RU2297990C1 - Polymeric-bituminous binding and the asphalt-concrete mixture prepared on its basis - Google Patents

Abstract

FIELD: chemical industry; chemical reactor and the method for production of hydrogen.

SUBSTANCE: the invention is pertaining to the polymeric-bituminous binding containing the bitumen, the polymer-butadiene-styrene thermoplast, the plasticizer - the industrial oil and the high-molecular surface-active substance. As the high-molecular surface-active substance it contains heavy fatty acids (HFA) representing the mixture of the high-molecular petroleum hydrocarbons of the common formula:

where R - the hydrocarbon radical with the contents of the carbon atoms from 12 up to 22 (C₁₂-C₂₂), at the following components ratio (in mass %): bitumen - 86-89, polymer-butadien-sterene thermoplast - 2.5-5, the industrial oil - 5.5-7.5, the indicated heavy fatty acids 1-3. Besides the true invention is pertaining to the asphalt-concrete mixture, which includes the filler consisting of the crushed stone, sand taken from the siftings of crushing and the mineral powder, the polymeric-bituminous binding and the stabilizing additive composed of the mineral fibers - the asbestos. As the polymeric-bituminous binding use the polymeric-bituminous binding taken according to the item 1 at the following components ratio, (in mass %): the crushed stone - 64-68, the sand taken from the crushing siftings - 16.5-18, the mineral powder - 9.5-11, the mineral fibers of the asbestos \tab- 0.35-0,45, the above indicated polymeric-bituminous binding - 6 -6.5. The invention ensures the improved binding qualities of the asphalt-concrete mixture.

EFFECT: the invention ensures the improved binding qualities of the asphalt-concrete mixture.

3 cl, 2 tbl, 3 ex

Description

The group of inventions relates to road-building materials and can be used for the construction of road, bridge and airfield coatings using a polymer-bitumen binder.

Known bitumen composition containing bitumen, styrene-butadiene thermoplastic elastomer and a surfactant (adhesive additive), which is used tall oil or the product of the interaction of tall oil and triethanolamine, in the following ratio of components in the composition, wt.%:

Bitumen 97.3-77.0 Styrene butadiene thermoplastic elastomer 2-6 Specified Surfactant 0.7-7.0

(see RF patent for the invention No. 2119513, IPC 6 C08L 95/00, C08L 53/02, C08L 93/00, priority dated 07/31/1997, publ. 09/27/1998, "Bituminous composition and method for its preparation").

A disadvantage of the known bituminous composition is poor adhesion to granite stone material using these adhesive additives. In addition, the bitumen composition has an unpleasant odor when using tall oil and triethanolamine as an adhesive additive.

The closest to a polymer-bitumen binder (the first claimed invention of the group) in terms of a set of essential features is a polymer-bitumen binder, including bitumen, styrene butadiene-styrene thermoplastic elastomer, thermoplastic elastomer stabilizer, which is a 1: 1 ratio of phospholitol NF, plasticizer (emollient) - industrial oil, high molecular weight surfactants (adhesive additives), which are orthophosphoric acid, carbon black and a polymer with a molecular weight of 2000-60000, having terminal functional groups containing nitrogen, oxygen, silicon atoms, and selected from the list

Polymer - Si (OS ₂ H ₅ ) ₃ ,

where the polymer is polystyrene, polyisoprene, polybutadiene, polystyrene-polyisoprene, polystyrene-polybutadiene in the following ratio of components, wt.%:

Plasticizer (Softener) 14-26 The above thermoplastic elastomer 2.5-4.5 The above polymer selected from the list 1.0-1.5 Above stabilizer 0.025-0.045 Orthophosphoric acid 0.01-0.2 Carbon black 0.1-3 Bitumen rest

(see RF patent for the invention No. 2211846, IPC 7 C08L 95/00, C08L 53/02, С04В 26/26, priority of 08/02/2002, publ. 09/10/2003, "Method for producing a polymer-bitumen binder (PBB) ").

The disadvantage of this method is the unsatisfactory mixing (distribution) of the polymer in the composition of the polymer-bitumen binder (PBB).

