RU2655334C2 - Composite rubber-bituminous binder and method of its obtaining - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the preparation of composite rubber-bituminous binders. Composite rubber-bituminous binders can be used in road construction to produce asphalt-concrete and bituminous-mineral mixtures, black crushed-stone, strengthening of soils and mixtures of stone materials, undercoat base, in industrial and civil construction - to conduct roofing and waterproofing works, to obtain rolled waterproofing materials and rubber-bituminous mastics. Method for preparing the composite rubber-bituminous binder is a preliminary thermomechanical treatment of rubber crumbs up to 1.5 mm in size from 30 to 60 % by weight in a construction bitumen binder of CB (construction bitumen) 60/90 or CB 90/130 grade in amount of 30 to 60 % by weight and a petroleum oil having an aromatic hydrocarbon content of at least 50 % by weight in an amount of 10 to 25 % by weight, to form a concentrated suspension of a rubber-bituminous composite, followed by thermomechanical mixing of the concentrated suspension of the rubber-bituminous composite in an amount of 30 to 60 % by weight with construction bitumen binder of CB 60/90 or CB 90/130 grade in an amount of 40 to 70 % by weight.

EFFECT: technical result of the invention is the expansion of the assortment of rubber-bituminous compositions with improved physicochemical characteristics (reduced brittleness temperature, high softening temperature and elasticity, good adhesion to the surface of stone materials, concretes, metals and other materials) obtained in bitumen boilers equipped with a stirring device, in the composition of which, there are no components having a hazard class for human exposure higher than the original petroleum bitumen.

1 cl, 2 tbl, 2 ex

Description

The invention relates to the production of composite rubber-bitumen binders containing viscous petroleum viscous road grades BND 60/90 and BND 90/130, crumb rubber from used car tires or other tire waste up to 1.5 mm in size and any petroleum oil with at least aromatic hydrocarbons 50 wt. % or any petroleum oil with an aromatic hydrocarbon content of at least 10 wt. % Composite rubber-bitumen binders can be used in road construction to produce asphalt concrete and bitumen-mineral mixtures, black gravel, soil and mixture of stone materials, priming the foundation, in industrial and civil construction - for roofing and waterproofing, obtaining rolled waterproofing materials and bitumen-rubber mastic.

Known bitumen composition, which is dissolved in bitumen devulcanized rubber, which is achieved by heating a mixture of bitumen, crumb rubber and additives of an organic base (aromatic or heteroaromatic amines, phosphines) in a sealed reactor (US Pat. Russia 2164927 C2, class C08L 95/00, publ. .: 04/10/2001). The method allows to obtain a homogeneous system with a low temperature of brittleness, however, the use of a sealed reactor involves working with excessive pressure and discontinuity of the process of obtaining a rubber-bitumen composite.

Known bitumen-rubber composition, including bitumen, hydrocarbon oil, liquid rubber and rubber crumb (US Pat. Russia 2162475 C2, CL C08L 95/00, publ.: 01/27/2001). The disadvantage of this asphalt mixture is its high cost due to the use of relatively expensive components of the bitumen-rubber composition: aromatic oil "SUNTEX" 790, butadiene rubber (in the present invention does not require the introduction of additional, expensive components to obtain improved physical and mechanical characteristics), as well as the complexity and the substantial duration of the cooking process.

Known modifying composition in accordance with patent RU 2458083 C1, C08L 95/00, publ.: 08/10/2012, D2. The specified modifying composition includes an active rubber powder up to 1 mm in size, a filler, which is ground mica or a mixture of ground mica and diatomite, containing from 15 to 25 wt. % ground mica, from 5 to 10 wt. % diatomite, from 1.0 to 2.5 wt. % adhesive and from 1.0 to 2.5 wt. % structuring additive. The disadvantages of this composition are the presence of toxic components (resins selected from phenol-formaldehyde resin, oligomeric epoxy ester resin, epoxy-diodian resin are used as an adhesive) and a narrow focus in accordance with the invention.

Known modifying composition in accordance with patent RU 2327719 C1, class. C08L 95/00, published: 06/27/2008. According to the specified method, the bitumen composition includes bitumen, vulcanized rubber crumb from used car tires and a naphthalene fraction of coal tar. The disadvantages of this composition and the method for its preparation are the complex technological process of its preparation using a screw device with a 1 mm diameter punch through dies, as well as the presence of a toxic component (naphthalene fraction of coal tar) in its composition.

