Asphalt mixture

Abstract

Provide an asphalt mixture that can exhibit excellent physical properties even when using asphalt recycled aggregate with advanced deterioration degree. 【Solution means】An asphalt mixture containing an amine compound represented by the following formula (I) and asphalt recycled aggregate. 【Chemical formula 1】 JPEG2026087482000029.jpg20131[In the formula, R a represents an alkyl group having 20 or less carbon atoms. R b and R c independently represent an alkyl group having 6 or more and 22 or less carbon atoms, or -(R d O) X -H. R d is an alkylene group having 2 or more and 4 or less carbon atoms, and x is the average number of moles of oxyalkylene groups added. When R b and R c are -(R d O) X -H, the total average number of moles of oxyalkylene groups added is 20 or less.]

Description

[Technical Field]

[0001] This invention relates to asphalt mixtures, methods for producing the same, and additives for recycling recycled asphalt aggregate. [Background technology]

[0002] Asphalt paving is used for roads, parking lots, freight yards, and sidewalks because it is relatively easy to lay and the time from the start of paving work to the start of traffic is short. This asphalt pavement is formed from an asphalt mixture in which aggregates are bound together with asphalt, and it has good hardness and durability.

[0003] In recent years, from the perspective of reducing environmental impact and rising crude oil prices, the use of recycled asphalt aggregate (recycled asphalt aggregate) as a new paving material has been increasing in popularity.

[0004] Patent Document 1 discloses an asphalt mixture for obtaining an asphalt pavement that is highly durable and can maintain its black color even after traffic is opened, which contains a polyester resin, a compound having 8 or more carbon atoms and a hydroxyl group or an amino group, asphalt, and aggregate, wherein the aggregate contains recycled asphalt aggregate. Patent Document 2 discloses an asphalt composition that includes recovered asphalt and an ester-functionalized regenerator, wherein the recovered asphalt includes aggregate and an asphalt oxide binder, and the regenerator is present in an amount effective in reducing the glass transition onset temperature of the asphalt oxide binder by at least 5°C compared to the glass transition onset temperature of an asphalt oxide binder without the regenerator. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-36018 [Patent Document 2] International Publication No. 2013 / 090283 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The asphalt contained in recycled asphalt aggregate has undergone thermal degradation, making it harder and more brittle compared to new asphalt. When using recycled asphalt aggregate, technologies are becoming widespread that soften the deteriorated asphalt by incorporating recycling additives, enabling the production of asphalt mixtures that are close to conventional quality. However, as the repeated use of recycled asphalt aggregate progresses and the proportion of recycled asphalt aggregate in the mix is ​​increasing, conventional recycling additives may not provide sufficient recycling effects. The technology described in Patent Document 1 effectively acts on the fixed asphalt in recycled asphalt aggregate, resulting in pavement with excellent durability and blackness. However, its effect on various types of recycled asphalt aggregate is low, and in particular, the softening effect is insufficient. The technology described in Patent Document 2 allows for the softening effect of hardened and deteriorated asphalt without compromising its necessary physical properties. However, this has been verified primarily on deteriorated asphalt that has been extracted and plasticized, and its effect on asphalt fixed in recycled aggregate is considered insufficient.

[0007] The present invention relates to an asphalt mixture that can exhibit excellent physical properties even when using recycled asphalt aggregate that has deteriorated to an advanced degree, a method for producing the same, and an additive for recycling recycled asphalt aggregate that can produce such an asphalt mixture. [Means for solving the problem]

[0008] The present invention relates to the following [1] to [3]. [1] An asphalt mixture comprising an amine compound represented by the following formula (I) and recycled asphalt aggregate. [Chemical formula] [In the formula, R a represents an alkyl group having 20 or less carbon atoms. R b and R c independently represent an alkyl group having 6 or more and 22 or less carbon atoms, or -(R d O) X -H. R d is an alkylene group having 2 or more and 4 or less carbon atoms, and x is the average number of moles of oxyalkylene groups added. R b and R c When is -(R d O) X -H, the total average number of moles of oxyalkylene groups added is 20 or less.) [2] A method for producing an asphalt mixture, comprising a step of mixing an amine compound represented by the following formula (I) and asphalt recycled aggregate. [Chemical formula] [In the formula, R a represents an alkyl group having 20 or less carbon atoms. R b and R c independently represent an alkyl group having 6 or more and 22 or less carbon atoms, or -(R d O) X -H. R d is an alkylene group having 2 or more and 4 or less carbon atoms, and x is the average number of moles of oxyalkylene groups added. R b and R c When is -(R d O) X -H, the total average number of moles of oxyalkylene groups added is 20 or less.) [3] An additive for recycling asphalt recycled aggregate, comprising an amine compound represented by the following formula (I). [Chemical formula] [In the formula, R a represents an alkyl group having 20 or less carbon atoms. R b and R c independently represent an alkyl group having 6 or more and 22 or less carbon atoms, or -(R d O)X -H represents R. d R is an alkylene group having 2 to 4 carbon atoms, and x is the average number of moles of oxyalkylene groups added. b and R c ga-(R d O) X -When H is present, the total average number of moles of oxyalkylene groups added is 20 or less. [Effects of the Invention]

[0009] The present invention provides an asphalt mixture that can exhibit excellent physical properties even when using recycled asphalt aggregate that has deteriorated to an advanced degree, a method for producing the same, and an additive for recycling recycled asphalt aggregate that can produce such an asphalt mixture. [Modes for carrying out the invention]

[0010] [Asphalt mixture] The asphalt mixture of the present invention comprises an amine compound represented by the following formula (I) and recycled asphalt aggregate. [ka] [In the formula, R a R represents an alkyl group with 20 or fewer carbon atoms. b and R c These are independently alkyl groups having 6 to 22 carbon atoms, or -(R d O) X -H represents R. d R is an alkylene group having 2 to 4 carbon atoms, and x is the average number of moles of oxyalkylene groups added. b and R c ga-(R d O) X -When H is present, the total average number of moles of oxyalkylene groups added is 20 or less. The asphalt mixture containing the amine compound represented by formula (I) above is useful because it interacts with the deteriorated asphalt fixed to the recycled asphalt aggregate, allowing it to exhibit excellent physical properties even when using recycled asphalt aggregate that has deteriorated to a high degree.

