The oil refining industry produces several types of bitumen: solid, semi-solid, and liquid. The latter are widely used in laying road surfaces, acting as a binder for crushed stone and mineral sand. The use of bitumen gives road surfaces strength and plasticity, allowing them to maintain their original performance characteristics under critical temperature conditions. Thanks to bitumen, asphalt does not melt in the heat and does not become brittle in winter.
Production and areas of use of petroleum road bitumen
Petroleum road bitumen (BND) is a flammable substance obtained by mixing viscous bitumen with special solvents - thinners. The properties of the resulting material make it possible to lay asphalt concrete even at sub-zero temperatures in the winter. After completion of the work, the thinners evaporate from the asphalt concrete mixture prepared in this way, bringing the working mixture to its original state and forming a smooth and reliable road surface. Liquid bitumens are divided into MG (slow-thickening) and SG (medium-thickening). MG petroleum road bitumen is used on construction sites located in climatic zones where the average monthly winter temperature ranges from +5 to -20 degrees. In this case, natural resinous oils and oily petroleum products are used as a diluent.
Characteristics, storage conditions, prices for MG bitumen
The fundamentally important qualities of BND are its resistance to organic solvents (benzene, gasoline, acetone, etc.), as well as its insolubility in water, alkaline and acid solutions. The dense and porous structure makes it waterproof and frost-resistant. MG bitumen must be stored and transported strictly in accordance with existing standards in specially equipped tanks. Today, domestic consumers have the opportunity to purchase this type of material, which meets state quality standards, directly from manufacturing enterprises. The presence of certificates will confirm the compliance of the goods with the current GOST. Prices for MG petroleum road bitumen fluctuate and depend on the current cost of petroleum products, but always remain within reasonable limits.
PETROLEUM ROAD LIQUID BITUMENS
Specifications
GOST 11955-82
STATE STANDARD OF THE USSR UNION
Date of introduction 01.01.84
This standard applies to liquid petroleum road bitumen used as a binding material in the construction of road surfaces, foundations and for other purposes.
Mandatory requirements for product quality are set out in clause 4 and clause.
(Changed edition, Amendment No. 2).
1. stamps
1.1. Depending on the speed of structure formation, liquid bitumen is divided into two classes:
thickening at an average speed, obtained by liquefying viscous road bitumen with liquid petroleum products (LP) and intended for the construction of permanent and lightweight road surfaces, as well as for the construction of their bases in all road-climatic zones of the country;
slow-thickening, obtained by diluting viscous road bitumen with liquid petroleum products (LP), and obtained from residual or partially oxidized petroleum products or their mixtures (LGO), intended for the production of cold asphalt concrete, as well as for the construction of lightweight road surfaces and bases in II-V road climatic zones and other purposes.
SG 40/70, SG 70/130, SG 130/200;
MG 40/70, MG 70/130, MG 130/200;
MGO 40/70, MGO 70/130, MGO 130/200.
