Bitumen penetration index. Viscous oil road bitumen (GOST)

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Public procurement has its own principles, rules and restrictions established by law. In case of their violation, fines under 44-FZ may be imposed on an unscrupulous party, an organization or a responsible employee.

Table 1. Sanctions for administrative violations in the field of public procurement: Article 7.29 of the Code of Administrative Offenses

Table 2. Articles 7.29.1, 7.29.2

Table 3. Article 7.29.3

Table 4. Article 7.30 of the Code of Administrative Offenses

Table 5. Article 7.31

Table 6. Article 7.31.1

Table 7. Article 7.32 of the Code of Administrative Offenses

Table 8. Articles 9.16, 19.5, 19.7.2 of the Code of Administrative Offenses

Petroleum Road Bitumens- irreplaceable materials that are part of asphalt mixtures, and are also used in the processing of the roadway and its impregnation. They are produced by processing petroleum products with the addition of various compounds and solvents. Depending on the purpose for which bitumen will be used, it can be either liquid or viscous.

Varieties of road bitumen

Viscous road bitumen is used in the repair and laying of road surfaces and airfield lanes. Its technical characteristics depend on the variety: BN or BND.

Oil road bitumen (BND) has a higher softening point and a lower brittleness temperature. In addition, penetration at 0° is of greater importance compared to BN. And the requirements for BND in terms of thermal stability are more stringent.

Marking of oil road bitumen

BND are marked depending on their technical characteristics. Depending on the climatic zone in which the road works will take place, certain types of bitumen are used:

• In areas where the average monthly temperature in the coldest season does not rise above -20 o, BND grades are used: 200\300, 130\200 or 90\130;
• In a warmer climatic zone, where the average monthly temperature of the cold season does not fall below -20 o, in addition to those listed above, bitumen grade 60\90 can be used;
• At an average monthly temperature from -5 o to -10 o, not only BND grades can be used, but also BN from 200\300 to 90\130;
• In the warmest climatic zones, where the average monthly temperature in winter does not fall below 0 o, BN 90\130 and 60\90 brands are used, as well as BND 90\130, 60\90 and 40\60.

Liquid bitumen, in turn, is produced by thinning viscous bitumen with the help of special solvents. The scope of their application is the production of cold asphalt concrete and road repair work. After laying the liquid bitumen, the thinner gradually evaporates, and the coating acquires the necessary hardness. However, this type of material is flammable due to its low flash point.

Coverage of issues related to the use of oil road bitumen at the exhibition

The annual Naftogaz exhibition, which takes place at the Expocentre Fairgrounds, highlights issues related to the leading industry of our country. The exhibition is one of the five largest industrial exhibitions in the world, which attracts special attention to it. This event provides a meeting place not only for the largest companies in the oil and gas industry, but also for service and equipment suppliers, as well as specialists in this field.

The Naftogaz exhibition provides an opportunity to assess the state of the industry, study new technologies and trends, and use this platform to effectively solve the problems of the industry. Since oil road bitumen is a product of the oil refining industry, the issue of their use is also disclosed at the exhibition. Everything related to the production and use of various types of bitumen can be learned at this event.

It is attended not only by the production flagships of our country, but also by the largest foreign companies. Traditionally, exhibitors from China, USA, Norway, Germany, Sweden, South Korea, France, Taiwan, Italy and Finland present their stands.

The popularity of oil road bitumen

Oil road bitumens do not lose their popularity and demand even in a difficult situation on the market. They are indispensable in many areas: road, construction, manufacturing and others. And given the constantly developing infrastructure of our country, as well as the construction of a new Trans-Siberian Railway, their importance is difficult to underestimate.

Read our other articles.

Petroleum road bitumen are divided into viscous and liquid. Viscous bitumen differ: BND ( oil road bitumen) and BN ( petroleum bitumen).

They produce five brands: BND 40/60, BND 60/90, BND 90/130, BND 130/200, BND 130/200 ; petroleum bitumen(BN) - four brands: BN 60/90, BN 90/130, BN 130/200, BN 200/300 (Table 1).

The letters BND mean " oil road bitumen”, numbers-fractions 40/60, 60/90, etc. indicate the limits of penetration depth of a standard needle at 25 ° C that are acceptable for the brand, indirectly characterizing bitumen viscosity. bitumen grades BND are characterized by good adhesion to stone materials and have a sufficiently high plasticity at low temperatures, resistant to climatic influences. Specifications for viscous oil bitumen standardized by GOST 22245-90.

Viscous petroleum road bitumen used for preparing hot, warm and cold asphalt mixes, for surface treatment, impregnation, and also for thinning to obtain liquid bitumen, used for preparing cold asphalt concrete, surface treatment and for mixing on the road, etc.