[0011] The asphalt mixture of the present invention can exhibit excellent physical properties even when using recycled asphalt aggregate that has deteriorated to an advanced degree. In this specification, an asphalt mixture capable of exhibiting excellent physical properties means an asphalt mixture that achieves both excellent durability and excellent workability during paving. The durability of asphalt pavement can be evaluated by Marshall stability, for example, as shown in the examples described later. The workability during paving can be evaluated by void ratio, for example, as shown in the examples described later.

[0012] In this invention, a large amount of recycled asphalt aggregate can be incorporated without impairing the pavement's properties. Therefore, it is expected that the generation of carbon dioxide derived from raw materials and costs can be significantly reduced, thereby contributing to reduced environmental impact and economic efficiency.

[0013] Although the detailed mechanism by which the effects of this invention are obtained is unknown, it is thought that a high softening effect was achieved by using a specific amine compound that has a high affinity for asphaltene, which is particularly deteriorated and modified in asphalt derived from recycled asphalt aggregate and takes on an aggregated structure.

[0014] <Recycled asphalt aggregate> The asphalt mixture of the present invention contains recycled asphalt aggregate as aggregate. Recycled asphalt aggregate is made by collecting used asphalt pavement, crushing it, and classifying it. Used asphalt pavements derived from recycled asphalt aggregate may contain asphalt and aggregate, and may contain other additives as needed.

[0015] Furthermore, the asphalt contained in recycled asphalt aggregate is physically and chemically degraded compared to new asphalt due to the influence of environmental factors such as heat and light. The physical and chemical properties of asphalt can be evaluated by measuring the penetration, softening point, flexural strength, fracture strain, and asphalt composition. Generally, asphalt in which the marten fraction has migrated to asphaltene and the penetration has decreased is often called degraded asphalt. However, even if the penetration of recycled asphalt is equivalent to that of new asphalt, changes in other properties may prevent it from exhibiting the same performance as new asphalt. In the present invention, the recycled asphalt aggregate is preferably a deteriorated recycled asphalt aggregate in which the penetration degree of the extracted asphalt is 25 or less. The penetration of asphalt contained in recycled asphalt aggregate can be measured according to the procedure of JIS K 2207:1996 for asphalt extracted according to "G028 Asphalt Extraction Test Method" in the "Pavement Survey and Test Method Handbook (FY2019 Edition)" (edited by the Japan Road Association).

[0016] Asphalt mixtures derived from used asphalt pavement contain aggregates. Examples of such aggregates include those commonly used in road paving asphalt mixtures, such as crushed stone, pebbles, gravel, sand, and ceramics. Furthermore, the asphalt mixture derived from the used asphalt pavement itself may use recycled asphalt aggregate as its aggregate.

[0017] <New Aggregates> The asphalt mixture of the present invention may contain novel aggregates in addition to recycled asphalt aggregates. Specific new aggregates can be arbitrarily selected and used, such as crushed stone, boulders, gravel, sand, and ceramics. In addition, coarse aggregates with a particle size of 2.36 mm or larger, fine aggregates with a particle size of 0.075 mm or larger and less than 2.36 mm, and fillers with a particle size of less than 0.075 mm can be used. Examples of coarse aggregate include crushed stone with a particle size range of 2.36 mm or more and less than 4.75 mm, crushed stone with a particle size range of 4.75 mm or more and less than 12.5 mm, crushed stone with a particle size range of 12.5 mm or more and less than 19 mm, and crushed stone with a particle size range of 19 mm or more and less than 31.5 mm. Examples of fine aggregates include river sand, hill sand, mountain sand, sea sand, crushed sand, fine sand, screenings, crushed stone dust, silica sand, artificial sand, glass cullet, and foundry sand. The particle sizes of coarse and fine aggregates are based on the sieving test method specified in JIS A5001:2008.

[0018] Examples of fillers include sand, fly ash, calcium carbonate-containing powders such as limestone powder, and slaked lime. Among these, calcium carbonate-containing powders are preferred from the viewpoint of improving the strength of asphalt pavement. From the viewpoint of improving the strength of the asphalt pavement, the average particle size of the filler is preferably 0.001 mm or more, more preferably 0.05 mm or less, more preferably 0.03 mm or less, and even more preferably 0.02 mm or less. Here, the average particle size is the average particle size at 50% volume accumulation (D 50 This means that it can be measured with a laser diffraction particle size distribution analyzer.

[0019] It is preferable to use both coarse and fine aggregates as aggregate. In this case, the mass ratio of coarse aggregate to fine aggregate is preferably 10 / 90 or more, more preferably 15 / 85 or more, even more preferably 20 / 80 or more, and preferably 90 / 10 or less, more preferably 80 / 20 or less, and even more preferably 70 / 30 or less, from the viewpoint of the durability of the asphalt pavement.

[0020] <Amine compounds> The asphalt mixture of the present invention comprises an amine compound represented by the following formula (I) and recycled asphalt aggregate. [ka] [In the formula, R aR represents an alkyl group with 20 or fewer carbon atoms. b and R c These are independently alkyl groups having 6 to 22 carbon atoms, or -(R d O) X -H represents R. d R is an alkylene group having 2 to 4 carbon atoms, and x is the average number of moles of oxyalkylene groups added. b and R c ga-(R d O) X -When H is present, the total average number of moles of oxyalkylene groups added is 20 or less. The asphalt mixture containing the amine compound represented by formula (I) above is useful because it interacts with the deteriorated asphalt fixed to the recycled asphalt aggregate, allowing it to exhibit excellent physical properties even when using recycled asphalt aggregate that has deteriorated to a high degree.

[0021] The aforementioned R a The alkyl group has 20 or fewer carbon atoms, and from the viewpoint of miscibility with asphalt components, the number of carbon atoms is preferably 19 or less, more preferably 18 or less, even more preferably 16 or less, and preferably 6 or more, more preferably 8 or more, and even more preferably 10 or more.

