Patent Application
20220145079
The invention is directed to a bituminous composition which is solid at ambient temperature, notably at high ambient temperature. This composition is advantageous when it is conditioned in a divided form, notably in the form of blocks or pellets. The invention also relates to the use of such a bituminous composition as a road binder and/or for different industrial applications. The present invention finally relates to a process for the transportation and/or the storage and/or the handling of bitumen in the form of a bituminous composition according to the invention.
Bitumen or bituminous binder is the main hydrocarbon binder used in the road-building sector and in civil engineering. To be used for these different applications, bitumen may has to respond to severe requirements regarding notably its physico-chemical and mechanical properties. Firstly, bitumen has to be sufficiently hard and present a good consistency at the temperatures of use in order to prevent rutting phenomena due to road traffic. Secondly, bitumen has to be sufficiently elastic in order to resist to distortions, to prevent the cracking of the bituminous mixes and/or to the stripping of the superficial aggregates caused by the road traffic and/or to temperature changes. At last, bitumen has to be sufficiently fluid at the temperatures of application, that should be the lowest as possible, in order to permit, for example, the formation of a good mix with the aggregates and an easy processing of the obtained bituminous mix on the road. A convenient bituminous binder has thus to combine hardness and consistency but also elasticity at the temperatures of use and a low viscosity at the temperatures of processing and application.
Generally, bitumen, taken alone, is not sufficiently elastic. In order to improve the elasticity of bitumen, it is common practice to add polymers, optionally crosslinked. However, crosslinking of the polymer chains is irreversible: once crosslinking achieved, it is impossible to turn back to the initial state that existed before the crosslinking reaction. Moreover, even if the crosslinked bituminous compositions have good elastic properties, the resulting bitumen/polymer compositions have a very high viscosity. One of the drawbacks of this high viscosity is the need to heat the crosslinked bitumen to a temperature of processing and application which is superior to that which is used for non-crosslinked bitumens. These increased temperatures of processing result in higher energetic costs and in the need of supplementary protections for the operators in contact with hot bitumen.
Depending on the intended application, it is necessary to find the good compromise between all the mechanical properties of the binder, notably between elasticity, hardness, consistency and viscosity, in particular viscosity at hot temperature.
Another important aspect associated to the use of bitumen concerns its transportation, handling and storage. Generally, bitumen is stored and transported under hot conditions, in bulk, in tank trucks or by boats at elevated temperatures of the order of 120° C. to 160° C. As a point of fact, the storage and the transportation of bitumen under hot conditions exhibit several disadvantages. First, the transportation of bitumen under hot conditions in the liquid form is considered to be dangerous and is highly restricted from a regulatory viewpoint. This mode of transportation does not present particular difficulties when the transportation equipment and infrastructures are in good condition. But if this is not the case, it can become problematic: if the tank truck is not sufficiently lagged, the viscosity of the bitumen can increase during an excessively long trip. Bitumen delivery distances are therefore limited. Second, keeping bitumen at elevated temperatures in vessels or in tank trucks consumes energy. In addition, keeping bitumen at elevated temperatures for a lengthy period of time can affect the properties of the bitumen and thus change the final performance qualities of the bituminous mix.
In order to overcome the problems of the transportation and the storage of bitumen under hot conditions, packagings which make possible the transportation and the storage of bitumens at ambient temperature have been developed. This mode of transportation of bitumen in packaging at ambient temperature represents only a minimal fraction of the amounts transported worldwide but it corresponds to real needs for geographic regions to which access by conventional transportation means are difficult and expensive.
U.S. Pat. No. 7,918,930 teaches the preparation of a bitumen base presenting some characteristics of a blown bitumen, the bitumen base being prepared by the addition of a blowing additive of general formula Ar1-R-Ar2. This document is not concerned with the transportation and/or the storage of the bituminous compositions.
WO 2008/107551 teaches the reversible reticulation of bitumen compositions based on the use of organogelators additives. The obtained bituminous compositions have a penetrability, measured at 25° C., of from about 40 to 70 l/10 mm.
WO 2016/16320 discloses the preparation of bitumen blocks comprising at least one chemical additive. The obtained blocks have a good creeping resistance and do not agglomerate during their transportation and/or handling and/or storage.
US 2015/152265 discloses a thermoreversibly cross-linked bituminous composition comprising:
WO 2017/203154 discloses a bitumen which is solid at ambient temperature, in the form of pellets comprising a core made of a first bituminous material and a coating layer made of a second bituminous material.
US 2018/155629 discloses a bitumen which is solid at ambient temperature, in the form of pellets comprising a core and a coating layer in which:
WO 2018/104660 discloses a method suitable for the preparation of bitumen pellets comprising a core and a coating layer, wherein the core comprises at least one bitumen base, and the coating layer comprises at least:
None of these documents discloses bituminous compositions comprising the association of the two additives as defined here-after.
The Applicant has now surprisingly discovered new bituminous compositions that are solid at ambient temperature and which may be used as road binder. The bituminous compositions according to the invention are advantageous in that they allow preventing and/or reducing more efficiently the phenomena of agglomeration or sticking, which may occur during the transportation and/or the handling and/or the storage at ambient temperature of bituminous composition in a divided form, notably at high ambient temperature and over extended periods of time. Bituminous compositions according to the invention are further advantageous in that their properties are maintained over time, notably during transportation and/or storage and/or handling. It is important that a balance be found between reducing bitumen units (pellets or blocks for example) sticking and producing a bitumen that has satisfying mechanical properties.
More specifically, the Applicant has discovered that the new bituminous compositions, conditioned in a divided form, notably in the form of blocks or pellets, have an improved creeping resistance. This creeping resistance is particularly important in extreme conditions of transportation and/or storage and/or handling and/or under compression, particularly under compression due to storage, over long periods of time.
The invention is directed to a bituminous composition comprising at least:
a) a bitumen base,
Ar1-R1—Ar2 (I)
wherein:
c) a second chemical additive chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde.
According to a favorite embodiment, the invention is directed to a bituminous composition which is solid at ambient temperature and in a divided form, said bituminous composition comprising at least:
a) a bitumen base,
b) a compound of general formula (I):
Ar1-R1-Ar2 (I)
wherein:
c) a second chemical additive chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde.
According to a favorite embodiment, the bituminous composition is in the form of blocks or pellets.
Preferably, the compound of general formula (I) is 2′,3-bis[(3-[3,5-di(tert-butyl)-4-hydroxyphenyl]propionyl)]propionohydrazide.
Preferably, the second chemical additive is chosen from sorbitol derivatives.
More preferably, the second chemical additive is 1,3:2,4-di-O-benzylidene-D-sorbitol.
Advantageously, the bituminous composition comprises from 0.1% to 10% by weight of one or several compounds of general formula (I), preferably from 0.2% to 5% by weight, more preferably from 0.3% to 2.5% by weight, and advantageously from 0.4% to 1.5% by weight, with respect to the total weight of the bituminous composition.
Advantageously, the bituminous composition comprises from 0.1% to 10% by weight of one or several chemical additive(s) chosen the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde, preferably from 0.15% to 5% by weight, more preferably from 0.2% to 2.5% by weight, and advantageously from 0.2% to 2% by weight, with respect to the total weight of the bituminous composition.