A known method of obtaining a rubber-bitumen binder from uc. Benefits G.A. Bonchenko, “Asphalt Concrete. Shear resistance and polymer modification technology "," Engineering ", M., 1994, that the addition of rubber crumb to bitumen leads to improved elasticity, crack resistance and dynamic strength of asphalt concrete, as well as to a softening temperature, while the best quality of bitumen modification is achieved using oil residues with a high content of aromatic components for plasticization.

In contrast to the study. Benefits the amount of rubber crumb is 20%, while the author suggests using from 3 to 5%. The proposed amount of rubber crumb (20%) helps to optimize the rheological properties of the resulting binder. At the same time, the penetration depth of the needle increases, the softening temperature rises, the fragility temperature decreases, which leads to an increase in crack resistance and dynamic strength. Due to the higher content of the amount of crumb rubber, the structure is more durable, which also helps to increase the elasticity of the system.

Closest to the proposed invention is a composition obtained in accordance with patent RU 2509787 C2, class. C08L 95/00, published: 03/20/2014. The method allows to obtain a bitumen-rubber composition comprising bitumen, rubber crumb from crushed waste automobile tires with a particle size of up to 1 mm (up to 1.5 mm in the present invention) and petroleum oil with a viscosity of 0.005-1.6 Pa · s at 60 ° C. The ratio of the components is as follows, wt. %: rubber crumb - 8-20 (in the present invention from 30 to 60), petroleum oil - 2-12 (in the present invention from 10 to 25), bitumen - the rest (in the present invention from 30 to 60). It is possible to introduce a block copolymer of the type polystyrene-polybutadiene-polystyrene in an amount of up to 0.2-5.0 wt. %, ethylene vinyl acetate in an amount up to 0.2-5.0 wt. %, polybutadiene in an amount of up to 0.2-5.0 wt. % (in the present invention does not require the introduction of additional components to obtain high elasticity). The disadvantages of this composition are low elasticity (high elasticity is achieved only with the additional introduction of block copolymers such as polystyrene-polybutadiene-polystyrene, ethylene vinyl acetate or polybutadiene), lack of information about the quality of adhesion to the surface of stone materials and restrictions on the types and brands of oil bitumen used.

The technical result of the invention is to expand the range of bitumen-rubber compositions with improved physicochemical characteristics (low brittle temperature, high softening temperature and elasticity, good adhesion to the surface of stone materials, concrete, metals and other materials) obtained in bitumen boilers equipped with mixing a device, in which there are no components having a hazard class for exposure to the human body is higher than the original oil bitumen.

Composite rubber-bitumen binder, consisting of viscous oil road viscous grades BND 60/90 or BND 90/130, crumb rubber up to 1.5 mm in size and any petroleum oil with an aromatic content of at least 50 wt. %, characterized in that the production method is divided into two stages and consists in preliminary thermomechanical processing of rubber crumb size up to 1.5 mm in an amount of from 30 to 60 wt. % in the medium of bitumen oil road viscous grades BND 60/90 or BND 90/130 in an amount of from 30 to 60 wt. % and any petroleum oil with an aromatic hydrocarbon content of at least 50 wt. % in an amount of from 10 to 25 wt. % to obtain a concentrated suspension of rubber-bitumen composite, followed by thermomechanical mixing of the concentrated suspension of rubber-bitumen composite in an amount of from 30 to 60 wt. % with viscous oil road viscous grades BND 60/90 or BND 90/130 in an amount of from 40 to 70 wt. %

The invention is expressed in the selection of components, composition and method for producing a composite rubber-bitumen binder, different from the prototype in that the production method is divided into two stages and consists in preliminary thermomechanical processing of crumb rubber with a size of up to 1.5 mm in an amount of from 30 to 60 wt. % in the medium of bitumen oil road viscous grades BND 60/90 or BND 90/130 in an amount of from 30 to 60 wt. % and any petroleum oil with an aromatic hydrocarbon content of at least 50 wt. % in an amount of from 10 to 25 wt. % to obtain a concentrated suspension of rubber-bitumen composite, followed by thermomechanical mixing of the concentrated suspension of rubber-bitumen composite in an amount of from 30 to 60 wt. % with viscous oil road viscous grades BND 60/90 or BND 90/130 in an amount of from 40 to 70 wt. %

To obtain a composite rubber-bitumen binder, it is necessary to use petroleum oils with an aromatic hydrocarbon content of at least 50 wt. % and rubber crumb size not exceeding 1.5 mm. The actual flash point of the used petroleum oil, determined in an open crucible, must be at least 220 ° C.

