thread (ductility), and brittleness temperature. These studies are, strictly speaking, not equivalent to direct determination of viscosity, but have wide practical application because they allow the consistency of bitumen to be quickly characterized. The main indicators characterizing the properties of bitumen also include adhesion, surface tension at the interface, cohesion, thermal, optical and dielectric properties. Comparable indicators, in addition, include weight loss during heating and changes in penetration after it, solubility in organic solvents, ash content, flash point, density, and rheological properties.

Natural bitumen is a component of fossil fuels. These include natural oil derivatives formed when the conservation of its deposits is disrupted as a result of chemical and biochemical oxidation, for example, asphalts, kerites, maltas, ozokerites, etc. Extraction is carried out mainly by quarry or mine methods (Bituminous sands).

Artificial (technical) bitumens are residual products from the refining of oil, coal and shale. The composition is similar to natural bitumen.

Bitumen has long been one of the most famous engineering and construction materials. Its adhesive and hydrophobic properties have been used since the dawn of civilization.

Some indicators are determined both for the initial bitumen and for bitumen after heating, which simulates the aging process. The standards set certain values ​​of quality indicators, which reflect the optimal composition of bitumen. This composition may be different for different applications of bitumen.

Penetration

Penetration is an indicator characterizing the depth of penetration of a body of a standard shape into semi-liquid and semi-solid products under a certain regime, which determines the ability of this body to penetrate into the product, and the product to resist this penetration. Penetration is determined by a penetrometer, the design of which and test procedure are given in GOST 11501-78; The penetration depth of the needle is taken to be 0.1 mm per unit of penetration. The penetration of road petroleum bitumen of various grades at 25 °C, a load of 100 G, for 5 seconds is 40-300 * 0.1 mm, and at 0 °C, a load of 200 G, for 60 seconds - from 13 to 50 * 0 .1 mm. Thus, depending on the temperature, load and duration of needle penetration, the penetration value changes significantly. Therefore, the conditions for its determination are specified in advance. Penetration indirectly characterizes the degree of hardness of bitumen. The higher the penetration of bitumen at a given softening temperature and at a given penetration - the softening temperature of bitumen, the higher its heat resistance. Bitumen with high heat resistance can be obtained by appropriate selection of raw materials, technological method and production mode.

Softening point

The softening temperature of bitumen is the temperature at which bitumen turns from a relatively solid state into a liquid one. The method for determining the softening temperature is conventional and not scientifically substantiated, but is widely used in practice. The test is carried out according to GOST 11506-73 by the “ring and ball” (R&B) method, and also sometimes by the Kremer-Sarnov method.

Penetration index is an indicator characterizing the degree of colloidality of bitumen or the deviation of its state from a purely viscous one. Based on the penetration index, bitumen is divided into three groups.

1) Bitumen with a penetration index of less than -2, without a dispersed phase or containing highly peptized asphaltenes (bitumens from cracking residues and pitches from coal tars). The elasticity of such bitumen is very small or practically equal to zero.

2) Bitumen with a penetration index from - 2 to +2 (residual and slightly oxidized).

3) Bitumen with a penetration index of more than +2 have significant elasticity and pronounced colloidal properties of gels. These are oxidized bitumens with high extensibility.

Brittle point

The brittleness point is the temperature at which a material breaks under the action of a briefly applied load. According to Fraas, this is the temperature at which the modulus of elasticity of bitumen with a loading duration of 11 seconds is the same for all bitumens and is equal to 1100 kg/cm2 (1.0787-108 n/m2). The brittleness temperature characterizes the behavior of bitumen in a road surface: the lower it is, the higher the quality of road bitumen. Oxidized bitumens have a lower brittleness point than other bitumens of the same penetration.

The brittleness temperature of road bitumen usually ranges from -2 to -30 °C. To determine it, use the method described in GOST 11507-78 with the addition according to clause 3.2.

Ductility

The extensibility (ductility) of bitumen is characterized by the distance over which it can be pulled into a thread before breaking. This indicator also indirectly characterizes the adhesion of bitumen and is associated with the nature of its components. Road petroleum bitumens have high extensibility - more than 40 cm. Increasing the extensibility of bitumen does not always correspond to an improvement in their properties. The quality of road bitumen cannot be judged by the elongation index, since the test conditions (stretching at a speed of 5 cm/min) differ from the operating conditions of bitumen in the road surface.

The extensibility of bitumens at 25 °C has a maximum value corresponding to their transition from the state of a Newtonian fluid to a structured one. The more bitumen deviates from the Newtonian flow, the lower its elongation at 25°C, but quite high at 0°C. Bitumen should have increased elongation at low temperatures (0 and 15°C) and moderate elongation at 25°C.

The method and design of the device for determining the extensibility of bitumen are given in GOST 11505-75.

Viscosity

The viscosity of bitumens more fully characterizes their consistency at various application temperatures compared to empirical indicators such as penetration and softening point. It can be easily and in a shorter time measured at any required temperature for the production and use of bitumen. It is desirable that bitumen, other things being equal, should have the highest viscosity at the maximum temperature of use and have as flat a viscosity-temperature curve as possible. At temperatures below 40 °C, bitumen is similar to solid systems, at temperatures from 40 to 140 °C - structured liquids, at temperatures above 140 °C - true liquids. Bitumen behaves like a true liquid when its viscosity drops to 102-103pz.

The viscosity of bitumen is determined in Engler, Saybolt and Furol viscometers, by the falling ball method, in a Fenske capillary, on a rotational viscometer, rheoviscometer, consistometer, etc.

Road bitumens are divided into viscous and liquid.

Viscous bitumen is used as a binding material in the construction and repair of road surfaces. The bulk of such bitumen is produced in Russia in accordance with GOST 22245-90.

Liquid bitumen is designed to extend the road construction season. In accordance with GOST 11955-82, they are obtained by mixing viscous BND bitumens with distillate fractions - thinners. After laying the coating, the thinner gradually evaporates.

Rheology of bitumen

Rheology (from the Greek rheos - flow, flow), the science of deformation and fluidity of matter. Rheology considers processes associated with irreversible residual deformations and the flow of various viscous and plastic materials (non-Newtonian fluids, dispersed systems, etc.), as well as the phenomena of stress relaxation, elastic aftereffect, etc.

