Asphalt composition, asphalt composition manufacturing apparatus, asphalt composition manufacturing system, asphalt mixture, asphalt composition manufacturing method, and asphalt mixture manufacturing method

Abstract

Provided is a technique for suppressing peeling between asphalt and aggregate to improve water resistance performance. An asphalt composition of the present disclosure is characterized by including 14-300 ppm by mass of silicon element in terms of silicon atom with respect to the asphalt composition. The asphalt composition includes an organic silane compound, and the organic silane compound is preferably a silane-modified petroleum resin, and more preferably a silane-modified hydrogenated petroleum resin having an organic silane structure.

Description

[Technical Field]

[0001] The present invention relates to an asphalt composition that improves water resistance by suppressing peeling between asphalt and aggregate, an apparatus for producing an asphalt composition, an asphalt composition production system, an asphalt mixture, a method for producing an asphalt composition, and a method for producing an asphalt mixture. [Background technology]

[0002] In recent years, the main cause of damage to asphalt pavement has been identified as asphalt peeling, which occurs when rainwater or groundwater penetrates between the asphalt and aggregate, causing the asphalt covering the surface of the aggregate to peel off. This peeling between asphalt and aggregate reduces the ability of the asphalt to bond the aggregate together, potentially making it more susceptible to damage such as cracks and potholes.

[0003] In order to address this peeling phenomenon between asphalt and aggregate, methods have been investigated for suppressing peeling between asphalt and aggregate by mixing into asphalt anti-stripping agents such as amines, amides, and resin acids such as dimer acid and rosin, saturated fatty acids such as stearic acid, palmitic acid, and myristic acid, and fatty acids such as unsaturated fatty acids such as oleic acid, linoleic acid, and ricilenoic acid (Patent Documents 1 and 2). However, these anti-stripping agents such as amines, amides, resin acids, and fatty acids are expensive, and even if added in excess of a certain amount, sufficient anti-stripping effects are not obtained, particularly for acidic rocks such as granite that contain a lot of silica. Therefore, there is a need for technology that suppresses peeling between asphalt and aggregate for these rocks and inorganic substances mixed in as fillers.

[0004] The technology disclosed in Patent Document 3 is an asphalt composition containing an asphalt base oil and a silane-containing coupling agent. However, because the base of the silane-containing coupling agent is a butadiene polymer, it has a low flash point, making it difficult to ensure stability of properties during storage in factories, warehouses, etc., and is also unsafe when stored in large quantities. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-121320 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-143340 [Patent Document 3] Patent No. 6475390 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, the present disclosure has been devised in consideration of the above points, and its purpose is to provide a technology that suppresses peeling between asphalt and aggregate and improves water resistance. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, an asphalt base oil; Silane-modified petroleum resin and, 、 Silicon element, converted into silicon atoms, is 14 mass ppm or more relative to the asphalt composition; 56 It is possible to provide a technology characterized by including ppm by mass or less. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a technology that suppresses separation between asphalt and aggregate and improves water resistance. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a first example of a system for producing an asphalt composition and an asphalt mixture that can be suitably used in this embodiment. [Figure 2] FIG. 1 is a diagram showing a first example of a method for producing an asphalt composition and an asphalt mixture that are preferably used in this embodiment. [Figure 3] FIG. 2 is a schematic diagram showing a second example of an asphalt mixture manufacturing system that can be suitably used in this embodiment. [Figure 4] FIG. 2 is a diagram showing a second example of a method for producing an asphalt mixture that is preferably used in this embodiment. [Figure 5] FIG. 10 is a schematic diagram showing a third example of an asphalt mixture manufacturing system that can be suitably used in this embodiment. [Figure 6] FIG. 10 is a diagram showing a third example of a method for producing an asphalt mixture that is preferably used in this embodiment. [Figure 7] FIG. 1 is a diagram illustrating the evaluation of water resistance of an asphalt mixture preferably used in this embodiment. [Figure 8] 1 is a graph showing an example of the correlation between the amount of settlement and the number of travel reciprocations of an asphalt mixture preferably used in this embodiment. [Figure 9] 1 is a diagram for explaining the evaluation method of the present disclosure, and is a graph in which the horizontal axis represents the number of round trips traveled and the vertical axis represents the difference in the amount of sinking. DETAILED DESCRIPTION OF THE INVENTION

[0010] As described above, the inventors conducted extensive research into the component compositions and content ratios of asphalt compositions and asphalt mixtures. As a result, they discovered that adding an organosilane compound improves water resistance by suppressing peeling between the asphalt and aggregate, which led to the completion of the present invention. Below, detailed descriptions are provided of embodiments of the asphalt composition, asphalt composition manufacturing apparatus, asphalt composition manufacturing system, asphalt mixture, asphalt composition manufacturing method, and asphalt mixture manufacturing method.

[0011] The peeling resistance described below indicates the adhesiveness between aggregate and asphalt, and as the peeling resistance increases, the asphalt becomes less likely to peel off from the aggregate.

[0012] The asphalt composition in this embodiment contains at least an asphalt base oil and an organosilane compound, and the organosilane compound contains silicon element in an amount of 14 ppm by mass or more and 300 ppm by mass or less, calculated as silicon atoms, relative to the asphalt composition.