To obtain a composite rubber-bitumen binder, viscous petroleum bitumen is used in accordance with GOST 22245-90 * or PNST 1-2012. The actual flash point of the used oil bitumen, determined in an open crucible, must be at least 220 ° C.

The claimed effect is achieved as follows: rubber crumbs up to 1.5 mm in size, having a temperature corresponding to the ambient temperature, in an amount of from 30 to 60 wt. % is added to the medium of bitumen oil road viscous grades BND 60/90 or BND 90/130 in an amount of from 30 to 60 wt. % and any petroleum oil with an aromatic hydrocarbon content of at least 50 wt. % in an amount of from 10 to 25 wt. %, heated in a bitumen boiler with constant stirring to a temperature of 200-210 ° C, after which the temperature of the mixture is brought to 195-205 ° C within 15-30 minutes and the mixture is continuously mixed for 1.5-2.0 hours with the formation concentrated suspension of rubber-bitumen composite. Immediately after receiving in a concentrated suspension of rubber-bitumen composite in an amount of from 30 to 60 wt. % add viscous petroleum bitumen or building petroleum bitumen or roofing petroleum bitumen or insulating petroleum bitumen in an amount of from 40 to 70 wt. % having a temperature of 80 to 205 ° C, the heating elements are turned off and the mixture is finally mixed for 10-15 minutes to obtain a composite rubber-bitumen binder. The heating temperature of the viscous petroleum road bitumen added to the concentrated suspension of the rubber-bitumen composite is prescribed so that the temperature of the finished composite rubber-bitumen binder is 150-170 ° C.

The separation of the cooking process into two stages with the formation of a concentrated suspension of rubber-bitumen composite contributes to a more uniform distribution of rubber crumb in the solvent, which eliminates the heterogeneity of the composition and promotes better mixing. As a result, heating together with bitumen does not allow overheating of bitumen, which also positively affects the entire structure of the binder.

This technology leads to the fact that specific chemical processes arise in the system that lead to the formation of new organic structures. The resulting organic systems contribute to the flow of chemical adhesive contacts with fillers, which significantly distinguishes it from the known compositions and leads to improved strength and performance properties (Table 2).

Example 1. The best option for implementing the method of obtaining.

Rubber crumb up to 1.5 mm in size, having a temperature corresponding to the ambient temperature, in an amount of from 30 to 60 wt. % is added to the medium of bitumen oil road viscous brand BND 90/130 in an amount of from 30 to 60 wt. % and oil PN-6Sh with an aromatic hydrocarbon content of at least 50 wt. % in an amount of from 10 to 25 wt. %, heated in a bitumen boiler with constant stirring to a temperature of 200-210 ° C, after which the temperature of the mixture is brought to 195-205 ° C within 15-30 minutes and the mixture is continuously mixed for 1.5-2.0 hours with the formation concentrated suspension of rubber-bitumen composite. Immediately after receiving in a concentrated suspension of rubber-bitumen composite in an amount of from 30 to 60 wt. % add bitumen oil road viscous brand BND 90/130 in an amount of from 40 to 70 wt. % having a temperature of 80 to 160 ° C, the heating elements are turned off and the mixture is finally mixed for 10-15 minutes to obtain a composite rubber-bitumen binder.

Example 2. A valid variant of the method of obtaining.

On Wednesday, bitumen oil road viscous brand BND 60/90 in an amount of from 30 to 60 wt. % and oil MS-20 with an aromatic hydrocarbon content of at least 50 wt. % in an amount of from 10 to 25 wt. %, heated in a bitumen boiler with constant stirring to a temperature of 200-210 ° C, add crumb rubber up to 1.5 mm in size, having a temperature corresponding to the ambient temperature, in an amount of from 10 to 20 wt. %, the mixture is continuously stirred for 10-20 minutes, rubber crumb is re-added up to 1.5 mm in size, having a temperature corresponding to the ambient temperature, in an amount of 10 to 20 wt. %, the mixture is continuously stirred for 30-40 minutes, rubber crumb is re-added up to 1.5 mm in size, having a temperature corresponding to the ambient temperature, in an amount of 10 to 20 wt. %, the mixture is continuously stirred for 50-60 minutes with the formation of a concentrated suspension of rubber-bitumen composite. The total content of rubber crumb in a concentrated suspension of rubber-bitumen composite should be from 30 to 60 wt. % Immediately after receiving in a concentrated suspension of rubber-bitumen composite in an amount of from 30 to 60 wt. % add bitumen oil road grade BN 60/90 in an amount of from 40 to 70 wt. % having a temperature of 80 to 170 ° C, the heating elements are turned off and the mixture is finally mixed for 10-15 minutes to obtain a composite rubber-bitumen binder.

