RU2550888C2 - Production of rubber-bitumen compound - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to construction materials and can be used for road construction, roofing, insulating and sealing jobs. In compliance with this invention, the mix of rubber chips and bitumen is activated by ultrasound at the following ratio, wt %: rubber chips - 13-15, bitumen making the rest. If required, rubber chips are introduced to bitumen heated to 180°C in the mixer. Said mix is missed for at least 10 minutes and activated by ultrasound unless rubber-bitumen compound results.

EFFECT: better softening and brittleness temperatures under severe climatic conditions.

7 cl, 1 tbl, 9 ex

Description

The invention relates to building materials with a wide range of applications and can be used for road, roofing, insulation, sealing works.

The most important characteristics of binders for building materials are temperature characteristics - softening temperature and brittleness temperature. The softening temperature of the binder determines the resistance to rutting (for example, asphalt concrete).

The temperature of binder brittleness to a large extent determines the crack resistance at low temperatures.

It is considered to be the following. The softening temperature should be at least 25 ° C higher than the highest temperature in the year in the region. The fragility temperature should not be higher than the lowest temperature of the year in this region.

Known polymer bitumen modifier, obtained in a convenient form for transportation and direct introduction into the bitumen mass at the place of its use in road construction with low brittle temperature and high softening temperature (patent RU 2158742, C1 2000), containing:

Road bitumen BND 60/90 or 90/130 50-80 Rubber crumb 10-25 Synthetic polyisoprene rubber SKI-3 1-5 A copolymer of ethylene with propylene or high-pressure polyethylene 1-10 Mineral oil (solar, industrial oil I-8A, naftaplast) 1-15

A significant drawback of this polymer modifier is that the problem is solved in that, as a modifying additive, the bitumen modifier additionally contains, in addition to crumb rubber, polymers - polyisoprene rubber and a copolymer of ethylene with propylene or high-pressure polyethylene PVED. This suggests that the potential inherent in the rubber tire waste associated with the devulcanization of rubber is not used.

Known rubber-containing polymer bitumen modifier (see RU No. 2266934, C08L 95/00, 2004), which includes bitumen, polyethylene, rubber crumb, fuel oil is used as a plasticizing agent, and building lime is used as a devulcanizing inorganic compound, while the polyethylene is introduced secondary to both low and high pressure. The modifier contains, wt.%: Bitumen BND 60/90 47-62, fuel oil grade 100 2-5, crumb rubber 30-35, secondary polyethylene (PE) 3-7, building lime 3.0-6.0.

The disadvantages of this invention are its complex composition, including 5 components (including an additional polymer and plasticizer) and low achievable brittle temperatures. The introduction of an additional polymer, secondary polyethylene, is explained by the low level of rubber crumb devulcanization, in which a sufficient amount of rubbers does not enter the bulk phase.

A known method of preparing a rubber-bitumen composition (see RU 2448134 C1, 2010). According to this invention, a method for preparing a rubber-bitumen composition comprises preparing a mixture of bitumen, rubber crumb and a plasticizer, characterized in that maleic anhydride is additionally used in the mixture, while vegetable oil is used as a plasticizer, and the above components are used in the composition in the following ratio, wt . %:

Rubber crumb 12.0-15.0 Plasticizer 5.0-20.0 Maleic Anhydride 0.3-0.5 Bitumen rest

The performance characteristics of the resulting rubber-bitumen compositions alone are quite high. But in combination, certain disadvantages are observed. So, at an excellent low temperature of brittleness (-55 ° C), the softening temperature of the composition is insufficient (44 ° C). And at the highest softening point (62 ° C), the fragility temperature is only -30 ° C.

In addition, vegetable oil is used as a plasticizer, which is a food product and, therefore, scarce.