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Standard for the brand |
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SG 40/70 |
SG 70/130 |
SG 130/200 |
MG 40/70 |
MG 70/130 |
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OKP 02 5611 0202 |
OKP 02 5611 0203 |
OKP 02 5611 0204 |
OKP 02 5611 0302 |
OKP 02 5611 0303 |
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1. Conditional viscosity according to a viscometer with a 5 mm hole at 60° With, with |
40-70 |
71-130 |
131-200 |
40-70 |
71-130 |
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2. Amount of evaporated diluent, %, not less |
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3. Softening temperature of the residue after determining the amount of evaporated thinner,° C, not lower |
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4. Flash point, determined in an open crucible,° C, not lower |
100 |
110 |
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5. Adhesion test with marble or sand |
Withstands in accordance with control sample No. 2 |
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Continuation
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Indicator name |
Standard for the brand |
Test method |
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MG 130/200 |
MGO 40/70 |
MGO 70/130 |
MGO 130/200 |
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OKP 02 5611 0304 |
OKP 02 5611 0403 |
OKP 02 5611 0401 |
OKP 02 5611 0402 |
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1. Conditional viscosity according to a viscometer with a 5 mm hole at 60° With, with |
131-200 |
40-70 |
71-130 |
131-200 |
4.3. If unsatisfactory test results are obtained for at least one of the indicators, repeat testing of a sample from a double sample is carried out. The results of repeated tests apply to the entire batch. 5. TEST METHODS5.2. The adhesion test with marble or sand is carried out according to for liquid bitumen grades MGO using method A, for grades SG and MG - using method B. Liquid bitumens, to which cationic substances have been added, are tested for adhesion to sand; liquid bitumen with anionic substances - with marble. 5.3. Conditional viscosity is determined by the following addition: the sample is pre-cooled to room temperature, kept for at least 1 hour, then heated for 2-3° C above test temperature. (Introduced additionally, Amendment No. 3). 6. PACKAGING, LABELING, TRANSPORTATION AND STORAGE6.1. Packaging, labeling, transportation and storage of liquid bitumen - according to . According to the degree of transport hazard, liquid bitumen is classified as hazard class 9, subclass 9.1, category 9.12 according to GOST 19433-88. Liquid bitumen of classes SG and MG should be stored in tanks equipped with safety valves. (Changed edition, Amendment No. 1, 2). 7. MANUFACTURER WARRANTY7.1. The manufacturer guarantees that the quality of liquid bitumen meets the requirements of this standard subject to the conditions of transportation and storage. 7.2. The guaranteed shelf life of liquid bitumen from the date of manufacture should be for the SG class - 6 months; MG class - 8 months; MGO class - 1 year. INFORMATION DATA1. DEVELOPED AND INTRODUCED by the Ministry of Oil Refining and Petrochemical Industry of the USSR DEVELOPERS V.V. Fryazinov, R.A. Akhmetova, N.I. Sherysheva, O.V. Karpova, N.A. Malikova, B.S. Maryshev, I.A. Plotnikova, L.M. Gokhman, D.S. Shemonaeva, S.L. Alexandrova, I. A. Chernobrivenko, A. G. Kashina 2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee on Standards dated 08.25.82 No. 3367 Change No. 2 Adopted by the Interstate Council for Standardization, Metrology and Certification (Minutes No. 6 of October 21, 1994) Registered by the Technical Secretariat of the IGU No. 1189
(, IUS 1-2006) 3. INSTEAD GOST 11955-74 4. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS 5. The validity period was lifted by decision of the Interstate Council for Standardization, Metrology and Certification (IUS 5-6-93) 6. REISSUE with Amendments No. 1, 2, approved in December 1987, October 1994 (IUS 4-88, 10-95) | ||||||||||||||||||||||
They are used as a binding material in the construction of road surfaces and foundations. At normal temperatures they have a slight viscosity, which provides the necessary workability. They are used in a state heated to 60-100 0 C.
Based on the speed of structure formation, liquid bitumen is divided into three classes: BG - fast-thickening, SG - medium-thickening, MG - slow-thickening, MGO - slow-thickening oxidized. According to GOST 11995-82 (see appendix, table), liquid bitumens of the BG and SG classes are used in the construction of improved road surfaces in all road and climatic zones of the country, when strengthening soils. MG grade bitumen – for the construction of lightweight road pavements. Bitumen is also used to create a protective film on a freshly laid concrete or cement-soil base. For general construction purposes, liquid bitumen is used as an impregnating material in the manufacture of rolled roofing and waterproofing materials. Based on viscosity, there are several grades of liquid bitumen in each class:
for class BG – BG 40/70, BG 70/130;
for the SG class – SG 40/70, SG 70/130, SG 130/200;
for MG class – MG 40/70, MG 70/130, MG 130/200.
The quality of liquid bitumen is assessed by: true viscosity, determined in a rotational or capillary viscometer; conditional viscosity; stability of the composition, characterized by the amount of diluent evaporated from the bitumen when it is kept at a certain temperature for a given time; the rate of formation of structure and properties, characterized by the softening temperature of the residue after determining the amount of evaporated thinner, flash point and active adhesion to marble or sand.