According to an embodiment, the sum of the weights of the compounds of general formula (I) and of the chemical additive(s) chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde represents from 0.2% to 10%, preferably from 0.3% to 7%, even more preferably from 0.4% to 5%, with respect to the total weight of the bituminous composition.
Preferably, the ratio of the weight of the compounds of general formula (I) to the weight of the chemical additive(s) chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde in the composition is from 0.1 to 10, preferably from 0.2 to 5, even more preferably from 0.4 to 2.5.
The invention also relates to a process for the preparation of a bituminous composition as defined above and as disclosed in more details here-under, said process comprising:
The invention is also directed to the use as road binder of a bituminous composition as defined above and as disclosed in more details here-under, preferably for the preparation of bituminous mixes.
The invention is also directed to a bituminous mix comprising:
According to a favorite embodiment, the bituminous mix is a road bituminous mix, a bituminous concrete or a bituminous mastic, preferably a road bituminous mix.
The invention is also directed to a process for the manufacture of bituminous mixes comprising at least one road binder and aggregates, the road binder being chosen from the bituminous compositions as defined above and as disclosed in more details here-under, said process comprising at least the following steps:
Advantageously, the process does not comprise a stage of heating the road binder before it is mixed with aggregates.
According to a favorite embodiment of the process, at least part of the aggregates originates from recycled bituminous mixes.
The invention also relates to the use of a bituminous composition as defined above and as disclosed in more details here-under for the preparation of a sealing coating, an insulating coating, a roofing material, a membrane or an impregnation layer.
The invention finally relates to a process for the transportation and/or the storage and/or the handling of bitumen, said bitumen being transported and/or stored and/or handled at ambient temperature, notably at high ambient temperature, in the form of a bituminous composition as defined above and as disclosed in more details here-under, preferably in a solid and divided form, notably in the form of blocks or pellets as defined above and as disclosed in more details here-under.
The present invention will now be described with occasional reference to the illustrated embodiments of the invention. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein, nor in any order of preference. Rather, these embodiments are provided so that this disclosure will be more thorough, and will convey the scope of the invention to those skilled in the art.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
As used herein, the term “consists essentially of” followed by one or more characteristics, means that may be included in the process or the material of the invention, besides explicitly listed components or steps, components or steps that do not materially affect the properties and characteristics of the invention.
The expression “comprised between X and Y” includes boundaries, unless explicitly stated otherwise. This expression means that the target range includes the X and Y values, and all values from X to Y.
Aspects of the present invention relates to a bitumen composition that may be subjected to an elevated ambient temperature, in particular a temperature ranging up to 100° C., preferably from 20° C. to 80° C.
In some exemplary embodiments, the bitumen is solid at ambient temperatures.
By “solid at ambient temperature” it is meant that the bitumen composition is in a solid state and exhibits a solid appearance at ambient temperature, whatever the conditions of transportation and/or of storage and/or of handling. More specifically, the bitumen composition retains its solid appearance throughout the transportation and/or storage and/or handling at ambient temperature. The bitumen composition does not creep at ambient temperature under its own weight and does not creep when it is subjected to forces of pressures resulting from the conditions of transportation and/or of storage and/or of handling.
The term “penetrability” is understood here to mean the “needle penetrability” or “pen value” measurement, which is carried out by means of an NF EN 1426 standardized test at 25° C. (P25) and/or ASTM D5/DSM. This penetrability characteristic is expressed in tenths of a millimeter (dmm or 1/10 mm). The needle penetrability, measured at 25° C., according to the NF EN 1426 standardized test, represents the measurement of the penetration into a bitumen sample, after a time of 5 seconds, of a needle, the weight of which with its support is 100 g. The standard NF EN 1426 replaces the equivalent standard NF T 66-004 of December 1986 with effect on Dec. 20, 1999 (decision of the Director General of AFNOR dated Nov. 20, 1999).
The term “softening point” is understood to mean the “ring-and-ball softening point” measurement which is carried out by means of an NF EN 1427 standardized test. The ring-and-ball softening point corresponds to the temperature at which a steel ball of standard diameter, after having passed through the material to be tested (stuck in a ring), reaches the bottom of a standardized tank filled with a liquid which is gradually heated and in which the apparatus has been immersed.
The invention firstly relates to a bituminous composition comprising at least:
a) a bitumen base,
b) a first chemical additive chosen from compounds of general formula (I):
Ar1-R1—Ar2 (I)
wherein:
c) a second chemical additive chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde.
According to a favorite embodiment, the invention relates to a bituminous composition consisting essentially of:
a) a bitumen base,
b) a first chemical additive chosen from compounds of general formula (I):
Ar1-R1—Ar2 (I)
wherein:
c) a second chemical additive chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde.
The Bitumen Base
The bituminous composition according to the invention may comprise one or several bitumen bases, notably bitumen bases of different origins.
Among the bitumen bases that may be used according to the invention, mention may first be made of bitumens of natural origin, those contained in deposits of natural bitumen, of natural asphalt or bituminous sands, and bitumens originating from the refining of crude oil.
Preferably, the bitumen bases are chosen from bitumen bases originating from the refining of crude oil or from bituminous sands, more preferably chosen from bitumen bases originating from the refining of crude oil.
The bitumen bases may be chosen from bitumen bases or mixtures of bitumen bases originating from the refining of crude oil, in particular bitumen bases containing asphaltenes or pitches.
The bitumen bases may be obtained by conventional processes for manufacturing bitumen bases at a refinery, in particular by direct distillation and/or vacuum distillation of oil. These bitumen bases may optionally be viscosity-reduced (visbroken) and/or deasphalted and/or air-rectified. It is common practice to perform vacuum distillation on the atmospheric residues originating from the atmospheric distillation of crude oil. This manufacturing process consequently corresponds to the sequence of atmospheric distillation and vacuum distillation, the feedstock supplying the vacuum distillation corresponding to the atmospheric distillation residues. These vacuum residues deriving from the vacuum distillation tower may also be used as bitumens.
It is also common practice to inject air into a feedstock usually composed of distillates and of heavy products originating from the vacuum distillation of atmospheric residues originating from the distillation of oil. This process makes it possible to obtain a blown or semi-blown or air-oxidized or air-rectified or partially air-rectified base. The various bitumen bases obtained by the refining processes may be combined with one another in order to obtain the best technical compromise. The bitumen base may also be a recycled bitumen base. The bitumen bases may be bitumen bases of hard grade or of soft grade.
According to the invention, for conventional processes for manufacturing bitumen bases, the process is performed at manufacturing temperatures of between 100° C. and 200° C., preferably between 140° C. and 200° C., more preferably between 140° C. and 170° C. The bitumen composition is stirred for a period of time of at least 10 minutes, preferably of between 30 minutes and 10 hours, more preferably between 1 hour and 6 hours. The term “manufacturing temperature” means the temperature of heating of the bitumen base(s) before mixing and also the mixing temperature. The temperature and the duration of the heating vary according to the amount of bitumen used and are defined by the standard NF EN 12594.
Preferably, the bitumen base used in the invention has a needle penetrability measured at 25° C. according to standard EN 1426 of from 30 to 330 l/10 mm, preferably from 30 to 220 l/10 mm.
According to some aspects of the invention, oxidized bitumens can be manufactured in a blowing unit by passing a stream of air and/or oxygen through a starting bituminous base. This operation can be carried out in the presence of an oxidation catalyst, for example phosphoric acid. Generally, the oxidation is carried out at elevated temperatures, of the order of 200° C. to 300° C., for relatively long periods of time typically of between 30 minutes and 2 hours, continuously or batchwise. The period of time and the temperature for oxidation are adjusted as a function of the properties targeted for the oxidized bitumen and as a function of the quality of the starting bitumen.