Viscous bitumen refer to a particular brand based on three main indicators: the depth of penetration of the needle, softening temperature and extensibility. Needle penetration depth and extensibility are normalized at two temperatures: 25 °C and 0 °C. According to physical and mechanical indicators viscous bitumen must comply with the requirements and standards specified in Table. one.

In table. 2 shows the definition bitumen penetration indices according to the depth of penetration of the needle at 25 ° C and softening temperature.

At intermediate values ​​of the needle penetration depth at 25 °C, the penetration index is determined by interpolation or by the formula

I.P. = -10,

where A \u003d (2.9031 - log P) / (T - 25),

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

T is the softening temperature, °C.

Bitumen brittleness temperature BN grades are allowed to be determined by the nomogram (Fig. 1).

Scope of bitumen in road construction must comply with the recommendations given in Table. 3.

Viscous road oil bitumen are combustible substances with a minimum ignition temperature of 368 °C. The maximum allowable concentration of bitumen hydrocarbon vapors in the air of the working area is 300 mg/m3.

According to the degree of impact on the body, bitumen are low-hazard substances and belong to the 4th hazard class.

When working with bitumen the room must be equipped and personal protective equipment must be used. When small amounts of bitumen ignite, it should be extinguished with sand, a felt mat or a foam fire extinguisher; a developed fire should be extinguished with a foam jet.

Bitumen production wastes (oxidation gases) are neutralized by burning in an afterburner.

Rice. 1. Nomogram for determining the brittleness temperature of road bitumen grades BN

Notes:

1) numbers on the straight lines - the depth of penetration of the needle at 25°C;

2) at P 0 / P 25 - equal to or greater than 0.27, its value must be taken adjusted according to schedule (a).

Table 1. Technical requirements for road oil bitumen (BND) and oil bitumen (BN)

Table 2. Bitumen penetration index determination table

Table 3. Scope of bitumen in road construction

Guaranteed shelf life of bitumen- one year from the date of manufacture.

Important indicators bitumen BND grades are an indicator of adhesion and a brittleness temperature. Unfortunately, the adhesion index, which characterizes the adhesive properties of bitumen to acidic and basic rocks, was not reflected in the existing GOST, which is certainly its disadvantage.

If available bitumen do not meet the necessary requirements, it is necessary to choose the composition of bitumen mixtures from oil bitumen of two different grades or mixtures of oil bitumen with natural ones. Most often, bitumens are improved by adding modifying additives, such as surfactants, etc.

Improved bitumen and their mixtures, the properties of which are optimized by special chemical treatment and the addition of plasticizers, are used mainly for the device of the upper layers of coatings in order to provide increased heat resistance and dynamic strength.

Before the publication of GOST 22245-90 on viscous oil road bitumen requirements for road bitumen were normalized by GOST 11954, which included requirements for bitumen brands BND and BN.

The developers of this GOST focused on oxidized bitumen III structural type according to the classification of A.S. Kolbanovskaya. This type of bitumen differs in intermediate properties from bitumen types I and II, i.e. incorporates both advantages and disadvantages of bitumen of extreme structural types. Bitumen grades BND have wider ranges of plasticity in relation to bitumen grades BN, but have lower elongation.

For residual bitumen grades BN some sources question their recommended scope and believe that these bitumen should be excluded from the existing GOST for viscous road bitumen. However, this point of view causes very strong objections and disagreement, which are well substantiated by G.N. Kiryukhin. The author notes that in most developed countries in road construction, residual bitumen, which belong to the II structural type, are widely used in road construction. These bitumen characterized by high extensibility, but at the same time they are characterized by narrow plasticity intervals (the difference between the softening temperature and the brittleness temperature). In domestic and foreign publications, there is a greater stability bitumen II structural type ("sol") to aging compared to type III bitumen ("sol-gel") and especially type I bitumen ("gel").

Definition of bitumen, properties of bitumen, application of bitumen

Bitumen definition information, bitumen properties, bitumen application

1. Properties

2. Test methods and relevant types of classifications

penetration

Softening temperature

Brittleness temperature

Ductility

Viscosity

Bitumen rheology

Solubility

3.

- Road

- Building

roofing

- Insulating

- fragile

Bitumen for filling battery mastics

4. Industrial production

Ways

Technology

5. Oil bitumen, composition, structure and properties

6. Bitumen solid fossil fuels

7. natural bitumen

8. Bituminous varnishes

9. How and how to remove bitumen from the paintwork of the car body

10. Bitumen in the environment

Bitumen is(from Latin bitumen - mountain resin) - solid or resinous products, which are a mixture of hydrocarbons and their nitrogenous, oxygenated, sulfurous and metal-containing derivatives. Bitumens are 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 bitumens depend on the methods of production, the quality of raw materials (the nature of the processed oil), as well as on the parameters of the thermolysis process - temperature, pressure, duration. Obtaining high-quality bitumen from oils of different nature (component composition) is possible with the correct determination of not only the contribution of a particular process to the overall technological scheme of production, 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 chemicals, is water- and gas-tight, resistant to various types of radiation and long-term thermal exposure. It is 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 the softening point, which is usually determined by the "ring and ball" method. The hardness of bitumen is evaluated by measuring penetration, and plasticity - by extensibility (ductility).