Technical requirements for liquid bitumen are given in the table (appendix).
2. Testing viscous bitumen.
When assessing the quality of viscous bitumen in the laboratory, the following is determined:
Depth of needle penetration.
Softening temperature.
Extensibility.
Flash point.
Penetration index.
2.1. Laboratory work No. 1.
Determination of needle penetration depth.
I . Theoretical part.
The depth of penetration of the needle (penetration) characterizes the relative viscosity of petroleum bitumen and is determined by measuring the depth of immersion of the penetrometer needle into a bitumen sample under a load of 100 + 0.25 g for 5 seconds at 25 0 C or under a load of 200 g for 60 seconds at 0 0 C.
The needle penetration depth indicator is the leading one when separating bitumen into grades.
II . Materials and equipment.
Penetrometer.
Stopwatch.
Metal cylindrical cup.
Crystallizer.
Thermometer up to 50 0 C.
III . Method of determination.
Prepare a sample of bitumen for testing.
Before the experiment, dehydrated bitumen at a temperature of about 150 0 C is passed through a sieve No. 07, poured into a cup, cooled to room temperature, and kept for an hour in water at a temperature of +25 and 0 0 C.
Determine the depth of needle penetration.
To determine the depth of needle penetration, a manual or automatic penetrometer is used (Fig. 2.1). The support platform of the penetrometer 1 is equipped with three set screws to bring it into a horizontal position. Attached to the support platform of the penetrometer are stands with brackets and a rotating object table for installing a crystallizer 6 with a metal cup containing the bitumen being tested. The upper bracket is equipped with a limb 2, divided by 360 0, and a ratchet 3. Each degree of the limb corresponds to a needle immersion of 0.1 mm. A freely falling rod 4 with a needle and a weight is attached to the lower bracket. The rod is fixed with a locking button 5. The penetrometer table is brought into a horizontal position using a level or plumb line.
After keeping the cup with bitumen in a water bath for 60-75 minutes, it is placed in a crystallizer with a capacity of at least 1 liter, filled with water so that it covers the bitumen with a layer of at least 10 mm. The water temperature in the crystallizer is 25 + 0.1 0 C.
The crystallizer is placed on the object stage. Using a mirror, bring the needle into contact with the surface of the bitumen, spaced at least 10 mm from the walls of the cup.
The rack 3 is brought to the upper platform of the rod 4 carrying the needle and the dial arrow 2 is set to zero and a count is taken.
Turn on the stopwatch and simultaneously press the lock button of the device, allowing the needle to freely enter the sample for 5 seconds.
The button is released, brought to the upper platform of the plunger with the needle and a count is taken along the dial. The difference between the second and first readings gives the penetration depth.
The determination is repeated at least three times in places spaced at least 10 mm apart from each other.
After each dive, the needle is washed with a solvent and wiped dry towards the tip.
In the case of determining the depth of penetration of the needle at 0 0 C, which is required when assessing the quality of BND grade bitumen, the duration of cooling of the bitumen in air is 60-90 minutes, the temperature of the water in the ice bath should be 0 + 0.1 0 C. The sample is kept in a bath for 60-90 minutes. The temperature of the water in the crystallizer during the test should be 0 + 0.1 0 C.
The arithmetic mean of three results of parallel determinations is taken as the needle penetration depth.
The discrepancy between the results of determining the depth of penetration of the needle (degrees) should not exceed the following values:
Rice. 2.1. Penetrometer.
1-support platform; 2-limb; 3-cremalier; 4- rod with needle; 5-stop button; 6-crystallizer.
IV . Laboratory journal.
V . Conclusion. Record the results.
Bitumen is a material widely used in construction, characterized by excellent hydrophobic and adhesive properties. It is mainly used for asphalting roads. This material is also very often used as a waterproofing agent in the construction of buildings and structures. In this article we will understand in detail what bitumen is, what its properties are and its scope of application.