[0013] The content of silicon element derived from the organosilane compound contained in the asphalt composition in this embodiment can be detected using JPI-5S-38-03 Lubricating Oil - Test Method for Added Elements - Inductively Coupled Plasma Atomic Emission Spectroscopy. Prior to spectroscopic analysis, a sample dissolved in kerosene was centrifuged at 28,930 G for 20 minutes to remove impurities from the asphalt by utilizing the difference in density, and the resulting supernatant was then spectroscopically analyzed.

[0014] The details of the composition of each component and the reasons for limiting the content thereof will be explained below.

[0015] (Asphalt base oil) Asphalt base oils include, for example, straight asphalt, solvent deasphalted asphalt such as propane deasphalted asphalt, solvent deasphalted oil, blown asphalt, semi-blown asphalt, and asphalts such as modified asphalt reinforced with SBS (styrene-butadiene-styrene copolymer), EEA (ethylene ethyl acrylate), etc., which may be used individually or in combination as appropriate.

[0016] In this embodiment, the content of the asphalt base oil in the entire asphalt composition is preferably 89.3% by weight or more and 99.5% by weight or less.

[0017] (Straight asphalt) The straight asphalt can be asphalt or a mixture thereof as specified in JIS K 2207. In this embodiment, the straight asphalt can be one equivalent to a penetration grade of 40-60 to 200-300.

[0018] (Solvent deasphalted oil) Solvent deasphalted oil is equivalent to the fraction (high viscosity lubricating oil fraction) extracted from vacuum distillation residue using a solvent (see "Petroleum Dictionary, 2nd Edition," edited by the Japan Petroleum Institute, 2005, p. 542). Propane or propane and butane may be used as the solvent.

[0019] (Solvent deasphalted asphalt) Solvent deasphalted asphalt is the residue obtained by extracting solvent deasphalted oil (high-viscosity lubricating oil fraction) from vacuum distillation residue (see "Petroleum Dictionary, 2nd Edition," edited by the Japan Petroleum Institute, 2005, p. 542). It is called propane deasphalted asphalt when propane or propane and butane are used as the solvent.

[0020] (blown asphalt) Blown asphalt is, for example, asphalt defined in JIS K 2207.

[0021] (Semi-blown asphalt) Semi-blown asphalt is, for example, the semi-blown asphalt defined in "Asphalt Pavement Guidelines," published by the Japan Road Association, January 13, 1997, p. 51, Table 3.3.4.

[0022] (organosilane compounds) The organosilane compound in this embodiment contains silicon element in an amount of 14 ppm by mass or more and 300 ppm by mass or less, calculated as silicon atoms, relative to the asphalt composition. If the organosilane compound contains silicon element in an amount of less than 14 ppm by mass relative to the asphalt composition, peeling between the asphalt and aggregate cannot be suppressed, and water resistance cannot be improved. Here, when asphalt is recovered from a typical asphalt pavement, silicon element derived from silica (SiO2) that cannot be completely separated into the asphalt composition may be contained in an amount of about 10 ppm by mass, calculated as silicon atoms. In such cases, since the silicon element is about 10 ppm by mass relative to the asphalt composition in terms of silicon atoms, peeling between the asphalt and aggregate cannot be suppressed, and water resistance cannot be improved. Furthermore, adding more than 300 ppm by mass not only saturates the effect of suppressing peeling, but also increases the cost of the asphalt composition.

[0023] The organosilane compound in this embodiment is, for example, a silane-modified petroleum resin (hereinafter referred to as silane-modified petroleum resin), which contains 0.1 to 10 mass % of silicon element in terms of silicon atoms. The silicon content of silane-modified petroleum resin can be measured by ICP atomic emission spectroscopy, such as JPI-5S-38-03 Lubricating Oil—Test Method for Added Elements—Inductively Coupled Plasma Atomic Emission Spectroscopy. Specifically, 0.1 g of silane-modified petroleum resin was heated in an electric furnace at 550°C for 12 hours, and the ash was dissolved in alkali to prepare a measurement solution. The silicon content was determined by ICP atomic emission spectroscopy (ICP atomic emission spectrometer: 720-ES, Agilent Technologies, Inc.). The silane-modified petroleum resin contains 0.1 to 10 mass %, preferably 0.3 to 8 mass %, and more preferably 0.5 to 2 mass % of silicon element in terms of silicon atoms relative to the silane-modified petroleum resin. The silane-modified petroleum resin is preferably a silane-modified hydrogenated petroleum resin having an organosilane structure, and particularly preferably a silane-modified hydrogenated petroleum resin in which an alkoxysilyl group is bonded to the main chain of the hydrogenated petroleum resin via a bonding moiety.

[0024] The term "petroleum resin" as used herein refers to a resin obtained by polymerizing or copolymerizing one or more unsaturated compounds selected from aliphatic olefins and aliphatic diolefins having 4 to 10 carbon atoms, which are obtained as by-products during the production of olefins such as ethylene by thermal decomposition of petroleum such as naphtha, or aromatic compounds having 8 or more carbon atoms and having an olefinically unsaturated bond. Petroleum resins can be broadly classified into, for example, "aliphatic petroleum resins" obtained by polymerizing aliphatic olefins or aliphatic diolefins, "aromatic petroleum resins" obtained by polymerizing aromatic compounds having olefinic unsaturated bonds, and "aliphatic-aromatic copolymer petroleum resins" obtained by copolymerizing aliphatic olefins or aliphatic diolefins with aromatic compounds having olefinic unsaturated bonds.

