RU2672417C1 - Modified by the petroleum bitumen asphalt-concrete mixture and the bitumen modifier - Google Patents

Abstract

FIELD: construction.SUBSTANCE: invention relates to the field of construction road materials, namely to the asphalt-concrete mixture composition, which includes gravel, sand and modified petroleum road bitumen, which contains single-walled carbon nanotubes in the amount of 0.005–0.5 wt.% and on natural products and vegetable oils phosphatides based adhesion additive, or based on the fatty acids amidoamines and imidazolines, or based on the tallow oil with polyalkylamine compounds reaction products.EFFECT: produced using this modified petroleum bitumen asphalt-concrete mixtures have the asphalt-concrete coating increased softening temperature and improved performance characteristics, which allows to use them for the highways, airfields, city streets and squares, and industrial enterprises roads coatings and bases construction.3 cl, 1 tbl

Description

The invention relates to the field of road building materials containing an organic binder, and can be used in the production of asphalt mixtures used for the coating and foundation of roads, airfields, city streets and squares, roads of industrial enterprises.

Asphalt-concrete mixture is a mixture prepared by mixing in a heated state crushed stone (gravel), natural or crushed sand, mineral powder and oil bitumen, taken in certain ratios [GOST 2198-2013].

The quality and service life of road asphalt pavements are largely determined by the quality of petroleum bitumen. An effective way to improve the quality of petroleum bitumen is to control their properties by using various modifying additives: polymers, surfactants, crosslinking additives, nanosized particles, etc.

Known, for example, asphalt mixture, including crushed stone, quartz-feldspar sand, mineral powder and modified petroleum bitumen [patent No. RU 2592509, IPC C08L 95/00, С04В 26/26, С04В 24/36]. In this mixture, bitumen is pre-modified with a fullerene mixture obtained by synthesis in an electric arc plasma-chemical reactor. Asphalt concrete made using petroleum bitumen modified in this way has good performance, however, industrial production of fullerenes does not exist and, accordingly, it is impossible to establish large-scale production of petroleum bitumen modified by the proposed method.

Another known asphalt mixture, including crushed stone, gravel screening, sand and modified oil bitumen grade BND 90/130 [patent No. RU 2515007, IPC C08L 95/00, C04B 26/26]. Petroleum bitumen included in this mixture is modified by multi-walled carbon nanotubes in an amount of 0.005% by weight of bitumen.

This asphalt mix is the closest analogue of the proposed asphalt mix and is taken as its prototype.

Modified carbon nanotubes petroleum bitumen, which is part of the aforementioned asphalt concrete mix prototype, is the closest analogue of the proposed modified petroleum bitumen and is taken as its prototype.

The disadvantages of the prototype is the impossibility of scaling and the high cost of the technology for modifying petroleum bitumen, providing for a long, for 6 hours, dispersion of carbon nanotubes in its volume by ultrasonic treatment.

The proposed asphalt mix, modified petroleum bitumen and modifier for bitumen solve the problem of producing asphalt mix and modified bitumen for this mixture in the standard technological process, which make it possible to improve the operational characteristics of asphalt concrete pavement based on them, in particular, to increase the softening temperature of the asphalt concrete pavement - one of the key indicators, determining the durability of the coating.

The problem is solved by the fact that the proposed asphalt mixture, including crushed stone, sand and modified petroleum bitumen, containing carbon nanotubes in an amount of 0.005-0.5 mass. % of its mass.

The problem is also solved by the fact that a modified petroleum bitumen is proposed containing carbon nanotubes in an amount of 0.005-0.5 mass. %

The carbon nanotubes contained in said petroleum bitumen are preferably single-walled.

Moreover, the named modified petroleum bitumen, including that which is part of the asphalt mixture, may contain an adhesive additive based on natural products and phosphatides of vegetable oils, or based on amido amines and imidazolines of fatty acids, or based on the products of the interaction of tall oil with polyalkyl polyamine compounds.

The proposed modified petroleum bitumen can be obtained in various ways. It is preferable to obtain it using a modifier.

To obtain the modified petroleum bitumen described above, a modifier is proposed containing an adhesive additive and carbon nanotubes in an amount of at least 1 mass. %

The adhesive additive included in the modifier can be made on the basis of natural products and phosphatides of vegetable oils, or on the basis of amidoamines and imidazolines of fatty acids, or on the basis of the products of the interaction of tall oil with polyalkylpolyamine compounds, or others not mentioned here.

The carbon nanotubes included in the modifier are preferably single-walled.

It should be noted that the technical solutions claimed here, namely, the asphalt mix, modified petroleum bitumen and a modifier for the named bitumen, are united by a single inventive concept and provide a technical result consisting in increasing the softening temperature obtained using asphalt concrete pavement, as well as simplifying the technology petroleum bitumen modification.

