RU2687940C2 - Bitumen composition effective at low temperature and at intermediate temperature - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a bitumen composition for coating roads or a highway, comprising: (a) from 20 to 90 wt. % of the total weight of said composition, at least one bitumen with needle penetration at 25 °C, greater than or equal to 600 tenths of millimeters, wherein value 900 tenths of millimeter is excluded, (b) from 9 to 70 % of the total weight of said composition, at least one blown bitumen with needle penetration at 25 °C, making from 10 to 50 tenths of millimeter, and (c) from 1 to 10 wt. % of the total weight of said composition, at least one cross-linkable polymer, where the polymer is selected from elastomers and/or plastomers, wherein percentages are based on the total weight of said composition, said bitumen composition demonstrates needle penetration value at 25 °C in range of 60 to 90 tenths of a millimeter, wherein said penetration values are measured according to standard NF EN 1426.

EFFECT: invention relates to bituminous binders, bitumen-mineral mixtures and roads or highways, in which characteristics at low temperature are especially improved while maintaining good characteristics at intermediate temperature.

25 cl, 5 tbl, 1 dwg

Description

The technical field to which the invention relates.

The present invention relates to the field of bitumen. In particular, the present invention relates to new bitumen compositions intended, in particular, to cover roads, highways, etc.

More specifically, the invention relates to bitumen compositions containing combinations of specific bitumens (mixtures) in combination with polymers, also special, and having good characteristics at different temperatures, in particular, improved or enhanced characteristics in environments where low temperatures occur, for example, winter season.

The invention also relates to asphalt binders, asphalt-mineral mixtures and roads or highways containing said asphalt compositions and having the same properties as these compositions.

The invention also relates to the use of these bitumen-mineral mixtures for obtaining roads or highways.

Technical context

In the field of asphalt pavements, the durability of the material, in particular, the bituminous composition, plays an important role. During the entire service life, the composition contained in asphalt pavements is subjected to various harmful physicochemical, mechanical, and weather effects, which make the coatings brittle and impair their overall characteristics.

At low temperatures (temperatures less than or equal to 0 ° C), the bitumen composition is brittle and brittle. This behavior causes such damage on the road or highway as the appearance of thermal cracks.

At an intermediate temperature (the operating temperature of the binder is from 25 ° C to 80 ° C), the bituminous composition has viscoelastic properties. In this viscoelastic state, too much mechanical stress (in particular, the weight of a heavy car) can lead to irreversible deformations of the coating (dents, pits, bumps and others). For example, the appearance of a well-known rut occurs due to the inability of the composition to resist irreversible deformation due to its viscous component.

During its entire life cycle on a road or highway and during cyclical seasonal changes, an ideal bitumen composition should be able to manifest its remarkable characteristics at both low and intermediate temperatures. In addition, the ideal composition should be able to maintain its characteristics for a long time, having good resistance to aging of its performance at low temperature.

The development of bitumen compositions containing bitumens that can simultaneously and adequately meet these many requirements is a very difficult problem to solve.

It is known that in practice bitumens can be classified according to the physical state in which they are located, which makes it possible to evaluate their consistency (associated with rheological properties). More specifically, bitumen can vary from state (or grade), which can be qualitatively qualified as rather “soft” (soft bitumen), to a condition (or grade) that qualifies as rather “hard” (solid bitumen), depending on the origin, composition and / or method of obtaining bitumen from oil. As is well known, this fundamental characteristic of bitumen consistency can be assessed more quantitatively by measurement, called "needle penetration", according to the standard test NF EN 1426 at 25 ° C (P ₂₅ ) or according to the standard Russian test GOST 11501-78 at 0 ° C. This characteristic of penetration is expressed in tenths of a millimeter (dmm). Needle penetration, measured at 25 ° C according to the standard test NF EN 1426, is a measure of needle penetration, the weight of which together with its support is 100 g, to a sample of bitumen over a period of 5 seconds. The norm NF EN 1426 replaced the similar NF T 66-004 of December 1986, and entered into force on December 20, 1999 (decision of the Director General of AFNOR, Association Française de Normalization of December 20, 1999). Needle penetration, measured at 0 ° C according to the standard Russian test GOST 11501-78, is a measure of needle penetration, the weight of which together with its support is 200 g, into a sample of bitumen over a period of 60 seconds.

Bitumen can also be characterized by its Brookfield dynamic viscosity, expressed in mPas and measured at 135 ° C, according to the standard test NF EN 13302.

This viscosity is measured on a Brookfield viscometer at 135 ° C. Needle penetration at 25 ° C, measured according to NF EN 1426, and Brookfield dynamic viscosity, measured according to NF EN 13302, are also related by the following equation: Penetration at 25 ° C = 423313 × viscosity ^-1.423 , where the viscosity expressed in mPa⋅s, and penetration at 25 ° C - in tenths of a millimeter.

Generally speaking, at a given temperature, the deeper the needle penetrates into the bitumen under study and the higher the penetration value, the more bitumen is qualified as “soft”. On the contrary, the smaller this needle penetrates into the bitumen under study and the lower the penetration value, the more bitumen is qualified as “hard”.

In attempts to solve the problems of improving bitumen compositions for use in road construction in the prior art it is proposed to use various bitumens in bitumen compositions:

- The use of soft bitumen makes it possible to improve performance at low temperatures, which results in a decrease in thermal cracking. However, the disadvantage of soft bitumen is a greater sensitivity to the intermediate temperature and, consequently, to the risk of rutting.

- The use of bitumen of the “hard” grade allows to improve the performance at an intermediate temperature due to the increased resistance to the occurrence of rutting, but to the detriment of brittleness at low temperature, manifested by an increase in thermal cracking.

- The use of "blown," or "half-blown," or "oxidized," or "air-blown," or "partially air-blown" (produced by injecting air into raw materials, usually consisting of distillates and heavy products formed during vacuum distillation of distillation residues atmospheric pressure, formed during the distillation of oil) allows to improve the performance at intermediate temperatures due to improved resistance to the occurrence of rutting. However, blown bitumen has a certain tendency to aging. In addition, since blown bitumens become harder than the original bitumen, their viscosity at a given temperature will be higher than that of the original bitumen. Likewise, in order to easily use blown bitumen, it must be brought to higher temperatures, which entails additional energy costs, the likely need for additional protection of workers and the danger of harmful smoke emissions.

- The addition of polymers to bitumens (such as bitumens modified with polymers) followed by a crosslinking process with a crosslinking agent can improve storage stability, elastic characteristics at 25 ° C, aging resistance and full durability of the bituminous composition. However, the applicant company has developed and patented a large number of cross-linked bitumen-polymer compositions, whose properties are markedly improved compared to non-polymer bitumen and compared to unstitched physical bitumen / polymer mixture. From the patents of the applicant, in particular, the following references can be cited: FR2376188, FR7818534, EP0799280, EP0690892. However, it was found that the addition of polymer to blown bitumen followed by cross-linking under uncontrolled conditions causes stability problems and does not allow for obtaining the entire set of desired characteristics.

- Finally, it is also known that, in order to improve the characteristics of bitumen at low temperature, an oil can be added as an additive to the composition as an additive, such as mineral base oil.

Patent application WO 00/78870 describes the use of oxidized bitumen and non-oxidized bitumen in bitumen-polymer compositions crosslinked to improve the physical properties of these compositions, in particular, to increase the softening temperature around the ring and ball (TBA) and Pfeiffer number (IP). In this document, non-oxidized bitumen preferably has penetration, according to the standard NF T 66008, in the range from 35 to 500 units, in particular, from 160 to 330. In the examples, non-oxidized bitumens with penetration in the range from 180 to 220 units are used.

Summary of Invention

Given this general context, the applicant company sought to develop new bitumen compositions that combine good characteristics at both low and intermediate temperatures, and, preferably, while maintaining an economically acceptable production cost.