Bitumens are 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, oil bitumen according to the production method is divided into residual, oxidized and compounded. Residual bitumens are soft fusible products, oxidized bitumen is elastic and thermostable. Bitumens obtained by oxidation of cracked residues contain a large amount of carbenes and carboids, which disrupt the uniformity of bitumens and impair their cementing properties.

Test methods and related types of classifications

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

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

Such indicators characterizing the properties of solid bitumen include the penetration depth of a standard needle (penetration), softening temperature, extensibility into a thread (ductility), brittleness temperature. These studies, strictly speaking, are not equivalent to the direct determination of viscosity, but find wide practical application, because they allow you to quickly characterize the consistency of bitumen. The main indicators characterizing the properties of bitumen can also include adhesion, surface tension at the phase boundary, cohesion, thermal, optical and dielectric properties. Among the comparable indicators, in addition, we can include the loss of mass during heating and the change in penetration after it, solubility in organic solvents, ash content, flash point, density, rheological properties.

Natural bitumen is an integral part of fossil fuels. These include natural derivatives of oil that are formed when the conservation of its deposits is violated as a result of chemical and biochemical oxidation, for example, asphalts, kerites, malts, ozocerites, etc. Production is carried out mainly by open pit or mine methods (tar sands).

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

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

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

penetration

Penetration is an indicator that characterizes the depth of penetration of a standard-shaped body 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 device of which and the test method are given in GOST 11501-78; the penetration depth of the needle by 0.1 mm was taken as a unit of penetration. Penetration of road oil bitumen of various grades at 25 °C, load 100 G, for 5 seconds is 40-300 * 0.1 mm, and at 0 ° C, load 200 G, for 60 seconds - from 13 to 50 * 0 .1 mm. Thus, depending on the temperature, load and duration of penetration of the needle, the penetration value changes significantly. Therefore, the conditions for its determination are stipulated in advance. Penetration indirectly characterizes the degree of bitumen hardness. 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 temperature

The softening point of bitumen is the temperature at which bitumen changes from a relatively solid state to a liquid state. The method for determining the softening point is conditional 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" method (KiSh), and sometimes by the Kremer-Sarnov method.

The penetration index is an indicator that characterizes the degree of bitumen colloidality or the deviation of its state from a purely viscous one. According to 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 cracked residues and coal tar pitches). The elasticity of such bitumens is very small or almost equal to zero.

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

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

Brittleness temperature

The brittle point is the temperature at which a material breaks under a short-term applied load. According to Fraas, this is the temperature at which the elastic modulus of bitumen with a loading time 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 the road surface: the lower it is, the higher the quality of the road bitumen. Oxidized bitumen has a lower brittleness temperature than other bitumen of the same penetration.

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

Ductility

The extensibility (ductility) of bitumen is characterized by the distance at which it can be pulled into a thread before breaking. This indicator also indirectly characterizes the stickiness of bitumen and is related to the nature of its components. Road oil bitumen has a high extensibility - more than 40 cm. An increase in the extensibility of bitumen does not always correspond to an improvement in their properties. According to the extensibility index, it is impossible to judge the quality of road bitumen, since the test conditions (extension 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 liquid to a structured one. The more the bitumen deviates from the Newtonian flow, the lower its extensibility at 25°C, but rather high at 0°C. Bitumen should have high extensibility at low temperatures (0 and 15°C) and moderate at 25°C.

The method and device 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 temperature. 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, have the highest viscosity at the maximum application temperature and have the most flat viscosity-temperature curve 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 is reduced to 102-103 poise.

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

Road bitumen is divided into viscous and liquid.

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

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

Bitumen rheology

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

The rheology of bitumens has not been studied enough. The main indicators determined in the study of 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 (modulus of elasticity, modulus of deformation, etc.). The behavior of bitumen under the action of external deforming forces is determined by a complex of mechanical properties, which include viscosity, elasticity, plasticity, brittleness, fatigue, creep, and strength. Each property depends on the temperature and the nature of the stress state and is associated with intermolecular interactions and the presence of structure. The rheological properties should not change significantly when bitumen is heated in bitumen boilers, when preparing and laying the mixture, and during a long service life.

By rheological properties, bitumens are divided into three types:

1) substances, the flow of which, under the action of a constant shear stress, obeys Newton's law, when the stress is removed, a state of inelastic elasticity sets in. 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 sol-gel bitumen of this type.

3) At a constant shear stress at the beginning of the 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, the elasticity is restored, this type of bitumen has a gel structure.