Known modifying composition for asphalt mixtures and a method for producing a modified asphalt mix (RU No. 2377262, C08J 11/06, С04В 26/26, 2006). According to this invention, the modifying composition for asphalt mixtures contains active rubber powder with a particle size of not more than 0.8 mm and with a specific geometric surface of at least 5000 cm ² / g, obtained by thermomechanical grinding of rubber vulcanizate in the presence of an anti-agglomerator selected from the group: paraffin , ozokerite and halogen-containing telomeric alcohols in an amount of 0.1-2.0% by weight of rubber vulcanizate, as well as needle-shaped metasilicate, a gelation initiator selected from the group: 4 ro-N-methylaniline, N-methyl-N, 4-dinitrosoaniline, N- (2-methyl-2-nitropropyl) -4-nitrosoaniline, N-nitrosodiphenylamine and at least one structuring agent with an increased induction period of structuring is not less than 30 min at a temperature of 160 ° C, selected from the group: oligomeric epoxy ester resin, epoxydianine resin, polycondensation resin, which promotes the formation of branched or mesh structures.

Since the main operational properties of asphalt concrete are mainly determined by the physicomechanical parameters of the binder, all modifiers (including polymer) introduced during the production of asphalt concrete are modifiers of the initial bitumen. Mixing with bitumen, they create a polymer-bitumen binder, which determines the properties of asphalt concrete.

However, for some reason, the authors of the invention, unfortunately, do not give the physicomechanical parameters of the resulting polymer-bitumen binder (although they give the indicators of the initial bitumen). It is noteworthy that, in addition to previously specially activated rubber crumb, the authors of the invention included polymers selected from the group: oligomeric epoxy ester resin, epoxydianide resin, polycondensation resin, which promotes the formation of branched or mesh structures.

This indicates that specially activated rubber powder does not create a spatial polymer structure in bitumen, which makes it possible to obtain a polymer binder with sufficiently high physical and mechanical characteristics (in particular, temperature).

Close in technical essence is the method of preparing a rubber-bitumen composition adopted for the prototype, including the preparation of a mixture of bitumen, rubber crumb and plasticizer (see RU No. 2178434, C08L 95/00, C08K 5/32, C08K 5/14, C04B 26/26, C08L 17/00, 2002).

A mixture of a compound or compounds selected from the group of nitrons capable of forming stable radicals and peroxide compounds is additionally introduced into the composition. Rubber is used in the form of distinguishable partially degraded particles and products of its destruction, contained in an amount of not less than 0.5 wt.% Calculated on the rubber before destruction. The rubber particles contain unsaturated bonds in an amount of at least 2% of the total number of bonds. The composition further comprises a mixture of the above nitron and peroxide compound, taken in a mass ratio of nitrons: peroxide compound from 3: 1 to 10: 1, respectively. The listed components are used in the following amounts: the above mixture of nitrons and peroxide compounds - 1-2 wt.%, The above mixture of rubber and products of its destruction - 5-30 wt.%, Bitumen - up to 100 wt.%.

The individual physicomechanical characteristics of this known bituminous composition are quite high, but the disadvantage of this solution is manifested in an unsatisfactory set of parameters such as softening and brittleness temperatures and elasticity. In particular, if the best indicator of brittleness temperature is reached (-28 ° C), then an unsatisfactory softening temperature (+ 50 ° C) corresponds to it, and if the best indicator of softening temperature (+ 92 ° C) is reached, then an unsatisfactory temperature of brittleness corresponds to it ( -18 ° C). And in all cases, the elasticity is very low (no more than 35%). Thus, the composition obtained in the framework of the known method cannot effectively work in the composition of coatings in harsh climatic conditions (at outdoor temperatures below -30 ° C and above + 30 ° C). Moreover, taking into account the influence of solar radiation leads to the requirements that the softening temperature of the binder be at least 55 ° C.

All of the analogues listed above are characterized by a fundamental common drawback - upon receipt of rubber-bitumen binders, the potential inherent in the rubber crumb of tire waste is not fully realized. This is mainly determined by the small amount of rubber formed during the rubber devulcanization. This, in particular, is reflected in the receipt of unsatisfactory brittle temperatures. The reason is that the amount of rubber is not enough to plasticize the composition, so you have to additionally introduce a plasticizer.