[0025] Examples of the aliphatic olefins having 4 to 10 carbon atoms include butene, pentene, hexene, and heptene. Examples of the aliphatic diolefins having 4 to 10 carbon atoms include butadiene, pentadiene, isoprene, piperylene, cyclopentadiene, dicyclopentadiene, and methylpentadiene. Examples of aromatic compounds having 8 or more carbon atoms and an olefinically unsaturated bond include styrene, α-methylstyrene, β-methylstyrene, vinyltoluene, vinylxylene, indene, methylindene, and ethylindene. Furthermore, the raw material compounds for this petroleum resin do not all need to be by-products of olefin production by thermal decomposition of petroleum such as naphtha, and chemically synthesized unsaturated compounds may also be used.

[0026] Preferable examples of petroleum resins include dicyclopentadiene-based petroleum resins obtained by polymerizing cyclopentadiene or dicyclopentadiene, dicyclopentadiene-styrene-based petroleum resins obtained by copolymerizing cyclopentadiene or dicyclopentadiene with styrene, C5-based petroleum resins obtained by polymerizing isoprene or piperylene, and C9-based petroleum resins obtained by polymerizing C9 monomers such as indene or vinyltoluene.

[0027] The term "hydrogenated petroleum resin" as used herein refers to a petroleum resin obtained by adding hydrogen atoms to the above-mentioned petroleum resin. Hydrogenated petroleum resins include fully hydrogenated petroleum resins in which substantially no unsaturated bonds remain and partially hydrogenated petroleum resins in which unsaturated bonds remain, and fully hydrogenated petroleum resins are preferred. As the hydrogenated petroleum resin, hydrogenated aliphatic-aromatic copolymer petroleum resin is preferred.

[0028] Furthermore, the phrase "an alkoxysilyl group is bonded to the main chain of a hydrogenated petroleum resin via a bonding portion" means that, for example, a bonding portion is directly bonded to a carbon atom contained in a hydrogenated polymer (hydrogenated petroleum resin) obtained by polymerizing aliphatic olefins, aliphatic diolefins, and an aromatic compound having an olefinically unsaturated bond, and adding hydrogen atoms, as described above, and further an alkoxysilyl group is bonded to the carbon atom. The alkoxysilyl group is preferably a trialkoxysilyl group having an alkoxy group of 1 to 20 carbon atoms, which may be linear or branched, and more preferably a trialkoxysilyl group having an alkoxy group of 1 to 10 carbon atoms, which may be linear or branched. Specific examples include a trimethoxysilyl group, a triethoxysilyl group, and a tripropoxysilyl group, with a trimethoxysilyl group and a triethoxysilyl group being preferred. The bonding portion may be any organic group having a valence of two or more that can bond to a carbon atom in the main chain of the hydrogenated petroleum resin and to which an alkoxysilyl group can be bonded, and is preferably an alkylene group, more preferably an alkylene group having 2 to 3 carbon atoms.

[0029] The asphalt composition having the above-mentioned component composition is blended (mixed) with at least aggregate to form an asphalt mixture, which is then laid, for example, on a predetermined base surface for road paving. Here, a first example of a manufacturing system for the asphalt composition and asphalt mixture having the above-mentioned component composition will be described with reference to FIG.

[0030] An asphalt production plant 100, which serves as a production system for an asphalt composition having the above-described component composition or an asphalt mixture containing this asphalt composition, is primarily composed of an asphalt base oil container 101 for storing and preserving asphalt base oil, and a first mixing container 102 for mixing the asphalt base oil with various additives such as the above-described organosilane compounds. Here, the asphalt production plant 100 may be configured to include any one or all of a first product container 103 for storing and preserving the asphalt composition produced by mixing, a first mixing device (mixing device) 105 provided in the first mixing container 102, an additive supply device 106 for supplying various additives, and a control device (control unit) 108 for controlling at least the first mixing device 105 and the additive supply device 106.

[0031] The asphalt base oil container 101 and the first mixing container 102 are connected by a first supply path 104, and a predetermined amount of asphalt base oil maintained at a predetermined temperature is supplied from the asphalt base oil container 101 to the first mixing container 102 via the first supply path 104. The first supply path 104 may be, for example, a pipe.

[0032] Similarly, the first mixing vessel 102 and the first product vessel 103 are connected by a second supply line 107, and the asphalt composition produced in the first mixing vessel 102 is transferred to the first product vessel 103, where it is stored and maintained at a predetermined temperature for a predetermined period of time. The second supply line 107 may be, for example, a pipe.

[0033] The first mixing vessel 102 is provided with an additive supply device 106 for supplying various additives such as an organic silane compound, and a first agitator (first mixer) 105 for agitating the asphalt base oil and the organic silane compound at a predetermined rotation speed. The asphalt composition manufacturing apparatus is mainly composed of the first mixing vessel 102 and the first agitator 105. Note that the asphalt composition manufacturing apparatus may also include the additive supply device 106 and a control device 108, which will be described later.

[0034] The control device 108 is a device that controls the temperature and supply amount of various materials, and is electrically connected to the first agitator 105 and the additive supply device 106 by wire or wirelessly.

[0035] The control device 108 also has at least a storage device (storage unit) 110 such as an HDD or CD that stores predetermined parameters, a processing device (processing unit) 109 such as a CPU that reads out each parameter and performs processing to control the target device, and an input device (input unit) 111 using a UI or the like for inputting each parameter, necessary data, and signals to execute necessary processing. The control device 108 may also have an output device such as a display or printer (not shown). The processing device 109, storage device 110, and input device 111 are electrically connected to each other.