[0022] The aforementioned R b and R c These are independently alkyl groups having 6 to 22 carbon atoms, or -(R d O) X -H

[0023] The aforementioned R d This is an alkylene group having 2 to 4 carbon atoms, and from the viewpoint of the mixability of the asphalt material, it is preferably 2 or more, and preferably 3 or less.

[0024] The aforementioned R b and R c ga-(R d O) XWhen it is -H, the above x is the average number of moles of oxyalkylene groups added, and its total is 20 or less, preferably 16 or less, more preferably 12 or less, and preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more, from the viewpoint of miscibility with asphalt components.

[0025] The aforementioned R b and R c When R is independently an alkyl group having 6 to 22 carbon atoms, a The group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group.

[0026] The asphalt mixture of the present invention preferably contains one or more amine compounds represented by the above formula (I) selected from dialkylmethylamines represented by the following formula (II) and polyoxyethylene alkylamines represented by the following general formula (III). [ka] [In the formula, R 1 and R 2 This independently represents an alkyl group having 6 to 22 carbon atoms. [ka] [In the formula, R 3 represents an alkyl group with 20 or fewer carbon atoms. a and b represent the average number of moles of oxyethylene groups added, and a+b is 20 or less. The amine compound represented by formula (I) above contains one or more selected from the dialkylmethylamine represented by formula (II) above and the polyoxyethylene alkylamine represented by the general formula (III) below. This compound exhibits high affinity for asphaltene, which is particularly deteriorated and modified in asphalt derived from recycled asphalt aggregate and takes on an aggregated structure, thereby providing a high softening effect and making it useful.

[0027] <Dialkylmethylamine> The asphalt mixture of the present invention preferably contains a dialkylmethylamine represented by the following formula (II) as the amine compound represented by formula (I) above. The dialkylmethylamine is a component that functions as a regeneration additive that restores the properties of deteriorated asphalt derived from recycled asphalt aggregate. [ka] [In the formula, R 1 and R 2 This independently represents an alkyl group having 6 to 22 carbon atoms.

[0028] Although the detailed mechanism by which the effects of this invention are obtained is unknown, it is thought that a high softening effect was obtained by using a specific dialkylmethylamine that has a high affinity for asphaltene, which is particularly deteriorated and modified in asphalt derived from recycled asphalt aggregate and takes on an aggregated structure.

[0029] In the formula, R 1 and R 2 R independently represents an alkyl group having 6 to 22 carbon atoms. 1 and R 2 The alkyl group represented by may be either a linear alkyl group or a branched alkyl group. 1 and R 2 The number of carbon atoms in the alkyl group represented is preferably 8 or more, more preferably 10 or more, even more preferably 12 or more, and preferably 20 or less, more preferably 16 or less, and even more preferably 14 or less.

[0030] In the dialkylmethylamine, R 1 and R 2 From the viewpoint of the effects of the present invention, the average number of carbon atoms in the alkyl group represented is preferably 8 or more and 22 or less, more preferably 10 or more, even more preferably 12 or more, and more preferably 20 or less, more preferably 18 or less, more preferably 16 or less, and more preferably 14 or less.

[0031] The aforementioned R 1 and R 2From the viewpoint of affinity with asphalt components, the total number of carbon atoms is preferably 16 or more, more preferably 20 or more, even more preferably 24 or more, and preferably 40 or less, more preferably 32 or less, and even more preferably 28 or less.

[0032] From the viewpoint of the effects of the present invention, the amine value of the dialkylmethylamine is preferably 70 to 220, more preferably 100 or more, and more preferably 180 or less.

[0033] As the dialkylmethylamine, a mixture of multiple compounds that satisfy the above requirements can be used. The average number of carbon atoms is calculated using only the dialkylmethylamine. In the manufacturing process of the dialkylmethylamine described above, compounds other than the dialkylmethylamine may be introduced as impurities, for example, due to unavoidable circumstances. The asphalt mixture of the present invention may contain such impurities.

[0034] Specific examples of the aforementioned dialkylmethylamines include didecylmonomethylamine, didodecylmethylamine, and dioctadecylmethylamine. The dialkylmethylamine according to the present invention can be manufactured in accordance with the manufacturing method described in Japanese Patent Publication No. 61-15865. Furthermore, commercially available products can be used as the dialkylmethylamine. Specifically, the "Farmin" series (product name) manufactured by Kao Corporation can be mentioned.

[0035] <Polyoxyethylene alkylamine> The asphalt mixture of the present invention preferably contains a polyoxyethylene alkylamine represented by the following formula (III) as the amine compound represented by formula (I) above. The polyoxyethylene alkylamine is a component that functions as a regeneration additive that restores the properties of deteriorated asphalt derived from recycled asphalt aggregate.

[0036] [ka] [In the formula, R 3 represents an alkyl group with 20 or fewer carbon atoms. a and b represent the average number of moles of oxyethylene groups added, and a+b is 20 or less.

[0037] Although the detailed mechanism by which the effects of this invention are obtained is unknown, it is thought that a high softening effect was obtained by using a specific polyoxyethylene alkylamine that has a high affinity for asphaltene, which is particularly deteriorated and modified in asphalt derived from recycled asphalt aggregate and takes on an aggregated structure.

[0038] In the formula, R 3 R represents an alkyl group with 20 or fewer carbon atoms. 3 R may be either a linear alkyl group or a branched alkyl group. 3 The number of carbon atoms in the alkyl group represented is preferably 12 or more, and 18 or less.

[0039] In formula (III), a and b represent the average number of moles of oxyethylene groups added, and their sum, a+b, is 20 or less. From the viewpoint of the present invention, a+b is preferably 2 or more and 15 or less, more preferably 2 or more, and more preferably 10 or less. Note that a and b are each 1 or more.

[0040] As the polyoxyethylene alkylamine, the above R 3 Multiple mixtures that satisfy the required number of carbon atoms and average number of added oxyethylene groups can be used. In the manufacturing process of the polyoxyethylene alkylamine described above, compounds other than the polyoxyethylene alkylamine may be introduced as impurities, for example, due to unavoidable circumstances. The asphalt mixture of the present invention may contain such impurities.