Advantageously, the bitumen bases are chosen from bitumens of natural origin; bitumens originating from bituminous sands; bitumens originating from the refining of crude oil such as the atmospheric distillation residues, the vacuum distillation residues, the visbroken residues, the semi-blown residues and their mixtures; and their combinations or from synthetic bitumens.
Preferably, the bituminous composition according to the invention comprises from 70 to 99.8% by weight of one or several bitumen bases, more preferably from 75% to 99.7% by weight, even more preferably from 80 to 99.6% by weight, and advantageously from 80% to 99% by weight, with respect to the total weight of the bituminous composition.
The First Chemical Additive
The bituminous composition according to the invention comprises at least one first chemical additive chosen from compounds of general formula (I):
Ar1-R1-Ar2 (I)
wherein:
Preferably, Ar1 and/or Ar2 are substituted by at least one alkyl group comprising from 1 to 10 carbon atoms, advantageously in one or more ortho positions with respect to the hydroxyl group(s); more preferably Ar1 and Ar2 are 3,5-dialkyl-4-hydroxyphenyl groups, advantageously 3,5-di(tert-butyl)-4-hydroxyphenyl groups.
Preferably, R1 is in the para position with respect to a hydroxyl group of Ar1 and/or Ar2.
Advantageously, the compound of general formula (I) is 2′,3-bis[(3-[3,5-di(tert-butyl)-4-hydroxyphenyl]propionyl)]propionohydrazide.
Preferably, the bituminous composition according to the invention comprises from 0.1 to 10% by weight of one of several compounds of general formula (I), with respect to the total weight of the bituminous composition.
More preferably, the bituminous composition according to the invention comprises at least 0.4% by weight of one or several compounds of general formula (I), with respect to the total weight of the bituminous composition
Preferably, the bituminous composition according to the invention comprises from 0.1% to 10% by weight of one or several compounds of general formula (I), more preferably from 0.2 to 5% by weight, even more preferably from 0.3% to 2.5% by weight, and advantageously from 0.4% to 1.5% by weight, with respect to the total weight of the bituminous composition.
The Second Chemical Additive
The bituminous composition according to the invention further comprises at least one second chemical additive chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde.
Among the polyols that may be used, mention may be made of sorbitol, xylitol, mannitol and/or ribitol. Preferably, the polyol is sorbitol.
Among the aldehydes that may be used, mention may be made of compounds of formula RCHO, wherein R is chosen from a C1-C11 alkyl, alkenyl, aryl or aralkyl radical, optionally substituted with one or more halogen atoms, and/or one or more C1-C6 alkoxy groups.
Advantageously, the second chemical additive comprises at least one function of general formula (II):
in which:
The organic compound is advantageously a sorbitol derivative. The term “sorbitol derivative” means any reaction product obtained from sorbitol, in particular any reaction product obtained by reacting an aldehyde with D-sorbitol. Sorbitol acetals, which are sorbitol derivatives, are obtained via this condensation reaction. 1,3:2,4-Di-O-benzylidene-D-sorbitol is obtained by reacting 1 mol of D-sorbitol and 2 mol of benzaldehyde and has the formula:
The sorbitol derivatives may thus all be condensation products of aldehydes, especially of aromatic aldehydes, with sorbitol. Sorbitol derivatives will then be obtained of general formula:
where Ar1 and Ar2, identical or different, are optionally substituted aromatic nuclei.
The sorbitol derivatives, other than 1,3:2,4-di-O-benzylidene-D-sorbitol, can include, for example, 1,3:2,4:5,6-tri-O-benzylidene-D-sorbitol, 2,4-mono-O-benzylidene-D-sorbitol, 1,3:2,4-bis(p-methylbenzylidene)sorbitol, 1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol, 1,3:2,4-bis(p-ethylbenzylidene)sorbitol, 1,3:2,4-bis(p-propylbenzylidene)sorbitol, 1,3:2,4-bis(p-butylbenzylidene)sorbitol, 1,3:2,4-bis(p-ethoxylbenzylidene)sorbitol, 1,3:2,4-bis(p-chlorobenzylidene)sorbitol, 1,3:2,4-bis(p-bromobenzylidene)sorbitol, 1,3:2,4-di-O-methylbenzylidene-D-sorbitol, 1,3:2,4-di-O-dimethylbenzylidene-D-sorbitol, 1,3:2,4-di-O-(4-methylbenzylidene)-D-sorbitol and 1,3:2,4-di-O-(4,3-dimethylbenzylidene)-D-sorbitol.
Preferably, the second chemical additive is 1,3:2,4-di-O-benzylidene-D-sorbitol.
Preferably, the bituminous composition according to the invention comprises from 0.1% to 10% by weight of one or several compounds chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde, more preferably from 0.15% to 5% by weight, even more preferentially from 0.2% to 2.5%, and advantageously from 0.2% to 2% by weight, with respect to the total weight of the bituminous composition.
Advantageously, in the bituminous composition according to the invention, the sum of the weights of the compounds of general formula (I) and of the chemical additive(s) chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde represents from 0.2% to 10%, preferably from 0.3% to 7%, even more preferably from 0.4% to 5%, with respect to the total weight of the bituminous composition.
Preferably, the ratio of the weights of the compounds of general formula (I) to the weight of the chemical additive(s) chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde in the bituminous composition is from 0.1 to 10, preferably from 0.2 to 5, even more preferably from 0.4 to 2.5.
Optional Additives
According to some embodiments of the invention, the bitumen base may further comprise at least one polymer additive and/or at least one fluxing agent.
As polymer suitable for bitumen, mention may be made by way of example of:
Preferably, the bituminous composition comprises from 0.05% to 15% by weight of polymer additive(s), preferably from 0.1% to 10% by weight, and more preferentially from 0.5% to 6% by weight, relative to the total weight of the bituminous composition.
According to a first variant, the bituminous composition comprises at least one polymer chosen from the elastomers.
Preferably, the elastomer is chosen from copolymers based on conjugated diene units and aromatic monovinyl hydrocarbon units, more preferably from the copolymers of styrene and butadiene.
Advantageously, the elastomer is chosen random and block copolymers, more advantageously from block copolymers.
More preferentially, the elastomer is chosen from SB (styrene/butadiene) block copolymers, SBS (styrene/butadiene/styrene) block copolymers and SBS* (styrene/butadiene/styrene) star copolymers.
Preferably, the bituminous composition according to the invention comprises from 0.05% to 15% by weight of elastomer(s), more preferentially from 0.1% to 10% by weight, even more preferentially from 0.5% to 6% by weight, relative to the total weight of the bituminous composition.
According to another variant, the bituminous composition comprises at least one polymer chosen from the olefinic polymer adjuvants.
Advantageously, the olefinic polymer adjuvant is chosen from the group consisting of (a) ethylene/glycidyl (meth)acrylate copolymers; (b) ethylene/monomer A/monomer B terpolymers and (c) the mixtures of these copolymers:
(a) The ethylene/glycidyl (meth)acrylate copolymers are advantageously chosen from random or block, preferably random, copolymers of ethylene and of a monomer chosen from glycidyl acrylate and glycidyl methacrylate, comprising from 50% to 99.7% by weight, preferably from 60% to 95% by weight, more preferentially from 60% to 90% by weight, of ethylene.