[0036] The asphalt production plant 100 may also be configured to include a second mixing vessel 112 that mixes the produced asphalt composition with aggregate to produce an asphalt mixture, and a second product vessel 113 that stores and preserves the asphalt mixture produced in the second mixing vessel 112. The asphalt production plant 100 may also be configured to include any one or all of a second mixing device (second mixing device) 115 provided in the second mixing vessel 112, an aggregate supply device 116 that supplies aggregate, and a control device (control unit) 108 for controlling the second mixing device 115 and the aggregate supply device 116.

[0037] The first product container 103 and the second mixing container 112 are connected by a third supply line 114. A predetermined amount of asphalt composition maintained at a predetermined temperature is supplied from the first product container 103 to the second mixing container 112 via the third supply line 114. The third supply line 114 may be, for example, a pipe.

[0038] The second mixing container 112 and the second product container 113 are connected by a fourth supply path 117, and the asphalt mixture produced in the second mixing container 112 is transferred to the second product container 113, where it is stored and maintained at a predetermined temperature for a predetermined period of time. The fourth supply path 117 may be, for example, a trolley, a bucket, a basket, or the like.

[0039] The second mixing vessel 112 is provided with an aggregate supply device 116 for supplying aggregate, and a second agitator (second mixer) 115 for agitating the aggregate and an asphalt composition containing an asphalt base oil and an organosilane compound at a predetermined rotation speed. The second mixing vessel 112 and the second agitator 115 mainly constitute an apparatus for producing an asphalt mixture. The apparatus for producing an asphalt mixture may also include the aggregate supply device 116.

[0040] The control device 108 is electrically connected to the second agitator 115 and the aggregate supply device 116.

[0041] Next, a first example of a method for producing an asphalt composition having the above-described component composition and a method for producing an asphalt mixture will be described with reference to Figure 2. The method for producing an asphalt composition includes an additive mixing step S101. The method for producing an asphalt mixture includes an asphalt mixture production step S100 in which an asphalt base oil, an organosilane compound, and aggregate are mixed. The asphalt mixture production step S100 includes, for example, an additive mixing step S101, a first storage step S102, and an aggregate mixing step S103.

[0042] (Additive mixing process: S101) In the additive mixing step S101, an asphalt base oil and an organosilane compound are mixed to produce an asphalt composition. In the additive mixing step S101, a predetermined amount of the organosilane compound is added to the asphalt base oil in a first mixing vessel 102. Then, in a first mixing device 105, the mixture is stirred and mixed for a predetermined period of time under conditions such as a temperature of 140°C or higher and a rotation speed of 2,000 rpm to 4,000 rpm. The asphalt composition produced in the additive mixing step S101 contains silicon element in an amount of 14 ppm by mass or more and 300 ppm by mass or less, calculated as silicon atoms.

[0043] (First storage step (asphalt composition storage step): S102) Next, in the first storage step S102, the asphalt composition produced in the additive mixing step S101 is transferred to a first product container 103 for temporary storage and safekeeping. At this time, the temperature in the product container may be controlled by, for example, a control device 108 so as to maintain a predetermined temperature.

[0044] (Aggregate mixing process: S103) In the aggregate mixing step S103, after the asphalt composition has been produced or stored, at least aggregate having a predetermined particle size is added to the asphalt composition as needed, and the mixture is mixed at a predetermined rotation speed at, for example, about 145°C to produce an asphalt mixture with the desired properties. This step is not necessary when selling or shipping the asphalt composition in its original form.

[0045] (Second storage process (asphalt mixture storage process): S104) In the second storage step S104, the asphalt mixture produced in the aggregate mixing step S103 is transferred to a second product container 113 for temporary storage and safekeeping. At this time, the temperature in the product container may be controlled by, for example, the control device 108 so as to maintain a predetermined temperature.

[0046] The asphalt composition of this embodiment contains silicon element in an amount of 14 ppm by mass or more and 300 ppm by mass or less, calculated as silicon atoms, relative to the asphalt composition. This improves peeling resistance. As a result, peeling between the asphalt and aggregate can be suppressed, thereby improving water resistance.

[0047] In addition, the asphalt composition of this embodiment has a high flash point, which ensures stability of properties during storage in factories, warehouses, etc., and also ensures safety during storage in large quantities.

[0048] In the asphalt mixture of this embodiment, at least aggregate is mixed with the asphalt composition having the above-described component composition. This improves peeling resistance. Therefore, peeling between the asphalt and the aggregate can be suppressed, and water resistance can be improved.

[0049] The asphalt mixture manufacturing method of this embodiment includes an asphalt mixture manufacturing step S100 in which an asphalt base oil, an organosilane compound, and aggregate are mixed. The asphalt composition containing the asphalt base oil and the organosilane compound contains silicon in an amount of 14 ppm by mass or more and 300 ppm by mass or less, calculated as silicon atoms. This improves peeling resistance. Therefore, peeling between the asphalt and the aggregate can be suppressed, thereby improving water resistance.

[0050] In the asphalt mixture manufacturing method of this embodiment, the asphalt mixture manufacturing process S100 includes an additive mixing process S101 in which an asphalt base oil is mixed with an organosilane compound to produce an asphalt composition, and an aggregate mixing process S103 in which aggregate is mixed with the asphalt composition produced in the additive mixing process S101. This makes it possible to suppress variation in the quality of the asphalt composition.