[0041] Specific examples of the polyoxyethylene alkylamine include polyoxyethylene laurylamine and polyoxyethylene stearylamine. The polyoxyethylene alkylamine according to the present invention can be produced by adding an alkylene oxide to an aliphatic primary amine having an alkyl group with 20 or fewer carbon atoms. For example, a polyoxyethylene alkylamine can be produced in accordance with the production method described in Japanese Patent Application Publication No. 11-158125. Furthermore, commercially available polyoxyethylene alkylamines can be used. Specifically, the "Amito" series (product name) manufactured by Kao Corporation is an example.

[0042] <New Asphalt> The asphalt mixture of the present invention may contain novel asphalt in addition to the asphalt contained in recycled asphalt aggregate. New asphalt, also known as virgin asphalt or unused asphalt, refers to asphalt that has never been used for asphalt paving. As for new asphalt, various types of asphalt can be used as long as they have no prior history of being used in asphalt pavement. Examples include straight asphalt, which is petroleum asphalt for paving, and modified asphalt. Modified asphalts include blown asphalt and polymer-modified asphalt, which is modified with polymer materials such as thermoplastic elastomers and thermoplastic resins. Straight asphalt refers to residual bituminous material obtained by subjecting crude oil to atmospheric distillation, vacuum distillation, etc. Blown asphalt refers to asphalt obtained by heating a mixture of straight asphalt and heavy oil, and then blowing air into it to oxidize it. It is preferable to select from straight asphalt and polymer-modified asphalt, with polymer-modified asphalt being more preferable from the viewpoint of durability of asphalt pavement, and straight asphalt being more preferable from the viewpoint of versatility. As for polymer-modified asphalt, asphalt modified with thermoplastic elastomer is more preferable. The modified asphalt is preferably polymer-modified asphalt, and more preferably polymer-modified asphalt modified with a thermoplastic elastomer.

[0043] (Thermoplastic elastomer) Examples of thermoplastic elastomers used in polymer-modified asphalt modified with thermoplastic elastomers include at least one selected from styrene / butadiene block copolymer, styrene / butadiene / styrene block copolymer, styrene / butadiene random copolymer, styrene / isoprene block copolymer, styrene / isoprene / styrene block copolymer, styrene / isoprene random copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid ester copolymer, styrene / ethylene / butylene / styrene copolymer, styrene / ethylene / propylene / styrene copolymer, polyurethane-based thermoplastic elastomer, polyolefin-based thermoplastic elastomer, isobutylene / isoprene copolymer, polyisoprene, polychloroprene, synthetic rubber other than those listed above, and natural rubber. The thermoplastic elastomer in the modified asphalt is preferably at least one selected from styrene / butadiene block copolymer, styrene / butadiene / styrene block copolymer, styrene / butadiene random copolymer, styrene / isoprene block copolymer, styrene / isoprene / styrene block copolymer, styrene / isoprene random copolymer, ethylene / vinyl acetate copolymer, and ethylene / acrylic acid ester copolymer. Among these, the thermoplastic elastomer is preferably at least one selected from styrene / butadiene block copolymer, styrene / butadiene / styrene block copolymer, styrene / butadiene random copolymer, styrene / isoprene block copolymer, styrene / isoprene / styrene block copolymer, styrene / isoprene random copolymer, and ethylene / acrylic acid ester copolymer, more preferably at least one selected from styrene / butadiene block copolymer, styrene / butadiene / styrene block copolymer, styrene / butadiene random copolymer, styrene / isoprene block copolymer, and styrene / isoprene random copolymer, and even more preferably at least one selected from styrene / butadiene random copolymer and styrene / butadiene / styrene block copolymer. The content of thermoplastic elastomer in polymer-modified asphalt is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 10% by mass or less, from the viewpoint of durability and surface aesthetics of the asphalt pavement.

[0044] <Content of each ingredient> From the viewpoint of the effects of the present invention, the aggregate content in the asphalt mixture is preferably 60% by mass or more and 99.9% by mass or less, more preferably 75% by mass or more, and even more preferably 80% by mass or more. In this invention, the aggregate content refers to the total content of recycled asphalt aggregate and any additional new aggregate. The asphalt content derived from the recycled asphalt aggregate is included in the aggregate content.

[0045] From the viewpoint of reusing waste materials from asphalt pavement, the content of recycled asphalt aggregate in the asphalt mixture is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, and 100 parts by mass or less, per 100 parts by mass of the asphalt mixture.

[0046] When the aggregate includes new aggregate, the content of recycled asphalt aggregate in the asphalt mixture is preferably 50 parts by mass or more, more preferably 75 parts by mass or more, even more preferably 90 parts by mass or more, and 100 parts by mass or less, out of 100 parts by mass of the total content of recycled asphalt aggregate and new aggregate.

[0047] The asphalt mixture of the present invention contains the recycled asphalt aggregate in an amount of preferably 60 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, and preferably 100 parts by mass or less, and more preferably 95 parts by mass or less, per 100 parts by mass of the total mass of the asphalt mixture.

[0048] The asphalt mixture of the present invention has an asphalt mixture in which, per 100 parts by mass of the total of asphalt in the recycled asphalt aggregate and the amine compound represented by formula (I), the content of the amine compound represented by formula (I) is preferably 3 parts by mass or more and 50 parts by mass or less, more preferably 4 parts by mass or more, even more preferably 5 parts by mass or more, preferably 50 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

[0049] The content of the amine compound represented by formula (I) in the asphalt mixture is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.3% by mass or more, and preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less.

[0050] In this specification, "asphalt derived from recycled asphalt aggregate" refers to the asphalt contained in recycled asphalt aggregate. Asphalt derived from recycled asphalt aggregate is distinguished from new asphalt. Asphalt derived from recycled asphalt aggregate is sometimes also referred to as deteriorated asphalt. The asphalt content in recycled asphalt aggregate can be measured by solvent extraction or ignition loss method. Typically, the asphalt content in recycled asphalt aggregate derived from used asphalt pavement is approximately 5.5% by mass. In this invention, the asphalt content derived from recycled asphalt aggregate is determined according to the method specified in AASHTO (American Association of State Highway and Transportation Officials) T 308-10 (2015), which is a loss on ignition measurement. Since recycled asphalt aggregate is included as aggregate, the amount of asphalt is determined from the loss on ignition of the recycled asphalt aggregate and used in the mix design calculation.