The present invention relates, in particular, to bitumen compositions, the characteristics of which are particularly improved at low temperature while maintaining good characteristics at intermediate temperatures.

Another objective of the present invention is to propose bitumen compositions having improved aging resistance characteristics at low temperature.

Another objective of the present invention is to propose bitumen compositions having good storage stability.

In particular, the present invention relates to bituminous compositions not containing or essentially not containing oil, improving compatibility, such as mineral base oil.

Another objective of the present invention is to propose a method for producing a bitumen composition that is reliable, reproducible, and corresponding to production rates, and which allows a ready-to-use, competitive product to be obtained that is stable during storage.

In particular, one of the objectives of the present invention is to propose bitumen binders, bitumen-mineral mixtures and roads or highways, obtained on the basis of the bitumen compositions indicated, combining good characteristics both at low temperature and intermediate temperature, while preferably economically acceptable production cost.

In particular, the present invention relates to asphalt binders, asphalt-mineral mixtures and roads or highways, which have particularly improved performance at low temperature while maintaining good performance at an intermediate temperature.

In particular, one of the objectives of the present invention is to offer bituminous binders, bitumen-mineral mixtures and roads or highways that have improved resistance to aging characteristics at low temperature.

Another objective of the present invention is to propose a method for producing a bitumen-mineral mixture, which is reliable, reproducible and corresponding to the rate of production, and which allows to obtain a ready-to-use competitive product that is stable during storage.

These and other problems are solved, according to the invention, thanks to a new bitumen composition containing:

(a) at least one bitumen with needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter, and a value of 900 tenths of a millimeter is excluded,

(b) at least one blown bitumen with needle penetration at 25 ° C, ranging from 10 to 50 tenths of a millimeter, and

(c) at least one polymer,

moreover, the specified values of penetration measured according to the standard NF EN 1426.

Preferably, bitumen (a) has a needle penetration at 25 ° C from 600 to 850 tenths of a millimeter.

Preferably the mass of the blown bitumen (b) is from 9% to 70% of the total weight of the specified composition, preferably from 20% to 65%, more preferably from 25% to 50%.

Preferably, the bitumen (a) and the blown bitumen (b) are selected from the residues of vacuum distillation of the distillation residues at atmospheric pressure resulting from the distillation of petroleum.

Preferably, the bitumen composition further comprises non-conductive bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter and / or unfinished bitumen with needle penetration at 25 ° C from 50 to 300 tenths of a millimeter, and the specified penetration values are measured according to NF EN 1426.

Preferably, the bitumen composition contains from 1 to 10% by weight of polymer based on the total weight of said composition, preferably from 3% to 7%, more preferably from 4% to 6%.

Preferably, the polymer is crosslinkable.

Preferably, the polymer is selected from elastomers and / or plastomers.

Preferably, the polymer is selected from random copolymers or block copolymers of a monovinyl aromatic hydrocarbon and a conjugated diene.

Preferably, the statistical copolymer or block copolymer of a monovinyl aromatic hydrocarbon and a conjugated diene is a copolymer of styrene and butadiene.

Preferably, the bituminous composition further comprises a crosslinking agent capable of crosslinking the polymer.

Preferably, the weight of the crosslinking agent is from 0.02% to 0.5% of the total weight of said composition, preferably from 0.05% to 0.3%, more preferably from 0.1% to 0.25%.

Preferably, the crosslinking agent is sulfur, used alone or in a mixture with vulcanization accelerators.

Preferably, the bitumen composition is characterized in that it contains from 10 ppm to 1000 ppm (by weight) of an oil that improves compatibility, such as a mineral base oil.

The invention relates also to a method for producing a bitumen composition, in which simultaneously or sequentially mixed:

(a) at least one bitumen with needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter, and a value of 900 tenths of a millimeter is excluded,

(b) at least one blown bitumen with needle penetration at 25 ° C, ranging from 10 to 50 tenths of a millimeter, and

(c) at least one polymer,

moreover, the specified values of penetration measured according to the standard NF EN 1426.

According to one embodiment, the method for producing a bitumen composition comprises the following steps:

i) preparation of the pre-mix by mixing:

(a) bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter excluded,

(b) at least one blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter,

moreover, this pre-mixture has a needle penetration at 25 ° C from 50 to 100 tenths of a millimeter, more preferably from 60 to 90 tenths of a millimeter,

ii) simultaneously or sequentially mixing said premix with bitumen having needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter being excluded, and at least one polymer

moreover, the specified values of penetration measured according to the standard NF EN 1426.

According to another embodiment, the method for producing a bitumen composition comprises the following steps:

i) preparation of the pre-mix by mixing:

(a) bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter excluded,

(b) at least one blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter,

moreover, this pre-mixture has a needle penetration at 25 ° C from 80 to 150 tenths of a millimeter, more preferably from 90 to 130 tenths of a millimeter,

ii) simultaneous or sequential mixing of the said premix with bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter being excluded, and at least one polymer,

moreover, the specified values of penetration measured according to the standard NF EN 1426.

Preferably, the temperature when mixing bitumen with needle penetration at 25 ° C is greater than or equal to 600 tenths of a millimeter, and a value of 900 tenths of a millimeter is excluded; blown bitumen with needle penetration at 25 ° C in the range from 10 to 50 tenths of a millimeter and polymer ranges from 135 ° C to 210 ° C, preferably from 150 ° C to 195 ° C, more preferably from 175 ° C to 190 ° C.

Preferably, the temperature during pre-mixing of the mixture and mixing of said pre-mixture with bitumen with needle penetration at 25 ° C is greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter being excluded and the polymer is from 135 ° C to 210 ° C, preferably from 150 ° C to 195 ° C, more preferably from 175 ° C to 190 ° C.

Preferably, the bitumen with needle penetration at 25 ° C is greater than or equal to 600 tenths of a millimeter, and a value of 900 tenths of a millimeter is excluded, has a penetration in the range of 600 to 850 tenths of a millimeter.

The invention relates also to the use of the bitumen composition according to the invention in the field of road construction, and this composition has needle penetration at 0 ° C, according to the Russian standard test GOST 11501-78, more than 30 tenths of a millimeter, preferably more than 32 tenths of a millimeter, and needle penetration at 25 ° C, according to the standard NF EN 1426, in the range from 60 to 90 tenths of a millimeter, preferably from 65 to 88 tenths of a millimeter.

The invention also relates to a bituminous binder comprising a bituminous composition according to the invention.

The invention also relates to a bituminous-mineral mixture containing a bituminous binder, granulate and optionally fine aggregate, sand, crushed stone.

The invention also relates to a method for producing a bituminous-mineral mixture, in which a bituminous binder and granulate are mixed at a temperature in the range from 170 ° C to 190 ° C, more preferably from 180 ° C to 185 ° C.

The invention also relates to roads or highways covered with a bitumen-mineral mixture according to the invention or prepared by the method described above.

The invention also relates to the use of the bitumen-mineral mixture according to the invention or prepared by the method described above for the production of road or highway coatings.

Characteristics at low temperature or susceptibility to thermal cracking of the final bitumen composition according to the invention can be assessed by the criterion of needle penetration at 0 ° C, according to the Russian standard test GOST 11501-78. To obtain good performance, it is advisable to set the amount of penetration at 0 ° C more than 30 tenths of a millimeter, preferably more than 32 tenths of a millimeter.

Characteristics at an intermediate temperature or susceptibility to ruts in the final bitumen composition according to the invention can be evaluated by the criterion of needle penetration at 25 ° C. To obtain good performance, it is advisable to set the amount of penetration at 25 ° C, according to the NF EN 1426 standard, in the range from 60 to 90 tenths of a millimeter, preferably from 65 to 88 tenths of a millimeter.