In other words, in analogues, the efficiency of devulcanization of rubber crumb of tire waste is insufficient. The efficiency of using rubber crumb of tire waste is determined by the amount of rubber formed as a result of rubber devulcanization. These molecules are a dispersed phase and form a polymer spatial network in the volume of bitumen (dispersed medium). With a certain number of rubber molecules in a given volume of the dispersion medium (bitumen), “saturation” of the bonds between them is achieved. In this case, the maximum value of the softening temperature of the rubber-bitumen composition is observed, but the fragility temperature remains almost like that of the initial bitumen. With a further increase in the number of rubber molecules in the bulk phase, their “excess” occurs, which is not included in the polymer spatial network. This "excess" of rubber plasticizes the composition. Moreover, the greater the "excess" of rubber molecules, the stronger the plasticization. This is expressed in the temperature characteristics of the bituminous compositions — at the same time lowering the softening and fragility temperatures.

The problem to which the claimed solution is directed is to provide the possibility of obtaining a rubber-bitumen composition with elevated softening and brittle temperatures, stored in harsh climatic conditions under high mechanical stresses.

The technical result achieved by solving the problem is expressed in providing the ability to obtain materials that effectively "work" in harsh climatic conditions (at outdoor temperatures below -30 ° C and above + 30 ° C) with increased mechanical loads in a wide range of building and road constructions.

The problem is solved in that: 1. A method of preparing a rubber-bitumen composition, including the preparation of a mixture of bitumen with crumb rubber, is characterized in that this mixture is additionally activated by ultrasound, and the above components are used in the composition in the following ratio, wt.%:

Rubber crumb  13.0-50.0 Bitumen  rest

in addition, during the preparation of the rubber-bitumen composition, rubber crumb is introduced in certain portions into the bitumen preheated to 180 ° C in the mixer, each time is mixed for at least 10 minutes and the mixture is activated by sonication, and these operations are performed until the rubber-bitumen composition of the given composition is obtained.

In addition, they use bitumen grade BND 90/130.

In addition, use rubber crumb tire waste fractions up to 1.5 mm without additional processing.

In addition, use a mixer made with the possibility of heating the mixture to 200 ° C.

In addition, the time of ultrasonic activation and the power of ultrasound are interconnected and depend on the mass of the mixture.

In addition, the process of preparing the rubber-bitumen composition is carried out at a temperature of at least 180 ° C.

In addition, the ultrasonic treatment of the mixture is carried out until the destruction and dispersion of the rubber crumb is completed, which is detected by controlling the viscosity of the mixture.

According to this scheme for producing an activated rubber-bitumen composition, the processing of a mixture of bitumen with crumb rubber is carried out by a powerful tool of nanotechnology - ultrasound [Khmelev V.N. The use of high-intensity ultrasound in industry / V.N.Khmelev, A.N. Slivin, R.V. Barsukov, S.N. Tsyganok, A.V. Shalunov. Alt. state tech. un-t, BTI. - Biysk: Publishing house Alt. state tech. University, 2010. 203 p.]. In this case, ultrasonic devices with submersible waveguides are used.

Moreover, under the influence of powerful cavitation phenomena in rubber, the bonds sulfur-carbon and carbon-carbon break [V.O. Abramov, O.V. Abramov, F.S. Dyachkovsky, D.F. Dyachkovsky, O.M. Gradov, J.V. Perlina, D.R. Razgon, T. Faust. Ultrasonic devulcanization of rubber (experimental studies), g. “Material Science”, 2005, No. 1, pp. 3-9.]. The results of our studies show that this leads to significant destruction of rubber crumb, as well as dispersion of the rubber molecules resulting from this to micro- and nanoscale [Gordey K. Korneychuk, Andrey K. Runov, Research De-vulcanization of Tires Rubber in an Ultrasonic Field Proceeding on the 13th International Conference and Seminar on Micro / Nanotechnologies and Electron Devices EDM 2012. P.94-98].