(b) The terpolymers are advantageously chosen from random or block, preferably random, terpolymers of ethylene, of a monomer A and of a monomer B.
The monomer A is chosen from vinyl acetate and C1 to C6 alkyl acrylates or methacrylates.
The monomer B is chosen from glycidyl acrylate and glycidyl methacrylate.
The ethylene/monomer A/monomer B terpolymers comprise from 0.5% to 40% by weight, preferably from 5% to 35% by weight, more preferably from 10% to 30% by weight, of units resulting from the monomer A and from 0.5% to 15% by weight, preferably from 2.5% to 15% by weight, of units resulting from the monomer B, the remainder being formed of units resulting from ethylene.
(c) The olefinic polymer adjuvant may consists of a mixture of two or more copolymers chosen from copolymers (a) and terpolymers (b).
The olefinic polymer adjuvant is, advantageously chosen from (b) ethylene/monomer A/monomer B terpolymers as defined above and the mixtures (c) comprising such terpolymers.
Preferably, the olefinic polymer adjuvant is chosen from (b) ethylene/monomer A/monomer B terpolymers as defined above and the mixtures (c) comprising at least 50% by weight of terpolymers (b), preferably at least 75% by weight, more preferably at least 90% by weight, with respect to the total weight of the mixture.
More preferably, the olefinic polymer adjuvant is chosen from random terpolymers (b) of ethylene, of a monomer A chosen from C1 to C6 alkyl acrylates or methacrylates and of a monomer B chosen from glycidyl acrylate and glycidyl methacrylate, comprising from 0.5% to 40% by weight, preferably from 5% to 35% by weight, more preferably from 10% to 30% by weight, of units resulting from the monomer A and from 0.5% to 15% by weight, preferably from 2.5% to 15% by weight, of units resulting from the monomer B, the remainder being formed of units resulting from ethylene.
Preferably, the number average molecular mass (Mn) of the olefinic polymer adjuvant, determined by gel permeation chromatography with a styrene standard, is from 5 000 to 50 000 g·mol−1, more preferably from 10 000 to 40 000 g·mol−1, even more preferably from 25 000 to 40 000 g·mol−1.
Preferably, the mass average molecular mass (Mw) of the olefinic polymer adjuvant, determined by gel permeation chromatography with a styrene standard, is from 10 000 to 250 000 g·mol−1, more preferably from 50 000 to 200 000 g·mol−1, even more preferably from 10 000 to 150 000 g·mol−1.
Advantageously, according to this embodiment, the bituminous composition comprises from 0.05% to 15% of one or several olefinic polymer adjuvants, more preferably from 0.1% to 10% by weight, even more preferably from 0.5% to 6% by weight, with respect to the total weight of the bituminous composition.
According to a specific embodiment, the bituminous composition comprises at least one elastomer and at least one olefinic polymer adjuvant.
Additional additives may also be included in the bitumen composition. Such additives include, for example vulcanization and/or crosslinking agents which are able to react with the polymer, notably with the elastomer and/or the plastomer, which may be functionalized and/or which may comprise reactive sites.
As vulcanization agents, mentions may be made by way of example of sulphur based vulcanization agents and its derivatives. Such vulcanization agents are generally introduced in a content of from 0.01% to 30% by weight, with respect to the weight of the elastomer.
As crosslinking agents, mentions may be made by way of example of cationic reticulation agents such as mono or polyacids; carboxylic anhydrides; esters of carboxylic acids; sulfonic, sulfuric, phosphoric or chloride acids; phenols. Such crosslinking agents are generally introduced in a content of from 0.01% to 30% by weight, with respect to the weight of the polymer. These agents are likely to react with the functionalized elastomer and/or plastomer. They may be used to complete and/or to substitute vulcanization agents.
The Bituminous Composition
Preferably, the bituminous composition according to the invention comprises, or better consists essentially of:
a) one or several bitumen bases,
b) one or several compounds of general formula (I),
c) one or several chemical additive(s) chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde, and
d) optionally, one or several polymer additive(s), preferably chosen from the elastomers and the olefinic polymer adjuvants as defined above.
More preferably, the bituminous composition according to the invention comprises, preferably consists essentially of:
a) from 80% to 99.8% by weight of one or several bitumen bases,
b) from 0.1 to 10% by weight of one or several compounds of general formula (I), and
c) from 0.1 to 10% by weight of one or several chemical additive(s) chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde,
with respect to the total weight of the bituminous composition.
Advantageously, the bituminous composition according to the invention comprises, preferably consists essentially of:
a) from 90% to 99.65% by weight of one or several bitumen bases,
b) from 0.2% to 5% by weight of one or several compounds of general formula (I), and
c) from 0.15 to 5% by weight of one or several chemical additive(s) chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde,
with respect to the total weight of the bituminous composition.
More advantageously, the bituminous composition according to the invention comprises, preferably consists essentially of:
a) from 95% to 99.5% % by weight of one or several bitumen bases,
b) from 0.3% to 2.5% by weight of one or several compounds of general formula (I), and
c) from 0.2 to 2.5% by weight of one or several chemical additive(s) chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde,
with respect to the total weight of the bituminous composition.
Even more advantageously, the bituminous composition according to the invention comprises, preferably consists essentially of:
a) from 96.5% to 99.4% by weight of one or several bitumen bases,
b) from 0.4% to 1.5% by weight of one or several compounds of general formula (I), and
c) from 0.2% to 2% by weight of one or several chemical additive(s) chosen from the reaction products of at least one C3-C12 polyol and of at least one C2-C12 aldehyde, with respect to the total weight of the bituminous composition.
Preferably, the bituminous composition according to the invention has a penetrability at 25° C., measured according to standard EN 1426, less than or equal to 50 l/10 mm, more preferentially from 5 to 45 l/10 mm, even more preferentially from 10 to 40 l/10 mm, and advantageously from 20 to 40 l/10 mm.
Preferably, the bituminous composition according to the invention has a ring-and-ball softening point, measured according to standard EN 1427, superior or equal to 80° C., more preferentially superior or equal to 90° C., even more preferentially superior or equal to 95° C., and advantageously superior or equal to 100° C.
Preferably, the bituminous composition according to the invention has a maximum force (Fmax) greater than or equal to 20 N, preferentially greater than or equal to 30 N, more preferentially of from 20 N to 250 N, and advantageously of from 30 N to 200 N.
In some advantageous embodiments, the bituminous composition according to the invention has a maximum force (Fmax) greater than or equal to 50 N, preferentially greater than or equal to 75 N, more preferentially greater than or equal to 100 N, and advantageously superior or equal to 150 N.
Preferably, according to these embodiments, the bituminous composition according to the invention has a maximum force (Fmax) of from 50 N to 250N, more preferentially from 75 N to 220 N, even more preferentially from 100 N to 200 N.
The maximum force (Fmax) may for example by measured with a texture analyzer commercialized by LLOYD Instruments under the name LF Plus and equipped with a thermal enclosure. The piston of the texture analyzer is a cylinder having a diameter of 25 mm and a height of 60 mm.