 The composition according to the invention preferably exhibits a needle penetration value in the range from 60 to 90 tenths of a millimeter, preferably from 65 to 88 tenths of a millimeter, the values are measured according to standard NF EN 1426.

The above penetration values provide an optimal compromise / balance between good properties at low temperatures or susceptibility to thermal cracking and good properties at intermediate temperatures or susceptibility to ruts, which must also have high-quality bitumen composition for use in road construction.

Similarly, in order to ensure an optimal compromise / balance between good properties at low temperatures or susceptibility to thermal cracking and good properties at intermediate temperatures or susceptibility to rutting, based on the AASHTO R29 and AASHTO M320-10 standards, a quality performance classification criteria was developed. Graded Asphalt Binder ", combining the lower application temperature and the upper application temperature. The lower application temperature value is determined by the BBR test pertaining to the AASHTO T313 standard, and the upper application temperature value is determined from the DSR test pertaining to the AASHTO T315 standard.

Under these conditions, in order to obtain good performance, it is advisable to set a lower application temperature that characterizes susceptibility to thermal cracking, below -30 ° C, preferably below -34 ° C. In parallel, it is also desirable that this characteristic mentioned above be combined with the upper application temperature, which characterizes the tendency to form rutting. It is desirable to set this upper application temperature above 70 ° C, preferably above 74 ° C.

The above application temperatures allow for an optimal compromise / balance between good properties at low temperatures or susceptibility to thermal cracking and good properties at intermediate temperatures or susceptibility to ruts, which must also have high-quality bitumen composition for use in road construction.

The aging resistance of the bitumen composition obtained according to the invention at low temperature can be estimated by measuring the temperature of the cracking of BBR, according to the AASHTO T313 standard, in different states of aging of the bitumen binder, namely:

- the original bituminous binder (standard condition),

- bituminous binder after aging under the conditions of Rolling Thin Film Oven Test (RTFOT, thin film rolling test), according to AASHTO T240, and

- bituminous binder after aging, according to the RTFOT test, with subsequent aging in a pressure vessel (Pressure Aging Vessel, PAV), according to the AASHTO R28 standard.

Under these conditions, in order to obtain good characteristics, it is desirable to control the change in the temperature of cracking of the BBR bituminous binder when going from the initial state to the state after aging RTFOT, and then PAV, in the range from -31 ° C to -24 ° C.

The storage stability of the bitumen composition prepared according to the invention can be estimated according to EN 13399:

- by changing the needle penetration at 25 ° C, measured according to the standard NF EN 1426, of the specified composition between the sample taken from the top of the tube with the sample and the sample taken from the bottom of the tube with the sample, and

- by changing the softening temperature around the ring and the ball (TBA), measured according to standard NF EN 1427, of the specified composition between the sample taken from the top of the tube with the sample and the sample taken from the bottom of the tube with the sample.

The procedure for measuring the penetration criteria and other characteristics used to define the present invention will become clear from the examples below.

Other objects, characteristics, and advantages of the present invention will become even more complete when studying the following detailed description.

Brief description of the figure

Figure 1 shows the correlation between needle penetration (also called permeability) at 25 ° C, expressed in tenths of a millimeter (dmm), and dynamic viscosity at 135 ° C, expressed in mPas, for bitumen.

Detailed description

Further throughout the description in the expression "greater than or equal to 600 tenths of a millimeter" it is implied that a value of 900 tenths of a millimeter is excluded.

Bituminous composition

Bituminous composition according to the invention contains:

(a) at least one bitumen with needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter,

(b) at least one blown bitumen with needle penetration at 25 ° C in the range of 10 to 50 tenths of a millimeter, and

(c) at least one polymer,

moreover, the specified values of penetration measured according to the standard NF EN 1426.

Among the bitumens suitable for use according to the invention, natural bitumens of natural origin may be mentioned, contained in deposits of natural bitumen, natural asphalt or tar sands. The bitumens according to the present invention may be bitumens coming from the refining of crude oil, in particular bitumens containing asphaltenes. Bitumen can be obtained by traditional methods of obtaining bitumen at refineries. In particular, there are bitumens corresponding to residues of direct distillation and / or residues of vacuum distillation of oil. It is accepted, in particular, to conduct vacuum distillation of atmospheric residues formed during the distillation of crude oil at atmospheric pressure. Thus, this method of obtaining corresponds to the sequence of distillation at atmospheric pressure and vacuum distillation, and the raw materials fed to vacuum distillation correspond to residues of atmospheric distillation. These vacuum distillation residues leaving the vacuum distillation column can also be used as bitumen.

In particular, the compound (a) according to the invention is a bitumen selected from vacuum distillation residues (RSV) atmospheric distillation residues formed during the distillation of petroleum. Bitumen (a) according to the invention is classified as “soft”, as it is characterized by needle penetration at 25 ° C, measured according to the NF EN 1426 standard, greater than or equal to 600 tenths of a millimeter. Bitumen (a) according to the invention may preferably have a needle penetration at 25 ° C from 600 to 850 tenths of a millimeter. Due to the correlation existing between needle penetration at 25 ° C and Brookfield dynamic viscosity at 135 ° C (as explained earlier), soft bitumen (a) according to the invention can have Brookfield dynamic viscosity from 78 to 100 mPa⋅s (see FIG. one).

The amount of bitumen (a) in the bitumen composition according to the invention can be from 20 to 90 wt.% From the total mass of the specified composition, preferably from 33% to 70%, more preferably from 47% to 68%.

In particular, the compound (b) according to the invention is a bitumen, also selected from vacuum distillation residues (RSV) atmospheric distillation residues from the distillation of petroleum that have undergone an additional “purge” operation. Therefore, bitumen (b) according to the invention is a “blown” bitumen. Blown bitumens can be produced at the purge facilities, passing air and / or oxygen through the original bituminous bed. This operation can be carried out in the presence of an oxidation catalyst, for example, phosphoric acid. Typically, purging is carried out at elevated temperatures, of the order of 200-300 ° C, for a relatively long period, usually between 30 minutes and 2 hours, in continuous mode or in portions. The duration and temperature of the purge are selected depending on the desired properties of the blown bitumen and depending on the quality of the original bitumen. The purpose of the purge operation is to make the treated bitumen harder. Thus, the blown bitumen according to the invention has a needle penetration at 25 ° C, measured according to the standard NF EN 1426, in the range from 10 to 50 tenths of a millimeter.

Preferably the amount of blown bitumen (b) in the bitumen composition according to the invention is from 9 to 70 wt.% From the total mass of the specified composition, preferably from 20% to 65%, more preferably from 25% to 50%.

The applicants found that the use of bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, in combination with blown bitumen with needle penetration at 25 ° C in the range from 10 to 50 tenths of a millimeter, unexpectedly improves the characteristics at a low temperature specified bitumen compositions while maintaining good performance at intermediate temperatures. In previous technologies, bitumen with penetration above 600 tenths of a millimeter was not used, and its combination with blown bitumen was not used to obtain good performance at low temperature. In technologies of the previous level, an oil that improves compatibility was used to impart an equivalent quality at low temperature.

Optionally, the bitumen composition according to the invention may also contain, according to the first embodiment, non-conductive bitumen of the “solid” grade, characterized by needle penetration at 25 ° C from 10 to 50 tenths of a millimeter, and / or, according to the second embodiment, the non-conductive bitumen of the “solid” mark, characterized by needle penetration at 25 ° C from 50 to 300 tenths of a millimeter, with the indicated penetration values measured according to the NF EN 1426 standard. Preferably, these non-expanded bitumens are also selected from the residual vacuum distillation (RSV) distillation residues tmosfernom pressure formed by the distillation of petroleum.