The process of developed cavitation under the action of ultrasound occurs only in a liquid medium, therefore, in the developed Method, a liquid substance is specially supported.

The proposed method for producing rubber-bitumen compositions using significant amounts of rubber crumb (up to 50%) uses the fact that ultrasonic treatment of mixtures of bitumen with rubber crumb significantly reduces the viscosity of the mixtures.

The latter allows the "stepwise" addition of rubber crumb followed by sonication of the mixture, so that the viscosity of the liquid mixture is kept sufficiently low throughout the process.

A comparative analysis of the features of the claimed solution with the signs of the prototype and analogues indicates the conformity of the claimed solution to the criterion of "novelty."

Signs indicating that “the mixture is additionally activated by ultrasound” provide high efficiency for the devulcanization of rubber crumb with the entry of a large number of rubber molecules (dispersed phase) into the bulk phase — a dispersion medium (bitumen), which not only provides the formation of a polymer spatial network, but also plasticization bitumen to a level that makes it possible to obtain lower temperature fragility of the composition. In addition, under the influence of powerful cavitation forces, the rubber crumb is destroyed and dispersed into very small discretely activated particles. Discrete activated rubber particles formed have an activated surface due to functional groups with unsaturated bonds. This leads to the fact that these particles bind to rubber molecules already in the bulk phase, creating a polymer spatial network with them, filling the dispersion medium - bitumen. However, the "excess" of discretely activated rubber particles, like the "excess" of rubber molecules, has a plasticizing effect. On the other hand, as a result of dispersion of the rubber crumb, the rubber pores are destroyed and the bitumen filling them (as a result of which the rubber crumb swells) replenishes the bulk phase. In addition, due to the devulcanization of rubber, the resulting rubber molecules are in turn dispersed under the influence of ultrasonic cavitation. Due to this, the viscosity of the resulting bituminous composition decreases sharply and, therefore, its manufacturability improves.

It should be noted that the study of the effect of ultrasonic treatment on the temperature characteristics of the initial bitumen BND 90/130 showed that their values did not change - they were as before the ultrasonic treatment (T _p = 51 ° C and T _xp = -20 ° C) . This fact confirms that the mechanism of action of ultrasound on a mixture of bitumen with rubber crumb is associated only with cavitation processes leading to the destruction and dispersion of rubber crumb and the resulting rubber molecules.

The effect of ultrasonic treatment can be judged by comparing the following experimental results. The resulting rubber-bitumen composition with only thermomechanical action at a temperature of 180 ° C had the following characteristics: T _p = 144 ° C, T _xp = -15 ° C, elasticity, penetration at 25 ° C P ²⁵ = 30 c.u.

The resulting rubber-bitumen composition according to the proposed method with ultrasonic treatment at the same temperature had the following characteristics: T _p = 68 ° C, T _xp = -35 ° C, P ²⁵ = 62.

It can be seen from the above example that the penetration of the composition doubled, i.e. the viscosity of the composition in the liquid state decreased significantly.

As a result of ultrasonic activation of a mixture of bitumen and rubber crumb, a rubber-bitumen composition is formed with a sufficiently high brittle temperature, satisfying the set criteria (should be lower than -30 ° C).

The “exit” of the bitumen concentration value beyond the lower limit of the declared range (below 50% - when the rubber crumb value is displayed above 50%) reduces the waterproofing properties of the composition, and the “exit” of the bitumen concentration value beyond the upper limit of the declared range (above 87% - when the value is displayed concentrations of crumb rubber below 13%) leads to the formation of a coating with insufficient brittle temperature.

Signs indicating that the temperature of the mixture, including bitumen and rubber crumb, 180 ° C (and then ultrasonic treatment) “support until the composition is finished” provide sufficient speed for the composition preparation process and at the same time exclude the loss of some components due to evaporation when the temperature is exceeded .