[0051] From the viewpoint of the effects of the present invention, the content of the amine compound represented by formula (I) in the asphalt mixture of the present invention is preferably 3 parts by mass or more and 30 parts by mass or less, more preferably 5 parts by mass or more, even more preferably 6 parts by mass or more, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, based on the total content of the three components: asphalt derived from recycled asphalt aggregate, the amine compound represented by formula (I), and optionally included new asphalt, per 100 parts by mass.

[0052] From the viewpoint of the effects of the present invention, the content of dialkylmethylamine in the asphalt mixture of the present invention is preferably 3 to 30 parts by mass, more preferably 5 parts by mass or more, even more preferably 6 parts by mass or more, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, based on the total content of the three components: asphalt derived from recycled asphalt aggregate, dialkylmethylamine, and optionally included new asphalt, per 100 parts by mass.

[0053] From the viewpoint of the effects of the present invention, the polyoxyethylene alkylamine content in the asphalt mixture of the present invention is preferably 3 to 30 parts by mass, more preferably 5 parts by mass or more, even more preferably 6 parts by mass or more, and more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less, based on 100 parts by mass of the total content of the three components: asphalt derived from recycled asphalt aggregate, polyoxyethylene alkylamine, and optionally included new asphalt.

[0054] From the viewpoint of the effects of the present invention, the content of the three components in the asphalt mixture—asphalt derived from recycled asphalt aggregate, the amine compound represented by the above formula (I), and optionally included novel asphalt—is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more, even more preferably 4% by mass or more, and even more preferably 15% by mass or less, and even more preferably 10% by mass or less.

[0055] From the viewpoint of the effects of the present invention, the content of the three components in the asphalt mixture—asphalt derived from recycled asphalt aggregate, dialkylmethylamine, and optionally novel asphalt—is preferably 1% to 20% by mass, more preferably 3% or more by mass, even more preferably 4% or more by mass, and even more preferably 15% or less by mass, and even more preferably 10% or less by mass.

[0056] From the viewpoint of the effects of the present invention, the content of the three components in the asphalt mixture—asphalt derived from recycled asphalt aggregate, polyoxyethylene alkylamine, and optionally novel asphalt—is preferably 1% to 20% by mass, more preferably 3% or more by mass, even more preferably 4% or more by mass, and even more preferably 15% or less by mass, and even more preferably 10% or less by mass.

[0057] Examples of suitable aggregate compositions in asphalt mixtures include the following (1) to (3). (1) Fine-grained asphalt containing coarse aggregate of 30% by volume or more and less than 45% by volume, fine aggregate of 30% by volume or more and 50% by volume or less, and asphalt composition of 5% by volume or more and 10% by volume or less. (2) An example of an asphalt mixture is, for example, dense-grained asphalt containing coarse aggregate of 45% by volume or more and less than 70% by volume, fine aggregate of 20% by volume or more and 45% by volume or less, and asphalt composition of 3% by volume or more and 10% by volume or less. (3) Porous asphalt containing coarse aggregate of 70% by volume or more and 80% by volume or less, fine aggregate of 10% by volume or more and 20% by volume or less, and asphalt composition of 3% by volume or more and 10% by volume or less. Note that regarding the blending ratio of asphalt in a conventional asphalt mixture containing aggregate and asphalt, it is usually used according to the optimum asphalt amount obtained from the "Blending Design of Asphalt Composition" described in the "Pavement Design and Construction Guidelines" issued by the Japan Road Association, a public interest incorporated foundation. In the present invention, the above optimum asphalt amount corresponds to the total amount of asphalt. However, it is not necessary to be limited to the method described in the "Pavement Design and Construction Guidelines", and it may be determined by other methods.

[0058] [Method for manufacturing asphalt mixture] The method for manufacturing the asphalt mixture of the present invention includes a step of mixing an amine compound represented by the following formula (I) and asphalt recycled aggregate. [Chemical formula] [In the formula, R a represents an alkyl group having 20 or less carbon atoms. R b and R c independently represent an alkyl group having 6 or more and 22 or less carbon atoms, or -(R d O) x -H. R d is an alkylene group having 2 or more and 4 or less carbon atoms, and x is the average addition molar number of oxyalkylene groups. R b and R c are -(R d O) xWhen it is -H, the total average number of moles of oxyalkylene groups added is 20 or less. In the method for producing the asphalt mixture, by including the amine compound represented by the above formula (I), excellent physical properties can be exhibited even when using asphalt recycled aggregates with advanced deterioration, which is useful due to the interaction with the deteriorated asphalt components adhering to the asphalt recycled aggregates.

[0059] The method for producing the asphalt mixture of the present invention preferably includes at least one selected from a dialkylmethylamine represented by the following formula (II) and a polyoxyethylenealkylamine represented by the following general formula (III) as the amine compound represented by the above formula (I).

Chemical formula

Chemical formula

[0060] The method for producing the asphalt mixture of the present invention preferably uses the asphalt recycled aggregate as a deteriorated asphalt recycled aggregate having a penetration of 25 or less of the extracted asphalt.

[0061] The present invention provides a method for producing an asphalt mixture, comprising the step of mixing recycled asphalt aggregate with an amine compound represented by the above formula (I) under heating conditions. The mixing process involves simultaneously or in any order mixing recycled asphalt aggregate and the amine compound represented by the above formula (I), as well as any additional new asphalt and new aggregate that can be added. Mixing under heating conditions is preferably carried out using heated recycled asphalt aggregate. When compounding new asphalt, from the viewpoint of durability and flexibility of the asphalt pavement, it is preferable to mix the above-mentioned amine compound with the recycled asphalt aggregate at the same time as or after the new asphalt. If the asphalt mixture contains new aggregate in addition to recycled asphalt aggregate, the recycled asphalt aggregate and the new aggregate can be mixed and used in such a way as described above. Specific methods for manufacturing asphalt mixtures include the simultaneous addition method and the pre-addition method. Both methods involve adding the amine compound to heated recycled asphalt aggregate. Addition methods include, for example, the pre-addition method in which the recycled asphalt aggregate and the amine compound are mixed in advance, or the simultaneous addition method in which the amine compound is added to the heated recycled asphalt aggregate simultaneously or in any order. Among these, the plant mix method is preferred from the viewpoint of exhibiting asphalt performance.