The rheology of bitumen has not been studied enough. The main indicators determined when studying the rheological properties of bitumen in the temperature range of preparation and laying of the mixture, as well as the operation of the coating, are the viscosity and deformation characteristics of bitumen (elastic modulus, deformation modulus, etc.). The behavior of bitumen under the influence of external deforming forces is determined by a set of mechanical properties, which include viscosity, elasticity, plasticity, fragility, fatigue, creep, and strength. Each property depends on temperature and the nature of the stressed state and is associated with intermolecular interactions and the presence of structure. Rheological properties should not change significantly when heating bitumen in bitumen boilers, preparing and laying the mixture and over a long service life.

Based on their rheological properties, bitumens are divided into three types:

1) substances, the flow of which under the influence of constant shear stress obeys Newton’s law; when the stress is removed, a state of inelastic elasticity occurs. These include viscous non-colloidal liquids, inelastic or weakly elastic sols.

2) Substances in which, at a constant shear stress, the shear rate after the onset of deformation decreases and after some time becomes almost constant, when the stress is removed, the elasticity is partially restored, the colloidal state of bits of this type is sol-gel.

3) With constant shear stress at the beginning of deformation, the flow rate decreases to a minimum and then increases, if the applied shear stress is greater than a certain value, after the stress is removed, elasticity is restored, bitumens of this type have a gel structure.

Solubility

Most existing methods for bitumen analysis are based on differences in the solubility of their components in a number of organic solvents. For the first time, a division based on this principle was proposed by Richardson, who divided bitumens into maltenes soluble in gasoline and asphaltenes insoluble in this solvent. Subsequently, Marquon, using adsorption on Fuller's earth, separated maltenes into oils and resins. Basically, this technique has been preserved to this day, but a large number of its varieties have appeared, making it possible to obtain narrower, but less representative fractions.

Application and quality requirements

The use of bitumen as one of the most famous engineering and construction materials is based on its adhesive and hydrophobic properties. The scope of application of bitumen is quite wide: it is used in the production of roofing and waterproofing materials, in the rubber industry, in the paint and varnish and cable industries, in the construction of buildings and structures, etc. Roofing bitumen is used for the production of roofing materials. They are divided into impregnating and covering (respectively for impregnating the base and obtaining a coating layer). Insulating bitumens are used to insulate pipelines to protect them from corrosion.

Currently, the areas of use are extremely wide. Suffice it to say:

road construction,

production of roofing materials,

application in the paint and cable industry,

construction of buildings and structures, laying pipelines, etc.

The main raw materials for production are residual products of oil refining: tars, deasphalting asphalts, extracts for selective purification of oil fractions. The use of natural bitumen is extremely small.

The main consumer of bitumen is road construction (about 90%), primarily due to the fact that petroleum bitumen is the cheapest and most versatile material for use as a binder in the construction of road surfaces. The use of bitumen in road construction allows road surfaces to withstand increased static and dynamic loads over a wide temperature range while maintaining long-term viability and weather resistance.

Viscous bitumens used in road surfaces are used as a binder between stone materials. The durability of the road surface largely depends on the brand of bitumen used and its quality. During the construction and repair of roads, bitumen can be diluted with a solvent (kerosene fraction). Liquefied bitumen is divided into fast-, medium- and slow-hardening grades. For pre-treatment of surfaces, bitumen emulsions are used, which are prepared using colloid mills by adding water and emulsifiers to the bitumen.

Let's take a closer look at bitumen for various purposes.

Road

The quality of road bitumen mainly determines the durability of road surfaces. The appearance of cracks on the road surface means that it has reached 85% of its service life. It has been established that the “brittleness temperature” indicator of bitumen characterizes the time before the onset of intensive cracking of the road surface, since its determination shows the most dangerous state of the road surface during sudden temperature changes in winter. The ratio of physico-chemical parameters of BND bitumen provides the road surface with the greatest shear resistance, crack resistance, long-term water and frost resistance.

Building

Construction grade bitumen BN, used for waterproofing building foundations, is characterized by low penetration and ductility and a high softening point (from 37 to 105 0C), i.e. they are refractory and hard. Construction bitumen is standardized according to GOST 6617 - 76

Construction bitumen is a complex mixture of hydrocarbons and heteroorganic compounds of various structures. The special structure of the substance gives it important properties that facilitate its effective use in a wide variety of areas of construction.

Construction bitumens BN 90/10 and BN 70/30 are used in processes such as waterproofing concrete structures and foundations, pipelines for various purposes, preliminary priming of bases for soft roofing; in addition, these grades are actively used in the production of bitumen varnishes and bitumen mastics , bitumen primer, hydroglass insulation and some other building materials.

Construction bitumen (including construction bitumen BN 90/10) is one of the most famous and important construction materials. Due to its adhesive and hydrophobic properties, construction bitumen is widely used in road construction, the manufacture of roofing materials, pipeline laying, and bitumen waterproofing of foundations of buildings and structures. Construction bitumen (including bitumen BN 90/10) is a complex mixture of hydrocarbons and heteroorganic compounds of various structures, which generally does not boil away at oil distillation temperatures. Determination of all compounds that make up bitumen is impossible. The group composition of bitumen determines its colloidal structure and rheological behavior and thus its technical properties, which are characterized by conditional quality indicators determined under standard conditions. Among these indicators, the most important are: penetration (the depth of penetration of a needle into bitumen), softening and brittleness temperatures, ductility (extensibility) - the ability of bitumen to stretch into a thread. Some indicators are determined both for the initial bitumen and for bitumen after heating, which simulates the aging process. The standards set certain values ​​of quality indicators, which reflect the optimal composition of bitumen. This composition can be different for different areas of application of bitumen: from bitumen waterproofing to repair and roofing.

The following types of bitumen are known:

Construction bitumen GOST 6617-76 BN 70/30, BN 90/10;

Insulating bitumen GOST 9812-74 BNI-IV, BNI-V;

Roofing bitumen GOST 9548-74 BNK-45/190, BNK-90/130;

Road bitumen GOST 22245-90, BND 90/130, BND 60/90.

Road bitumens are divided into viscous and liquid. Viscous bitumen is used as a binding material in the construction and repair of road surfaces. The main quantity of such bitumen is produced in accordance with GOST 22245-90.