The amount of unblown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter and / or the amount of unblown bitumen with needle penetration at 25 ° C from 50 to 300 tenths of a millimeter in the bitumen composition according to the invention can be from 5 to 30 wt.%, preferably from 10 to 25% of the total weight of said composition.

The bituminous composition according to the invention contains at least one polymer. This polymer is preferably crosslinkable. The polymer according to the invention can be selected from elastomers and / or plastomers. As examples of polymers for bitumen can be called:

- elastomers, such as statistical copolymers or block copolymers of monovinyl aromatic hydrocarbon and conjugated diene, such as statistical copolymers or block copolymers of styrene and butadiene: copolymers SB (styrene and butadiene), SBS (styrene-butadiene-styrene), SIS (styrene -isoprene-styrene), SBS * (styrene-butadiene-styrene stellate structure), SBR (styrene-β-butadiene rubber), EPDM (modified ethylene-propylene-diene), polychloroprene, polynorbornene and, optionally, polyolefins, such as polyethylene PE, HDPE (high density polyethylene ti), polypropylene PP,

- plastomers, such as EVA (ethylene / vinyl acetate copolymer), EMA (ethylene / methyl acrylate copolymer), copolymers of olefins and esters of unsaturated carboxylic acids, EBA (ethylene / butyl acrylate copolymer), elastomeric polyolefin copolymers, polyolefins of a polyethylene / butyl acrylate; acrylic acid, methacrylic acid or maleic anhydride esters, copolymers and ternary copolymers of ethylene and glycidyl methacrylate, ethylene / propylene copolymers, rubbers, polyisobutylenes, SEBS (copolymer of styrene, ethylene, butylene and styrene ), ABS (acrylonitrile / butadiene / styrene).

Preferred polymers are copolymers based on conjugated diene units and monovinyl aromatic hydrocarbon units, which in particular can be crosslinked.

The conjugated diene is preferably selected from dienes containing from 4 to 8 carbon atoms, for example, 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene , 1,3-pentadiene, 1,2-hexadiene, chloroprene, carboxylated butadiene and / or carboxylated isoprene. Preferably, the conjugated diene is butadiene.

The monovinyl aromatic hydrocarbon is preferably selected from styrene, ortho-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 2,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinyltoluene, and / or vinylxylene. The preferred monovinyl hydrocarbon is styrene.

In particular, the polymer consists of one or more copolymers selected from monovinyl aromatic hydrocarbon and conjugated diene copolymers, in particular styrene and butadiene, linear or star-shaped, in the form of double-block, three-block and / or strongly branched macromolecules, optionally with or without a statistical transition block preferably with a statistical transition unit.

Preferably, the polymer is a monobinyl aromatic hydrocarbon and a conjugated diene triblock copolymer, such as styrene / butadiene / styrene triblock copolymers (SBS).

According to one embodiment, the copolymer of a monovinyl aromatic hydrocarbon and a conjugated diene, in particular styrene and butadiene, has an average molecular weight Mw in the range from 10,000 to 500,000 Daltons, preferably from 50,000 to 250,000, more preferably from 50,000 to 200,000, even more preferably from 100,000 to 180,000, even more preferably from 120,000 to 160,000. The molecular weight of the copolymer is measured by GPC chromatography with a polystyrene standard, according to ASTM D3536.

The monovinyl aromatic hydrocarbon and conjugated diene copolymer, in particular, styrene and butadiene, preferably has a weight content of monovinyl aromatic hydrocarbon, in particular, styrene, in the range from 5 to 50 wt.% Of the weight of the copolymer, preferably from 20% to 40%.

The monovinyl aromatic hydrocarbon copolymer and the conjugated diene, in particular, styrene and butadiene, preferably has a weight content of the conjugated diene, in particular, butadiene, in the range from 50 to 95 wt.% By weight of the copolymer, preferably from 60% to 80%.

Among the units of the conjugated diene, there are links with 1,4 double bonds originating from the conjugated diene and links with 1,2 double bonds originating from the conjugated diene. The 1,4 double bonds derived from the conjugated diene are understood to mean the units formed by the addition of the conjugated diene to the position 1,4 in the polymerization of the conjugated diene. Under the double bonds of 1,2, derived from the conjugated diene, understand the links formed by the addition of a conjugated diene to the position 1,2 in the polymerization of a conjugated diene. The result of this 1,2-addition is a double vinyl bond, called a pendant.

The monovinyl aromatic hydrocarbon copolymer and the conjugated diene, in particular, styrene and butadiene, preferably has a double bond units content of 1.2 from the conjugated diene, in particular, butadiene, ranging from 5 to 50 wt.% Calculated on the total weight of conjugated diene units. in particular, butadiene, preferably from 5% to 40%, more preferably from 5% to 30%, even more preferably from 5% to 25%, even more preferably from 5% to 15%. The monovinyl aromatic hydrocarbon and conjugated diene copolymer defined above, in particular styrene and butadiene, having a content of double bonds of 1,2, originating from conjugated diene, in particular, butadiene, can be used with or without a crosslinking agent, as it is self-crosslinking "i.e. the branches of the copolymer are stitched, connecting to each other through double vinyl bonds, called suspended.

Typically, the polymer is used in an amount of from 1 to 10 wt.% Of the total mass of the bitumen composition, preferably from 3% to 7%, more preferably from 4% to 6%.

This polymer, preferably crosslinkable, may optionally be crosslinked. Suitable for cross-linking agents can be very different in nature and can be selected depending on the type or types of polymers contained in the bituminous composition according to the invention. The crosslinking agent may be sulfur, used alone or in a mixture with vulcanization accelerators. These vulcanization accelerators are either hydrocarbyl polysulfides, or vulcanization accelerators — sulfur donors, or vulcanization accelerators that are not sulfur donors. The hydrocarbyl polysulfides can be selected from the polysulfides defined in patent FR2528439. Vulcanization accelerators, which are sulfur donors, can be selected from thiuram polysulfides, such as, for example, tetrabutylthiuram disulfides, tetraethylthiuram disulfides, and tetramethylthiuram disulfides. Vulcanization accelerators, non-sulfur donors, suitable for use according to the invention may be sulfur compounds selected, in particular, from mercaptobenzothiazole and its derivatives, dithiocarbamates and their derivatives and thiuram monosulfides and their derivatives. For example, zinc-2-mercaptobenzothiazole, zinc dibutyldithiocarbamate, tetramethylthiuram monosulfide can be mentioned. For details on vulcanization accelerators, both non-sulfur donors and suitable for use according to the invention, refer to patents EP0360656, EP0409683 and FR2528439.

A quantity of a crosslinking agent is usually used in the range of from 0.02 to 0.5% by weight of the total weight of the bituminous composition, preferably from 0.05% to 0.3%, more preferably from 0.1% to 0.25%.

It has been found that the addition of a crosslinking agent to the bituminous compositions according to the invention can improve storage stability.

In addition, the inventors found that using bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, in combination with blown bitumen with needle penetration at 25 ° C in the range of 10 to 50 tenths of a millimeter, and in combination with the addition of a polymer and a crosslinking agent unexpectedly allows you to improve the aging resistance of the characteristics of these bituminous compositions at low temperature.

Adhesive improvers and / or surfactants can also be added to the bituminous composition of the invention. They can be selected from alkyl derivatives, derivatives of alkyl polyamines, derivatives of alkylamide polyamines, derivatives of alkylamide polyamines, and derivatives of quaternary ammonium salts, used alone or in a mixture. It is possible to name, in particular, fatty propylenediamines, fatty amido amines, quaternary ammonium compounds obtained by quaternization of fatty propylenediamines, fatty propylene polyamines.

Preferably, the number of agents that improve adhesion, and / or the amount of surfactant in the bitumen composition according to the invention is from 0.05 to 5 wt.% From the total mass of the specified composition, preferably from 0.1% to 2%.