A cylindrical metallic box comprising 60 g of the bituminous composition to analyze is introduced inside the thermal enclosure settled at a temperature of 50° C. The cylindrical piston is initially placed in contact with the superior surface of the bituminous composition. Then, the piston is put in a vertical movement to the bottom of the box, at a constant velocity equal to 1 mm/min and over a calibrated distance of 10 mm in order to apply to the superior surface of the bituminous composition a compression strength. The texture analyzer measures the maximal force (Fmax) applied by the piston on the surface of the bituminous composition at 50° C.
The determination of the maximal force (Fmax) allows evaluating the capacity of the bituminous composition to resist to the deformation, when it is submitted to a specific mass having a constant applied velocity. The higher the maximal force (Fmax) is, the better the compression strength a bituminous block or of bituminous pellets obtained from the bituminous composition.
Preferably, the bituminous composition according to the invention has a deformability at 65° C. strictly inferior to the deformability at 65° C. of the bitumen base, taken alone.
Preferably, the bituminous composition according to the invention has a deformability at 65° C., less than or equal to 900%, more preferentially less than or equal to 500%, even more preferentially less than or equal to 250%, and advantageously from inferior or equal to 50%.
The deformability of a bituminous composition may for example be determined according to the following protocol.
The bituminous composition to be analyzed is first poured in a circular silicon mold and then cooled at ambient temperature for at least 1 hour before being unmolded.
The lower plate of an ANTON PAAR Physica MCR 301 plate-plate rheometer is heated at a temperature of 65° C. Once the temperature has been reached, the rheometer is equipped with a PP25 mobile before being blanked. The gap of the rheometer is fixed at 2 mm. The unmolded solid bituminous composition is placed on the heated plan. The height of the mobile is then adjusted to 2.1 mm and the surplus of bituminous composition overflowing under the mobile is cut out by using a heated spatula. The gap of the rheometer is finally re-adjusted at 2 mm and the bell, previously heated at 65° C., is placed over the whole instrument. The measurement is launched as soon as the rheometer indicates a normal force value equal to 0 N. The constraint applied to the sample is set at 100 Pa and the acquisition time at 7200 s.
Bituminous Composition which is Solid and in a Divided Form at Ambient Temperature
According to an embodiment of the invention, the bituminous composition is solid at ambient temperature and in a divided form.
Preferably, according to this embodiment, the bituminous composition according to the invention further comprises at least one olefinic polymer adjuvant as defined above.
Advantageously, according to this embodiment, the bituminous composition according to the invention is conditioned in the form of bituminous blocks or bituminous pellets.
Bituminous Blocks
According to a first variant, the bituminous composition according to the invention is in the form of bitumen blocks.
The term “bitumen block” is intended to mean a block of road bitumen having a weight of between 1 kg and 1000 kg, preferably between 1 kg and 200 kg, more preferentially between 1 kg and 50 kg, even more preferentially between 5 kg and 25 kg, even more preferentially between 10 kg and 30 kg, said block advantageously being parallelepipedal, preferably being cobblestone-shaped.
The bitumen block preferably has a volume of between 1000 cm3 and 50 000 cm3, preferably between 5000 cm3 and 25 000 cm3, more preferentially between 10 000 cm3 and 30 000 cm3, even more preferentially between 14 000 cm3 and 25 000 cm3.
When the bitumen block is handled manually by a person, the weight of the bitumen block may vary from 1 to 20 kg, and from 20 to 50 kg in the case of handling by 2 people. When the handling is carried out by mechanical equipment, the weight of the bitumen block may vary from 50 to 1000 kg.
The bitumen block is advantageously wrapped in a hot-melt film according to any known method, preferably by a film made of polypropylene, polyethylene or a mixture of polyethylene and polypropylene. The bituminous composition packaged in bitumen blocks wrapped in a hot-melt film has the advantage of being ready to use, that is to say it may be heated directly in the melter without prior unwrapping or optionally introduced into the mixing unit for manufacturing road mixes. The hot-melt material that melts with the bitumen does not affect the properties of said bitumen.
The bitumen block may also be packaged in a box according to any known process.
In particular, the bitumen block is packaged in a box by pouring the hot bitumen into a box, the wall of the inner face of which is silicone based, then cooled, the dimensions of the box being suited to the desired bitumen block weight and/or volume.
When the bitumen block according to the invention is wrapped in a hot-melt film or is packaged in a box, the applicant has demonstrated that the deterioration of said hot-melt film or of said box during the transportation and/or storage, under cold conditions, of said bitumen block, did not give rise to the creeping of said bitumen. Consequently, the bitumen blocks according to the invention retain their initial shape and do not adhere to one another during their transportation and/or storage under cold conditions, despite the fact that the hot-melt film or the box may be damaged. The absence of creep of the bitumen in block form during its transportation and/or storage under cold conditions is due to the presence of the chemical compounds of formula (I) and (II) within the bitumen.
Bituminous Pellets
According to a second variant, the bituminous composition according to the invention is in the form of bituminous pellets.
The bitumen pellets may have, within the same population of pellets, one or more distinct shapes.
Preferably, the pellets have cylindrical, spherical, hemispherical, ovoid or tetrahedral form.
According to a first embodiment of the invention, the size of the bitumen pellets is such that the longest average dimension is preferably less than or equal to 50 mm, more preferentially from 1 to 30 mm, more preferentially from 5 to 20 mm, even more preferentially from 2 to 10 mm.
Preferably, when the bituminous pellets have a spherical, hemispherical or ovoid form, the size of the bituminous pellets is such that the longest average dimension is from 3 to 30 mm, more preferentially from 2 to 20 mm, even more preferentially from 2 to 10 mm.
Preferably, when the bituminous pellets have a tetrahedral form, the size of the bituminous pellets is such that the longest average dimension is from 2 to 60 mm, more preferentially from 5 to 50 mm, even more preferentially from 10 to 50 mm.
For example, the use of a die makes it possible to control the manufacture of pellets of a chosen size. Sieving makes it possible to select pellets according to their size.
Preferably, the bitumen pellets have a weight of from 0.1 g to 50 g, preferably between from 0.2 g to 30 g, more preferentially from 0.2 g to 20 g.
Preferably, when the bituminous pellets have a spherical, hemispherical or ovoide form, the pellets have a weight of from 0.2 g to 10 g, more preferably from 0.2 to 5 g.
Preferably, when the bituminous pellets have a tetrahedral form, the pellets have a weight of from 0.1 g to 50 g, preferentially from 0.2 g to 50 g more preferably from 0.2 to 20 g.
According to a specific embodiment, the bitumen pellets are covered over at least a portion of their surface with an anti-sticking compound, preferably over their whole surface.
In the context of the invention, the term “anti-sticking compound” is intended to mean any compound which limits the agglomeration and/or the adhesion of the blocks or the pellets to one another during transportation thereof and/or storage thereof at ambient temperature and which ensures that they are fluid when they are handled.
Preferably, the anti-sticking compound is chosen from anti-caking agents, viscosifying compounds and their mixtures.
Anti-Caking Agents According to a first variant, the anti-sticking compound is chosen from anti-caking compounds.
The anti-caking compound is of mineral or organic origin, preferably of mineral origin.