The presence in the PBB of carbon black (0.1-3%) reduces the stability of the composition to delamination, causes technological difficulties (deposition of the solid phase of carbon on the walls and bottoms of storage tanks and binder preparation, worsens pumpability through pipelines, pumps and through valves, contributes to accelerated coking properties of binder heating pipelines).

Phosphoric acid present in the composition (0.01-0.2%) causes accelerated corrosion of steel tanks and pipelines, worsens the environment, since during the storage, processing of PBB and preparation of asphalt mixtures in asphalt plants (ABZ), acid fumes appear, moreover, not only the equipment of bitumen bases is exposed to corrosion, but also the expensive ABZ equipment and road equipment - asphalt mixing plants, vehicle bodies for transporting asphalt, asphalt pavers and asphalt loading cranes oh mixture.

In addition, high molecular weight surfactants (adhesive additives) complicate the preparation of PBBs, as they require its special preparation (synthesis) from chemical ingredients.

Known asphalt mixture, including a filler consisting of crushed stone and sand from crushing screenings, bitumen and a stabilizing additive, which is chrysotile asbestos fraction 2.8-5.0 of the fourth group of the brand A-4-30, with bitumen and chrysotile asbestos taken in the ratio (7-13): 1 in the following ratio of components, wt.%:

Sand from crushing screenings 27-38 Bitumen 5.2-7.0 Chrysotile asbestos fraction 2.8-5.0 mm the fourth group of brand A-4-30 0.4-1.0 Crushed stone rest

(see RF patent for invention No. 2229451, priority of July 28, 2003, IPC 7 С04В 26/26, published on May 27, 2004. “Asphalt-concrete mixture”).

A disadvantage of the known mixture is the unsatisfactory durability of the coating due to insufficiently high adhesion of bitumen to the surface of the crushed stone used, as a result of which shear deformations of the pavement occur, since PBB is peeled off from the crushed stone. Premature destruction of asphalt concrete pavements significantly reduces their durability (the overhaul life of coatings is sharply reduced by 1.5-2.5 times).

The closest to the claimed asphalt concrete mixture (the second claimed invention of the group), by the set of essential features, is an asphalt concrete mixture including a filler consisting of crushed stone, sand from crushing screenings and activated mineral powder, a polymer-bitumen binder and stabilizing additive - asbestos mineral fibers (see Overview information "Construction of road and airfield coatings from crushed stone and mastic asphalt concrete mixtures." - M.: Publishing house "Informavtodor", 2003. - p.2, 31-33, 39).

A disadvantage of the known asphalt mixture is the unsatisfactory durability of the coating due to the fact that the PBB, which is part of the asphalt concrete mixture, has low resistance to delamination, as a result of which the adhesion of the PBB to the filler surface is poor.

As a result of the operation of asphalt concrete pavements based on the known asphalt concrete mixture, PBB is peeled off from crushed stone as a result of dynamic loads caused by heavy vehicles and high traffic intensity, as well as as a result of temperature loads caused by high temperature extremes that reduce the moisture resistance of the coating, which leads to destruction the integrity of the coating and, as a consequence, the need for repairs.

The claimed group of inventions - a polymer-bitumen binder and asphalt-concrete mixture based on it - provides for the expansion of the arsenal of technical means for obtaining durable road, bridge and airfield coatings with high performance characteristics, in particular, such as resistance to plastic shear deformations, resistance to temperature and dynamic loads.