Preferably, the bituminous composition according to the invention does not contain an oil which improves compatibility, such as a mineral base oil, or substantially does not contain such an oil. The composition may contain in trace amounts from 10 ppm to 1000 ppm (by weight) of an oil that improves compatibility, such as mineral base oil. An oil that improves compatibility, such as a mineral base oil, is an oil compound that is separated from vacuum residues or atmospheric distillation residues in the oil refining steps.

According to one particular embodiment, the bituminous composition contains, based on the total weight of the specified composition:

- from 20% to 90% bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter (a),

- from 9% to 70% of blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter (b),

- from 1% to 10% polymer (c).

Preferably the bitumen composition contains, based on the total mass of the specified composition:

- from 33% to 70% of compound (a),

- from 20% to 65% of compound (b),

- from 3% to 7% of compound (c),

- from 0.02% to 0.5% of a crosslinking agent.

In addition, the bituminous composition may also contain from 5% to 30% of other non-extinguished bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter and / or other non-conductive bitumen with needle penetration at 25 ° C from 50 to 300 tenths of a millimeter.

According to another particular embodiment, the bitumen composition consists essentially of (by weight, based on the total weight of the specified composition):

- from 20% to 90% bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter (a),

- from 9% to 70% of blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter (b),

- from 1% to 10% polymer (c).

Preferably, the bituminous composition consists essentially of the following substances (by weight, calculated on the total weight of the specified composition):

- from 33% to 70% of compound (a),

- from 20% to 65% of compound (b),

- from 3% to 7% of compound (c),

- from 0.02% to 0.5% of a crosslinking agent.

Preferably, compound (a) has needle penetration at 25 ° C in the range of from 600 to 850 tenths of a millimeter.

Bituminous binder

Various uses of the bitumen compositions according to the invention are envisaged. In particular, bituminous compositions can be used for the preparation of bituminous binder.

According to one particular embodiment, the bituminous binder contains the bituminous composition described above.

The bituminous binder according to the invention can, in turn, be used to obtain a combination with a granulate.

Bituminous and mineral mix

The object of the invention are also bitumen-mineral mixtures containing bitumen binder according to the invention, defined above, granules and optionally fine aggregate, sand, crushed stone. If we are talking about the use in road construction, the invention relates, in particular, to the bitumen-mineral mixture as a material for the construction and repair of the highway and its cover, as well as for the implementation of any road work.

By bitumen-mineral mixture is meant a mixture of a bitumen binder composition with granules and optionally mineral fillers. The granulate is a mineral and / or synthetic granulate, in particular, recycled crushed paving material with a size of more than 2 mm, preferably in the range from 2 mm to 20 mm, and mineral fillers consist of a fine fraction (particles smaller than 0.063 mm), sand (particles ranging in size from 0.063 mm to 2 mm) and optionally crushed stone (particles larger than 2 mm, preferably from 2 mm to 4 mm). According to the invention, the term "granulate" means a granulate that meets the requirements of an application in the field of road construction. This granulate is preferably obtained by crushing massive rocks or alluvial rocks. Thus, granulate means granulated material used in construction. The granulate can be natural, artificial or reusable. The term "natural granulate" means a granulate that has not undergone any deformation except mechanical. The term "artificial granulate" means a granulate of mineral origin, obtained as a result of an industrial process involving thermal or other transformations. The term "recycled granulate" means granulate obtained by processing inorganic materials traditionally used in construction.

In particular, the granules used in the invention are granules for roads that meet the relevant standards: NF EN 13043 in Europe and ASTM C33 in the USA. The particle size fractions (d / D) of the components of the bituminous-mineral mixtures, which are the subject of a number of French technical specifications for the product NF P98-130 - NF P98-141, which are suitable for use according to the invention, are as follows: 0/2 (sand), 0 / 4, 2/4 (crushed stone), 0 / 6.3, 2 / 6.3 and 4 / 6.3. These particle size fractions are treated in the spirit of XP PI8-540, currently replaced by XP PI 8-545.

Bitumen-mineral mixtures are used to create roads and are pressed by a roller in the place of their application.

Preferably the bitumen-mineral mixture according to the invention contains from 3.5 to 7 wt.% Bitumen binder from the total mass of the mixture, preferably from 4 to 6.5 wt.%.

Roads or Highways

If we are talking about the use in road construction, the invention also applies to roads or highways covered with a bituminous-mineral mixture as defined above.

Surprisingly, due to the use of the above-described bitumen composition according to the invention, bituminous binders, bitumen-mineral mixtures and roads or highways, obtained on the basis of this composition, have remarkable characteristics at low temperature while maintaining good characteristics at intermediate temperatures.

Preferably, the bitumen binders, bitumen-mineral mixtures and roads or highways, obtained using these bitumen compositions, have improved aging resistance of their characteristics at low temperature.

Methods for producing a bitumen composition and a bitumen-mineral mixture

The object of the invention is also a method of obtaining a bitumen composition, in which simultaneously or sequentially mixed:

(a) at least one bitumen with needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter,

(b) at least one blown bitumen with needle penetration at 25 ° C, ranging from 10 to 50 tenths of a millimeter, and

(c) at least one polymer,

moreover, the specified values of penetration measured according to the standard NF EN 1426.

According to one embodiment, the method for producing a bitumen composition comprises the following steps:

i) preparation of the pre-mix by mixing:

(a) bitumen with needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter,

(b) at least one blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter,

moreover, this pre-mixture has a needle penetration at 25 ° C from 50 to 100 tenths of a millimeter, more preferably from 60 to 90 tenths of a millimeter,

ii) simultaneously or sequentially mixing said premix with bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, and at least one polymer,

moreover, the specified values of penetration measured according to the standard NF EN 1426.

According to another embodiment, the method for producing a bitumen composition comprises the following steps:

i) preparation of the pre-mix by mixing:

(a) bitumen with needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter,

(b) at least one blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter,

moreover, this pre-mixture has a needle penetration at 25 ° C from 80 to 150 tenths of a millimeter, more preferably from 90 to 130 tenths of a millimeter,

ii) simultaneously or sequentially mixing said pre-mix with bitumen having needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter and at least one polymer,

moreover, the specified values of penetration measured according to the standard NF EN 1426.

Preferably the temperature when mixing bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter and polymer ranges from 135 ° C to 210 ° C, preferably from 150 ° C to 195 ° C, more preferably from 175 ° C to 190 ° C.

Preferably, the temperature during the preliminary mixing and mixing of the said preliminary mixture with bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, and the polymer ranges from 135 ° C to 210 ° C, preferably from 150 ° C to 195 ° C, more preferably from 175 ° C to 190 ° C.

Preferably, bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, has a penetration in the range from 600 to 850 tenths of a millimeter or a Brookfield dynamic viscosity at 135 ° C in the range from 78 to 100 mPa смотритеs (see Fig. 1 ).

Preferably bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, and blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter are added to the reactor and heated to 185 ° C. The polymer, in turn, is introduced into the reactor and, if necessary, the crosslinking agent, and heated to a temperature of 185 ° C. The mixture can then be transferred to a mill with a high shearing force, which contributes to obtaining a good dispersion and a good distribution of the polymer and crosslinking agent. Then the mixture is usually transferred to the tank for ripening for 30-120 min before use.

The inventors have found that the use of the method for producing the bitumen composition according to the invention is reliable, reproducible and is in accordance with the production rate and allows to obtain a competitive product that is stable during storage, being ready for use.

The object of the invention is also a method of obtaining a bitumen-mineral mixture, in which the bitumen binder according to the invention is mixed with a granulate at a temperature typically in the range of 170 ° C to 190 ° C, more preferably from 180 ° C to 185 ° C.