In practice, the preparation of the objects described here — asphalt mix, modified petroleum bitumen, and a modifier for bitumen — is carried out as follows.

At the first stage, a modifier for oil bitumen is prepared, containing an adhesive additive and a nanodispersed component — carbon nanotubes in an amount of at least 1 mass. %

The adhesive additive included in the modifier is selected from a number of substances based on natural products and phosphatides of vegetable oils, such as Azole 1003, or based on amido amines and imidazolines of fatty acids, such as Azole 1002, or based on the products of the interaction of tall oil with polyalkylpolyamine compounds, for example "Adhesol", or other substances suitable for these purposes.

The use of adhesive additives from the series: “Azole 1003”, or “Azole 1002”, or “Adhesol” as a carrier medium for the preparation of a modifier allows to increase the adhesion of petroleum bitumen to the mineral part of asphalt mixtures, as well as to stabilize the properties of petroleum bitumen in the production of asphalt concrete mixtures in road construction.

Carbon nanotubes, preferably single-walled, are mixed with an adhesive additive to a content of at least 1 mass. % Since carbon nanotubes tend to agglomerate, the mixture undergoes mechanical activation to disperse the carbon nanotubes in a carrier medium. Mechanical activation is carried out by applying shear forces to the mixture using tools such as a three-roll, or bead, or ball or planetary mill, or using other tools not mentioned here.

The modifier prepared as described above may be a paste or liquid mass, depending on the concentration of carbon nanotubes and the properties of the carrier medium. For example, a modifier with a concentration of carbon nanotubes of 1 mass. % based on the adhesive additive "Azole 1003" is a liquid, while an increase in the concentration of carbon nanotubes to 10 mass. % by weight of the modifier results in a paste-like consistency modifier.

At the second stage, the preparation of modified petroleum bitumen is carried out using the modifier described above.

The preparation of modified petroleum bitumen is carried out by introducing the above modifier into the original petroleum bitumen using a mixer, includes the following stages:

- heating the original oil bitumen to a temperature of 150-155 ° C;

- the introduction of a modifier with a given concentration of carbon nanotubes in a heated oil bitumen;

- mixing a mixture of petroleum bitumen with a modifier using a high shear mixer until the carbon nanotubes are evenly distributed in the volume of petroleum bitumen (until a homogeneous homogeneous mass is obtained);

- sample degassing in a pressure chamber (degasser).

The prepared samples of petroleum bitumen modified with carbon nanotubes (the concentration of carbon nanotubes varied within the range of 0.005-0.5 wt.% By weight of bitumen) were tested in the laboratory for compliance with the requirements of GOST 22245. The softening temperatures measured according to the main characteristics of the obtained modified petroleum bitumen were taken the method of "Rings and Ball" (KiS), the elasticity and adhesion of bitumen to the surface of crushed stone from acid rock.

Thus obtained modified petroleum bitumen is an independent product and can be used for various purposes, in particular, as part of an asphalt mix.

In the third stage, the preparation of the asphalt mixture based on the above modified petroleum bitumen is carried out.

The basis is the well-known method of preparing asphalt mix according to GOST 9128 3/4 84, in accordance with which the mineral components are mixed in mixing plants - crushed stone (or gravel) and sand with petroleum bitumen, taken in determined proportions.

The proposed method uses petroleum bitumen modified with single-walled carbon nanotubes, which are contained in an amount of 0.005-0.5 mass. % by weight of bitumen.

A mixture of mineral components and petroleum bitumen is mixed in specialized devices, after which the asphalt mixture is ready for use.

Modification of petroleum bitumen with carbon nanotubes in an amount of 0.005-0.5 mass. % by weight of bitumen leads to an increase in the softening temperature of the asphalt concrete pavement to 91 ° C, which is 2 times higher than the value for the initial bitumen grade BND 60/90 (control sample No. 7 in Table 1); the appearance of elastic properties at 25 ° C and at 0 ° C; a significant increase in the adhesive properties of petroleum bitumen.

Thus, the proposed technical solutions can improve the properties of the asphalt concrete pavement in the creation of which they participate, namely, to increase the softening temperature of the asphalt concrete pavement and increase its service life.

The invention is supported by the following examples of specific performance, which illustrate the invention, but do not limit them to themselves.

Example 1

At the first stage, a modifier for oil bitumen is prepared according to the following.

Single-walled carbon nanotubes are mixed with an adhesive additive based on the products of the interaction of tall oil with Adhesol 6 polyalkylpolyamine compounds when they are contained in a mixture of 1% by weight.

The prepared mixture of carbon nanotubes and an adhesive additive is machined using a three-roll mill.