In accordance with GOST 22245-90, two types of viscous construction bitumen are produced: BND and BN. All construction bitumens are marked by penetration at 25 °C. With equal penetration at 25 °C, BND bitumens have a higher softening point, lower brittleness temperature and higher penetration values ​​at 0 °C than BN bitumens (construction bitumen BN 90/10, BN 70/30). At the same time, for BND bitumen, requirements for ductility at 0 ° C are established, and the requirements for ductility at 25 ° C are less stringent in comparison with BN bitumen (construction bitumen BN 90/10, BN 70/30). The requirements for the thermal stability of BND bitumen are more stringent. Recommendations for use depend on the type of construction bitumen and their penetration at 25 °C. In the first road-climatic zone, when the average monthly temperature of the coldest season is not higher than -20 ° C, it is recommended to use bitumens BND 200/300, BND 130/200, BND 90/130; in the second and third zones at temperatures within -10...-20 °C - bitumen BND 200/300, BND130/200, BND90/130, BND 60/90; in the second, third and fourth zones at a temperature of -5...-10 °C - bitumens BN 200/300, BN 130/200, BN 90/130, BND 130/200, BND 90/130, BND 60/90, BND 40/60; in the fourth and fifth climatic zones at a temperature not lower than 5 ° C - bitumens BN 90/130, BN 60/90, BND 90/130, BND 60/90, BND 40/60. Liquid bitumen is designed to extend the road construction season. In accordance with GOST 11955-82, they are obtained by mixing viscous BND bitumens with distillate fractions - thinners. After laying the coating, the thinner gradually evaporates. The use of liquid road bitumen does not meet modern requirements for energy saving and environmental protection. In addition, their low flash point determines their fire hazard. Construction bitumen BN 90/10 is used in various construction works, in particular for bitumen waterproofing of building foundations.

Construction bitumen (bitumen BN 90/10, BN 70/30) is used for bitumen waterproofing of concrete structures; for bitumen waterproofing of foundations; for preliminary priming of the base under a soft roof. Also, construction bitumen (bitumen BN 90/10, BN 70/30) is used for the production of bitumen mastics, bitumen primer, hydroglass insulation, etc.

Construction bitumen (bitumen BN 90/10, BN 70/30) is produced in briquettes of 25 kg. Some manufacturers of construction bitumen (bitumen BN 90/10, BN 70/30) produce construction bitumen (bitumen BN 90/10, BN 70/30) in drums of 25-50 kg.

Bitumen waterproofing is the cheapest of all types of waterproofing for concrete and foundations. Bituminous waterproofing is molten bitumen BN 90/10 (bitumen BN 70/30) applied to the surface of the concrete (foundation). It is possible to add solvents such as white spirit, nefras, or kerosene (gasoline) to BN 90/10 bitumen (BN 70/30 bitumen). Bitumen waterproofing using open fire is possible only in places where it is permitted by fire safety rules; in other cases, bitumen BN 90/10, BN 70/30 and the solvents indicated above should be used for bitumen waterproofing. Also, for bitumen waterproofing, it is possible to use ready-to-use bitumen mastic that already contains a solvent (a fire-free type of bitumen waterproofing). This type of bitumen waterproofing is more expensive, but time-consuming it is much more economical. Both internal and external bitumen waterproofing is possible. The choice of waterproofing (be it bitumen waterproofing, waterproofing with rolled fused materials or waterproofing with dry mixtures) depends only on individual tastes.

Roofing

Approximately the same quality indicators have been established for NBR roofing bitumens, but their brittleness temperature is also standardized. They are used as impregnating materials (for producing roofing felt and roofing felt) and for covering roofs.

Insulating

BNI insulating bitumens are used to insulate pipelines to prevent them from corrosion. With low penetration and low ductility, they must be quite refractory (especially for battery mastics). In addition, solubility in toluene or chloroform is standardized for mastics (at least 99.5%, i.e. almost complete solubility).

fragile

There are two brands of brittle bitumen, which soften at 100 - 110 0C and 125 - 135 0C, have scanty penetration and more stringent solubility standards. They are used in the paint, tire and electrical industries

Bitumen for filling battery mastics

Below is the characteristics of bitumen for filling battery mastics in accordance with GOST 8771 - 76:

Softening temperature, 0C - 105 – 115

Penetration at 25 0C, 0.1 mm - 10 – 16

Ductility at 25 0C, cm, not less than 1

Solubility in toluene or chloroform, %, not less than 99.50

Change in mass after heating, %, no more than 0.50

Flash point, 0C, not lower than 260

Penetration index, not less than 4

Industrial production

The production of petroleum varieties of bitumen is carried out:

blowing tar with air

distillation of fuel oils with deep selection of distillates

deasphalting of tars with propane.

Compounding of products from various processes is also widely used. The main production process in the CIS countries is oxidation - blowing tars with air.

In accordance with production methods, grades are divided into oxidized, residual, precipitated and compounded. Bitumen is also classified according to areas of application.

Currently, the bulk of brands produced in the post-Soviet space are:

Petroleum road liquid bitumen (GOST 11955-82)

Petroleum construction bitumen (GOST 6617-76)

Perhaps one of the universal building materials, which is used in a wide variety of areas of construction and is used at different stages

construction of new buildings is construction bitumen. Its use has become

almost a tradition and an important element of the entire construction process. Therefore, the scope of its use today is so wide

Methods

The production of petroleum bitumen is one of the thermal processes of oil refining. The main parameters of thermal processes that affect the range, material balance and quality of the resulting products are the quality of raw materials, pressure, temperature and duration of thermolysis (thermal process).

The main raw materials for the production of bitumen in our country are residual products of oil refining: tars, deasphalting asphalts, extracts of selective purification of oil fractions, etc.

There are three main methods for producing petroleum bitumen.

By concentrating oil residues by distilling them in a vacuum, residual bitumens are obtained. To obtain residual bitumen, only raw materials with a high content of asphalt-resinous substances, which are present in sufficient quantities in heavy, highly resinous sulfurous oils, can be used. In the processes of vacuum distillation and deasphalting, residual and precipitated bitumens are obtained. The main purpose of these processes is the extraction of distillate fractions for the production of motor fuels - in the case of the first, preparation of raw materials for the production of base oils (initial stage) - in the case of the second. At the same time, the by-products of these processes - distillation tar and deasphalting asphalt - meet the requirements for raw materials in the production of bitumen or they are used as raw materials in the production of oxidized bitumen.