The inventors have found that the application of the method for producing a bitumen-mineral mixture according to the invention is reliable, reproducible and is in accordance with the rate of production and allows to obtain a competitive product that is stable during storage, being ready for use.

Application

The object of the invention is the use of bitumen-mineral mixtures according to the invention or bitumen-mineral mixtures obtained by the method described above, to obtain road or highway pavements.

The object of the invention is also the use of the bitumen composition according to the invention to reduce thermal cracking at low temperature and improve resistance to the occurrence of rutting at an intermediate temperature at the bitumen binder and / or bitumen-mineral mixture, and / or roads or highways.

The object of the invention is also the use of the bitumen composition according to the invention to improve the resistance to aging characteristics at low temperature bitumen binder and / or bitumen-mineral mixture, and / or roads or highways.

Finally, an object of the invention is the use of the bitumen composition according to the invention for road construction, where this composition has needle penetration at 0 ° C, according to the Russian standard test GOST 11501-78, more than 30 tenths of a millimeter, preferably more than 32 tenths of a millimeter, and needle penetration at 25 ° C, according to the standard NF EN 1426, in the range from 60 to 90 tenths of a millimeter, preferably from 65 to 88 tenths of a millimeter.

Examples

Bituminous compositions

The following different products were used:

- soft bitumen, designated B ₁ , having needle penetration at 25 ° C, equal to 810 tenths of a millimeter (dmm), measured according to the standard NF EN 1426;

- non-conductive bitumen of the mark “solid”, designated B ₂ , having needle penetration at 25 ° C, equal to 15 dmm, measured according to the standard NF EN 1426;

- blown bitumen of “solid” grade, designated B ₃ , having needle penetration at 25 ° C, equal to 15 dmm, measured according to the standard NF EN 1426;

- triblock copolymer styrene / butadiene / styrene (SBS), containing 30 wt.% styrene based on the weight of the copolymer and 9% of butadiene units with a double bond of 1.2 from the mass of butadiene, molecular weight Mw 151,000 Dalton;

- cross-linking agent: the product PAXL®, manufactured by the applicant.

These three types of bitumen used are derived from residual vacuum distillation (RSV) distillation residues at atmospheric pressure formed during the distillation of petroleum.

Prepare various bitumen compositions:

- The bituminous composition C ₁ , not according to the invention, contains 100% by weight of bitumen B ₁ , as defined above.

- Bituminous composition C ₂ , not according to the invention, contains 95.10 wt.% Bitumen B ₁ , 4.76 wt.% Polymer and 0.14 wt.% Cross-linking agent from the total mass of the specified composition, as defined above.

- Bitumen composition C ₃ , not according to the invention, contains 48.50 wt.% Bitumen B ₁ , 46.60 wt.% Bitumen B ₂ , 4.76 wt.% Polymer and 0.14 wt.% Cross-linking agent from the total mass specified composition, as defined above.

- Bituminous composition C ₄ according to the invention contains 58.01 wt.% Bitumen B ₁ , 37.09 wt.% Bitumen B ₃ , 4.76 wt.% Polymer and 0.14 wt.% Cross-linking agent from the total mass of the specified compositions defined above.

Said composition C ₄ , as defined in the invention, can also be obtained by a pre-mix compound obtained from bitumen B ₁ and bitumen B ₃ , characterized in that the intermediate bitumen composition thus obtained has needle penetration at 25 ° C in the range from 50 to 100 dmm more preferably from 60 to 90 dmm. Then the preliminary mixture is again combined with bitumen B ₁ . Then the bituminous composition is combined with the polymer and crosslinking agent in the above weight contents to form the bituminous composition according to the invention.

The specified composition C ₄ defined in the invention can also be obtained by combining a pre-mixture obtained from bitumen B ₁ and bitumen B ₃ , characterized in that the thus obtained intermediate bitumen composition has needle penetration at 25 ° C in the range from 80 to 150 dmm, more preferably from 90 to 130 dmm. Then the preliminary mixture is again combined with bitumen B ₁ . The bituminous composition is then combined with the polymer and crosslinking agent in the above-mentioned weight contents in order to obtain the bituminous composition according to the invention.

- Bitumen composition C ₅ according to the invention contains 58.10 wt.% Bitumen B ₁ , 37.14 wt.% Bitumen B ₃ , 4.76 wt.% Polymer based on the total mass of the specified composition, as defined above.

The specified composition C ₅ defined in the invention, can also be obtained by the methods described above, and this method includes both the step of preparing the pre-mix and the step of mixing the pre-mix with the B ₁ bitumen and polymer.

Table 1
Bituminous compositions C ₁ C ₂ C ₃ C ₄ C ₅ B ₁ 100% 95.10% 48.50% 58.01% 58.10% B ₂ - 46.60% B ₃ - 37.09% 37.14% polymer - 4.76% 4.76% 4.76% 4.76% crosslinking agent - 0.14% 0.14% 0.14%

The C ₂ bituminous composition is prepared by mixing the above compounds at 185 ° C.

The C ₃ bituminous composition is prepared by mixing the above compounds at 185 ° C.

The C ₄ bituminous composition is prepared by mixing the above compounds at 185 ° C.

The C ₅ bituminous composition is prepared by mixing the above compounds at a temperature of 185 ° C.

Bitumens B ₁ , B ₃ and, optionally, B ₂ are added to the reactor and heated to a temperature of 185 ° C, in turn, a polymer and, if necessary, a crosslinking agent are introduced into the reactor and heated to a temperature of 185 ° C. The mixture is then transferred to a mill with a high shearing force, which contributes to obtaining good dispersion and good distribution of the polymer and crosslinking agent. Then the mixture is transferred to the maturing tank for 30-120 minutes before using it.

The specified bitumen composition according to the invention can also be obtained by preparing a preliminary mixture obtained in a reactor at 185 ° C from bitumen B ₁ and bitumen B ₃ , characterized in that the intermediate bitumen composition thus obtained has a needle penetration at 25 ° C in the interval from 50 up to 100 dmm, more preferably from 60 to 90 dmm.

Then the preliminary mixture is again combined with bitumen B ₁ in the reactor at 185 ° C. Then in the specified reactor at 185 ° C polymer is injected and, if necessary, a crosslinking agent in the above mass contents, to obtain a bitumen composition according to the invention.

The specified bituminous composition according to the invention can also be obtained by preparing a preliminary mixture in the reactor at 185 ° C, based on the B ₁ bitumen and the B ₃ bitumen, characterized in that the intermediate bitumen composition thus obtained has a needle penetration at 25 ° C in the interval from 80 up to 150 tenths of a millimeter, more preferably from 90 to 130 dmm. Then the preliminary mixture is again combined with bitumen B ₁ in the reactor at 185 ° C. Then in the specified reactor at 185 ° C polymer is injected and, if necessary, a crosslinking agent in the above mass contents, to obtain a bitumen composition according to the invention.

The above needle penetration values at 25 ° C are measured according to NF EN 1426.

Characteristics of bitumen compositions at different temperatures

In order to ensure an optimal compromise / balance between good properties at low temperatures or susceptibility to thermal cracking and good properties at intermediate temperatures or susceptibility to rutting, they strive to obtain needle penetration for bitumen compositions at 0 ° C above 30 dmm in combination with needle penetration at 25 ° C in the range from 60 to 90 dmm.