The specified technical result is achieved by the fact that the known polymer-bitumen binder containing bitumen, a polymer - styrene-butadiene thermoplastic elastomer, a plasticizer - industrial oil and a high molecular weight surfactant, according to the first invention in the group contains heavy fatty acids as a high molecular weight surfactant (TFA), which is a mixture of high molecular weight hydrocarbons of oil of the General formula:

,

,

where R is a hydrocarbon radical with a carbon atom content of 12 to 22 (C ₁₂ -C ₂₂ ), in the following ratio of components, wt.%:

Bitumen 86-89 Polymer - styrene butadiene thermoplastic elastomer 2,5-5 Industrial oil 5.5-7.5 The above TLC 1-3

According to the second invention, in a group in a known asphalt concrete mixture comprising a filler consisting of crushed stone, sand from crushing screenings and mineral powder, a polymer-bitumen binder and a stabilizing additive - mineral asbestos fibers, a polymer-bitumen binder according to the first is used as a polymer-bitumen binder the invention, in the following ratio of components, wt.%:

Crushed stone 64-68 Sand from crushing screenings 16.5-18 Mineral powder 9.5-11 Mineral fibers of asbestos 0.35-0.45 The above polymer-bitumen binder 6-6.5

Asphalt mixture as mineral fibers of asbestos contains chrysotile asbestos.

According to the first invention in the group, the claimed composition of a polymer-bitumen binder with the specified ratio of components provides a bituminous binder with properties inherent in elastomers, which leads to greater elastic deformability, lower brittleness at low temperatures and at the same time to increase the shear stability of the road surface obtained using the inventive polymer - bitumen at high operating temperatures, resistance to temperature and dynamic loads.

The introduction of heavy fatty acids (TFA) as a high molecular weight surfactant in the composition of the polymer-bitumen binder (PBB) within the claimed limits due to the hydrocarbon component and the adhesive-plasticizing properties of the TFA molecules, improves the distribution of components in the PBB and PBB in the asphalt mixture, which ensures high adhesion of the polymer-bitumen binder with the filler (mineral part) of the asphalt mix.

According to the second invention, the use of the inventive asphalt-concrete mixture of the inventive polymer-bitumen binder allows to achieve greater elastic deformability, reduce brittleness at low temperatures and at the same time increase the shear resistance of the coating at high operating temperatures due to the fact that the PBB is evenly distributed throughout the volume of the asphalt mixture properties inherent in elastomers.

Asphalt concrete mixture as mineral fibers of asbestos (stabilizing additive) contains chrysotile asbestos, which is a non-metallic mineral raw material belonging to the group of magnesian hydrosilicates (3MgO · 2SiO ₂ · 2H ₂ O) with a fibrous-tubular structure. Chrysotile asbestos has high heat resistance up to 700-800 ° C and electrical, heat, sound insulation properties, chemically inert, resistant to alkalis. When interacting with water at atmospheric temperatures, it is hydrophilic, hygroscopicity is weak. Having a developed fine-fiber structure, chrysotile asbestos, when heated to 70 ° C, sharply reduces the water-holding ability and loses hygroscopic water. Chrysotile asbestos refers to environmentally friendly materials, as it has a low biological aggressiveness of exposure to living organisms and is able to dissolve in an acidic environment. The asphalt concrete mixture has the best properties when using chrysotile asbestos in its composition, a fraction of 2.8-5.0 mm of the fourth group of grade A-4-30.

Both technical solutions are interconnected and form a single inventive concept.

To obtain an asphalt-concrete mixture, which is used for the construction of road, bridge and airfield coatings with the required properties, a new polymer-bitumen binder was developed.

The use of the inventive polymer-bitumen binder in the inventive asphalt mix allows us to provide a technical result - the expansion of the arsenal of technical means to obtain durable road, bridge and airfield coatings with high performance characteristics, in particular, such as resistance to plastic shear deformations, resistance to temperature and dynamic loads .

Therefore, the claimed group of inventions, which is a part and whole, satisfies the requirement of unity of invention.

Technical solutions that coincide with the totality of the essential features of the claimed group of inventions have not been identified, which allows us to conclude that they comply with such a patentability condition as "novelty."

The claimed essential features of inventions that predetermine the receipt of the specified technical result, do not explicitly follow from the prior art, which allows us to conclude that the claimed inventions in the group correspond to such a patentability condition as "inventive step".

The patentability condition "industrial applicability" is confirmed by specific examples of obtaining a polymer-bitumen binder and asphalt mixture using this polymer-bitumen binder, set forth in the "Information confirming the possibility of carrying out the invention" section.