[0062] The present invention provides a method for producing an asphalt mixture, comprising the step of mixing recycled asphalt aggregate with a dialkylmethylamine represented by the above formula (II) under heating conditions. The mixing process involves simultaneously or in any order mixing recycled asphalt aggregate and dialkylmethylamine represented by the above formula (II), as well as any additional new asphalt and new aggregate that can be added. Mixing under heating conditions is preferably carried out using heated recycled asphalt aggregate. When compounding new asphalt, from the viewpoint of durability and flexibility of the asphalt pavement, it is preferable to mix the above-mentioned dialkylmethylamine with the recycled asphalt aggregate at the same time as or after the new asphalt. If the asphalt mixture contains new aggregate in addition to recycled asphalt aggregate, the recycled asphalt aggregate and the new aggregate can be mixed and used in such a way as described above. Specific methods for manufacturing asphalt mixtures include the simultaneous addition method and the pre-addition method. Both methods involve adding the dialkylmethylamine to heated recycled asphalt aggregate. Addition methods include, for example, the pre-addition method in which the recycled asphalt aggregate and the dialkylmethylamine are mixed in advance, or the simultaneous addition method in which the dialkylmethylamine is added to the heated recycled asphalt aggregate simultaneously or in any order. Among these, the plant mix method is preferred from the viewpoint of exhibiting asphalt performance.

[0063] The present invention provides a method for producing an asphalt mixture, comprising the step of mixing recycled asphalt aggregate with a polyoxyethylene alkylamine represented by the above formula (III) under heating conditions. The mixing process involves simultaneously or in any order mixing recycled asphalt aggregate and polyoxyethylene alkylamine represented by the above formula (III), as well as optional new asphalt and new aggregate. Mixing under heating conditions is preferably carried out using heated recycled asphalt aggregate. When compounding new asphalt, from the viewpoint of durability and flexibility of the asphalt pavement, it is preferable to mix the above-mentioned polyoxyethylene alkylamine with the recycled asphalt aggregate at the same time as or after the new asphalt. If the asphalt mixture contains new aggregate in addition to recycled asphalt aggregate, the recycled asphalt aggregate and the new aggregate can be mixed and used in such a way as described above. Specific methods for manufacturing asphalt mixtures include methods such as the simultaneous addition method and the pre-addition method. Both methods involve adding the polyoxyethylene alkylamine to heated recycled asphalt aggregate. Examples of addition methods include the pre-addition method, in which the recycled asphalt aggregate and the polyoxyethylene alkylamine are mixed in advance, or the simultaneous addition method, in which the polyoxyethylene alkylamine is added to the heated recycled asphalt aggregate simultaneously or in any order.

[0064] From the viewpoint of improving durability through sufficient mixing, the heating temperature is preferably 160°C or higher, more preferably 165°C or higher, and even more preferably 170°C or higher. Furthermore, from the viewpoint of performance stability, it is preferably 350°C or lower, more preferably 250°C or lower, and even more preferably 200°C or lower.

[0065] [Additives for recycling recycled asphalt aggregate] The asphalt recycled aggregate recycling additive of the present invention contains an amine compound represented by the following formula (I). [ka] [In the formula, R a R represents an alkyl group with 20 or fewer carbon atoms. b and R c These are independently alkyl groups having 6 to 22 carbon atoms, or -(R d O) x -H represents R. d R is an alkylene group having 2 to 4 carbon atoms, and x is the average number of moles of oxyalkylene groups added. b and R c ga-(R d O) x -When H is present, the total average number of moles of oxyalkylene groups added is 20 or less. The aforementioned additive for recycling recycled asphalt aggregate contains an amine compound represented by formula (I) above. This compound interacts with the deteriorated asphalt components fixed to the recycled asphalt aggregate, enabling the use of recycled asphalt aggregate that has deteriorated to a high degree, thereby allowing it to exhibit excellent physical properties and proving useful.

[0066] The recycled additive for asphalt aggregate of the present invention preferably contains one or more amine compounds represented by the above formula (I) selected from dialkylmethylamines represented by the following formula (II) and polyoxyethylene alkylamines represented by the following general formula (III). [ka] [In the formula, R 1 and R 2 This independently represents an alkyl group having 6 to 22 carbon atoms. [ka] [In the formula, R 3 represents an alkyl group with 20 or fewer carbon atoms. a and b represent the average number of moles of oxyethylene groups added, and a+b is 20 or less. The amine compound represented by formula (I) contained in the recycling additive for the recycled asphalt aggregate includes one or more selected from the dialkylmethylamine represented by formula (II) and the polyoxyethylene alkylamine represented by the general formula (III) below. This allows the compound to exhibit high affinity for asphaltene, which is particularly deteriorated and modified in the asphalt derived from the recycled asphalt aggregate and takes on an aggregated structure, thereby providing a high softening effect and making it useful.

[0067] [Paving Method] The asphalt mixture of the present invention is suitable for paving, and suitable applications for paving include roads, parking lots, and the like. The paving method includes the step of applying the aforementioned asphalt mixture to the area to be paved to form an asphalt paving material layer. The asphalt paving material layer is usually a base layer or a surface layer, and from the viewpoint of improving deflection resistance and crack resistance, it is preferably a surface layer.