Characteristics at low temperature or susceptibility to thermal cracking, as well as characteristics at intermediate temperatures or susceptibility to ruts for bituminous compositions C ₁ -C ₅ were evaluated by measuring needle penetration of each of these compositions at 0 ° C and at 25 ° C. The results are shown in the following table 2.

table 2
Characteristics of bitumen compositions
at low temperature and at intermediate temperature Sought penetration C ₁ C ₂ C ₃ C ₄ C ₅ Penetration in dmm at 0 ° C ⁽¹⁾ > 30 > 60 63 24 39 32 Penetration in dmm at 25 ° C ⁽²⁾ 60-90 > 600 336 72 73 74 ⁽¹⁾ Penetration in tenths of a millimeter, measured according to the Russian standard GOST 11501-78.
⁽²⁾ Penetration in tenths of a millimeter, measured according to NF EN 1426.

It was established that, despite the good characteristics at low temperature, the characteristics of the bitumen compositions C ₁ and C ₂ at the intermediate temperature deteriorated, i.e. there is a significant sensitivity to the intermediate temperature and, therefore, the risk of ruts on the road, since the corresponding penetration at 25 ° C for these compositions is very high (above 600 dmm for C ₁ and equal to 336 dmm for C ₂ ).

On the contrary, it was found that, despite the good characteristics at an intermediate temperature, the characteristics of the C ₅ bitumen composition deteriorated at low temperatures, i.e. there is considerable brittleness at low temperatures and, therefore, the risk of thermal cracking, since penetration is very low (equal to 24 dmm) .

However, it has surprisingly been found that the C ₄ and C ₅ bitumen compositions containing a combination of soft B ₁ bitumen and blown B ₃ bitumen (as previously defined and consistent with the invention) have good characteristics both at low temperature and intermediate temperature; their penetration at 0 ° C and at 25 ° C, respectively, is in the range of the values sought. Thus, the C ₄ and C ₅ bituminous compositions according to the invention have particularly improved performance at low temperature while maintaining good performance at an intermediate temperature, unlike the C ₃ bituminous composition containing a combination of soft B ₁ bitumen and non-conductive B ₂ bitumen as defined above.

Similarly, to ensure an optimal compromise / balance between good properties at low temperature or susceptibility to thermal cracking and good properties at intermediate temperatures or susceptibility to ruts, based on the standards AASHTO R29 and AASHTO M320-10, the criterion "Performance Graded Asphalt Binder" ( classification of bitumen binder by quality), combining the lower temperature of the application and the upper temperature of the application.

The lower temperature value of the application is determined in the BBR experiment pertaining to the AASHTO T313 standard, and the upper temperature value of the application is determined in the DSR experiment pertaining to the AASHTO T315 standard.

Characteristics at low temperature or susceptibility to thermal cracking, as well as characteristics at intermediate temperatures or the susceptibility of the C ₃ and C ₄ bituminous compositions to the occurrence of rutting, were evaluated by measuring the lower application temperature and the upper application temperature. The results are in the following table 3.

Table 3
Upper and lower temperatures of the use of bitumen compositions C ₃ C ₄ PG mark at low temperature (° C) ⁽³⁾ -28 -34 PG mark at high temperature (° C) ⁽³⁾ 70 76 ⁽³⁾ Temperature (in degrees Celsius), measured according to the standards AASHTO R29, AASHTO M320-10, AASHTO T313, AASHTO T315.

It has been established that the minimum application temperature (lower temperature) for the bitumen composition C _{4 is} lower than that for the bitumen composition C ₃ . Similarly, the maximum application temperature (upper temperature) of the bitumen composition C ₄ according to the invention is higher than that of the bitumen composition C ₃ . In addition, the guaranteed range of application for the C ₄ composition according to the invention is wider than for the comparative composition C ₃ , which is a very significant practical advantage for use in a mixture in extreme climatic conditions (very hot / very cold), in particular, for road coatings.

Evaluation of resistance to aging characteristics of bitumen compositions at low temperature

The aging resistance of the C ₃ and C ₄ bituminous compositions with respect to their low temperature characteristics was evaluated by measuring the temperature of the BBR cracking in different states of aging of the bitumen binder, namely: the original binder (standard state), the binder after aging according to the Rolling Thin Film Oven Test ( RTFOT, a thin film rolling test in the oven), and a binder after aging according to the RTFOT test, followed by aging in a pressure vessel (PAV). The results are shown in the following table 4.

Table 4
Stability characteristics of bitumen compositions during storage BBR temperature ⁽⁴⁾ C ₃ C ₄ The initial state (S * = 300 MPa) ⁽⁴⁾ -24,6 -thirty (m ** = 0.3) ⁽⁴⁾ -25,3 -30,3 Condition after aging RTFOT ⁽⁵⁾ (S * = 300 MPa) ⁽⁴⁾ -24,5 -29 (m ** = 0.3) ⁽⁴⁾ -24,2 -28,5 Condition after aging RTFOT ⁽⁵⁾ , then PAV ⁽⁶⁾ (S * = 300 MPa) ⁽⁴⁾ -22,4 -27,8 (m ** = 0.3) ⁽⁴⁾ -21,5 -24,6 ⁽⁴⁾ The temperature (in degrees Celsius) of BBR cracking according to AASHTO T313.
⁽⁵⁾ Aging method for RTFOT bituminous binder according to AASHTO T240 standard.
⁽⁶⁾ PAV bituminous binder aging method according to AASHTO R28 standard.
* S: shear modulus
** m: slope value

It is established that the temperature of the cracking of BBR, which determines the characteristics of the bitumen composition at low temperature, is lower in the bitumen composition C ₄ according to the invention (S = -30 ° C and m = -30.3 ° C) than in the C ₃ bitumen composition (S = -24.6 ° C and m = -25.3 ° C). In addition, when different aging methods are used (RTFOT and RTFOT / PAV), the BBR temperature, which determines the characteristics of the bitumen composition at low temperature, in the C ₄ bitumen composition according to the invention (S = -27.8 ° C and m = -24, 6 ° C) is always lower than that of the bitumen composition C ₃ (S = -22.4 ° C and m = -21.5 ° C).

In addition, it was found that the characteristics at low temperature after aging the C ₄ bitumen composition (RTFOT and RTFOT / PAV) are higher than those of the C ₃ bitumen composition before aging (in the initial state) (C ₄ S = -29 ° C <C ₃ S = -24.6 ° C and C ₄ S = -27.8 ° C <C ₃ S = -24.6 ° C).

Thus, these results show that using soft B ₁ bitumen in combination with blown B ₃ bitumen (defined above and consistent with the invention) in combination with the addition of a polymer and crosslinking agent can improve the aging resistance of the bitumen composition at low temperature.

Evaluation of the stability of bitumen compositions

Based on the sample kept in a closed container in the form of a tube for toothpaste and placed in an oven at 180 ° C for 3 days, according to standard EN 13399, the storage stability of the C ₃ -C ₅ bitumen compositions was measured by measuring the difference of needle penetrations at 25 ° C between the sample taken from the top of the tube with the sample and the sample taken from the bottom of the tube with the sample, as well as the difference in softening temperature around the ring and the ball (TBA) between the sample taken from the top of the tube with the sample and the sample taken from the bottom of the sample tube for each of these compositions. The results are shown in table 5 below.

Table 5
Storage stability of bitumen compositions C ₃ C ₄ C ₅ Penetration in dmm at 25 ° C, top ⁽⁷⁾ 82 97 136 Penetration in dmm at 25 ° C, bottom ⁽⁸⁾ 83 86 31 Δ (penetration) in dmm at 25 ° C ⁽⁹⁾ one eleven 105 TBA (° C) upper part ⁽¹⁰⁾ 78.2 77.2 83.2 TBA (° C) lower part ⁽¹¹⁾ 78 79,8 73 Δ (TBA) (° C) ⁽¹²⁾ 0.2 2.6 10.2 ⁽⁷⁾ and ⁽⁸⁾ Penetration, in tenths of a millimeter, measured according to the standard NF EN 1426.
⁽⁹⁾ Δ means the difference of penetration between the sample taken from the top of the tube with the sample and the sample taken from the bottom of the tube with the sample.
⁽¹⁰⁾ and ^(1l) Ring and ball temperature, measured according to EN 1427.
⁽¹²⁾ Δ means the temperature difference between the ring and the ball between the sample taken from the top of the tube with the sample and the sample taken from the bottom of the tube with the sample.