A sign indicating that "the operation of mixing the mixture with rubber crumb is conducted for at least 10 minutes", ensures uniform distribution of rubber crumb in the bitumen. Exceeding this indicator leads to an unjustified increase in the energy intensity of the mixture preparation process.

The features of the third claim, specifying the characteristics of rubber crumb (lack of additional processing and particle size), minimize the cost of the component due to the lack of additional mechanical processing and at the same time (by minimizing particle size) provide a reduction in the duration of the process of its devulcanization.

To prepare the composition, use: bitumen grade BND 90/130 (GOST 22245-90) - road oil bitumen; rubber crumb - a tire waste product, fraction up to 1.5 mm.

To prepare the composition, devices of known design are used, made in the form of a container equipped with a paddle mixer and means for maintaining the temperature regime of at least 200 ° C.

For ultrasonic treatment, ultrasonic devices with submersible waveguides are used. Possible use and flow apparatus.

The composition is prepared and used as follows.

When preparing and using the composition, the following set of safety measures must be observed:

- employees must be provided with personal protective equipment in accordance with GOST 12.4.103 (overalls, aprons, leather boots, respiratory protection equipment - respirators with an aerosol filter, goggles for eye protection);

- work associated with the use of the composition should be carried out in accordance with the "Sanitary rules for the organization of technological processes and hygienic requirements for production equipment" GOST 12.3.002, GOST 12.3.035;

- work related to the preparation and use of the composition in enclosed spaces should only be carried out with continuously operating supply and exhaust ventilation or with the use of respiratory protection, while the use of open flame is prohibited;

- when working in enclosed spaces, the use of luminaires only in explosion-proof design is permitted;

- Before starting work, it is necessary to check the serviceability of electrical equipment and the presence of grounding in order to avoid sparking.

The invention is illustrated, but not limited to, by the following examples.

Note. Before preparing rubber-bitumen mixtures, the rubber crumb of tire waste is dried to a constant weight at a temperature of at least 120 ° C.

Example 1. 135 g of BND 90/130 grade bitumen are placed in a mixer and heated to a temperature of 180 ° C. Then, 15 g (10 wt.%) Of crumb rubber is introduced therein, the resulting mixture is stirred at a speed of 200 rpm for 10 minutes. Next, the resulting mixture is activated for 30 minutes with an ultrasonic power of 150 W using an ultrasonic apparatus with an immersion waveguide. Then, to increase the uniformity of the mixture, it is stirred at a speed of 200 rpm for 10 minutes.

After that, the resulting rubber-bitumen composition is ready for further use.

Example 2. 140.5 g of bitumen grade BND 90/130 are placed in a mixer and heated to a temperature of 180 ° C. Then, 19.5 g (13 wt.%) Of crumb rubber is introduced therein, the resulting mixture is stirred at a speed of 200 rpm for 10 minutes. Next, the resulting mixture is activated for 30 minutes with an ultrasonic power of 150 W using an ultrasonic apparatus with an immersion waveguide. Then, to increase the uniformity of the mixture, it is stirred at a speed of 200 rpm for 10 minutes.

After that, the resulting rubber-bitumen composition is ready for further use.

Example 3. 127.5 g of bitumen grade BND 90/130 are placed in the mixer and heated to a temperature of 180 ° C. Then 22.5 g (15 wt.%) Of crumb rubber is introduced therein, the resulting mixture is stirred at a speed of 200 rpm for 10 minutes. Next, the resulting mixture is activated for 30 minutes with an ultrasonic power of 150 W using an ultrasonic apparatus with an immersed waveguide. Then, to increase the uniformity of the mixture, it is stirred at a speed of 200 rpm for 10 minutes.

After that, the resulting rubber-bitumen composition is ready for further use.