[0051] Next, a second example of an asphalt mixture manufacturing system having the above-described component composition will be described with reference to FIG. 3. In the second example, an organosilane compound is added and mixed when asphalt base oil and aggregate are mixed. Specifically, the asphalt base oil, organosilane compound, and aggregate are mixed simultaneously. Note that detailed description of the same configuration as the first example of the asphalt manufacturing system described above will be omitted.

[0052] In the asphalt production plant 100 of the second example, an asphalt base oil container 101 and a first mixing container 102 are connected by a first supply path 104. A predetermined amount of asphalt base oil maintained at a predetermined temperature is supplied from the asphalt base oil container 101 to the first mixing container 102 via the first supply path 104. The first supply path 104 may be, for example, a pipe.

[0053] The first mixing vessel 102 is provided with an additive supply device 106 for supplying various additives such as an organosilane compound, an aggregate supply device 116 for supplying aggregate, and a first agitator (first mixer) 105 for agitating the asphalt base oil, the organosilane compound, and the aggregate at a predetermined rotation speed. In the first mixing vessel 102, the asphalt base oil, the organosilane compound, and the aggregate can be simultaneously mixed by the first agitator 105 to produce an asphalt mixture. The produced asphalt mixture contains an asphalt composition that includes the asphalt base oil and the organosilane compound.

[0054] The first mixing container 102 and the first product container 103 are connected by a second supply path 107, and the asphalt mixture produced in the first mixing container 102 is transferred to the first product container 103, where it is stored and maintained at a predetermined temperature for a predetermined period of time. The second supply path 107 may be, for example, a trolley, a bucket, or a basket.

[0055] Next, a method for producing an asphalt mixture having the above-mentioned component composition will be described with reference to Figure 4. The method for producing an asphalt mixture includes an asphalt mixture production step S200 in which asphalt base oil, an organosilane compound, and aggregate are mixed. The asphalt mixture production step S200 includes, for example, an aggregate mixing step S201 and a first storage step S202.

[0056] (Aggregate mixing process: S201) In the aggregate mixing step S201, asphalt base oil, an organosilane compound, and aggregates are simultaneously mixed to produce an asphalt mixture. In the aggregate mixing step S201, the asphalt base oil, the organosilane compound, and the aggregates are supplied to a first mixing vessel 102. The asphalt base oil, the organosilane compound, and the aggregates are then stirred and mixed in a first mixing device 105 for a predetermined time, such as at 130°C or higher for 30 seconds or longer, or preferably at 145°C or higher for 45 seconds or longer, to produce an asphalt mixture. The asphalt mixture includes an asphalt composition containing asphalt base oil and an organosilane compound. The asphalt composition contained in the asphalt mixture contains silicon element in an amount of 14 ppm by mass or more and 300 ppm by mass or less, calculated as silicon atoms.

[0057] (First storage process (asphalt mixture storage process): S202) Next, in a first storage step S202, the produced asphalt mixture is transferred to a first product container 103 for temporary storage and safekeeping. At this time, the temperature in the product container may be controlled by, for example, a control device 108 so as to maintain a predetermined temperature.

[0058] Here, in the asphalt production plant, asphalt base oil and aggregates are stored by type. In this regard, in the asphalt mixture production method of this embodiment, the asphalt mixture production process includes an aggregate mixing process in which asphalt base oil, organosilane compound, and aggregate are simultaneously mixed. This makes it possible to select the type of asphalt base oil and aggregate to be mixed with the organosilane compound depending on the demand for the asphalt mixture. This allows for flexible response to demand for asphalt mixtures.

[0059] Furthermore, in the method for producing an asphalt mixture according to this embodiment, it is possible to omit a container for storing an asphalt composition containing an asphalt base oil and an organosilane compound and use an existing container for storing asphalt base oil, thereby enabling space savings in the asphalt production plant.

[0060] In addition, in the method for producing an asphalt mixture according to this embodiment, the asphalt base oil, the organosilane compound, and the aggregate are simultaneously mixed to produce the asphalt mixture. In other words, the asphalt mixture can be produced by mixing them once. This makes it possible to improve the production efficiency of the asphalt mixture.

[0061] Next, a third example of an asphalt mixture manufacturing system having the above-described component composition will be described with reference to FIG. 5. In the third example, an organosilane compound is added and mixed when asphalt base oil and aggregate are mixed. Specifically, after asphalt base oil and aggregate are mixed to produce an asphalt mixture, an organosilane compound is added to and mixed with the asphalt mixture. Note that detailed description of the same configuration as the first example of the asphalt manufacturing system described above will be omitted.

[0062] In the asphalt production plant 100 of the third example, an asphalt base oil container 101 and a first mixing container 102 are connected by a first supply path 104, and a predetermined amount of asphalt base oil maintained at a predetermined temperature is supplied from the asphalt base oil container 101 to the first mixing container 102 via the first supply path 104. The first supply path 104 may be, for example, a pipe.

[0063] The first mixing vessel 102 is provided with an aggregate supply device 116 for supplying aggregate, and a first agitator (first mixer) 105 that agitates the asphalt base oil and aggregate at a predetermined rotation speed. In the first mixing vessel 102, the asphalt base oil and aggregate can be mixed by the first agitator 105. In the first mixing vessel 102, an asphalt mixture containing the asphalt base oil and aggregate can be produced.

[0064] The first mixing container 102 and the first product container 103 are connected by a second supply path 107, and the asphalt mixture produced in the first mixing container 102 is transferred to the first product container 103, where it is stored and maintained at a predetermined temperature for a predetermined period of time. The second supply path 107 may be, for example, a trolley, a bucket, or a basket.