Preferably, the anti-caking compound is chosen from: talc; fines, also known as fillers, generally with a diameter of less than 125 μm, such as siliceous fines, with the exception of limestone fines; sand, such as Fontainebleau sand; cement; carbon; wood residues, such as lignin, lignosulfonate, conifer needle powders or conifer cone powders, in particular of pine; rice husk ash; glass powder; clays, such as kaolin, bentonite or vermiculite; alumina, such as alumina hydrates; silica; silica derivatives, such as pyrogenic or fumed silica, in particular hydrophobic or hydrophilic pyrogenic or fumed silica, silicates, silicon hydroxides and other silicon oxides; plastic powder; lime; plaster; rubber compost; polymer powder, where the polymers are such as styrene/butadiene (SB) copolymers or styrene/butadiene/styrene (SBS) copolymers, and the mixtures of these materials.
Advantageously, the anti-caking compound is chosen from: fines, generally with a diameter of less than 125 μm, with the exception of limestone fines; wood residues, such as lignin, lignosulfonate, conifer needle powders or conifer cone powders, in particular of pine; sand, such as Fontainebleau sand; glass powder; pyrogenic or fumed silica, in particular hydrophobic or hydrophilic pyrogenic or fumed silica and their mixtures.
Viscosifying Compounds
According a second variant, the anti-sticking compound is chosen from viscosifying compounds.
In the context of the invention, the term “viscosifying compound” is intended to mean any compound which increases the viscosity of a liquid or composition.
Preferably, the viscosifying compound is a material which has dynamic viscosity greater than or equal to 50 mPa·s, preferably from 50 mPa·s to 550 mPa·s, more preferably from 80 mPa·s to 450 mPa·s, the viscosity being a Brookfield viscosity measured at 65° C. The viscosity of the viscosifying compound is measured with a Brookfield CAP 2000+ viscometer at a rotation speed equal to 750 revolution per minute. For each sample, the measure is performed after 30 seconds.
Preferably, the viscosifying compound is chosen from:
More preferably, the viscosifying compound is chosen from:
Advantageously, the viscosifying compound is chosen from cellulosic ethers.
Preferably, the anti-sticking agent covers at least 50% of the surface of the bituminous pellets, more preferably at least 60%, even more preferably at least 70%, advantageously at least 80%, and more advantageously at least 90% of the surface of the bituminous pellets.
Advantageously, the content of anti-sticking agent present on the surface on the bituminous pellets represents from 0.2 to 10% by weight, preferably from 0.5 to 8% by weight, more preferably from 0.5 to 5% by weight, with respect to the total weight of the granules.
Preferably, the thickness of the layer of anti-sticking agent is greater than or equal to 20 μm, more preferably from 20 μm to 1 mm, even more preferably from 20 to 100 μm.
Process for the Preparation of the Bituminous Composition
The present invention also concerns a process for the preparation of a bituminous composition as defined above, said process comprising:
i) contacting, at a temperature of from 70° C. to 220° C., at least:
ii) optionally, shaping the obtained bituminous composition, notably in a divided form, preferably in the form of pellets or blocks as defined above.
The compound(s) of general formula (I), the reaction product(s) of at least one C3-C12 polyol and of at least one C2-C12 aldehyde, and optionally the polymer(s) may be added to the bitumen simultaneously or by successive additions.
Preferably, the compound(s) of general formula (I), the reaction product(s) of at least one C3-C12 polyol and of at least one C2-C12 aldehyde, and optionally the polymer(s) are contacted with the bitumen base at a temperature ranging from 90° C. to 180° C., more preferably from 110° C. to 180° C.
The bitumen base used in the above-defined process may be pure or additivated, notably with a polymer, in an anhydrous or emulsion form, or even in association with agglomerates in the form of a bituminous mix.
Advantageously, the process for the preparation of a bituminous composition according to the invention comprises the following steps:
A) the introduction of the bitumen in a reactor equipped with mixing means and its heating at a temperature ranging from 70° C. to 220° C., preferably from 90° C. to 180° C., more preferably from 110° C. to 180° C.,
B) the simultaneous and/or successive additions of the compound(s) of general formula (I) and of the reaction product(s) of at least one C3-C12 polyol and of at least one C2-C12 aldehyde,
C) optionally, the addition of the polymer(s), preferably chosen from the olefinic polymer adjuvant(s),
D) the mixture of the bituminous composition at a temperature ranging from 70° C. to 220° C., preferably from 90° C. to 180° C., more preferably from 110° C. to 180° C., until obtaining a homogenous composition, and
E) optionally, the shaping of the bituminous composition obtained at the end of step D), notably in a divided form, preferably in the form of pellets or blocks.
According to a specific embodiment, steps B) and C) are performed simultaneously in such a way that the compound(s) of formula (I) and the reaction product(s) of at least one C3-C12 polyol and of at least one C2-C12 aldehyde and the polymer(s) are simultaneously added to the hot bitumen.
In the context of bituminous blocks as defined above, step E) may be performed according to any industrially known process. The shaping of the bituminous blocks may for example be performed by extrusion, molding, or according to the manufacturing process described in the document US 2011/0290695.
According to a specific embodiment, and still in the context of the preparation of bituminous blocks, the process as defined above may optionally be followed by an additional step F) of wrapping the obtained bituminous block with a hot-melt film as defined above. The additional step F) may be performed according to any known process
In the context of the preparation of bituminous pellets as defined above, step F) may be performed according to any known methods. Mention may be made by way of examples of the manufacturing methods described in U.S. Pat. No. 3,026,568, WO 2009/153324, WO 2012/168380 or WO 2018/104660. According to a specific embodiment, the shaping of the pellets is performed by draining, in particular by using a drum. Other methods may also be used for the fabrication of the pellets such as for example molding, extrusion, co-extrusion technics, . . . .
According to a specific embodiment, and still in the context of the preparation of bituminous pellets, the process as defined above may optionally be followed by an additional step F′) of coating the obtained pellets, over all of parts of its surface, with at least one anti-sticking agent as defined above.
The additional step of coating F′) may be performed according to any known process. In particular, step F′) may be performed by dipping the bituminous pellets obtained at the end of step E) in a coating composition comprising at least one anti-sticking agent, optionally followed by a step of drying.
Process for the Transportation and/or Storage and/or Handling of Bitumen
The invention also relates to a process for the transportation and/or storage and/or handling of bitumen, said bitumen being transported and/or stored and/or handled at ambient temperature, notably at high ambient temperature, in the form of a bituminous composition according to the invention, preferably in a solid and divided form, notably in the form of pellets or blocks as defined above.
Preferably, the bituminous composition according to the invention is transported and/or stored at ambient temperature, notably at an elevated ambient temperature, for a period of time of greater than or equal to 2 months, preferably of greater than or equal to 3 months.
The term “ambient temperature” is understood to mean the temperature resulting from the climatic conditions under which the bitumen is transported and/or stored and/or handled. More specifically, the ambient temperature is equivalent to the temperature achieved during the transportation and/or storage and/or handling of the bitumen, it being understood that the ambient temperature implies that no contribution of heat is contributed other than that resulting from the climatic conditions.
As a consequence, the ambient temperature may reach elevated values, less than 100° C. during the summer, in particular in geographical areas with a hot climate.
Preferably, the ambient temperature is less than 100° C. Advantageously, the ambient temperature is from 20 to 50° C., preferably from 25° C. to 50° C., more preferably from 25 to 40° C.
Preferably, the elevated ambient temperature is from 40° C. to 90° C., preferably from 50° C. to 85° C., more preferably from 50° C. to 75° C., more preferably still from 50° C. to 70° C.