Definition
Bitumen is a dense, viscous, black, resin-like substance. It is usually supplied in pieces, which are melted before use. The composition of bitumen is very complex. It is a combination of a hydrocarbon base with its derivatives, as well as metals, oxygen and nitrogen. Various heteroorganic compounds are also present in this material. In general, the composition of bitumen is so rich that identification of all its components is simply impossible.
How it is produced
The main product used to prepare bitumen is oil. There are only three main types of this material:
- Concentrating oil residues by vacuum distillation. The final product is soft and fusible. Using this method, bitumen is obtained from highly resinous (sulphurous) oil.
- Oxidation of tar (oil residue) by blowing it with oxygen at a temperature of +180...+300 degrees. This method produces a heat-stable elastic material.
- Mixing of residual and oxidized petroleum products with distillates.
Natural bitumen
Most often, this material is produced artificially using the three technologies described above. However, there is also natural bitumen, the characteristics and uses of which are approximately the same as regular bitumen. It occurs in nature and forms unique lenses. Natural bitumen is practically never found in its pure form. Most often it impregnates some sedimentary layer. Typically these are rocks such as sandstone or limestone. In this case, pure natural bitumen is obtained by first grinding stones. Sometimes such asphalt rock is simply thoroughly ground and used in road construction.
Types of bitumen by area of use
According to the area of application, this material is divided into four large groups:
- Construction bitumen. Used for foundations, submerged wooden structures, etc.
- Roofing. It is used to protect roofs of residential, industrial and public buildings from moisture.
- Petroleum road bitumen. The most common option used for preparing asphalts.
- Insulating. Used to protect metal pipelines from moisture and corrosion.
Road bitumen
This hydrophobic material is most often used in the construction of highways. There are two main types of road bitumen:
- Viscous. Obtained from petroleum.
- Liquid. This variety is made from viscous bitumen. Petroleum products are used as a diluent.
Viscous petroleum road bitumen is used in the construction of highways in the warm season. Liquid material is used in cold weather. Viscous bitumen is heated to its melting point before laying. Liquid material can be used either cold or heated. Some time after laying, due to oxidative processes, such bitumen thickens and forms a dense, moisture-proof elastic film.
What characteristics should you pay attention to when purchasing?
There are only three main parameters by which the quality of bitumen can be determined:
- softening temperature indicator;
- ductility (degree of ductility of the bitumen thread);
- penetration (viscosity).
The latter indicator is determined by immersing a needle or cone in bitumen at a certain temperature.
Marking
It is very easy to find out which bitumen is intended for which type of work. To do this, you need to look at the markings.
- Construction bitumen is marked with the letters BN.
- Road - BN or BND.
- Roofing - BNK.
After the letters in the marking there are two numbers separated by a forward slash. The first number indicates the softening point, the second - the degree of viscosity. The latter is determined by immersing a needle in bitumen at a temperature of 25 o C.
Brands of viscous road bitumen
As already mentioned, such material is supplied in pieces or in barrels. When paving, BN (petroleum bitumen) and BND (petroleum road bitumen) are used. According to GOST, only ten types of this material are produced (BDN from 200/300 to 40/60, BN from 200/300 to 60/90).
Liquid road bitumen
This material is marked separately. There are only two varieties of it:
- SG - thickening at medium speed.
- MG - thickening slowly. This variety is used in road construction in climatic zones II-V.
In this case, after the letters there are also two numbers separated by a slash, indicating the permissible range of ductility (at a temperature of 60 o C with a 5 mm hole on the viscometer).
When purchasing a batch, you need to check the certificate (passport) for liquid petroleum road bitumen. The SG brand, just like MG, BDN and BN, must comply with GOST+. We’ll talk about what this document is a little lower.
Safety precautions when working with bitumen
You should be quite careful when using this material. Bitumen is flammable. The fire hazard of a particular brand is determined by the following indicator: It is higher for viscous construction, road, roofing and insulating bitumens, and lower for liquid bitumens. Therefore, when working with the latter you should be especially careful.
Among other things, when performing operations related to the application, storage, transportation, etc. of bitumen, according to industrial safety rules, it is necessary to wear special clothing. This protects the worker from hot, difficult-to-wash drops coming into contact with the skin.