For the preparation of polymer-bitumen binder (PBB), the following initial components were used.

1. Bitumen

PBBs are prepared on the basis of bitumen grade BND according to GOST 22245-90 "Viscous petroleum bitumen. Technical conditions."

2. Polymer - styrene-butadiene thermoplastic elastomer

Styrene-butadiene thermoplastic elastomer DST-30-01 is produced in accordance with TU 38.103267-99 "Styrene-butadiene thermoplastic elastomers".

3. Plasticizer - industrial oil

Industrial oils are used for the preparation of PBB according to GOST 20788 of brands I-20A, I-30A, I-40A, I-50A.

4. High molecular weight surfactant - TFA

For the preparation of PBB, TFAs of local production (the manufacturer is located in the Ural region) are used, which are supplied in accordance with TU 2453-001-38576343-2002 “Surface-active TFA additive”.

The production of a polymer-bitumen binder is carried out by mixing in a mixer all the components of the composition, filed in the calculated amount, followed by passing the composition through a colloidal mill to the second mixer. Then this process is repeated. The temperature for the preparation of PBBs should not exceed 160 ° C, and the duration of the production process of PBB should not exceed 60 minutes

The prepared polymer-bitumen binder had the following composition presented in examples 1-3.

Example 1

Bitumen 89% Polymer - styrene butadiene thermoplastic elastomer 3.5% Industrial oil 6.5% SAW - TLC one%

Example 2

Bitumen 88.5% Polymer - styrene butadiene thermoplastic elastomer 3.5% Industrial oil 6.5% SAW - TLC 1.5%

Example 3

Bitumen 88.0% Polymer - styrene butadiene thermoplastic elastomer 3.5% Industrial oil 6.5% SAW - TLC 2%

Table 1 shows the physicomechanical properties of the polymer-bitumen binder using TFA as a surfactant:

Table 1 Name of indicators of polymer-bitumen binder and unit of measurement Indicator value 1. The depth of penetration of the needle is 0.1 mm at 25 ° C 128 at 0 ° С 59 2. Elongation, cm at 25 ° C More than 70 at 0 ° С 54 3. The softening temperature of the ring and ball, ° C 53.0 4. The temperature of brittleness, ° C -28.0 5. Elasticity,% at 25 ° C 91 at 0 ° С 78 6. Bonding with granite great 7. The interval of plasticity, ° C 81 8. Uniformity uniformly

From the data of Table 1 it can be seen that the inventive polymer-bitumen binder using TFA as a surfactant has high physical and mechanical properties, in particular, the ductility interval is 81 ° C, and adhesion to granite is estimated to be excellent, which determines the increase in its resistance to aging.

To prepare the asphalt mixture used the following source components.

1. Filler (Mineral Material):

A) Crushed stone

For the preparation of the asphalt mix, crushed stone with a grain size of 5-10, 10-15, 15-20 mm from dense rocks is used according to GOST 8267-93. Crushed stone must meet the requirements of GOST 9128-97 for large aggregate used in asphalt mixtures of type A grade 1.

According to the shape of the grains used crushed stone should be cuboid and belong to the 1st group. The content of lamellar and needle-shaped grains should not exceed 15%.

B) Sand from crushing screenings

Sand from rock crushing screenings must meet the requirements of GOST 8736-93. The strength of the sand should not be lower than 1000, the content of clay particles in the sand, determined by the swelling method, should not exceed 0.5%, while the content of grains smaller than 0.16 mm in the sand from the screenings of crushing is not standardized.

B) Mineral powder

For the preparation of the asphalt-concrete mixture, the inactivated magnesite powder of the Shabrovsky talc plant is used, which meets the requirements of GOST 16557-78.

Density, g / cm ³ - 2.06

Porosity,% - 33.3

Swelling of samples from a mixture of powder with a binder,% - 1.5

Bitumen rate, gr. - 62

Humidity,% by weight - 0.2

True density, g / cm ³ - 3.1

2. Stabilizing additive

A stabilizing fibrous additive - mineral asbestos fibers - for dispersed binder reinforcement, which uses chrysotile asbestos, which best prevents the segregation and peeling (swelling) of the binder from the crushed stone surface at high technological temperatures. The stabilizing additives are subject to technical requirements for heat resistance, humidity and uniformity.