Solubility

Most of the existing methods for bitumen analysis are based on the difference 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 bitumen 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 well-known engineering and construction materials is based on its adhesive and hydrophobic properties. The scope 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 impregnation and cover (respectively, for the impregnation of the base and obtaining the cover layer). Insulating bitumens are used to insulate pipelines in order 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 varnish industry,

construction of buildings and structures, laying of pipelines, etc.

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

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 road paving. The use of bitumen in road construction allows the road surface to withstand increased static and dynamic loads in a wide temperature range while maintaining long-term viability and weather resistance.

Viscous bitumen used in road pavement is used as a binder between stone materials. The durability of the pavement largely depends on the brand of bitumen used and its quality. During the construction and repair of roads, bitumen can be thinned with a solvent (kerosene fraction). Liquefied bitumens are divided into fast, medium and slow hardening grades. For preliminary surface treatment, 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 in the road surface means that it has reached 85% of its service life. It has been established that the index "brittleness temperature" of bitumen characterizes the time before the onset of intensive cracking of the roadway, since its definition shows the most dangerous state of the road surface during sudden temperature changes in winter. The ratio of physical and chemical parameters of BND bitumen provides the road surface with the highest shear resistance, crack resistance, long-term water and frost resistance.

Building

Bitumens of building grades BN, used for waterproofing the foundations of buildings, are distinguished by low penetration and ductility and high softening temperature (from 37 to 105 0С), i.e. they are hard and tough. Construction bitumen is standardized according to GOST 6617 - 76

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

Building bitumen BN 90/10 and BN 70/30 are used in such processes 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 process of manufacturing bituminous varnishes, bituminous mastics , bituminous primer, hydrostekloizol and some other building materials.

Building bitumen (including building bitumen BN 90/10) is one of the most famous and important building materials. Due to its adhesive and hydrophobic properties, construction bitumen is widely used in road construction, the manufacture of roofing materials, the laying of pipelines, and bituminous waterproofing of foundations of buildings and structures. Building bitumen (including BN 90/10 bitumen) is a complex mixture of hydrocarbons and heteroorganic compounds of various structures, which basically does not boil away at oil distillation temperatures. It is not possible to determine all the compounds that make up bitumen. The group composition of bitumen predetermines 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 (depth of penetration of the 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 original bitumen and for the bitumen after heating, which imitates the aging process. Standards set certain values ​​of quality indicators, which reflects the optimal composition of bitumen. This composition can be different for different applications of bitumen: from bituminous waterproofing to repair and roofing.

The following types of bitumen are known:

Building 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 bitumen is divided into viscous and liquid. Viscous bitumen is used as a binder in the construction and repair of road surfaces. The main amount 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 bitumen has a higher softening point, lower brittleness temperature and higher penetration values ​​at 0 °C than BN bitumen (construction bitumen BN 90/10, BN 70/30). At the same time, requirements for ductility at 0 °С are set for BND bitumen, and the requirements for ductility at 25 °С are less stringent in comparison with BN bitumen (construction bitumen BN 90/10, BN 70/30) . The requirements for thermal stability of BND bitumen are more stringent. Recommendations for use depend on the type of construction bitumen and its 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 bitumen 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 - bitumen 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 - bitumen BN 90/130, BN 60/90, BND 90/130, BND 60/90, BND 40/60. Liquid bitumens are designed to lengthen the road construction season. In accordance with GOST 11955-82, they are obtained by mixing BND viscous bitumen 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 predetermines their fire hazard. Building bitumen BN 90/10 is used in various construction works, in particular for bituminous waterproofing of building foundations.

Construction bitumen (bitumen BN 90/10, BN 70/30) is used for bituminous waterproofing of concrete structures; for bituminous waterproofing of foundations; for preliminary priming of the base under a soft roof. Also, building bitumen (bitumen BN 90/10, BN 70/30) is used for the manufacture of bituminous mastics, bituminous primer, hydrostekloizol, 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.

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

roofing

Approximately the same quality indicators are established for BNK roofing bitumen, but the brittleness temperature is also normalized for them. They are used as impregnation (to obtain roofing felt and roofing felt) and for roofing.

Insulating

BNI insulating bitumens are used for pipeline insulation to prevent them from corrosion. With low penetration and low ductility, they should be sufficiently refractory (especially for battery mastics). In addition, for mastics, solubility in toluene or chloroform is normalized (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 a characteristic of bitumen for filling battery mastics according to 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

Weight change after warming up, %, no more than 0.50

Flash point, 0С, not lower than 260

Penetration index, not less than 4

industrial production

The production of petroleum varieties of bitumen is carried out:

blowing tars with air

distillation of fuel oils with deep selection of distillates

tar deasphalting with propane.

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

In accordance with the production methods, grades are divided into oxidized, residual, precipitated and compounded. Classify bitumen and by application.