Oxidation of various oil residues and their compositions with air oxygen at a temperature of 180 – 300 0C (oxidized bitumen). Oxidation with air can significantly increase the content of asphalt-resin substances, the most desirable component in the composition of bitumen. To produce oxidized bitumen, BashNIINP proposed to classify oils according to the content (%, wt.) of asphaltenes (A), resins (C) and solid paraffins (P) in them. Oil is considered suitable for the production of oxidized bitumen if the following conditions are met: The main process of bitumen production is oxidation - blowing tar with air. Oxidized bitumens are produced in batch and continuous apparatuses. The latter are more economical and easier to maintain. The principle of producing oxidized bitumen is based on compaction reactions at elevated temperatures in the presence of air, leading to an increase in the concentration of asphaltenes, which contribute to an increase in the softening temperature of bitumen, and resins, which improve the adhesive and elastic properties of the commercial product. Apparatuses used in the production of bitumen are tubular reactors or oxidation columns. When obtaining construction bitumens, the first ones are preferred, while the second ones are preferred for road bitumens.

By mixing various oxidized and residual bitumens, as well as oil residues and distillates, compounded bitumens are obtained.

Residual bitumens are soft, fusible products, oxidized ones are elastic and heat-stable. Bitumen obtained by oxidation of cracking residues contain a large amount of carbenes and carboids, which disrupt the homogeneity of bitumen and impair their cementing properties.

Technology

Residual bitumen is produced from fuel oil with a high concentration of asphalt-resinous substances by vacuum distillation as a residue from this distillation. Let us remember that fuel oil is a residue from the atmospheric distillation of oil.

Let us dwell in more detail on the oxidation of tars or residual bitumen with atmospheric oxygen. The main process parameters are temperature, air flow and pressure.

The higher the temperature, the faster the oxidation process occurs, but at too high a temperature, the formation of carbenes and carboids accelerates, which make bitumen undesirably increased fragility. Usually the temperature is maintained at 250 - 280 0C.

The higher the air flow, the less time is required for oxidation. If the air flow is excessively high, the temperature in the oxidation column may increase above the permissible level. Therefore, air flow is the main control parameter for maintaining the desired temperature. The total air consumption depends on the chemical composition of the raw material and the quality of the resulting bitumen and ranges from 50 to 400 m3 / t of bitumen.

When the pressure in the reaction zone increases, it intensifies the process, and the quality of the oxidized bitumen improves. In particular, bitumen penetration increases at a constant softening temperature. Typically the pressure ranges from 0.3 to 0.8 MPa.

The main apparatus is an oxidation column with a diameter of 3400 mm and a height of 21,500 mm.

The technological mode of the process is as follows:

temperature, 0С:

raw materials leaving the furnace 180 – 250

in the oxidation column, not higher than 290

bitumen at the exit from the refrigerator 170 – 200

loading bitumen into tanks 170 – 180

pressure in the oxidation column, MPa 0.3 – 08

air consumption, m3 / t bitumen 50 – 400

thermal effect of the process, kJ / kg bitumen 168 – 502

oxidation products, % 3 -11

Finally, the third way to obtain bitumen is compounding. This method is the final stage of bitumen production and uses as components both bitumen obtained in the form of vacuum distillation residues and oxidized bitumen. In addition, one of the important components of the compounds are extracts of selective purification of distillate oils and deasphalting compounds, since, being a concentrate of polycyclic multi-ring aromatics, they give the bitumen elasticity and good extensibility.

Technological mode of such an installation:

temperature, 0С:

raw materials at the entrance to the installation 100 – 120

oxidation in reactors 260

bitumen after refrigerators 170

pressure, MPa:

air at the inlet to the mixers 0.9

mixture at the reactor inlet 0.8

air consumption, m3 / m3 product 100 – 150

recycled: feed ratio 6:1

The capacity of bitumen production plants is from 120 to 500 thousand tons/year.

Petroleum bitumens, composition, structure and properties

Petroleum bitumens are solid, viscoplastic or liquid products of petroleum refining. According to the chemical composition, bitumen is a complex mixture of high molecular weight hydrocarbons and their non-metallic derivatives of nitrogen, oxygen and sulfur, completely soluble in carbon disulfide. To study bitumen, they are divided into main groups of hydrocarbons (similar in properties) - oils, resins, asphaltenes, asphaltogenic acids and their anhydrides.

Oils are a mixture of cyclic hydrocarbons (mainly naphthenic series) of light yellow color with a density of less than 1 and a molecular weight of 300...500; The increased oil content in bitumens gives them mobility and fluidity. The amount of oils in bitumen ranges from 45...60%.

Resins are dark brown viscoplastic substances with a density of about 1 and a molecular weight of up to 1000. Resins have a more complex composition of hydrocarbons than oils. They consist mainly of neutral oxygen heterocyclic compounds and give bitumen greater ductility and elasticity. Resin content 15.,30%.

Asphaltenes and their modifications (carbenes and carboids) are solid, infusible substances with a density slightly greater than 1 and a molecular weight of 1000...5000 or more. This group of hydrocarbons is an essential component of bitumen. The increased content of asphaltenes in bitumen determines its high viscosity and temperature stability. The total content of asphaltenes in various bitumens is 5...30% or more.

Carbenes and carboids are found in bitumen relatively rarely in small quantities (1...2%) and contribute to increasing the fragility of bitumen.

Asphalt acids and their anhydrides are brownish substances with a resinous consistency with a density of more than 1. They belong to the group of polynaphthenic acids and can be not only viscous, but also solid. Asphaltogenic acids are the surface-active part of bitumen and help to increase its adhesion to the surface of mineral aggregates. Their content in petroleum bitumen is about 1%.

The above groups of bitumen hydrocarbons form a complex disperse system - a colloidal solution, in which the liquid medium is oils and a solution of resins in oils, and the solid phase is represented by asphaltenes, on the surface of which asphaltogenic acids are adsorbed. Oils, resins and asphaltenes are included in the composition of bitumen in various proportions and thereby predetermine their structure. Depending on the quantitative content of oils, resins and asphaltenes (as well as on the heating temperature), the colloidal structure of bitumen - “gel”, “sol”, “solgel” - undergoes changes from the “sol” type to the “gel” type. The gel structure is characteristic of solid bitumen at a temperature of 2O...25°C and is usually caused by an increased content of asphaltenes. The sol structure is characteristic of bitumens of liquid consistency with a high content of resins and oils.

