Bitumen is an indispensable component of construction. Thanks to its unique characteristics, bitumen has firmly established itself in the construction industry. Its practicality, durability and low cost leave no chance for alternative building materials.

Characteristics of bitumen

Bitumen is an asphalt-like material produced artificially. It is the final product of processing natural bitumen, residues after processing coal, oil, shale resins and peat extracts.

Depending on the components and characteristics, several types of bitumen are distinguished:

• Natural bitumen is a by-product during the extraction of petroleum products from various rocks. They are characterized by high resistance to acids, alkalis, and water.

• Construction bitumen is a product of petroleum distillation and mixing with various construction components (oil production residues, asphalt, etc.). For working with roofing materials and for high-rise work, bitumen of the BNK 45/180, BNK 45/90, BNK 90/40 or BNK 90/30 brands is usually used. They are characterized by high resistance to moisture and high temperatures. Compared to roofing bitumen, construction bitumen has greater fire resistance.

• Road bitumen is the most popular type of bitumen. The main brands of road bitumen: BND 40/60, BND 60/90, BND 90/130, BND 130/200 and BND 200/300. It is characterized by a high penetration coefficient (penetration into the environment). Bitumen with high penetration rates are relevant for northern regions, and with lower ones - for southern regions.

The characteristics of bitumen are constantly changing and improving. So, in order to improve the qualities of this building material, various artificial additives are added to it, which specifically enhance certain characteristics. Typically, such chemical ingredients increase resistance to sudden temperature changes, cold or heat.

The main characteristics by which the quality of bitumen can be assessed:

Extensibility,

Temperature indicators for fragility,

Softening temperature indicators,

Penetration level.

Accordingly, chemical additives for bitumen are aimed at improving these characteristics. The price of bitumen directly depends on the quality and intended use of the building material. Optimized brands that are resistant to heavy loads and have good elongation will cost more. As a rule, all the necessary indicators are reflected on the bitumen labeling.

Application of bitumen

The type of bitumen determines the scope of its application in construction.

Natural bitumen

Today, construction or road bitumen is very popular. But despite the obvious superiority of artificial bitumen in mass construction, natural bitumen is actively used in other industrial sectors.

Natural bitumen with special characteristics (non-oxidized composition) is very popular for road construction in Western countries. Unoxidized high-quality bitumen can only be produced using new generation equipment.

There are a lot of similar industries in the West, which explains the difference in the demand for natural bitumen in the post-Soviet space and in Western countries. Every motorist can feel this difference by comparing the quality of the road surface.

Road bitumen

Road bitumen has proven itself when working in the most difficult and unfavorable conditions. It perfectly withstands heavy loads, which makes it an ideal material for the construction of road surfaces. It is widely used in the production of asphalt concrete and asphalt.

As a component of asphalt pavements, road bitumen acts as a binder, holding all the ingredients together. Thanks to its distinctive characteristics, crushed stone, river sand and the remaining ingredients of the asphalt mixture form a strong, homogeneous mass.

The density of bitumen divides it into two types:

• viscous,
• liquid.

Viscous bitumen is relevant as a binder for road construction or repair. Liquid bitumen is used to extend the construction period of road surfaces.

The quality and durability of the road surface largely depends on the characteristics of road bitumen and the degree of its compliance with GOST standards. The use of high-quality materials significantly increases the service life of roads, avoiding the appearance of cracks, potholes and similar defects. You can buy high-quality bitumen from the manufacturer or from direct suppliers.

Construction bitumen

Without construction bitumen, not a single foundation pouring, roofing or repair work is possible. Construction bitumen is obtained during oil refining and comes in two types: solid and liquid.

• The solid type of bitumen is convenient to transport, but it requires heating at the construction site. Softening of hard ingots is carried out using special equipment - bitumen cookers. The temperature of bitumen must be quite high in order to successfully use it for roofing or waterproofing.

• Liquid bitumen requires special transportation conditions - it is delivered to the construction site in a special bitumen truck, adapted for transporting dark oil products. The peculiarity of the liquid type of bitumen is that it must be used as quickly as possible. It is used for sealing joints on buildings, making bitumen mastics and roofing work.