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

Oil road liquid bitumen (GOST 11955-82)

Oil construction bitumen (GOST 6617-76)

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

construction of new buildings, is building bitumen. Its application has become

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

Ways

The production of petroleum bitumen is one of the thermal processes of oil refining. The main parameters of thermal processes that affect the assortment, material balance and quality of the products obtained 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 the 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.

Residual bitumen is obtained by concentrating oil residues by distilling them in a vacuum. To obtain residual bitumen, only raw materials with a high content of asphalt-resinous substances, which are present in sufficient quantities in heavy, high-resinous sour 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, the preparation of raw materials for the production of base oils (initial stage) - in the case of the second. At the same time, 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.

Air oxygen oxidation of various oil residues and their compositions at a temperature of 180 - 300 0C (oxidized bitumen). Oxidation with air can significantly increase the content of asphalt-resinous substances, the most desirable component in the bitumen composition. For the production of oxidized bitumen, BashNIINP proposed to classify oils according to the content (%, wt.) in them of asphaltenes (A), resins (C) and solid paraffins (P). Oil is considered suitable for the production of oxidized bitumen if the following condition is met: The main process for the production of bitumen is oxidation - blowing tars with air. Oxidized bitumen is obtained in devices of periodic and continuous action. The latter are more economical and easier to maintain. The principle of obtaining 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. Apparatus used in bitumen production are tubular reactors or oxidizing towers. When receiving building bitumen, the first ones are preferable, road - the second ones.

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 bitumen is elastic and thermostable. Bitumens obtained by oxidation of cracked residues contain a large amount of carbenes and carboids, which disrupt the uniformity of bitumens and impair their cementing properties.

Technology

Residual bitumen is produced from fuel oils with a high concentration of asphalt-resin substances by vacuum distillation as a residue of this distillation. Recall 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, but at too high a temperature, the formation of carbenes and carboids is accelerated, which give the bitumen an undesirable increased brittleness. Usually the temperature is maintained at the level of 250 - 280 0С.

The greater the air flow, the less time required for oxidation. If the air flow rate is too high, the temperature in the oxidizer tower may rise above the permissible level. Therefore, the 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.

The pressure in the reaction zone with its increase 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 at the outlet of the furnace 180 - 250

in the oxidizing column, not higher than 290

bitumen at the exit from the refrigerator 170 - 200

pouring bitumen into tanks 170 – 180

pressure in the oxidizing column, MPa 0.3 - 08

air consumption, m3 / t of bitumen 50 – 400

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

oxidation products, % 3 -11

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

The technological mode of such an installation:

temperature, 0С:

raw materials at the entrance to the plant 100 - 120

oxidation in reactors 260

bitumen after coolers 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

ratio recycle: raw material 6:1

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

Oil bitumen, composition, structure and properties

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

Oils - a mixture of cyclic hydrocarbons (mainly of the naphthenic series) of light yellow color with a density of less than 1 and a molecular weight of 300 ... 500; the increased content of oils in bitumens gives them mobility, fluidity. The amount of oils in bitumens 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 oxygen heterocyclic compounds of a neutral nature 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 somewhat 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 thermal stability. The total content of asphaltenes in various bitumens is 5...30% or more.

Carbenes and carboids are relatively rare in bitumen in small quantities (1...2%) and contribute to the increase in bitumen fragility.

Asphatic acids and their anhydrides are brownish resinous substances 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 increase its adhesion to the surface of mineral aggregates. Their content in oil bitumen is about 1%.

The above groups of bitumen hydrocarbons form a complex dispersed 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 part of bitumen in various proportions and thus 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” undergo changes from the “sol” type to the “gel” type. The gel structure is typical for solid bitumens at a temperature of 2O ... 25 ° C and is usually due to an increased content of asphaltenes. The structure of the sol is inherent in bitumen of a liquid consistency with a high content of resins and oils.

The most important properties of bitumens that characterize their quality are viscosity, plasticity, softening and brittleness temperatures; in addition, it should be noted high adhesion, which determines the ability of bitumen to link mineral grains of aggregates 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 the viscosity, which depends mainly on temperature and group composition. Viscosity is the resistance of the inner layers of bitumen to movement relative to each other. For many bitumens, the viscosity is variable and decreases with increasing shear stress or strain rate gradient. When the temperature rises, the viscosity decreases, when it decreases, the viscosity increases rapidly, and at negative temperatures, the bitumen becomes brittle. To measure the structural viscosity, various instruments are used to determine the viscosity in absolute units (Pa-s) or express it in conventional units. To characterize the viscosity, more precisely the value of the reverse viscosity, i.e. the fluidity of bitumen, a conditional indicator is taken - the depth of penetration of the needle into bitumen (penetration). The depth of penetration of the needle into the bitumen is determined on the device - penetrometer when a load of 100 g is applied 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 penetration of the needle 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, load duration and temperature increase. The plastic properties of solid and viscous bitumen are conditionally characterized by extensibility (ductility) - the ability to stretch into thin threads under the action of external constant forces. Extensibility is determined on a special device - a ductility meter at a rate of deformation of a bitumen sample in the form of a "eight" of 5 cm/min, test temperatures of 25 and 0°C. The length of the thread at the moment of rupture of the sample, expressed in centimeters, serves as an indicator of extensibility. Plastic properties of bitumen depend on temperature, group composition and structure. So, for example, with an increase in the content of resins and asphaltenes, the plasticity at a constant temperature of bitumens increases.