The most important properties of bitumen that characterize their quality are viscosity, plasticity, softening and brittleness temperatures; in addition, it should be noted the high adhesion, which determines the ability of bitumen to bind mineral grains of fillers into a monolith; they are also capable of imparting hydrophobic properties to materials treated with bitumen.

The main characteristic of the structural and mechanical properties of bitumen is viscosity, which depends mainly on temperature and group composition. Viscosity is the resistance of the internal layers of bitumen to movement relative to each other. For many bitumens, viscosity is variable and decreases with increasing shear stress or strain rate gradient. As the temperature rises, the viscosity decreases, as it decreases, the viscosity increases rapidly, and at subzero temperatures, bitumen becomes brittle. To measure structural viscosity, various instruments are used that make it possible to determine viscosity in absolute units (Pa-s) or express it in conventional units. To characterize viscosity, or more precisely the value of inverse viscosity, i.e. the fluidity of bitumen, a conditional indicator is adopted - the depth of penetration of the needle into the bitumen (penetration). The depth of penetration of a needle into bitumen is determined using a penetrometer by applying a load weighing 100 g to the needle for 5 s at a temperature of 25°C or 0°C with a load of 200 g for 60 s. The penetration of solid or viscous bitumen is expressed in units (degrees) equal to 0.1 mm of needle penetration into the bitumen. The higher the viscosity, the less penetration of the needle into the bitumen.

Plasticity is an important property of bitumen. It increases with increasing oil content, duration of load and temperature. The plastic properties of hard and viscous bitumen are conventionally characterized by extensibility (ductility) - the ability to stretch into thin threads under the influence of external constant forces. Extensibility is determined using a special device - a ductilometer at a deformation rate of a bitumen sample in the form of a “figure of eight” of 5 cm/min, test temperatures of 25 and 0 ° C. An indicator of elongation is the length of the thread at the moment the sample breaks, expressed in centimeters. The plastic properties of bitumen depend on temperature, group composition and structure. For example, with an increase in the content of resins and asphaltenes, the plasticity of bitumen increases at a constant temperature.

An essential characteristic of the properties of bitumen is also the softening temperature, determined on the “ring and ball” device (“K and Sh”). The softening temperature of bitumen, expressed in degrees Celsius, corresponds to the temperature of the water bath in the glass of the device at the moment when the bitumen present in brass ring (diameter 16.0 mm), deforming under the influence of a metal ball weighing 3.5 g and gradual heating of water at a speed of 5°C per minute, will touch the bottom shelf of the stand. The bottom shelf of the device stand is at a standard distance from the ring, equal to 25 mm. The softening temperature of viscous and hard bitumen fluctuates in. range from 20 to 95°C.

To characterize the thermal properties of bitumen, in addition to the softening temperature, the brittleness temperature is determined.

Flash point is the temperature at which vapors formed when heating bitumen in an open crucible ignite from an applied flame. The flash point is determined using a standard device and is noted according to the thermometer reading at the moment the bitumen vapor flashes. The flash point of solid and viscous bitumen is usually above 200°C and characterizes the degree of flammability of bitumen when it is heated.

An essential feature of bitumens is their high adhesion - sticking to the surface of various mineral and organic materials. There are many methods and instruments for determining adhesion. One of them is the visual method, by which the degree of adhesion of bitumen to the surface of mineral materials is assessed on a five-point scale. Excellent adhesion of bitumen 5 points in the case when the bitumen film on the surface of gravel or crushed stone is completely preserved after boiling in distilled water. Very poor adhesion, rated as one point, when the bitumen film after boiling is completely dislodged from the mineral grains and floats to the surface of the water.

Depending on the indicators of basic properties, especially viscosity, plasticity and softening point, petroleum bitumens are divided into grades:

For road construction, according to GOST, five grades are provided from BND (petroleum road bitumen)-200/300 to BND-40/60, where the fraction numbers indicate the permissible limits for a given grade of change in penetration indicators at 25 ° C, and four grades BN from 200 /300 to BN-60/90.

For construction work, according to GOST, there are three grades designated “BN” - petroleum bitumen: BN-50/50, BN-70/30 and BN-90/10, where the numerator of the fraction corresponds to the softening temperature according to “K and Sh” ( ring and ball), and the denominator indicates the average values ​​of the limits of change in penetration at 25°C.

For roofing work, according to GOST, the following grades are provided: BNK (petroleum roofing bitumen)-45/180, BNK-90/40 and 90/30, as well as BNK-45/190. In this case, the numerator of the fraction corresponds to the average value of the softening temperature indicators according to “K and Sh”, and the denominator corresponds to the average value of the penetration indicators at 25С.

In addition to solid and viscoplastic bitumen of the indicated grades, there are liquid bitumen. Liquid bitumens at room temperature have low viscosity, i.e., liquid consistency, and are used in construction in a cold or slightly heated state (up to 50...60°C).

Due to the evaporation of volatile fractions and oxidation processes, liquid bitumen gradually thickens. Depending on the rate of thickening, liquid petroleum bitumen is produced in two classes: medium-thickening (SG class) and slow-thickening (MG class). Liquid bitumen of the SG class is produced by liquefying ordinary, viscous bitumen with light thinners such as kerosene. To obtain MG class bitumen, thinners of coal or petroleum origin (oil, fuel oil, etc.) are used. Depending on the viscosity indicators, road liquid bitumens of the SG and MG classes are each divided into three grades; these bitumens must meet the requirements of GOST.

Petroleum bitumens are produced at oil refineries from various oils that differ from each other in chemical composition and properties.

Oil at factories undergoes fractional distillation to obtain light products (gasoline, naphtha, kerosene), lubricating oils and other types of petroleum products. Oil residues after selecting lighter weight fractions - tar, cracking - are subsequently used as raw materials to produce petroleum bitumen of specified properties. Currently, petroleum bitumen is obtained by atmospheric-vacuum distillation of oil (residual bitumen); oxidation of oil residues (oxidized bitumen) and mixing of residues formed during the distillation of oil (compounded bitumen).

Residual bitumens are low-viscosity products and are usually subject to oxidation.

Oxidized bitumens are produced by blowing air through oil residues (tar) in special oxidation units to a given viscosity. As a result of the interaction of atmospheric oxygen with tar during the blowing process, the formation of high-molecular components of oxidized bitumen and an increase in its viscosity occurs. Recently, the method of continuous oxidation of bitumen has been developed. Oil residues at a temperature of about -210°C enter the reactor, where, using special devices (dispersants), air is sucked in and distributed in the oxidized product. In this technology, along with the intensification of the oxidation process, the quality of oxidized bitumen improves.