From this table it follows that the addition of a crosslinking agent to the bitumen composition according to the invention leads to a decrease in the penetration change at 25 ° C for such a composition. Indeed, the penetration varies from 105 dmm for a C ₅ composition according to the invention without a crosslinking agent to 11 dmm for a C ₄ composition according to the invention with a crosslinking agent.

Similarly, it was found that by adding a cross-linking agent to the bitumen composition according to the invention, the difference in softening temperature over the ring and the ball of such a composition decreases. Indeed, it varies from 10.2 ° C for a C ₃ composition according to the invention without a crosslinking agent to 2.6 ° C for a C ₄ composition according to the invention with a crosslinking agent.

These results reflect a more or less homogeneous character (settling phenomenon) of bitumen compositions at a given time and storage temperature: 3 days at 180 ° C. So, the smaller the difference between the sample taken from the top of the tube with the sample and the sample taken from the bottom of the tube with the sample, the better the composition remains homogeneous in time.

Thus, these results show that the addition of a crosslinking agent to the bitumen composition according to the invention makes it possible to improve storage stability and to obtain storage stability that is at least equivalent to the stability of the bitumen composition C ₃ containing a combination of soft bitumen B ₁ and non-conductive bitumen B ₂ , defined above.

Claims (47)

1. Bituminous composition for road or highway coverage, containing: (a) from 20 to 90 wt.% of the total mass of the specified composition, at least one bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, and a value of 900 tenths of a millimeter is excluded, (b) from 9 to 70% of the total weight of the specified composition, at least one blown bitumen with needle penetration at 25 ° C, ranging from 10 to 50 tenths of a millimeter, and (c) from 1 to 10 wt.% of the total mass of the specified composition, at least one crosslinkable polymer, where the polymer is selected from elastomers and / or plastomers, moreover, the percentages are calculated on the total weight of the specified composition, this composition of bitumen demonstrates the value of needle penetration at 25 ° C in the range from 60 to 90 tenths of a millimeter, moreover, the specified values of penetration measured according to the standard NF EN 1426. 2. The composition according to claim 1, in which the bitumen (a) has a needle penetration at 25 ° C in the range from 600 to 850 tenths of a millimeter. 3. The composition according to claim 1 or 2, showing the needle penetration value in the range from 65 to 88 tenths of a millimeter, the values are measured according to the standard NF EN 1426. 4. Composition according to any one of claims 1 to 3, in which the amount of bitumen (a) is from 33 to 70%, preferably from 47 to 68%. 5. Composition according to any one of claims 1 to 4, in which the mass of the blown bitumen (b) is from 20 to 65%, preferably from 25 to 50%. 6. Composition according to any one of claims 1 to 5, in which the bitumen (a) and the blown bitumen (b) are selected from the residues of vacuum distillation of the distillation residues at atmospheric pressure resulting from the distillation of oil. 7. Composition according to any one of claims 1 to 6, further comprising non-conductive bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter and / or non-conductive bitumen with needle penetration at 25 ° C from 50 to 300 tenths of a millimeter, and penetration values are measured according to standard NF EN 1426. 8. Composition according to any one of claims 1 to 7, containing from 3 to 7 wt.% Polymer based on the total weight of the specified composition, preferably from 4 to 6%. 9. Composition according to any one of claims 1 to 8, in which the polymer is selected from random copolymers or block copolymers of a monovinyl aromatic hydrocarbon and a conjugated diene. 10. The composition according to claim 9, in which the statistical copolymer or block copolymer of a monovinyl aromatic hydrocarbon and a conjugated diene is a copolymer of styrene and butadiene. 11. Composition according to any one of claims 1 to 10, further comprising a crosslinking agent. 12. The composition according to claim 11, in which the mass of the crosslinking agent is from 0.02 to 0.5% of the total mass of the specified composition, preferably from 0.05 to 0.3%, more preferably from 0.1 to 0.25 % 13. Composition according to any one of paragraphs.11, 12, in which the crosslinking agent is sulfur, used alone or in a mixture with vulcanization accelerators. 14. Composition according to any one of paragraphs.1-13, characterized in that the composition contains from 10 to 1000 ppm (by weight) oil that improves compatibility, such as mineral base oil. 15. A method of obtaining a bituminous composition according to any one of claims 1 to 14, in which simultaneously or sequentially mixed: (a) at least one bitumen with needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter, and a value of 900 tenths of a millimeter is excluded, (b) at least one blown bitumen with needle penetration at 25 ° C, ranging from 10 to 50 tenths of a millimeter, and (c) at least one polymer, moreover, the specified values of penetration measured according to the standard NF EN 1426. 16. The method according to clause 15, comprising the following steps: i) preparation of the pre-mix by mixing: (a) bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter excluded, (b) at least one blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter, moreover, this pre-mixture has a needle penetration at 25 ° C from 50 to 100 tenths of a millimeter, more preferably from 60 to 90 tenths of a millimeter; ii) simultaneously or sequentially mixing said premix with bitumen having needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter being excluded, and at least one polymer moreover, the specified values of penetration measured according to the standard NF EN 1426. 17. The method according to clause 15, comprising the following steps: i) preparation of the pre-mix by mixing: (a) bitumen with needle penetration at 25 ° C, greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter excluded, (b) at least one blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter, moreover, this pre-mixture has a needle penetration at 25 ° C from 80 to 150 tenths of a millimeter, more preferably from 90 to 130 tenths of a millimeter; ii) simultaneously or sequentially mixing said premix with bitumen having needle penetration at 25 ° C greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter being excluded, and at least one polymer moreover, the specified values of penetration measured according to the standard NF EN 1426. 18. The method according to claim 15, wherein the temperature during the mixing of bitumen with needle penetration at 25 ° C is greater than or equal to 600 tenths of a millimeter, with a value of 900 tenths of a millimeter excluded; blown bitumen with needle penetration at 25 ° C from 10 to 50 tenths of a millimeter, and the polymer is from 135 to 210 ° C, preferably from 150 to 195 ° C, more preferably from 175 to 190 ° C. 19. A method according to any one of claims 16, 17, wherein the temperature during pre-mixing and during mixing of bitumen with needle penetration at 25 ° C is greater than or equal to 600 tenths of a millimeter, and a value of 900 tenths of a millimeter is excluded, and the polymer is from 135 to 210 ° C, preferably from 150 to 195 ° C, more preferably from 175 to 190 ° C. 20. The use of bitumen composition according to any one of claims 1 to 14 in road construction, and this composition has a needle penetration at 0 ° C, according to the standard Russian test GOST 11501-78, more than 30 tenths of a millimeter, preferably more than 32 tenths of a millimeter, and preferably , needle penetration at 25 ° C, according to the standard NF EN 1426, from 60 to 90 tenths of a millimeter, preferably from 65 to 88 tenths of a millimeter. 21. Bituminous binder containing a bitumen composition according to any one of claims 1 to 14. 22. Bituminous mineral mixture containing bituminous binder according to claim 21, granulate and optionally fine aggregate, sand, crushed stone. 23. The method for producing a bitumen-mineral mixture according to claim 22, wherein the bitumen binder according to claim 21 is mixed and the granulate is at a temperature of from 170 to 190 ° C, more preferably from 180 to 185 ° C. 24. Roads or highways, covered with bitumen-mineral mixture according to item 22 or prepared according to item 23. 25. The use of bitumen-mineral mixture according to claim 22 or prepared according to claim 23 for obtaining pavements of roads or highways.

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