The resulting modifier has a liquid consistency and consists of an adhesive additive and single-walled carbon nanotubes.

At the second stage, the preparation of modified oil bitumen is carried out.

The preparation of modified oil bitumen is carried out by introducing the obtained modifier (concentration of carbon nanotubes 1 wt.%) Into the original oil bitumen grade BND 60/90 produced by JSC Gazpromneft-Moscow Refinery. For this:

- heat the original oil bitumen to a temperature of 160 ° C;

- the modifier is mixed with heated oil bitumen in such a ratio that the content of single-walled carbon nanotubes in the finished modified oil bitumen is equal to 0.005 mass. %;

- mix this mixture using a Silverson L5M-A colloidal mill for 30 minutes at rpm 9100-10500;

- remove the bubbles of entrained air from the modified bitumen.

At the third stage, an asphalt mixture is prepared. To do this, prepare the mineral component of the mixture containing 65 mass. % crushed stone, 29 mass. % sand, and heated to 160 ° C, to which 6 masses were added. % of modified petroleum bitumen containing 0.005% of the mass of single-walled carbon nanotubes, also heated to 160 ° C. The prepared mixture is mixed in a mixing unit until uniform.

The resulting asphalt mixture is used as a road surface. The test results of the obtained modified samples of bitumen are presented in Table 1 (Column 1).

Asphalt concrete, including this bitumen, has a softening temperature of 55 ° C and a brittle temperature of 22 ° C.

Example 2

The same as in example 1, but the modifier is based on the adhesive additive "Azole 1002". The test results of the obtained modified samples of bitumen are presented in Table 1 (Column 2).

Asphalt concrete, including this bitumen, has a softening temperature of 57 ° C and a brittle temperature of 25 ° C.

Example 3

The same as in example 1, but the modifier is made on the basis of the adhesive additive "Azole 1003". The test results of the obtained modified samples of bitumen are presented in Table 1 (Column 3).

Asphalt concrete, including this bitumen, has a softening temperature of 57 ° C and a brittle temperature of 22 ° C.

Example 4

The same as in example 1, but the content of single-walled carbon nanotubes in oil bitumen is 0.5 mass. % The test results of the obtained modified samples of bitumen are presented in Table 1 (Column 4).

Asphalt concrete, including this bitumen, has a softening temperature of 77 ° C and a brittle temperature of 28 ° C.

Example 5

The same as in example 1, but the modifier is made on the basis of the adhesive additive "Azol 1002" with the content of single-walled carbon nanotubes in oil bitumen equal to 0.5 mass. %

The test results of the obtained modified samples of bitumen are presented in Table 1 (Column 5).

Asphalt concrete, including this bitumen, has a softening temperature of 79 ° C and a fragility temperature of 28 ° C.

Example 6

The same as in example 1, but the modifier is based on the adhesive additive "Azol 1003" with a content of single-walled carbon nanotubes in oil bitumen equal to 0.5 mass. %

The test results of the obtained modified samples of bitumen are presented in Table 1 (Column 6).

Asphalt concrete, including this bitumen, has a softening temperature of 93 ° C and a fragility temperature of 15 ° C.

Example 7

Same as in example 1, but petroleum bitumen does not contain carbon nanotubes, i.e. control sample.

The test results of the obtained unmodified samples of bitumen are presented in Table 1 (Column 7).

Asphalt concrete, including this bitumen, has a softening temperature of 50 ° C and a brittle temperature of 20 ° C.

Claims (3)

1. Asphalt mixture, including crushed stone, sand and oil road bitumen, modified with single-walled carbon nanotubes, characterized in that the said bitumen contains carbon nanotubes in an amount of 0.005-0.5 mass. %, as well as an adhesive additive based on natural products and phosphatides of vegetable oils, or based on amidoamines and imidazolines of fatty acids, or based on the products of the interaction of tall oil with polyalkylpolyamine compounds. 2. Modified oil road bitumen containing single-walled carbon nanotubes, characterized in that it contains carbon nanotubes in an amount of 0.005-0.5 mass. %, as well as an adhesive additive based on natural products and phosphatides of vegetable oils, or based on amidoamines and imidazolines of fatty acids, or based on the products of the interaction of tall oil with polyalkylpolyamine compounds. 3. A modifier for petroleum bitumen containing an adhesive additive and a nanodispersed component, characterized in that the nanodispersed component is single-walled carbon nanotubes contained in an amount of 1-10 mass. %, and the adhesive additive is selected from a number of substances based on natural products and phosphatides of vegetable oils, or based on amidoamines and imidazolines of fatty acids, or based on the products of the interaction of tall oil with polyalkylpolyamine compounds.