Mixed (compounded) bitumens are produced mainly by mixing deasphalting bitumen (the residual product after treating tar with liquid propane) with oil distillates.

Petroleum bitumens, both solid or viscoplastic and liquid, are widely used in construction. They are used for the construction of road surfaces, airfield surfaces, flat roofs, irrigation canals, and the production of waterproofing and roofing materials in the paint and varnish and chemical industries.

Solid fossil fuel bitumens

Mix of org. substances contained in peat, coals and capable of dissolving in low-boiling, weakly polar org. solutions at the boiling point of the latter.

The bitumen content in peat ranges from 5.6 to 28.5%. When processing peat, decomposition. Solvents yield is (%): ether - 3.5, gasoline - 5.0, benzene - 8.0, dichloroethane - 10.5, a mixture of ethanol and benzene (1:1) - 12. Peat bitumen is a yellow, brown or black powder or oily solid. They contain 65-75% C and 9-12% H, their so-called droplet. 55-75°C, acid number 20-60. Org. the mass of peat bitumen consists of waxy (50-80%), resin acids, hydrocarbons and resins. Waxy acids have a m.p. 77-90°C, acid numbers 116-160, mol. m. 340-380. The oil content in bitumen is 14-22%.

In brown coals, the amount of bitumen varies widely (10-20%); Max. the yield is achieved by treating earthy brown coals with an alcohol-benzene mixture (1:1). Brown coal bitumen is a brown solid oily substance; elemental composition: 77-80% C, 9-12% H; t. dropfall. 90-92°C, acid number 35-36. The wax content in bitumens of earthy brown coals reaches 70-80%, in bitumens of other types - 29-30%; resin content resp. 20-30 and 70-71%. Waxes contain 80% C, 13% H, 0.6% O; mp 80°C, acid number 23.

The yield of bitumen when treating coal with an alcohol-benzene mixture (1:1) is 0.5-4.0%. Such bitumens are solid, dark-colored resinous substances; contain 82-87% C and 7-10% H; acid number 40.

Peat and brown coal bitumens are of practical value, mainly. their waxy part, called mountain wax (montan wax)

Natural bitumens

Natural bitumen is a semi-solid or solid mixture of predominantly hydrocarbon composition, soluble in organic solvents. Genetically, they are, to varying degrees, degassed, having lost light fractions, viscous-semi-solid natural derivatives of oil - malta, asphalt, asphaltite.

Natural bitumen is a component of fossil fuels. These include natural oil derivatives formed when the conservation of its deposits is disrupted as a result of chemical and biochemical oxidation, for example, asphalts, kerites, maltas, ozokerites, etc. Extraction is carried out mainly by quarry or mine methods.

Traditional bitumens are used less and less, but bitumen-polymer materials and synthetic oil produced from them are very popular. This symbolizes a new era in the development of the bitumen market. The largest reserves of bitumen are in Canada. In recent years, the rate of bitumen extraction for the production of synthetic oil based on it has been steadily increasing.

Bituminous varnishes

Bituminous varnishes are solutions of natural or artificial bitumen in organic solvents. Bituminous varnishes are prepared from natural bitumen containing a minimal amount of ash and sulfur (asphaltite), or artificial bitumen obtained from chemical refining of oil. Solvents for bitumen varnishes are turpentine, white spirit, solvent, xylene, etc. Bituminous varnishes are prepared by fusing bitumen with natural (for example, rosin) or synthetic (for example, artificial copal) resins at a temperature of 280 ° C; then solvents are introduced into the cooled (170°C) melt. In the production of oil-based bitumen varnishes, in addition, drying oils (for example, linseed, tung) and driers (lead, manganese or cobalt salts of fatty acids) are introduced.

Depending on the purpose and conditions of use, the composition of bitumen varnishes can be significantly changed, obtaining varnishes with different viscosity, hiding power, and drying time (from 0.3 to 3 hours). A major defect of bituminous varnishes is their tendency to thicken under the influence of atmospheric oxygen; it is usually eliminated by adding a small amount of turpentine to the varnish before use.

Bituminous varnishes are applied to objects to be painted using methods common to paints and varnishes (for example, by brush, spraying). Oil-based bitumen varnishes form irreversible (insoluble) films, while oil-free ones form reversible (soluble) films. Coatings based on bitumen varnishes have good weather, acid and water resistance, as well as high electrical insulating properties. Disadvantages of coatings are the frequent formation of “rash” (solid inclusions on the surface of the film) and “pox” (round exposures that reach the surface being painted).

How and with what to remove bitumen from the paintwork of a car body

Our car owners encounter the appearance of bitumen “patterns” on the car body quite often, especially in hot weather, because when repairing asphalt pavement, builders pour bitumen in excess onto the road or lay a very thin layer of crushed stone. You can get rid of traces of bitumen in various ways. We decided to try them out to see from our own experience the effectiveness of this or that drug and to learn the specifics of their use. During the mini-test, it turned out that, depending on the “strength” of the cleaning properties, bitumen removers can be divided into two groups - for the rapid removal of fresh dirt and universal ones, i.e. for both fresh and old stains.

On fresh tracks

The auto chemical market mainly offers products for effectively removing fresh bitumen stains. There is nothing surprising about this. To prevent the liquid fraction of bitumen from penetrating into the layer of varnish and paint and leaving its yellow mark there forever, these contaminants must be removed before they are completely dry. This feature made it possible to produce many drugs of this group with a low content of solvents (alcohols) and the addition of surfactants (surfactants). The composition of preparations with surfactants is selected in such a way as to obtain good cleaning properties and at the same time reduce volatility, toxicity, and also eliminate negative effects on the varnish and paint layer. The use of solvents in their pure form is limited by large losses from evaporation when spraying them from aerosols - the most convenient method of application to the surface.

If you want to preserve the paintwork in its original form in the summer, these preparations must be kept in the trunk of the car at all times, and not in the garage or at home. You must also have soft rags, shampoo and a bottle of water with you for preliminary and subsequent body washing.