The bituminous compositions according to the invention in a divided form exhibit the advantage that the divided form is retained. Thus, the compositions can be handled, after storage and/or transportation at an elevated ambient temperature. The bituminous compositions according to the invention in a divided form can be transported and/or stored and/or handled in optimal conditions, in particular without creeping during their transport and/or storage, even at an elevated ambient temperature and without degradation of their properties.
Applications
The bituminous compositions according to the invention may be used for different applications, notably for the preparation of an anhydrous bituminous binder, of a bituminous emulsion, of a bitumen/polymer composition or of a fluxed bitumen.
Road Applications
The invention also relates to the use as road binder of a bituminous composition according to the invention, preferably in a solid and divided form, notably in the form of pellets or blocks as defined above.
Preferably, the bituminous composition according to the invention is used, optionally in mixtures with aggregates, possibly originating from recycled bituminous mixes, for the preparation of surface dressings, hot bituminous mixes, cold bituminous mixes, cold-poured bituminous mixes, grave emulsions, base layers, bond layers, tie layers and running layers.
Bituminous mixes are used as materials for the construction and maintenance of road foundations and their surfacing, an also for carrying out all road works. As other combinations of a bituminous binder and road aggregates having specific properties, mention may be made, for example, of anti-rutting layers, draining bituminous mixes, or asphalts (mixtures between a bituminous binder and aggregates of the sand type).
The invention also relates to a process for the preparation of bituminous mixes comprising at least one road binder and aggregates, the road binder being chosen from the bituminous compositions according to the invention, notably in a solid and divided form at ambient temperature, and in particular in the form of pellets or blocks as defined above.
Preferably, the process for the manufacture of bituminous mixes according to the invention comprises at least the following steps:
Advantageously, at least part of the aggregates used for the preparation of the bituminous mix are recycled aggregates, notably obtained from recycled bituminous mixes.
In the case where the bituminous composition according to the invention is in the form of blocks or pellets, the process for the manufacture of bituminous mixes of the invention does not require a stage of heating the solid and divided bituminous composition before mixing with the aggregates because, on contact with the hot aggregates, the bitumen which is solid at ambient temperature melts.
The invention also relates to a bituminous mix comprising:
(i) a bituminous composition according to the invention,
(ii) aggregates, and/or inorganic fillers and/or synthetic fillers.
Preferably, the bituminous mix according to the invention is a road bituminous mix, a bituminous concrete or a bituminous mastic.
The invention also concerns a process for the manufacture of a surface dressing, a hot bituminous mix, a cold bituminous mix, a cold-poured bituminous mix or a grave emulsion, the binder being mixed with aggregates, notably obtained from recycled bituminous mixes, said process comprising at least the preparation of a bituminous composition according to the invention, notably in a solid and divided form at ambient temperature, and in particular in the form of pellets or blocks as defined above.
The invention also relates to the use of a bituminous composition according to the invention, notably in a divided and solid form at ambient temperature and in particular in the form of pellets or blocks as defined above, for different industrial applications, notably for the preparation of a sealing coating, an insulating coating, a roofing material, a membrane or an impregnation layer.
The bituminous compositions according to the invention are particularly suitable for the preparation of waterproofing membranes, anti-noise membranes, insulating membranes, surface coatings, carpet tiles and impregnation membrane.
The invention finally relates to a process for the manufacture of a sealing coating, an insulating coating, a roofing material, a membrane or an impregnation layer, said process comprising the use of a bituminous composition according to the invention, notably in a divided and solid form at ambient temperature and in particular in the form of pellets or blocks as defined above.
The various embodiments, alternative forms, preferences and advantages described above for each of the subject matters of the invention apply to all the subject matters of the invention and can be taken separately or in combination.
The invention is illustrated by the following examples given as non-limiting.
In the following examples, the percentages are indicated by weight, unless otherwise specified.
1. Material and Methods
Definition of the Parameters
The rheological and mechanical characteristics of the compositions to which reference is made in these examples are measured by the methods listed in Table 1.
Materials
The Bitumen Base:
The bituminous compositions are prepared from the bitumen base B0 of PG64-22 grade, having a penetrability P25 of 65 l/10 mm and a Ring and Ball Softening temperature (RBT) of 48° C.
The Chemical Additives:
Method for the Preparation of the Bituminous Compositions
The bitumen base was introduced into a reactor maintained at a temperature ranging from 165 to 230° C. with stirring at 300 revolutions/min for two hours. The additives were subsequently introduced into the reactor. The contents of the reactor were maintained at hot temperature with stirring at 300 revolutions/min for 45 minutes.
Method for the Preparation of a Bituminous Block
Around 0.5 kg of the bituminous composition prepared above heated at a temperature of 160° C. is poured in a rectangular steel mold covered with a polyethylene thermofusible film. The mold is then cooled at ambient temperature and the block of bituminous composition finally unmolded.
Method for the Preparation of Bituminous Pellets
I—Preparation of the Core of the Bituminous Pellets
1.1 General Method for the Preparation of the Core of the Bituminous Pellets
The bituminous composition prepared above is heated at a temperature ranging from 150 to 180° C. for two hours in an oven before being poured into a silicone mold having different holes of spherical shape so as to form the cores of pellets. After 30 minutes, the bituminous binder composition in the form of uncoated pellets is demolded, the surplus of binder is levelled off with a blade heated with a Bunsen burner and the obtained bituminous core are stored in a tray coated with silicone paper.
The obtained bituminous cores are finally cooled at room temperature from 10 to 15 minutes.
1.2 General Method for the Preparation of the Core of the Bituminous Pellets According to an Industrial Process
For the implementation of this method, use may be made of a device and of a process as described in great detail in U.S. Pat. No. 4,279,579. Various models of this device are commercially available from the company Sandvik under the trade name Rotoform.
The bituminous composition prepared above is poured into the reservoir of such a device and maintained at a temperature of from 130 to 160° C.
An injection nozzle or several injection nozzles make(s) possible the transfer of the bituminous composition into the double pelletizing drum comprising an external rotating drum, the two drums being equipped with slots, nozzles and orifices making possible the pelletizing of drops of bituminous composition through the first fixed drum and orifices having a diameter of between 2 and 10 mm of the external rotating drum. The drops of bituminous composition are deposited on the upper face of a tread, horizontal, driven by rollers.
II—Coating of the Core of the Bituminous Pellets
The bituminous cores obtained in I—are poured into a coating composition. They are shaken manually in the coating composition for few minutes and then removed before being placed on a plate and cooled at ambient temperature (about 30° C.).
Solid bituminous pellets with a core/shell structure are finally obtained.
Protocol for the Measurement of the Maximum Force (Fmax)
The bituminous composition was tested to evaluate the compression strength of the composition submitted at a specific mass having a constant applied velocity. The compressive strength was evaluated by the measurement of the maximum force (Fmax) applied on the surface of the bituminous composition without observing any deformation of the bituminous composition. The test was executed at a temperature of 50° C.
The maximum force (Fmax) was measured with a texture analyzer commercialized by LLOYD Instruments under the name LF Plus and equipped with a thermal enclosure. The piston of the texture analyzer is a cylinder having a diameter of 25 mm and a height of 60 mm.