Example 4. In a mixer placed 117 g of bitumen grade BND 90/130 and heated to a temperature of 180 ° C. Then, 33 g (22 wt.%) Of crumb rubber is introduced therein, the resulting mixture is stirred at a speed of 200 rpm for 10 minutes. Next, the resulting mixture is activated for 30 minutes with an ultrasonic power of 150 W using an ultrasonic apparatus with an immersion waveguide. Then, to increase the uniformity of the mixture, it is stirred at a speed of 200 rpm for 10 minutes.

After that, the resulting rubber-bitumen composition is ready for further use.

Example 5. 225 g of BND 90/130 grade bitumen are placed in a mixer and heated to a temperature of 180 ° C. Then, 75 g (25 wt.%) Of crumb rubber is introduced therein, the resulting mixture is stirred at a speed of 200 rpm for 10 minutes. Next, the resulting mixture is activated for 60 minutes with an ultrasonic power of 150 W using an ultrasonic apparatus with a submersible waveguide. Then, to increase the uniformity of the mixture, it is stirred at a speed of 200 rpm for 10 minutes.

After that, the resulting rubber-bitumen composition is ready for further use.

Example 6. 105 g of BND 90/130 grade bitumen are placed in a mixer and heated to a temperature of 180 ° C. Then, 45 g (30 wt.%) Rubber crumbs are introduced in portions, the resulting mixture is stirred at a speed of 200 rpm for 10 minutes. Next, the resulting mixture is activated for 30 minutes with an ultrasonic power of 150 W using an ultrasonic apparatus with an immersion waveguide. Then, to increase the uniformity of the mixture, it is stirred at a speed of 200 rpm for 10 minutes.

After that, the resulting rubber-bitumen composition is ready for further use.

Example 7. In the mixer, 90 g of bitumen grade BND 90/130 is placed and heated to a temperature of 180 ° C. Then 60 g (40 wt.%) Of crumb rubber are introduced in portions as follows. 30 g of rubber crumb is introduced forward (obtaining a mixture with 25 wt.%), The resulting mixture is stirred at a speed of 200 rpm for 10 minutes, and then 10 minutes is activated with an ultrasonic power of 150 W using an ultrasonic apparatus with an immersed waveguide. Then, to increase the homogeneity of the mixture, it is mixed at a speed of 200 rpm for 5 minutes. Then, three more times 10 g of rubber crumb is successively introduced, each time repeating the previous operations of thermomechanical and ultrasonic treatment of the mixture. After such a “step-by-step” introduction of rubber crumb and subsequent processing of the mixture, the composition is ready for further use.

Example 8. In a mixer placed 75 g of bitumen grade BND 90/130 and heated to a temperature of 180 ° C. Then, 75 g (50 wt.%) Of crumb rubber is introduced in portions as follows. 30 g of rubber crumb is introduced forward (obtaining, approximately, a mixture with 28.6 wt.%), The resulting mixture is stirred at a speed of 200 rpm for 10 minutes, and then activated for 10 minutes with an ultrasonic power of 150 W using an ultrasonic apparatus with an immersion waveguide. Then, to increase the homogeneity of the mixture, it is mixed at a speed of 200 rpm for 5 minutes. Then, three more g of rubber crumb is introduced three more times successively, each time repeating all previous operations of thermomechanical and ultrasonic treatment of the mixture. After such a “step-by-step” introduction of rubber crumb and subsequent processing of the mixture, the composition is ready for further use.

Example 9. In a mixer, 75 g of bitumen grade BND 90/130 is placed and heated to a temperature of 180 ° C. Then 78.06 g (51 wt.%) Of crumb rubber are introduced therein in portions as follows. 30 g of rubber crumb is introduced forward (obtaining, approximately, a mixture with 27.6 wt.%), The resulting mixture is stirred at a speed of 200 rpm for 10 minutes, and then activated for 10 minutes with an ultrasonic power of 150 W using an ultrasonic apparatus with an immersion waveguide. Then, to increase the homogeneity of the mixture, it is mixed at a speed of 200 rpm for 5 minutes. Then, 16.2 g of rubber crumb is introduced three more times successively, each time repeating all previous operations of thermomechanical and ultrasonic treatment of the mixture. After such a “step-by-step” introduction of rubber crumb and subsequent processing of the mixture, the composition is ready for further use.