An essential characteristic of the properties of bitumen is also the softening temperature, determined on the device "ring and ball" ("K and Sh"). The softening temperature of bitumen, expressed in degrees Celsius, corresponds to the temperature of the water bath in the device glass at the moment when the bitumen present in brass ring (diameter 16.0 mm), deformed under the influence of a metal ball weighing 3.5 g and gradual heating of water at a rate of 5 ° C per minute, touches the bottom shelf of the stand. The lower shelf of the device stand is at a standard distance from the ring, equal to 25 mm. The softening temperature of viscous and solid bitumens varies 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 - the temperature at which the vapors formed when bitumen is heated in an open crucible ignite from the flame. The flash point is determined on a standard instrument and noted by the thermometer at the time of the flash of bitumen vapor. The flash point of solid and viscous bitumen is usually above 200°C and characterizes the degree of flammability of the bitumen when it is heated.

An essential feature of bitumen 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 a visual method, according to which the degree of bitumen adhesion to the surface of mineral materials is evaluated on a five-point scale. Excellent adhesion of bitumen 5 points in the case when the film of bitumen on the surface of gravel or crushed stone is completely preserved after boiling in distilled water. Very poor adhesion, rated one point, when the bitumen film after boiling is completely displaced from the mineral grains and floats to the surface of the water.

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

For road construction according to GOST, there are five grades from BND (road oil bitumen) -200/300 to BND-40/60, where the fraction numbers indicate the limits of change in penetration rates at 25 ° C that are acceptable for this grade, and four BN grades from 200 /300 to BN-60/90.

For construction work in accordance with GOST, three grades are provided, 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 indicator according to "K and Sh" ( ring and ball), and the denominator - indicate 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 (roofing oil 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 for "K and W", and the denominator corresponds to the average value of the penetration indicators by 25 CC.

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

Due to the evaporation of volatile fractions and oxidation processes, liquid bitumen gradually thickens. Depending on the thickening rate, liquid petroleum bitumens are produced in two classes - thickening at an average speed (class SG) and slowly thickening (class MG). Liquid bitumen of class SG is produced by diluting 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 SG and MG classes are each divided into three grades; these bitumens must meet the requirements of GOST.

Petroleum bitumen is obtained at refineries from various oils that differ from each other in chemical composition and properties.

Oil at refineries is subjected to fractional distillation in order to obtain light products (gasoline, naphtha, kerosene), lubricating oils and other types of petroleum products. Oil residues after selection of fractions lighter in mass - tar, cracking - are subsequently used as raw materials for obtaining oil bitumens of given properties. Currently, oil 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 bitumen is a low viscosity product and is usually oxidized.

Oxidized bitumen is obtained by blowing oil residues (tar) with air at special oxidizing plants to a predetermined 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 occurs and its viscosity increases. Recently mastered the method of continuous oxidation of bitumen. Oil residues at a temperature of about -210°C enter the reactor, where air is sucked in with the help of special devices (dispersers) and distributed in the oxidized product. In this technology, along with the intensification of the oxidation process, the quality of oxidized bitumen is improved.

Mixed (compounded) bitumen is obtained mainly by mixing deasphalting bitumen (residual product after processing 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 pavements, flat roofs, irrigation canals, the production of waterproofing and roofing materials in the paint and varnish and chemical industries.

Bitumens of solid fossil fuels

Mix org. substances contained in peat, coals and capable of dissolving in low-boiling, slightly 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 decomp. solvents, the yield of B. is (%): ether - 3.5, gasoline - 5.0, benzene - 8.0, dichloroethane - 10.5, a mixture of ethanol with benzene (1: 1) -12. Peat bitumen is powders or oily solids that are yellow, brown, or black in color. They contain 65-75% C and 9-12% H, their so-called drip. 55-75°C, acid number 20-60. Org. the mass of peat bitumen consists of wax (50-80%), resin acids, hydrocarbons and resins. Waxy acids have so pl. 77-90°С, acid numbers 116-160, mol. m. 340-380. The content of oils in bitumen is 14-22%.