Fresh bitumen can be removed not only with auto chemicals, but also with a product that is generally available and well known to car enthusiasts - margarine. Unlike aerosols, which are recommended to be sprayed onto a cool body, it is better to apply margarine to a warm, but not hot surface - this way it melts faster and mixes well with viscous bitumen when rubbed. Of course, cleaning with margarine is not as convenient as cleaning with aerosol cans, especially since you can’t carry it in the car for a long time in the summer - it will leak. This kind of anti-bitumen can be used only in extreme cases.

Old stains

What should car owners do who missed the chance to wash the bitumen before it dries? We managed to find two specialized products that effectively remove old “thick” bitumen stains: the Swedish brand Dinitrol – Cleaner with fresh citrus scent No. 7230 and the German Henkel Teroson – Teer Entferner.

The peculiarity of their use is that the preparations should be applied to a cooled surface. In addition, it takes some time to dissolve the bitumen, and if its layer is thick, the operation will need to be repeated several times. To make the bitumen removal process more pleasant, the Swedes added lemon flavor to their isopropyl alcohol-based product. However, it does not neutralize the evaporation of alcohol, which is dangerous to human health. Other preparations dissolve old bitumen less effectively. They can be used to remove bitumen patterns of thin threads or dots.

Old bitumen stains can be removed with ordinary solvent, solvent and kerosene. In this case, the surface must be moistened generously and rubbed with a soft cloth. Working with these more affordable “preparations,” of course, is not as convenient as working with specialized aerosols, since you also need to have rubber gloves, preferably a respirator. These non-traditional car accessories will help you avoid further problems with washing, the condition of your hand skin, and headaches from fumes from evaporating solvents. When using these “preparations,” it is advisable to wash the cleaned surface with shampoo before it dries completely - this is the only way to avoid the appearance of streaks and greasy stains. The use of these products can sometimes cause the surface to become dull and lose its shine, so it is better not to use them for new cars.

It is worth noting that all of the listed products, although they dissolve hardened bitumen, are not able to remove the yellow marks that remain on the paintwork. You can get rid of them only by expensive repainting, which rarely anyone does. And yellow traces of bitumen on the body are a serious reason for reducing the value of the car when selling it.

Nuances of technology

Even after short trips, dust settles on the surface of the body. When rubbing bitumen stains, it becomes an abrasive and contributes to the formation of dull stains. To avoid this, before removing bitumen, the car or its individual areas contaminated with bitumen must be thoroughly washed. After removing bitumen stains and washing the body with shampoo, it is advisable to apply polish to the paintwork. This cosmetic operation will restore the shine to the surface.

For human health, it is very important to follow the safety precautions described in the instructions for the use of special medications. The most common requirements are to avoid inhalation of product vapors and avoid prolonged contact with skin. Specific recommendations on safety precautions and features of use are indicated on the label, so it is better to purchase drugs with Russian-language instructions.

If you drive more quietly, you will be cleaner

Removing bitumen from a body is not a pleasant operation. Our tips will help you avoid car pollution or reduce it to a minimum.

When driving onto a road with bitumen melted from the heat, you should switch to

"safe" driving:

low speed (30-50 km/h), especially if there is heavy traffic on the road;

minimum number of maneuvers - when turning the wheels, viscous bitumen will be removed from them

splash directly onto the body;

movement outside the compacted track, on which the bitumen “floats” more strongly;

a large distance to the truck driving ahead, from under whose wheels flying

bitumen, especially in the absence of splash guards.

Bitum in the environment

In the environment, bitumen lies under our feet in the form of road surfaces - asphalt. Asphalt is made from viscous petroleum road bitumen. Cracks and seams in asphalt pavements are sealed with bitumen-polymer sealant. The main properties of viscous petroleum road bitumens are good binding ability to stone material, high plasticity at low temperatures and resistance to climatic influences. Depending on the main properties, viscous petroleum road bitumens are divided into brands: BND 40/60, BND 60/90, BND 90/130, BND 130/200 and BND 200/300; oil (BN) - four grades: BN 60/90; BN 90/130, BN 130/200, BN 200/300; the numbers of the fraction indicate the permissible limits of penetration indicators for a given brand at 25° C.

To transport bitumen from the manufacturer's plant, it is poured from a bunker into automobile or railway tanks, molds or containers using the hermetically sealed bitumen filling method. Since bitumen is poured in a molten state at a high heating temperature, the hermetically sealed bitumen pouring method eliminates the possibility of injury to operating personnel.

Due to its low cost, as well as its insolubility in water, bitumen and its modifications have found wide application in the production of waterproofing and adhesive materials, without which no construction industry can now do.

Bitumen roofing coatings are most widespread in the construction industry. Currently, a wide variety of bitumen roofing coatings are produced, such as bitumen mastics, basic and baseless rolled bitumen roofing materials, waterproofing built-up bitumen materials - k, bitumen shingles, etc.

Welded waterproofing bitumen materials became widespread in the 70-80s. and are currently in use. These include hot bitumen mastics and rolled roofing materials, which are applied to the concrete surface by heating to 160-180° C. Bitumen mastics are divided into cold and hot, depending on their composition. A huge variety of bitumen mastics with different basic and physico-chemical properties, purpose and method of application are confirmed by a certificate of bitumen mastics. A bitumen mastic certificate is issued after a thorough study of the composition by a research institute.

In construction and repair work on insulation and thermal insulation of buildings, bitumen and its modifications are widely used. When insulating seams and joints between metal - concrete, wood - concrete or metal - wood, a bitumen-polymer sealant is used. When performing thermal insulation of walls, attics and roof structures, in vertical and inclined walls in attics, in interfloor partitions and ceilings, bitumen adhesive without organic solvents is used. During use, such glue does not emit sharp and harmful odors, like glue with organic solvents in the form of gasoline, kerosene, trichlorethylene, etc. The most common natural, environmentally friendly solvent for bitumen and its modifications is kukersol. It is possible to carry out work without harm to health with bitumen glue without an organic solvent in poorly ventilated and enclosed spaces, such as basements and attics.

Thus, the widespread use of bitumen plays a huge role in all areas of human life.

Sources

kromizol.com YUS-LTD

www.toyota.com.ua Official website of Toyota

www.soyuz.kiev.ua Izolit

ru.wikipedia.org Wikipedia - the free encyclopedia

www.materialsworld.ru World of building materials

www.chemport.ru Chemical portal

www.akpr.ru Academy of Industrial Market Conditions

dic.academic.ru Dictionaries and encyclopedias on Academics

Bitumen is a material widely used in construction, characterized by excellent hydrophobic and adhesive properties. It is mainly used for asphalting roads. This material is also very often used as a waterproofing agent in the construction of buildings and structures. In this article we will understand in detail what bitumen is, what its properties are and its scope of application.