The measured temperature characteristics of the activated compositions, the compositions of which are shown in examples 1-9, are presented in table 1.

Table 1 Performance characteristics of bituminous composition Example No. Softening point, ° C Fragility temperature, С Plasticity Interval, ° C one 55 -25 80 2 74 -thirty 104 3 72 -31 109 four 70 -33 103 5 73 -35 103 6 76 -36 106 7 84 -38 114 8 96 -45 136 9 102 -47 157 Prototype fifty -28 78 Original bitumen BND 90/130 51 -20 ° C 71

Example No. 1 (see table 1) shows that the content in the mixture of rubber crumb in the amount of 10% does not provide the necessary brittleness temperature of the resulting rubber-bitumen composition.

Example No. 5 illustrates the feature of the claimed solution "In addition, the time of ultrasonic activation and the power of ultrasound are interconnected and depend on the mass of the mixture."

Example No. 9 shows that the upper limit of the concentration of rubber crumb in the mixture is limited by a very high softening point. From this example it is seen that the activated rubber-bitumen composition obtained from a mixture with a concentration of rubber crumb equal to 51% has a softening temperature of 102 ° C. Such a high softening temperature creates great technological difficulties for using the resulting composition, since it will require heating above 200 ° C to bring it into a liquid and fluid state.

The test results obtained according to the invention of rubber-bitumen compositions shown in the table show that they are characterized by much greater intervals of plasticity compared to similar characteristics of the prototype.

The advantage of the present invention over analogues and prototype is the increased cost-effectiveness of the rubber-bitumen composition obtained according to this invention by replacing part of bitumen, plasticizers and additional polymers with rubber crumb of tire waste, which is continuously replenished as a secondary product of the automotive industry (the amount of tire waste in the world and in Russia increases from every year).

It should also be borne in mind that the rubber crumb of tire waste contains valuable additives (for example, antioxidants), which, when degraded, under the action of ultrasound, pass into the bulk phase. As a result, there is no need to introduce special additives in the resulting activated rubber-bitumen composition.

The finished composition is used as a material for a wide range of applications - it can be used for road, roofing, insulation, sealing works. Moreover, it is preferable to use it in granular form, for example, in the form of an asphalt binder [A.V. Rudensky, A.L. Shumik. Strength properties of asphalt binders. “Building materials”, No. 6, 2008].

Claims (7)

1. A method of preparing a rubber-bitumen composition, including the preparation of a mixture of bitumen with crumb rubber, is characterized in that this mixture is additionally activated by ultrasound, and the above components in the composition are used in the following ratio, wt. %:
Rubber crumb 13.0-50.0 Bitumen rest
in addition, during the preparation of the rubber-bitumen composition, rubber crumb is introduced in portions if necessary into the bitumen preheated to 180 ° C in the mixer, each time mixed at a speed of 200 rpm for at least 10 minutes and the mixture is activated by sonication after each portion of the crumb is introduced, moreover these operations are carried out to obtain a rubber-bitumen composition. 2. The method according to p. 1, characterized in that they use bitumen grade BND 90/130. 3. The method according to p. 1, characterized in that the rubber crumb of tire waste fractions of up to 1.5 mm is used, while the rubber crumb is dried to a constant weight before preparing the rubber-bitumen mixture. 4. The method according to p. 1, characterized in that they use a mixer made with the possibility of heating the mixture to 200 ° C. 5. The method according to p. 1, characterized in that the time of ultrasonic activation and the power of ultrasound are interconnected and depend on the mass of the mixture. 6. The method according to p. 1, characterized in that the process of preparing a rubber-bitumen composition is carried out at a temperature of at least 180 ° C. 7. The method according to p. 1, characterized in that the ultrasonic treatment of the mixture is carried out until the destruction and dispersion of the rubber crumb, which is revealed by controlling the viscosity of the mixture.