[0065] The first product container 103 and the second mixing container 112 are connected by a third supply path 114. A predetermined amount of asphalt mixture maintained at a predetermined temperature is supplied from the first product container 103 to the second mixing container 112 via the third supply path 114. The third supply path 114 may be, for example, a trolley, a bucket, or a basket.

[0066] The second mixing container 112 and the second product container 113 are connected by a fourth supply path 117, and the asphalt mixture produced in the second mixing container 112 is transferred to the second product container 113, where it is stored and maintained at a predetermined temperature for a predetermined period of time. The fourth supply path 117 may be, for example, a trolley, a bucket, or a basket.

[0067] The second mixing vessel 112 is provided with an additive supply device 106 for supplying various additives such as an organosilane compound, and a second mixing device (second mixer) 115 for mixing an asphalt mixture containing asphalt base oil and aggregate with the organosilane compound at a predetermined rotation speed. In the second mixing vessel 112, an asphalt mixture can be produced by mixing the asphalt base oil, the organosilane compound, and the aggregate. The produced asphalt mixture contains an asphalt composition containing the asphalt base oil and the organosilane compound.

[0068] Next, a third example of a method for producing an asphalt mixture having the above-mentioned component composition will be described with reference to Figure 6. The method for producing an asphalt mixture includes an asphalt mixture production step S300 in which asphalt base oil, an organosilane compound, and aggregate are mixed. The asphalt mixture production step S300 includes, for example, an aggregate mixing step S301, a first storage step S302, an additive mixing step S303, and a second storage step S304.

[0069] (Aggregate mixing process: S301) In the aggregate mixing step S301, asphalt base oil and aggregate are mixed to produce an asphalt mixture. The asphalt base oil and aggregate are stirred and mixed in a first stirring device 105, for example, at about 145°C, at a predetermined rotation speed, for a predetermined time to produce the asphalt mixture.

[0070] (First storage process (asphalt mixture storage process): S302) Next, in a first storage step S302, the asphalt mixture produced in the aggregate mixing step S301 is transferred to a first product container 103 for temporary storage and safekeeping. At this time, the temperature in the product container may be controlled by, for example, a control device 108 so as to maintain a predetermined temperature.

[0071] (Additive mixing process: S303) In the additive mixing step S303, after the asphalt mixture is produced or stored, the asphalt mixture is mixed with an organosilane compound. In the additive mixing step S303, a predetermined amount of the organosilane compound is added to the asphalt mixture, and the mixture is stirred and mixed in the second mixing device 115 for a predetermined period of time, such as mixing at 130°C or higher for 30 seconds or more, preferably at 145°C or higher for 45 seconds or more, to produce an asphalt mixture. The asphalt mixture produced in the additive mixing step S303 contains an asphalt composition containing an asphalt base oil and an organosilane compound. The asphalt composition contained in the asphalt mixture contains 14 ppm by mass or more and 300 ppm by mass or less of silicon atom-equivalent silicon.

[0072] (Second storage process (asphalt mixture storage process): S304) Next, in the second storage step S304, the asphalt mixture produced in the additive mixing step S303 is transferred to the second product container 113 for temporary storage and safekeeping. At this time, the temperature in the product container may be controlled by, for example, the control device 108 so as to maintain a predetermined temperature.

[0073] In the asphalt mixture manufacturing method of this embodiment, the asphalt mixture manufacturing process S300 includes an aggregate mixing process S301 in which asphalt base oil and aggregate are mixed to produce an asphalt mixture, and an additive mixing process S303 in which an organosilane compound is mixed with the asphalt mixture produced in the aggregate mixing process S301. This allows the type of asphalt mixture to be mixed with the organosilane compound to be selected depending on the demand for asphalt mixture. This allows for flexible response to demand for asphalt mixtures.

[0074] Furthermore, in the method for producing an asphalt mixture according to this embodiment, it is possible to omit a container for storing an asphalt composition containing an asphalt base oil and an organosilane compound and use an existing container for storing asphalt base oil, thereby enabling space savings in the asphalt production plant.

[0075] A specific method for preparing a test specimen for evaluating the water resistance performance of the asphalt composition of the present invention is described below.

[0076] Crushed hard sandstone is used as aggregate, and crushed limestone stone powder is used to prepare the fine particles (components with small particle diameters) to create the test specimens.

[0077] The stone powder made from crushed limestone used to adjust the particle size of the aggregate must conform to JIS A 5008 "Limestone powder for paving" and have a passing mass percentage of 100% for a sieve opening of 600 μm, 90-100% for a sieve opening of 150 μm, and 70-100% for a sieve opening of 75 μm, and a moisture content of 1% or less.

[0078] Crushed stone and stone powder that satisfied these properties were used as aggregate, and the aggregate mix shown in Table 1 was adjusted, and test specimens were prepared under the conditions shown in Table 2.

[0079] The actual preparation of the specimen can be broadly divided into two steps: mixing the asphalt composition with aggregate, and compacting it. For mixing, prepare 600g of asphalt composition heated to 155℃ and 10,119g of aggregate heated to 165℃.

[0080] First, the aggregate was placed in the mixer and mixed for 60 seconds until uniform. Mixing was stopped temporarily, and 600 g of asphalt composition was added to the mixer. The asphalt composition and aggregate were then mixed for 120 seconds.