Bitumen quality certificate
Bitumen sold by enterprises must comply with GOST 2245-90 standards. However, today many companies produce products of this type with improved characteristics. Therefore, bitumens of one or another new brand are accompanied by special certificates certified by the heads of laboratories, also called passports. They indicate parameters such as penetration, ductility, softening point of the product, etc.
Such a document is issued not only for viscous, but also for petroleum road liquid MG bitumen. The quality certificate is a guarantee that the characteristics of the material comply with those declared by the manufacturer. The company seal must be affixed to the document.
Of course, there must be a passport for liquid petroleum road bitumen SG, as well as for roofing and insulating bitumen. New brands of this material include, for example, BND-U and Euro BV. In relation to them, quality standards are determined not by GOST, but by TU and STO. When producing Euro BV, the requirements of the European standard EN 12591 are also taken into account.
Most common brands
In construction, petroleum road bitumen 90/10 is most often used. Manufacturers produce and sell it in huge quantities. It is used to waterproof foundations, underground parts of wooden supporting structures, interpanel seams, basements and walls. It is distinguished from another fairly popular brand, BN 70/30, by a higher melting point. This expands the scope of its use, since the film produced by it is able to withstand high heating temperatures.
In the construction of highways, petroleum road bitumen MG130/200 is often used. It is usually used in those regions where the air temperature in winter does not fall below 20 o C. This material forms a reliable and very smooth road surface.
Softening temperature (about C) | Residue after evaporation of the thinner - 30 |
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Flash point | ||
Ductility | At a temperature of 25 o C 1 cm | 131-200 at 60 o C and hole diameter 5 mm |
Penetration | At a temperature of 25 o C - 5-20 | |
Amount of diluent evaporated | Not less than 5% |
Petroleum bitumen for road, construction and roofing is a material that is in great demand on the market. Many companies produce it today. Therefore, choosing a quality product will not be difficult at all. The main thing is to pay attention to the labeling and buy the most suitable option in this particular case.
Liquid petroleum road bitumens , having a fluid state at positive temperatures, is used as a binding material in asphalt concrete mixtures used both in cold (with a temperature of 15...20 ° C) and in warm conditions, heated to a temperature of about 100 ° C. Liquid bitumens obtained mainly by compounding viscous bitumen with a thinner. Such bitumen is often called liquefied. Sometimes liquid bitumen obtained as a residue from oil refining. Properties liquefied bitumen are largely determined by the properties of the thinners used. With time liquid bitumen thicken due to the evaporation of volatile fractions, oxidation and other processes. The most important properties of liquid bitumen: viscosity, thickening rate and properties of the residue after evaporation of volatile fractions, adhesion, flash point, weather resistance, etc. One of the most important signs of bitumen liquefaction is the rate of formation of their structure, which determines the rate of formation of coatings. Depending on the rate of evaporation of light fractions of liquefaction and the rate of thickening (structure formation) liquid bitumen are divided into two classes: 1) medium-thickening (SG) - thickening at an average speed and obtained by diluting viscous road bitumen with liquid petroleum products; 2) slow-thickening (MG) and MGO grades obtained from residual or partially oxidized petroleum products or mixtures thereof. Bitumen class is established by the amount of evaporated diluent when keeping a sample of bitumen in a thermostat at a certain temperature or a vacuum thermostat.
Depending on the class and viscosity, liquid bitumens have grades:
SG 40/70, SG 70/130, SG 130/200;
MG 40/70, MG 70/130, MG 130/200;
MGO 40/70, MGO 70/130, MGO 130/200.
Numbers in indexes grades of bitumen mean the limits of conditional viscosity using a viscometer with a 5 mm hole at 60 °C, in seconds. Bitumens of MG and SG classes until recently, they were practically not produced in our country, although GOST 11955 provides for such bitumens. Liquid bitumens must be manufactured in accordance with the requirements of the GOST 11955 standard (Table 1).