[0068] The thickness of the asphalt pavement layer is preferably 3 cm or more, more preferably 4 cm or more, even more preferably 4.5 cm or more, and preferably 7 cm or less, more preferably 6 cm or less, and even more preferably 5.5 cm or less, from the viewpoint of improving deflection resistance and crack resistance. In another embodiment of the present invention, the asphalt pavement layer can be a thin-layer pavement, and the thickness of the surface layer is preferably 1 cm or more, more preferably 1.5 cm or more, even more preferably 2 cm or more, and preferably 4 cm or less, more preferably 3.5 cm or less, and even more preferably 3 cm or less. The asphalt mixture can be compacted using a known construction machinery setup and a similar method. When used as a heated asphalt mixture, the compaction temperature is preferably 100°C or higher, more preferably 120°C or higher, even more preferably 130°C or higher, and preferably 200°C or lower, more preferably 180°C or lower, from the viewpoint of improving the deflection resistance and crack resistance of the asphalt pavement. [Examples]

[0069] In the following examples and comparative examples, unless otherwise specified, parts and percentages are based on mass.

[0070] (Embodiment 1) The following details the case where the amine compound represented by formula (I) above is the dialkylmethylamine represented by formula (II) above.

[0071] The dialkylmethylamines (1) to (7) used are shown in Table 1 below. The dialkylmethylamines (1) to (7) were prepared based on Examples 5 and 6 of Japanese Patent Publication No. 61-15865.

[0072] [Table 1]

[0073] Example 1-1 (1) Preparation of asphalt mixture 1.3 kg of recycled asphalt aggregate with the composition shown below, heated to 165°C, was placed in a frying pan, 8 g of dialkylmethylamine (1) was added, and the mixture was mixed for 2 minutes to obtain an asphalt mixture.

[0074] <Composition of aggregates> Asphalt recycled aggregate passage mass percentage: Sieve mesh size 15 mm: 99.7% by mass Sieve mesh size 10 mm: 84.3% by mass Sieve mesh size 5 mm: 70.1% by mass Sieve mesh size 2.5 mm: 52.3% by mass Sieve mesh size 1.2 mm: 30.7% by mass Sieve mesh size 0.6 mm: 21.4% by mass Sieve mesh size 0.3 mm: 9.8% by mass Sieve mesh size 0.15 mm: 4.1% by mass

[0075] The asphalt content (asphalt derived from recycled asphalt aggregate) in 1.3 kg of recycled asphalt aggregate was 72 g. The asphalt content derived from recycled asphalt aggregate was determined according to the method specified in AASHTO T 308-10 (2015). The content of dialkylmethylamine (1) in the asphalt mixture was set to 10 parts by mass per 100 parts by mass of the total content of asphalt derived from recycled asphalt aggregate and dialkylmethylamine. Furthermore, the penetration degree of the asphalt derived from recycled asphalt aggregate was 21. The penetration degree was measured according to the procedure of JIS K 2207:1996 for asphalt extracted according to "G028 Asphalt Extraction Test Method" in the "Pavement Survey and Testing Methods Handbook (FY2019 Edition)" (edited by the Japan Road Association).

[0076] (2) Measurement of Marshall stability 1.2 kg of the obtained asphalt mixture was weighed out, and cylindrical specimens were prepared using a Marshall test compaction machine (manufactured by Nakajima Gihan Co., Ltd., "Automatic Asphalt Compaction Machine"). The specimens were slowly cooled to room temperature and demolded using a demolding machine. Four asphalt specimens were prepared. After demolding, the cylindrical specimens were immersed in a 60°C constant temperature water bath for 30 minutes. Following this, they were subjected to a Marshall stability test according to "B001 Marshall Stability Test Method" in the "Pavement Survey and Testing Methods Handbook (FY2019 Edition)" (compiled by the Japan Road Association), and the Marshall stability (kN) of asphalt specimen M-1 was measured. Marshall stability refers to the maximum load required to break an asphalt specimen; a higher value indicates superior durability of the asphalt pavement. The results are shown in Table 2.

[0077] (3) Measurement of void ratio The void ratio of the asphalt specimen M-1 was determined from its air and water weights in accordance with the measurement method specified in "B008-1 Density Test Method for Dense-Graded Asphalt Mixtures, etc." in Volume 3 of the "Pavement Survey and Testing Methods Handbook (FY2019 Edition)" (edited by the Japan Road Association).

[0078] Specifically, the porosity was calculated according to the following formula. Porosity = 100 × {1 - (bulk density of the specimen) / (theoretical maximum density)} The various physical properties used to calculate the porosity were calculated according to the following formula. Bulk density of the test specimen = (mass in air) / (mass on surface dry - mass in water) Theoretical maximum density=2.505 Note that surface-dry weight refers to the mass of the specimen after immersing it in water for 3 minutes and then wiping the surface.

[0079] By measuring the void ratio under identical conditions, the workability of the asphalt mixture can be evaluated. The results are shown in Table 2.

[0080] Examples 1-2 An asphalt mixture was obtained in the same manner as in Example 1-1, except that the content of dialkylmethylamine (1) was 3.8 g (5 parts by mass per 100 parts by mass of the total content of asphalt derived from recycled asphalt aggregate and dialkylmethylamine). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0081] Examples 1-3 An asphalt mixture was obtained in the same manner as in Example 1-1, except that the content of dialkylmethylamine (1) was 12.7 g (15 parts by mass per 100 parts by mass of the total content of asphalt derived from recycled asphalt aggregate and dialkylmethylamine). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0082] Examples 1-4 to 1-9 Replace with 8g of dialkylmethylamine(1), 1759982997983_6 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 8 g of dialkylmethylamine (2) to (7) shown was used. Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0083] Comparative Example 1-1 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 8 g of dialkylmethylamine (1) was not used. Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0084] Comparative Example 1-2 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 8 g of laurylamine was used instead of 8 g of dialkylmethylamine (1). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0085] Comparative Examples 1-3 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 8 g of dimethyl laurylamine was used instead of 8 g of dialkylmethylamine (1). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0086] Comparative Example 1-4 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 12.7 g of dimethyl laurylamine (15 parts by mass per 100 parts by mass of the total content of asphalt derived from recycled asphalt aggregate and dimethyl laurylamine) was used instead of 8 g of dialkylmethylamine (1). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0087] [Table 2]

[0088] As shown in Examples 1-1 to 1-9, the asphalt mixture of the present invention exhibits high Marshall stability and low porosity, and therefore can exhibit excellent physical properties even when using recycled asphalt aggregate that has deteriorated to an advanced degree. In Examples 1-1, 1-4, and 1-5, particularly low porosity was observed, indicating that dialkylmethylamines with a relatively large number of carbon atoms (12 or more) were especially effective. Furthermore, it was found that the more effective the dialkylmethylamine, the more effective it was in improving both durability and workability. This is thought to be because fluidizing the solidified binder in the recycled asphalt aggregate made it possible to improve durability and workability.