[0081] After mixing, the asphalt composition and aggregate were placed in a wheel tracking test formwork (internal dimensions: length 30.0 cm, width 30.0 cm, depth 5.0 cm) and compacted. Compaction was applied to the mixed asphalt by rolling a cylindrical roller with a radius of 460 mm at the compaction temperature shown in Table 2 below. This compaction was carried out in two stages: primary compaction and secondary compaction. The mixture was then dried for 8 hours to complete the preparation of the test specimen.

[0082] [Table 1]

[0083] [Table 2]

[0084] The method for evaluating the water resistance of the asphalt composition of the present invention will now be described. A water resistance evaluation test was conducted using a double wheel tracking tester (78-PV33D06, manufactured by IPS Global Controls), which is a small-size device, with reference to BS EN 12697-22:2003 Bituminous mixtures—test methods for hot mix asphalt Part 22: Wheel tracking test.

[0085] The specimen prepared by the above-mentioned method was placed in a double wheel tracking test machine and immersed in a water bath maintained at 60°C, simulating the summer road surface temperature, for two hours with the water level at least 2 mm higher than the specimen's top surface, to produce specimen 5, measuring 30 x 30 x 5 cm, as shown in Figure 7. Next, specimen 5 was placed in the same 60°C water bath as used for curing, with the water level at least 2 mm higher than the specimen's top surface, and run back and forth in the direction indicated by the arrow in the figure at a pace of 26.5 round trips per minute while applying a downward load of 700 N with wheel 11. Incidentally, the running position of wheel 11 was the same as that used for curing, with the water level at least 2 mm higher than the specimen's top surface.

[0086] FIG. 8 shows an example of the deformation of a test specimen, i.e., the amount of subsidence (mm), relative to the number of reciprocating wheel runs on the test specimen in a water resistance evaluation test. As the number of reciprocating runs increases, the amount of subsidence due to the reciprocating run of the wheel 11 increases. This subsidence is the depth (mm) of subsidence from the surface of the test specimen 5 in the depth direction. The test was terminated either when the amount of subsidence reached 20 mm or when the wheel had completed 10,000 reciprocating runs.

[0087] To evaluate each specimen, the above-mentioned water resistance evaluation test was conducted on the specimen, the amount of subsidence on the specimen surface was measured every 200 strokes after 1000 strokes, and the difference in the amount of subsidence that appeared every 200 strokes was calculated. Then, in a graph (Fig. 9) where the horizontal axis is the number of strokes and the vertical axis is the difference in the amount of subsidence, the slope of the approximate line formed by the difference in the amount of subsidence and the number of strokes after the number of strokes at which the calculated difference in the amount of subsidence reaches a minimum was further calculated.

[0088] If the slope of the approximation line formed by the difference in settlement and the number of travels is less than 0 after the number of travels at which the difference in settlement reaches its minimum, it means that the difference in settlement continues to decrease, and no inflection point for separation has occurred. In this case, even if load is continued beyond the number of travels at which the difference in settlement reaches its minimum, there is no inflection point, and separation between the asphalt and aggregate is suppressed, and the settlement tends to increase while maintaining a convex upward state. For this reason, if there is no inflection point, it is evaluated as being possible to improve the asphalt's separation resistance, and this is represented by a "○" in Table 3. On the other hand, if this slope (the slope of the approximation line formed by the difference in settlement and the number of travels) is positive, there is an inflection point. In this case, even if load is continued beyond the number of travels at which the difference in settlement reaches its minimum, there is an inflection point, and separation between the asphalt and aggregate occurs, transitioning from a convex upward state to a convex downward state, and the settlement tends to increase. For this reason, if there is an inflection point, it is evaluated as being impossible to improve the asphalt's separation resistance, and this is represented by a "×" in Table 3. Furthermore, if the settlement reached 20 mm before 10,000 round trips, the test was terminated, and the specimen was deemed to have been destroyed. In this case, the specimen was significantly deformed by running under load in a 60°C water bath and was deemed to have poor water resistance. Therefore, the specimen was deemed to have a peeling inflection point in the water resistance evaluation test, meaning that the asphalt peeling resistance could not be improved.

[0089] The following provides a specific explanation of examples and comparative examples in which the present embodiment is used. Table 3 shows the specifications of the asphalt compositions of Examples 1 to 6 and Comparative Examples 1 to 5, as well as the evaluation results of the asphalt peeling resistance. [Table 3]

[0090] The asphalt base oil used in Examples 1, 2, 3, 4, 5, 6, Comparative Examples 1, 2, 3, 4, and 5 is straight asphalt with a penetration grade of 60 to 80. Typical properties include a penetration of 67 (1 / 10 mm), a softening point of 48.0°C, and a density at 15°C of 1.036 kg / m 3 is.

[0091] The organosilane compound used in Examples 1, 2, 3, 4, 5, 6, Comparative Examples 1, and 2 was a silane-modified hydrogenated petroleum resin in which a trimethoxysilyl group was bonded to the main chain of a fully hydrogenated dicyclopentadiene-styrene petroleum resin via an alkylene group serving as the bonding site. The organosilane compound used had a melting point of 100°C, a flash point of 234°C, and a bromine number of 2.5g / 100g. In Examples 1 to 4 and Comparative Examples 1 and 2, an asphalt composition was produced by mixing an asphalt base oil with the organosilane compound, and then the asphalt composition was mixed with aggregate to produce an asphalt mixture. In Examples 5 and 6, the organosilane compound was mixed when mixing the asphalt base oil with the aggregate to produce an asphalt mixture.