Bitumen They are complex mixtures of high molecular weight petroleum hydrocarbons and their non-hydrocarbon derivatives. Bitumen can be natural or artificial (petroleum). Petroleum bitumens are products of refining oil and its resinous residues. Depending on the production method, residual, oxidized, cracked and compounded bitumens are distinguished.

Residual bitumen – (tars) – solid or almost solid substances obtained as a residue during the atmospheric-vacuum distillation of high-resin oil.

Oxidized bitumens obtained by oxidation of oil residues with atmospheric oxygen.

Cracking bitumens – obtained as a residue during cracking (thermal or catalytic) of petroleum and petroleum oils.

Compounded bitumens obtained by mixing.

The physicochemical properties of bitumen depend on the nature of oils and oil residues and on the technological method of their processing.

Depending on the viscosity, petroleum bitumen is divided into solid, semi-solid (viscous) and liquid.

Solid petroleum bitumens designed for general construction work. They are characterized by high viscosity, heat resistance, and low plasticity. The following grades of solid bitumen are produced:

A) petroleum bitumen for construction(GOST 6617-76) grades BN 50/50; BN 70/30; BN 90/10; the first digit (numerator) indicates the softening temperature, and the denominator is the average value of the needle penetration depth;

b ) petroleum roofing bitumen, used for roofing work. They are divided into brands BNK 45/80, BNK 90/40, BNK 90/30 (GOST 9548-74), where the numerator corresponds to the softening temperature value, 0 C, and the denominator corresponds to the depth of penetration of the needle.

V) petroleum insulating bitumens used to insulate pipelines from corrosion and are divided into three grades: BNI-IV-3, BNI-IV; BNI-V.

G) special petroleum bitumens used in the paint, tire, and electrical industries, divided into grades B, V, G (GOST ? )

1.2. Viscous petroleum road bitumens.

They are used as a binding material in the construction of road and airfield pavements and in the construction industry (hydro-, heat-, vapor barrier and roofing materials).

In accordance with GOST 22245-90, viscous road bitumens are divided into grades (see table in the appendix). The grade of bitumen is determined by a set of quality indicators.

a) Viscous petroleum bitumens BN 200/300, BN 130/200, BN 90/130, BN 60/90.

B) Improved viscous road bitumens BND 200/300, BND 130/200, BND 90/130, BND 60/90, BND 40/60.

The numerical index shows the interval of change in the depth of needle penetration. For example, BND 60/90 is petroleum road bitumen with a needle penetration depth of 60-90 mm. The quality of bitumen is assessed by conditional viscosity, characterized by the penetration depth of a standard needle at 25 and 0 0 C; deformability, characterized by the extensibility of a standard bitumen sample at temperatures of 25 and 0 0 C; softening temperature and brittleness temperature, characterizing the temperature transition of bitumen from a viscoelastic to a brittle state (the so-called plasticity range); adhesion and activity of bitumen in relation to stone materials, determined by adhesion to marble or sand; stability of the properties of bitumen at high temperatures, characterized by a change in the softening temperature after heating; penetration index, characterizing the temperature sensitivity of bitumen in the range of operating temperatures; the ability of bitumen not to ignite during technological operations, characterized by its flash point. Before testing, samples are dehydrated by careful heating to a temperature 80-100 0 C above the softening temperature, but not higher than 180 0 C and not higher than 120 0 C. Dehydrated and molten bitumen must be filtered through a metal sieve No. 07 and mixed thoroughly until air bubbles are completely removed .

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, bitumens are 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 bitumens 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 condition 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 - bitumens 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 occur. 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 minimum 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

Back in ancient times. Capitals such as Babylon or Assyria used bitumen as a building material as far back as 3 thousand years BC. e. It perfectly served as a cementing or waterproofing material.

This substance can be divided into several groups, which are determined based on the organic composition of the building material. As for tar bitumen, this includes all types of tar and pitches. So, they are tar and natural organic.