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

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

Of practical value are the bitumen of peat and brown coal, in the main. their waxy part, called mountain wax (montan wax)

natural bitumen

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

Natural bitumen is an integral part of fossil fuels. These include natural derivatives of oil formed when the conservation of its deposits is violated as a result of chemical and biochemical oxidation, for example, asphalts, kerites, malts, ozocerites, etc. Production is carried out mainly by open pit or mine methods.

Traditional bitumens are used less and less, but bitumen-polymer materials and synthetic oil produced on their basis 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, bitumen production rates have been steadily growing here for the production of synthetic oil based on it.

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 (asphaltites), or artificial bitumen obtained from the chemical processing of oil. Solvents for bituminous 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 copals) resins at a temperature of 280 ° C; then solvents are introduced into the cooled (170°C) melt. In the production of oil bituminous 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 bituminous varnishes can be significantly changed, obtaining varnishes with different viscosity, hiding power, and drying time (from 0.3 to 3 hours). A big defect in bituminous varnishes is the tendency to thicken under the influence of atmospheric oxygen; usually it is eliminated by introducing a small amount of turpentine into the varnish before use.

Bituminous varnishes are applied to the objects to be painted by methods common to paints and varnishes (for example, by brushing, spraying). Oil-based bituminous varnishes form irreversible (insoluble) films, and oil-free - reversible (soluble). Coatings based on bituminous varnishes have good weather, acid and water resistance, as well as high electrical insulating properties. Disadvantages of coatings - often formed "rash" (hard inclusions on the surface of the film) and "pox" (round denudation reaching the surface to be painted).

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

With the appearance of bituminous "patterns" on the car body, especially in hot weather, our car owners encounter quite often, because when repairing the asphalt pavement, builders pour bitumen in excess on the road or put a very thin layer of gravel. There are various ways to get rid of traces of bitumen. We decided to try them out in order to see for ourselves the effectiveness of a particular drug and find out the features of their use. During the mini-test, it turned out that, depending on the “strength” of the detergent properties, bitumen removers can be conditionally divided into two groups - for the rapid removal of fresh dirt and universal, i.e. for both fresh and old stains.

On fresh tracks

On the auto chemical goods market, mainly preparations for the effective removal of fresh bituminous stains are presented. There is nothing surprising in this. So that the liquid fraction of bitumen does not penetrate into the layer of varnish and paint and does not leave its yellow mark there forever, these contaminants must be removed before they are completely dry. This feature made it possible to manufacture many preparations of this group with a low content of solvents (alcohols) and the addition of surface-active substances (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 the negative impact on the varnish and paint layer. The use of solvents in their pure form is limited by high evaporation losses when they are sprayed from aerosols - the most convenient method of application to the surface.

If you want to keep the paintwork in its original form in the summer, these drugs must be constantly kept in the trunk of the car, and not in the garage or at home. You must also have a soft cloth, shampoo and a bottle of water with you for pre-washing and after-washing the body.

Fresh bitumen can be removed not only with car chemicals, but also with a commonly available and well-known tool for motorists - margarine. Unlike aerosols, which are recommended to be sprayed on an unheated body, it is better to apply margarine on 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 using products in aerosol cans, especially since you can’t take it in the car for a long time in the summer - it will leak. This kind of antibitumen can be used only in extreme cases.

old stains

And what about car owners who missed the chance to wash the bitumen before it dries? We managed to find two specialized products that effectively remove old “thick” bituminous 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 chilled surface. In addition, exposure for some time is required to dissolve the bitumen, and with a thick layer of it, the operation will need to be repeated several times. To make the bitumen removal process more enjoyable, the Swedes have added lemon flavor to their isopropyl alcohol preparation. However, it does not neutralize the evaporation of alcohol hazardous to human health. Other preparations dissolve old bitumen less effectively. They can be used to remove bituminous patterns from thin threads or dots.

Old bitumen stains are also removed with a common solvent, solvent and kerosene. In this case, the surface must be abundantly moistened and rubbed with a soft cloth. Working with these more accessible "drugs", of course, is not as convenient as with specialized ones in 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, hand skin condition and headaches from evaporating solvent fumes. When using these “drugs”, it is advisable to wash the cleaned surface with shampoo before it is completely dry - this is the only way to avoid the appearance of stains and greasy stains. The use of these products can sometimes cause the surface to become matte 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 the frozen 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 is rarely done. And yellow traces of bitumen on the body are a serious reason to reduce the cost of a car when selling it.

Technology nuances

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

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

The quieter you go - the cleaner you will be

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

Entering the road with bitumen melted from the heat, you should switch to the mode

"safe" driving:

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

the minimum number of maneuvers - when the wheels are everted, viscous bitumen from them will

spray directly on the body;

movement outside the rolled track, on which the bitumen "floats" more strongly;

a large distance to the truck ahead, from under the wheels of which it flies

bitumen, especially in the absence of mudguards.