These compositions contribute to the chemisorption interaction of crumb rubber, with the formation of chemisorption bridge bonds with bitumen. Especially presented compositions affect the adsorption capacity of the main rocks, which allows to improve the complex technological and operational properties of the coating.

In accordance with the theory of dispersed structures P.A. Rebinder these compounds contribute to improved adhesion to stone materials, while increasing the corrosion resistance of the coating, significantly reduces the formation and increases the durability of road structures.

The content in the oil in an amount of from 10 to 25 wt. % leads to a minimum dilution of the claimed composition, which allows to optimize the amount of the liquid phase, which makes it possible to reduce ductility and obtain the structural frame of the resulting binder.

The claimed effect is due to the division of the process of obtaining a composite rubber-bitumen binder into two stages with the intermediate production of a concentrated suspension of rubber-bitumen composite. The optimal ratio of petroleum bitumen, petroleum oil and rubber crumb in a concentrated suspension of rubber-bitumen composite at a given temperature-time treatment conditions determines the good wettability of the rubber crumb, its swelling and partial dissolution with the formation of rubber-containing components that improve the physicochemical properties of composite rubber-bituminous binders. Mixing a concentrated suspension of a rubber-bitumen composite with oil bitumen at the second stage of obtaining composite rubber-bitumen binders contributes to the most sparing regime of high-temperature exposure to oil bitumen, since long-term high-temperature exposure to oil bitumen worsens its properties and promotes rapid aging.

Some compositions of composite rubber-bitumen binders and temperature-time regimes for their preparation are presented in table 1.

Notes:

BND1 - viscous oil road bitumen grade BND 60/90;

BND2 - viscous oil road bitumen grade BND 90/130;

M1 - petroleum oil PN-6Sh;

M2 - oil MS-20;

P1 - rubber crumb size less than 1.0 mm;

P2 - rubber crumb size less than 1.5 mm;

RBV - composite rubber-bitumen binder;

C - concentrated suspension of rubber-bitumen composite.

Composite rubber-bitumen binders are tested according to GOST 11501, GOST 11505, GOST 11506, GOST 11507, GOST 11508, GOST 18180. Table 2 shows the physicochemical properties of composite rubber-bitumen binders, the compositions of which correspond to the data presented in table 1, in comparison with the prototype.

Notes: n / a - no data; PR is a prototype.

The use of the invention allows to obtain composite rubber-bitumen binders having comparable, and in some indicators (elasticity, fragility temperature according to Fraas) improved physico-chemical parameters compared with the known rubber-bitumen compositions.

The invention improves the durability of asphalt concrete and bitumen-mineral mixtures, structural layers of road pavement of roads made of black gravel, soil and stone materials reinforced with organic binders, built-up roofs of buildings and structures, waterproofing layers. In addition, it contributes to the protection of the environment through the disposal of rubber waste.

The predominant use of the proposed composite rubber-bitumen binder, unlike analogues, is:

- the presence of only three components having a hazard class for exposure to the human body is not higher than that of the original bitumen;

- the possibility of obtaining standard bitumen equipment without upgrading it;

- maximum preservation of the properties of oil bitumen, a significant slowdown in their aging in the process of obtaining;

- ensuring high elasticity without additional introduction of polymers from the class of thermoplastic elastomers;

- providing high adhesion to the surface of stone materials, concretes, metals and other materials without the additional introduction of surface-active substances.

Claims (1)

A method of obtaining a composite rubber-bitumen binder, characterized in that it consists in preliminary thermomechanical processing of rubber crumb size up to 1.5 mm in an amount of from 30 to 60 wt.% In the medium of bitumen oil road viscous grade BND 60/90 or BND 90/130 in the amount from 30 to 60 wt.% and petroleum oil with an aromatic hydrocarbon content of at least 50 wt.% in an amount of 10 to 25 wt.% to obtain a concentrated suspension of rubber-bitumen composite, followed by thermomechanical mixing of the concentrated suspension and rubber-bitumen composite in an amount of from 30 to 60 wt.% with viscous oil road viscosity grade BND 60/90 or BND 90/130 in an amount of from 40 to 70 wt.%.