Definition

Bitumen is a dense, viscous, black, resin-like substance. It is usually supplied in pieces, which are melted before use. The composition of bitumen is very complex. It is a combination of a hydrocarbon base with its derivatives, as well as metals, oxygen and nitrogen. Various heteroorganic compounds are also present in this material. In general, the composition of bitumen is so rich that identification of all its components is simply impossible.

How it is produced

The main product used to prepare bitumen is oil. There are only three main types of this material:

1. Concentrating oil residues by vacuum distillation. The final product is soft and fusible. Using this method, bitumen is obtained from highly resinous (sulphurous) oil.
2. Oxidation of tar (oil residue) by blowing it with oxygen at a temperature of +180...+300 degrees. This method produces a heat-stable elastic material.
3. Mixing of residual and oxidized petroleum products with distillates.

Natural bitumen

Most often, this material is produced artificially using the three technologies described above. However, there is also natural bitumen, the characteristics and uses of which are approximately the same as regular bitumen. It occurs in nature and forms unique lenses. Natural bitumen is practically never found in its pure form. Most often it impregnates some sedimentary layer. Typically these are rocks such as sandstone or limestone. In this case, pure natural bitumen is obtained by first grinding stones. Sometimes such asphalt rock is simply thoroughly ground and used in road construction.

Types of bitumen by area of ​​use

According to the area of ​​application, this material is divided into four large groups:

• Construction bitumen. Used for foundations, submerged wooden structures, etc.
• Roofing. It is used to protect roofs of residential, industrial and public buildings from moisture.
• Petroleum road bitumen. The most common option used for preparing asphalts.
• Insulating. Used to protect metal pipelines from moisture and corrosion.

Road bitumen

This hydrophobic material is most often used in the construction of highways. There are two main types of road bitumen:

• Viscous. Obtained from petroleum.
• Liquid. This variety is made from viscous bitumen. Petroleum products are used as a diluent.

Viscous petroleum road bitumen is used in the construction of highways in the warm season. Liquid material is used in cold weather. Viscous bitumen is heated to its melting point before laying. Liquid material can be used either cold or heated. Some time after laying, due to oxidative processes, such bitumen thickens and forms a dense, moisture-proof elastic film.

What characteristics should you pay attention to when purchasing?

There are only three main parameters by which the quality of bitumen can be determined:

• softening temperature indicator;
• ductility (degree of ductility of the bitumen thread);
• penetration (viscosity).

The latter indicator is determined by immersing a needle or cone in bitumen at a certain temperature.

Marking

It is very easy to find out which bitumen is intended for which type of work. To do this, you need to look at the markings.

• Construction bitumen is marked with the letters BN.
• Road - BN or BND.
• Roofing - BNK.

After the letters in the marking there are two numbers separated by a forward slash. The first number indicates the softening point, the second - the degree of viscosity. The latter is determined by immersing a needle in bitumen at a temperature of 25 o C.

Brands of viscous road bitumen

As already mentioned, such material is supplied in pieces or in barrels. When paving, BN (petroleum bitumen) and BND (petroleum road bitumen) are used. According to GOST, only ten types of this material are produced (BDN from 200/300 to 40/60, BN from 200/300 to 60/90).

Liquid road bitumen

This material is marked separately. There are only two varieties of it:

1. SG - thickening at medium speed.
2. MG - thickening slowly. This variety is used in road construction in climatic zones II-V.

In this case, after the letters there are also two numbers separated by a slash, indicating the permissible range of ductility (at a temperature of 60 o C with a 5 mm hole on the viscometer).

When purchasing a batch, you need to check the certificate (passport) for liquid petroleum road bitumen. The SG brand, just like MG, BDN and BN, must comply with GOST+. We’ll talk about what this document is a little lower.

Safety precautions when working with bitumen

You should be quite careful when using this material. Bitumen is flammable. The fire hazard of a particular brand is determined by the following indicator: It is higher for viscous construction, road, roofing and insulating bitumens, and lower for liquid bitumens. Therefore, when working with the latter you should be especially careful.

Among other things, when performing operations related to the application, storage, transportation, etc. of bitumen, according to industrial safety rules, it is necessary to wear special clothing. This protects the worker from hot, difficult-to-wash drops coming into contact with the skin.

Bitumen quality certificate

Bitumen sold by enterprises must comply with GOST 2245-90 standards. However, today many companies produce products of this type with improved characteristics. Therefore, bitumens of one or another new brand are accompanied by special certificates certified by the heads of laboratories, also called passports. They indicate parameters such as penetration, ductility, softening point of the product, etc.

Such a document is issued not only for viscous, but also for petroleum road liquid MG bitumen. The quality certificate is a guarantee that the characteristics of the material comply with those declared by the manufacturer. The company seal must be affixed to the document.

Of course, there must be a passport for liquid petroleum road bitumen SG, as well as for roofing and insulating bitumen. New brands of this material include, for example, BND-U and Euro BV. In relation to them, quality standards are determined not by GOST, but by TU and STO. When producing Euro BV, the requirements of the European standard EN 12591 are also taken into account.

Most common brands

In construction, petroleum road bitumen 90/10 is most often used. Manufacturers produce and sell it in huge quantities. It is used to waterproof foundations, underground parts of wooden supporting structures, interpanel seams, basements and walls. It is distinguished from another fairly popular brand, BN 70/30, by a higher melting point. This expands the scope of its use, since the film produced by it is able to withstand high heating temperatures.

In the construction of highways, petroleum road bitumen MG130/200 is often used. It is usually used in those regions where the air temperature in winter does not fall below 20 o C. This material forms a reliable and very smooth road surface.

Softening temperature (about C)		Residue after evaporation of the thinner - 30
Flash point
Ductility	At a temperature of 25 o C 1 cm	131-200 at 60 o C and hole diameter 5 mm
Penetration	At a temperature of 25 o C - 5-20
Amount of diluent evaporated		Not less than 5%

Petroleum bitumen for road, construction and roofing is a material that is in great demand on the market. Many companies produce it today. Therefore, choosing a quality product will not be difficult at all. The main thing is to pay attention to the labeling and buy the most suitable option in this particular case.