The stabilizing additive - chrysotile asbestos of a fraction of 2.8-5.0 mm, grade A-4-30 of the Asbestovskoye deposit has the commercial name "Chrysotope" and is produced according to TU 5718-011-0281476-2004.

Technical characteristics of chrysotile asbestos:

Humidity - 4.3%

Heat resistance at t 220 ° C by mass change during heating - 5%

3. Polymer-bitumen binder (preparation of a polymer-bitumen binder is described above).

The preparation of the asphalt mixture was carried out as follows.

Hot asphalt mixtures are prepared in asphalt mixing plants (ACS) with forced mixing of the components, by mixing in the heated state crushed stone, sand from the screenings of crushing, mineral powder, polymer-bitumen binder, as well as a stabilizing additive.

ACS dosing devices should ensure the accuracy of component dosing: for crushed stone ± 2%, for sand ± 3%, for mineral powder and binder ± 1.5%, for stabilizing additives ± 2%. ACS must have an automatic control system or control system that allows monitoring of process parameters.

The stabilizing additive is usually added to the filler mixture before combining it with a polymer-bitumen binder (PBB).

Physico-mechanical properties of asphalt concrete prepared using the inventive PBB are presented in Table 2.

table 2 The name of indicators The values of indicators for roads of the II brand for the II road-climatic zone, satisfying the requirements of GOST 12801 Actual values of the properties of asphalt concrete prepared using the inventive PBB 1. The compressive strength at temperature, MPa 50 ° C Not less than 1.2 1.75 20 ° C Not less than 2.5 3,55 0 ° C No more than 11.0 6.00 2. Water resistance of dense asphalt concrete Not less than 0.90 0.96 3. Water resistance of dense asphalt concrete with prolonged water saturation Not less than 0.85 0.94 4. Water saturation,% 1.5-4.0 0.9 5. The porosity of the filler (mineral part),% No more than 19.0 18.5 6. The average density, g / cm ³ - 2,38 7, Swelling,% - 0.02 8. The ratio of R ₀ / R ₅₀ 9.2 3.42

From Table 2 it can be seen that the inventive asphalt mix using the inventive polymer-bitumen binder has high physical and mechanical properties exceeding those specified by GOST 12801.

The period between overhauls of the coating of the claimed asphalt mix using the inventive polymer-bitumen binder, calculated by the actual indicators of physical and mechanical properties, reaches 16 years, which exceeds the actual figures by 2.5 times.

Claims (3)

1. A polymer-bitumen binder containing bitumen, a polymer - styrene-butadiene-thermoplastic elastomer, a plasticizer - industrial oil and a high molecular weight surfactant, characterized in that the polymer-bitumen binder contains heavy fatty acids as a high molecular weight surfactant (TFA) representing a mixture of high molecular weight oil hydrocarbons of the general formula

where R is a hydrocarbon radical with a carbon atom content of 12 to 22 (C ₁₂ -C ₂₂ ), in the following ratio of components, wt.%: Bitumen 86-89 Polymer - styrene butadiene thermoplastic elastomer 2,5-5 Industrial oil 5.5-7.5 The above TLC 1-3 2. Asphalt-concrete mixture, including a filler consisting of crushed stone, sand from crushing screenings and mineral powder, a polymer-bitumen binder and a stabilizing additive - mineral asbestos fibers, characterized in that a polymer-bitumen binder according to claim 1 is used as a polymer-bitumen binder. 1, in the following ratio of components, wt.%: Crushed stone 64-68 Sand from crushing screenings 16.5-18 Mineral powder 9.5-11 Mineral fibers of asbestos 0.35-0.45 The above polymer-bitumen binder 6-6.5 3. Asphalt mixture according to claim 2, characterized in that it contains chrysotile asbestos as mineral fibers of asbestos.