Bitum in the environment

In the environment, bitumen lies under our feet in the form of a road surface - asphalt. Asphalt is produced from viscous petroleum road bitumen. Cracks and seams of asphalt pavements are sealed with bituminous polymer sealant. The main properties of viscous oil road bitumen are good binding ability with stone material, high plasticity at low temperatures and resistance to climatic influences. Depending on the basic properties, viscous oil road bitumens are divided into grades: 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 fraction numbers indicate the limits of penetration rates at 25 ° C that are acceptable for this brand.

To transport bitumen from the manufacturer's plant, it is poured from the bunker into road or rail tanks, molds or containers using the method of hermetic pouring of bitumen. Since the bitumen is poured in a molten state with a high heating temperature, the method of hermetic pouring of bitumen eliminates the possibility of damage to the operating personnel.

Due to the low cost, as well as the property of insolubility in water, bitumen and its modifications are widely used in the production of waterproofing and adhesive materials, without which no construction industry can do now.

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

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

Bitumen and its modifications are widely used in the construction and repair work on insulation and thermal insulation of buildings. When insulating seams and joints of metal - concrete, wood - concrete or metal - wood, 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, bituminous glue 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 bituminous adhesive without an organic solvent in poorly ventilated and enclosed areas, such as basements, 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 Toyota official website

www.soyuz.kiev.ua Izolit

en.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 Conjuncture

dic.academic.ru Dictionaries and encyclopedias on Academicians

The penetration index characterizes the thermal sensitivity of bituminous binders. For this purpose, a simpler indicator is also used - the plasticity interval of bitumen, defined as the difference in softening and brittleness temperatures of bitumen (the method was proposed by Professor M. I. Rudenskaya). The penetration index is calculated as an abstract number: IP = ,

Depth of needle penetration into bitumen at 25°C, 0.1mm;

Bitumen softening point, °С.

Bitumens with a penetration index of -2 to +2 are suitable for road construction. Plasticity interval 55 - 75 °С. Bitumens with a penetration index of less than -2, having a higher weather resistance, are characterized by a lower softening point and a higher brittleness temperature (their plasticity interval is usually less than 55 ° C). Bitumen with a penetration index of more than +2, although not so temperature sensitive, has little stretch, and is less weather resistant. The determination of the penetration index is based on the establishment of a certain relationship between the softening temperature of the bitumen and the depth of penetration of the instrument needle into it.

Determination of the content of water-soluble compounds in bitumen. The leaching of water-soluble compounds from asphalt concrete and bitumen-mineral coatings and bases by atmospheric precipitation causes premature destruction of pavements. The essence of the method is in their transfer to a water extract and subsequent determination of the mass after evaporation of the water. An indicator of the content of water-soluble compounds is the ratio of the mass of bituminous components released from the water extract after its boiling to the initial mass of the test bitumen sample.

Method for determining the adhesion of bitumen to the mineral part. From an average sample of an asphalt concrete mixture prepared in a laboratory or at a factory, two 50 g samples are weighed on technical scales and one of them is placed on the grid. The second sample is left for subsequent comparison with the mixture that has passed the test. The chemical beaker is filled with a 15% solution of common salt in distilled water to about 2/3 of the volume and placed on an electric stove, sand "bath" or over the flame of a gas burner. The grid with a sample of the asphalt concrete mixture is lowered into a glass with a boiling solution of common salt so that the layer of the boiling solution above the grid is at least 30 - 40 mm. When testing viscous bitumen, the mesh with the test sample is kept for 30 minutes in a boiling solution, and when testing liquid bitumen - for 5 minutes. The boiling of the solution should not be violent. Bitumen, which floated to the surface of the mixture during boiling, is removed with filter paper. After the specified time, the grid with the mixture is transferred to a glass of cold water to cool and wash off the salt that has settled on the particles of the mixture, after which the mixture is placed on filter paper to evaporate the water. Adhesion is evaluated after complete drying of the mixture. Bitumen is considered to have passed the test for adhesion to the mineral part of the asphalt concrete mixture if, after the test, the entire surface of the mineral materials is covered with bitumen.

Flash point. Tests are carried out in an open crucible, determining the temperature at which bitumen vapors heated under standard conditions form a mixture with air that flashes when a flame is brought to it. This indicator is needed to establish the bitumen melting mode and prepare hot mastics, asphalt concrete, etc. from it. The test of bitumen is carried out in an apparatus consisting of a large crucible filled with sand, heated by a burner, and an internal crucible into which molten bitumen is poured. Before testing, the bitumen sample is dehydrated by melting and holding it until foaming stops.

The flash point of bitumen is taken as the temperature indicated by a thermometer when a blue flame appears at least over part of its surface. When testing, air movement and bright lighting should be avoided so as not to obstruct the observation of the moment of the flash.