[0092] The petroleum resin used in Comparative Examples 3 and 4 was a fully hydrogenated dicyclopentadiene-styrene-based petroleum resin that had not been silane-modified. The petroleum resin used had a melting point of 100°C, a flash point of 234°C, and a bromine number of 2.5g / 100g.

[0093] Furthermore, the content of silicon element derived from organosilane compounds contained in the asphalt compositions of Examples 1, 2, 3, 4, 5, 6, and Comparative Examples 1, 2, 3, and 4 was measured using inductively coupled plasma atomic emission spectrometry in accordance with JPI-5S-38-03 Lubricating Oils - Test Method for Added Elements. Prior to the spectroscopic analysis, each test specimen dissolved in kerosene was centrifuged at 28,930 G for 20 minutes to remove impurities in the asphalt by utilizing the difference in density, and the resulting supernatant was subjected to spectroscopic analysis.

[0094] In Examples 1 to 6, the above-mentioned slope is a negative value and there is no inflection point. This makes it possible to improve the peeling resistance of the asphalt. Therefore, peeling between the asphalt and the aggregate can be suppressed, and water resistance performance can be improved.

[0095] Furthermore, in Examples 1 to 4, the asphalt mixtures were prepared by mixing an asphalt base oil and an organosilane compound to produce an asphalt composition, and then mixing aggregate with the asphalt mixture. In Examples 5 and 6, the asphalt mixtures were prepared by mixing the organosilane compound with the asphalt base oil and aggregate. In other words, the peeling resistance of the asphalt can be improved whether the asphalt base oil and the organosilane compound are mixed together and then mixed with aggregate, or whether the organosilane compound is mixed when mixing the asphalt base oil and aggregate. Therefore, peeling between the asphalt and the aggregate can be suppressed, and water resistance can be improved.

[0096] In contrast, in Comparative Examples 1 to 4, the above-mentioned slope is a positive value and there is an inflection point. As a result, it is not possible to improve the peeling resistance of the asphalt. As a result, it is not possible to suppress peeling between the asphalt and the aggregate, and it is not possible to improve water resistance.

[0097] In Comparative Example 5, no organic silane compound was added. The settlement reached 20 mm before the number of travels reached 10,000, so peeling between the asphalt and aggregate could not be suppressed and water resistance could not be improved. [Explanation of symbols]

[0098] 100: Asphalt manufacturing plant 101: Asphalt base oil container 102: First mixing vessel 103: First product container 104: First supply route 105: First stirring device 106: Additive supply device 107: Second supply route 108: Control device 109: Processing equipment 110: Storage device 111: Input device 112: Second mixing vessel 113: Second product container 114: The third supply route 115: Second stirring device 116: Aggregate supply device 117: The fourth supply route

Claims

1. An asphalt base oil and a silane-modified petroleum resin, Contains silicon element in an amount of 14 ppm by mass or more and 56 ppm by mass or less in terms of silicon atoms; An asphalt composition characterized by:

2. The silicon element is 0.1% by mass or more and 10% by mass or less in terms of silicon atoms relative to the silane-modified petroleum resin. The asphalt composition according to claim 1, characterized in that

3. The silane-modified petroleum resin is a silane-modified hydrogenated petroleum resin. The asphalt composition according to claim 1, characterized in that

4. The silane-modified petroleum resin is a silane-modified petroleum resin obtained by polymerizing one or more selected from the following group: (a) a petroleum resin obtained by polymerizing cyclopentadiene; (b) a petroleum resin obtained by polymerizing dicyclopentadiene; (c) a petroleum resin obtained by copolymerizing cyclopentadiene and styrene, and (d) petroleum resin obtained by copolymerizing dicyclopentadiene and styrene; The asphalt composition according to claim 1, characterized in that

5. Producing the asphalt composition according to any one of claims 1 to 4. A manufacturing device characterized by:

6. Producing the asphalt composition according to any one of claims 1 to 4. A manufacturing system characterized by:

7. The asphalt composition according to any one of claims 1 to 4 is mixed with at least aggregate. Asphalt mixture characterized by:

8. and adding a silane-modified petroleum resin to the asphalt base oil to contain silicon element in an amount of 14 ppm by mass or more and 56 ppm by mass or less in terms of silicon atoms. A method for producing an asphalt composition, characterized by:

9. The method includes a step of manufacturing an asphalt mixture by mixing an asphalt base oil, a silane-modified petroleum resin, and an aggregate, The asphalt composition containing the asphalt base oil and the silane-modified petroleum resin contains silicon atoms in an amount of 14 ppm by mass or more and 56 ppm by mass or less in terms of silicon atoms; A method for producing asphalt mixture, characterized by:

10. The asphalt mixture manufacturing process includes: an additive mixing step of mixing the asphalt base oil with the silane-modified petroleum resin to form the asphalt composition; The method includes an aggregate mixing step of mixing the asphalt composition produced in the additive mixing step with the aggregate, The method for producing an asphalt mixture according to claim 9, characterized by:

11. The asphalt mixture manufacturing process includes: an aggregate mixing step of simultaneously mixing the asphalt base oil, the silane-modified petroleum resin, and the aggregate; The method for producing an asphalt mixture according to claim 9, characterized by:

12. The asphalt mixture manufacturing process includes: an aggregate mixing step of mixing the asphalt base oil and the aggregate to produce an asphalt mixture; an additive mixing step of mixing the asphalt mixture produced in the aggregate mixing step with the silane-modified petroleum resin; The method for producing an asphalt mixture according to claim 9, characterized by:

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