A cylindrical metallic box comprising 60 g of the bituminous composition was introduced inside the thermal enclosure settled at a temperature of 50° C. The cylindrical piston was initially placed in contact with the superior surface of the bituminous composition. Then, the piston was put in a vertical movement to the bottom of the box, at a constant velocity equal to 1 mm/min and over a calibrated distance of 10 mm in order to apply to the superior surface of the bituminous composition a compression strength. The texture analyzer measures the maximal force (Fmax) applied by the piston on the surface of the bituminous composition at 50° C.
The determination of the maximal force (Fmax) allows evaluating the capacity of the bituminous composition to resist to the deformation. The higher the maximal force (Fmax) is, the better the compression strength a bituminous block or pellet obtained from the bituminous composition.
Protocol for the Measurement of the Deformability (Def.)
The bituminous composition to be analyzed is first poured in a circular silicon mold and then cooled at ambient temperature for at least 1 hour before being unmolded.
The lower plate of an ANTON PAAR Physica MCR 301 plate-plate rheometer is heated at a temperature of 65° C. Once the temperature has been reached, the rheometer is equipped with a PP25 mobile before being blanked. The gap of the rheometer is fixed at 2 mm. The unmolded solid bituminous composition is placed on the heated plan. The height of the mobile is then adjusted to 2.1 mm and the surplus of bituminous composition overflowing under the mobile is cut out by using a heated spatula. The gap of the rheometer is finally re-adjusted at 2 mm and the bell, previously heated at 65° C., is placed over the whole instrument. The measurement is launched as soon as the rheometer indicates a normal force value equal to 0 N. The constraint applied to the sample is set at 100 Pa and the acquisition time at 7200 s.
2. Preparation of the Different Compositions
The bituminous compositions C1 to C10 corresponding to the mixtures defined in the following Table 2 are prepared according to the above-described protocol.
Compositions C3, C6, C9 and C10 are according to the invention.
Compositions C1, C2, C4, C5, C7 and C8 are comparative.
3. Rheological and Mechanical Properties of the Bitumen Compositions
The rheological and mechanical properties of the compositions C1 to C10 and of the bitumen bases B1 and B2 have been measured according to the above-defined protocols.
The results are given in the following Table 3.
Penetrability at 25° C.
Compositions C1 to C10 have a reduced penetrability (from 25 to 50 l/10 mm) as compared to the bitumen base B0 (65 l/10 mm).
The addition of at least one chemical additive A1 or A2 leads to a hardening of the bitumen base.
Composition C3 according to the invention (P25=39 l/10 mm) has a reduced penetrability as compared to compositions C1 (P25=50 l/10 mm) and C2 (P25=44 l/10 mm) comprising only one of the additives A1 and A2.
Composition C6 according to the invention (P25=23 l/10 mm) also has a reduced penetrability as compared to compositions C4 (P25=34 l/10 mm) and C5 (P25=27 l/10 mm) comprising only one of the additives A1 and A2.
Similarly, composition C9 according to the invention (P25=40 l/10 mm) has a reduced penetrability as compared to compositions C7 (P25=44 l/10 mm) and C8 (P25=46 l/10 mm) comprising only one of the additives A1 and A2.
The additivation of a bitumen base with the association of the additives A1 and A2 leads to a significant decrease of the penetrability, as compared to the same bitumen base additivated with only one of the two additives.
This demonstrates a synergy between additives A1 and A2, which results in a bituminous composition having an improved penetrability value.
Ring-and-Ball Softening Temperature (RBSP)
Compositions C1 to C10 (RBSP ranging from 65.5 to more than 150° C.) have a significantly increased ring-and-ball softening temperature as compared to the bitumen base B0 (RBSP=48° C.).
The addition of at least one chemical additive A1 or A2 leads to a significant increase of the ring-and-ball softening temperature of the bituminous composition.
Composition C3 according to the invention (RBSP=117.5° C.) has an increased ring-and-ball softening temperature as compared to compositions C1 (RBSP=92.5° C.) and C2 (RBSP=112° C.) comprising only one of the additives A1 and A2.
Composition C6 according to the invention (RBSP>150° C.) has a ring-and-ball softening temperature superior or equal to that of compositions C4 (RBSP=110° C.) and C5 (RBSP>150° C.) comprising only one of the additives A1 and A2.
Similarly, composition C9 according to the invention (RBSP=95.5° C.) has a ring-and-ball softening temperature superior or equal to that of compositions C7 (RBSP=95.5° C.) and C8 (RBSP=68.5° C.) comprising only one of the additives A1 and A2.
Maximum Force (Fmax)
Compositions C1 to C10 have an increased maximum force value (from 1.55 to 196 N) as compared to the bitumen base B0 (Fmax=0.9 N).
The addition of at least one chemical additive A1 or A2 leads to a significant increase of the maximum force value of the bituminous composition.
Composition C3 according to the invention (Fmax=87 N) has an increased maximum force value as compared to compositions C1 (Fmax=71.8 N) and C2 (Fmax=10 N) comprising only one of the additives A1 and A2.
Composition C6 according to the invention (Fmax=196 N) also has a significantly increased maximum force value as compared to compositions C4 (Fmax=91.6 N) and C5 (Fmax=60 N) comprising only one of the additives A1 and A2.
Similarly, composition C9 according to the invention (Fmax=32.3 N) has an increased maximum force value as compared to compositions C7 (Fmax=26.2 N) and C8 (Fmax=1.55 N) comprising only one of the additives A1 and A2.
The additivation of a bitumen base with the association of the additives A1 and A2 leads to a significant increase of the maximum force value, as compared to the same bitumen base additivated with only one of the two additives.
This demonstrates a synergy between additives A1 and A2, which results in bituminous compositions having an improved deformation stress.
Conditioned in a divided form, and notably in the form of blocks or pellets, the compositions according to the invention are stable during their storage. In particular, blocks and/or pellets obtained from a composition according to the invention have an improved creeping resistance as compared to the compositions of the prior art.
Deformability
Compositions C1 to C10 have a reduced deformability at 65° C. (from 0.0065 to 890%) as compared to the bitumen base B0 (Def.=5.105%).
The addition of at least one chemical additive A1 or A2 significantly reduces the deformation of a bituminous composition.
Composition C3 according to the invention (Def.=37.6%) has a reduced deformability at 65° C. as compared to compositions C1 (Def.=636%) and C2 (Def.=347%) comprising only one of the additives A1 and A2.
Composition C6 according to the invention (Def.=0.0065%) also has a significantly reduced deformability at 65° C. as compared to compositions C4 (Def.=0.13%) and C5 (Def=1.58%) comprising only one of the additives A1 and A2.
Similarly, composition C9 according to the invention (Def.=890%) has a significantly reduced deformability at 65° C. as compared to compositions C7 (Def.=1,187%) and C8 (Def=172,218%) comprising only one of the additives A1 and A2.
The additivation of a bitumen base with the association of the additives A1 and A2 leads to the obtention of compositions with a significantly reduced deformability, as compared to the same bitumen base additivated with only one of the two additives.
This demonstrates a synergy between additives A1 and A2, which results in bituminous compositions having an improved deformation stress.
Conditioned in a divided form, and notably in the form of blocks or pellets, the compositions according to the invention are stable during their storage. In particular, blocks obtained from a composition according to the invention are less deformable than the compositions of the prior art.
In addition, these compositions provide bituminous mixes, bituminous concretes and bituminous mastics with satisfying mechanical properties.
| Number | Date | Country | Kind |
|---|---|---|---|
| 19305321.2 | Mar 2019 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/055809 | 3/5/2020 | WO | 00 |