Thickening at medium speed liquid bitumen (SL) are intended for the construction of permanent and lightweight road surfaces, as well as for the construction of their foundations in all road and climatic zones of the country. Slow-thickening bitumen (MG and MGO) are intended for the production of cold asphalt concrete, as well as for the construction of lightweight road surfaces and foundations in road climatic zones II-V and for other purposes.
Liquid petroleum bitumens SG class is prepared by diluting viscous bitumen with kerosene, gasoline, naphtha, etc. Slow-thickening MG bitumens are produced by using oil products, natural tarry oils, fuel oil, etc. as a thinner. Slow-thickening bitumen can be natural - heavy resinous oils. Liquefaction viscous bitumen often changes the dispersed structure of the binder, often causing coagulation of the dispersed phase, which negatively affects its properties. Therefore, in each specific case, the thinner must be appropriately selected taking into account its fractional composition and polarity, similar to viscous bitumen.
For cooking liquid bitumen by liquefaction, viscous bitumen should have a temperature not exceeding 120 ° C (approximately 80-90 ° C when using light thinners). Used in these conditions viscous road bitumen according to GOST 22245-90 with a needle penetration depth of no more than 90.
Table 1. Technical requirements for petroleum liquid road bitumen grades SG, MG and MGO
No. |
The name of indicators |
MG 40/70 |
MG 70/130 |
MG 130/200 |
MGO 40/70 |
MGO 70/130 |
MGO 130/200 |
SG 40/70 |
SG 70/130 |
SG 130/200 |
Test method |
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Conditional viscosity according to a viscometer with a 5 mm hole at 60°C, s |
according to GOST 11503 |
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Amount of evaporated diluent, %, not less |
according to GOST 11504 |
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Softening temperature of the residue after determining the amount of evaporated thinner, °C, not lower |
according to GOST 11506 |
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| 4 | Flash point determined in an open crucible, °C, not lower | 100 | 110 | 110 | 120 | 160 | 180 | 45 | 50 | 60 | according to GOST 4333 | |||
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Adhesion test with marble and sand |
Withstands in accordance with control sample No. 2 |
according to GOST 11508 |
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The fractional composition of petroleum products used as diluents is indicated in table. 2.
IN liquid bitumen To ensure the necessary adhesion to marble or sand, surfactants (anionic or cationic) are introduced if necessary.
When draining, filling and using liquid bitumen, the following heating temperatures are set for brands:
from 70 to 80 °C - for SG 40/70; MG 40/70;
from 80 to 90 °C - for SG 70/130; MG 70/130;
from 90 to 100 °C - for SG 130/200; MG 130/200; MGO 40/70; MGO 70/130; MGO 130/200.
Table 2. Fractional composition of diluents for bitumen grade BND 60/90
Liquid bitumens— flammable substances with a self-ignition temperature not lower than 300 °C. When liquefying viscous bitumen in an open system, the temperature of the bitumen supplied for mixing with the liquefier should not exceed 120 °C. Mixing of viscous bitumen with a diluent is carried out with inert gas or circulation.
Liquid bitumens, to which cationic substances are added, are tested for adhesion to sand. Liquid bitumen with anionic substances - with marble.
The guaranteed shelf life of liquid bitumen for the SG class is 6 months, the MG class is 8 months, and the MGO class is 1 year.
Test methods
Liquid bitumen samples selected according to GOST 2517-85. The mass of the combined sample of each brand of liquid bitumen is 1.0 kg.
The test for adhesion to marble and sand is carried out according to GOST 11508 for liquid bitumen of MGO grades using method A, for SG and MG - using method B.
Liquid bitumens, to which cationic substances are added, are tested for adhesion to sand;
liquid bitumen with anionic substances - with marble.
Packaging, labeling, transportation and storage. Packaging, labeling, transportation and storage of liquid bitumen in accordance with GOST 1510-84 with the following additions:
liquid bitumens of SG and MG classes must be stored in tanks equipped with safety valves;
the document on the quality of liquid bitumen indicates the mineral material (sand or marble) with which the adhesion test was carried out.