The following can be classified as bituminous:

• Natural bitumen. Such a substance comes in liquid and solid form, consisting mostly of organic substances and their non-metallic derivatives. This substance is obtained as a result of the natural processing of oil with oxidizing polymers. Mainly, bitumen of natural origin is found in places of oil deposits or forms special asphalt swamps. By the way, such rocks are rare, and in most cases they penetrate the so-called sedimentary rocks;
• Asphalt powder. Bitumen is a substance that can be stored in rocks such as limestone. In further processing, this substance is extracted or used as asphalt powder;
• Artificial (petroleum) bitumen. Material obtained from petroleum refining. The technology used for processing distinguishes the following types of bitumen: residual, oxidized, cracked;
• Tar bitumen. It is extracted by squeezing oil fractions from fuel oil. This substance is an excellent binder and the basis for the production of any type of bitumen.

Physico-mechanical features of construction bitumen

Areas of use

Of course, bitumen (as building materials) has become extremely widespread in hydraulic engineering, road or industrial and commercial construction. Today they are used in the form of roofing materials, promote commercial construction and are used in road repair work.

The binding organic substance combines well and interacts with rubber or polymer, which can only improve the overall quality of bitumen products in accordance with the requirements and standards of modern construction.

The video shows the preparation and use of road bitumen grades BND 90/130 and BND 60/90:

Composition, structure and characteristics of the material

The average composition of bitumen varies in the following ratio of elements: 75-80% carbon, 10-15% hydrogen, up to 10% sulfur and up to 5% oxygen. The solid part of this building material is hydrocarbons and their derivatives at the molecular level. In its structure, this substance resembles a colloidal system in which asphaltenes are dispersed in a dispersion medium of oil and resin.

These elements that make up bitumen also determine a number of properties and characteristics that the material has. For example, an increased percentage of asphaltenes and resins entails an increase in hardness, density and melting point.

Otherwise, that is, with an increased level of oils, the bitumen softens and becomes lighter and more fusible. According to GOST 22245 90, the oil and resin content in bitumen must be average and balanced, otherwise it will acquire excessive plasticity and viscosity.

The degree of bitumen viscosity directly depends on the degree of heating. Increasing the temperature will increase the viscosity, and decreasing it will make the material harder. At zero or sub-zero temperatures, bitumen becomes a rather brittle material.

Bitumen also has another important property: it is not soluble in water, but is completely or partially soluble in acidic substances such as chloroform, benzene or carbon disulfide, and has a low heat capacity. According to the certificate of conformity, bitumen must have a density that is within 1.5 g/cm3. But when calculating the total mass of bitumen, the weight of 1 liter will be calculated through the density of 1 kg/m3.

Bitumen has a wide range of features and useful properties that bring it to the leading level among other binding building materials. Hydrophobicity and solubility in most modern solvents, softening and increase in viscosity with gradual heating, plasticity and adhesion - all these properties should be possessed by high-quality bitumen.

What is penetration index

Penetration is an indicator that characterizes the properties of bitumen in solid form. In other words, this is the depth to which the needle penetrates at a bitumen temperature of 25 degrees. To determine this coefficient, a special device, Penetrometer, is used.

The measurement process involves measuring the penetration depth of a calibrated needle, taking into account a given period of time and a constant load. This measurement is made at a given bitumen temperature and calculates the immersion depth of the needle, which is measured in a ratio of 1 to 10 mm. Among three similar measurements, the average is selected, which is the penetration index.

Table of comparative characteristics of construction grades of bitumen

Table of comparative characteristics of roofing bitumen grades

It is worth mentioning another qualitative indicator that perfectly characterizes bitumen as a road (liquid or viscous), construction insulation and roofing material - this is the specific and volumetric gravity. According to all technological and construction standards, the specific gravity of bitumen should be no more than 1 g/cm. cube at its boiling point. All these indicators must be indicated in the product passport.

What hazard class does bitumen have?

The main problem that arises with is the need to transport it in liquid form at the appropriate temperature. Since the temperature in the tank must be higher than 100 degrees, but lower than the ignition temperature, bitumen is given hazard class 9, which is called “Liquid at elevated temperature. Highly flammable." This substance has a high heat capacity, so its transportation must be approached with great care.

Finally

is a high-quality binder that is widely used in construction. This substance is suitable for various types of work. Transportation of bitumen is a rather labor-intensive process that requires not only special tanks, but also a technical passport.

Do not also forget that bitumen is an organic-based substance that has its own shelf life of 1 calendar year. Due to some difficulties during transportation, it can be given a 4, although this material is simply irreplaceable in construction.

A few more words about construction bitumen:

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