[0089] (Embodiment 2) The following details the case where the amine compound represented by formula (I) above is a polyoxyethylene alkylamine represented by formula (III) above.

[0090] The polyoxyethylene alkylamines (1) to (7) used are shown in Table 3 below. Note that the polyoxyethylene alkylamines (1) to (7) were produced by changing the type of aliphatic primary amine used as a raw material and the amount of ethylene oxide, based on Example 1 of Japanese Patent Publication No. 11-158125.

[0091] [Table 3]

[0092] Example 2-1 (1) Preparation of asphalt mixture 1.3 kg of recycled asphalt aggregate with the composition shown below, heated to 165°C, was placed in a frying pan, 8.7 g of polyoxyethylene alkylamine (1) was added, and the mixture was mixed for 2 minutes to obtain an asphalt mixture.

[0093] <Composition of aggregates> Asphalt recycled aggregate passage mass percentage: Sieve mesh size 15 mm: 100% by mass Sieve mesh size 10 mm: 74.5% by mass Sieve mesh size 5 mm: 64.3% by mass Sieve mesh size 2.5 mm: 46.8% by mass Sieve mesh size 1.2 mm: 33.6% by mass Sieve mesh size 0.6 mm: 18.3% by mass Sieve mesh size 0.3 mm: 9.8% by mass Sieve mesh size 0.15 mm: 2.4% by mass

[0094] The asphalt content (asphalt derived from recycled asphalt aggregate) in 1.3 kg of recycled asphalt aggregate was 78 g. The asphalt content derived from recycled asphalt aggregate was determined according to the method specified in AASHTO T 308-10 (2015). The content of polyoxyethylene alkylamine (1) in the asphalt mixture was set to 10 parts by mass per 100 parts by mass of the total content of asphalt derived from recycled asphalt aggregate and polyoxyethylene alkylamine (1). Furthermore, the penetration degree of the asphalt derived from recycled asphalt aggregate was 7. The penetration degree was measured according to the procedure of JIS K 2207:1996 for asphalt extracted according to "G028 Asphalt Extraction Test Method" in the "Pavement Survey and Testing Methods Handbook (FY2019 Edition)" (edited by the Japan Road Association).

[0095] (2) Measurement of Marshall stability 1.2 kg of the obtained asphalt mixture was weighed out, and cylindrical specimens were prepared using a Marshall test compaction machine (manufactured by Nakajima Gihan Co., Ltd., "Automatic Asphalt Compaction Machine"). The specimens were slowly cooled to room temperature and demolded using a demolding machine. Four asphalt specimens were prepared. After demolding, the cylindrical specimens were immersed in a 60°C constant temperature water bath for 30 minutes. Then, they were subjected to a Marshall stability test according to "B001 Marshall Stability Test Method" in the "Pavement Survey and Testing Methods Handbook (FY2019 Edition)" (compiled by the Japan Road Association), and the Marshall stability (kN) of asphalt specimen 1 was measured. Marshall stability refers to the maximum load required to break an asphalt specimen; a higher value indicates superior durability of the asphalt pavement. The results are shown in Table 4.

[0096] (3) Measurement of void ratio The void ratio of the asphalt specimen M-1 was determined from its air and water weights in accordance with the measurement method specified in "B008-1 Density Test Method for Dense-Graded Asphalt Mixtures, etc." in Volume 3 of the "Pavement Survey and Testing Methods Handbook (FY2019 Edition)" (edited by the Japan Road Association).

[0097] Specifically, the porosity was calculated according to the following formula. Porosity = 100 × {1 - (bulk density of the specimen) / (theoretical maximum density)} The various physical properties used to calculate the porosity were calculated according to the following formula. Bulk density of the test specimen = (mass in air) / (mass on surface dry - mass in water) Theoretical maximum density=2.512 Note that surface-dry weight refers to the mass of the specimen after immersing it in water for 3 minutes and then wiping the surface.

[0098] By measuring the void ratio under identical conditions, the workability of the asphalt mixture can be evaluated. The results are shown in Table 4.

[0099] Example 2-2 An asphalt mixture was obtained in the same manner as in Example 2-1, except that the content of polyoxyethylene alkylamine (1) was 4.1 g (5 parts by mass per 100 parts by mass of the total content of asphalt derived from recycled asphalt aggregate and polyoxyethylene alkylamine (1)). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 2-1. The results are shown in Table 4.

[0100] Examples 2-3 An asphalt mixture was obtained in the same manner as in Example 2-1, except that the content of polyoxyethylene alkylamine (1) was 13.8 g (15 parts by mass per 100 parts by mass of the total content of asphalt derived from recycled asphalt aggregate and polyoxyethylene alkylamine (1)). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 2-1. The results are shown in Table 4.

[0101] Examples 2-4 to 2-8 An asphalt mixture was obtained in the same manner as in Example 2-1, except that 8.7 g of polyoxyethylene alkylamines (2) to (6) shown in Table 3 were used instead of 8.7 g of polyoxyethylene alkylamine (1). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 2-1. The results are shown in Table 4.

[0102] Comparative Example 2-1 An asphalt mixture was obtained in the same manner as in Example 2-1, except that 8.7 g of polyoxyethylene alkylamine (1) was not used. Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 2-1. The results are shown in Table 4.

[0103] Comparative Example 2-2 An asphalt mixture was obtained in the same manner as in Example 2-1, except that 8.7 g of the recycling additive "ReproVital 500" (trade name, manufactured by Idemitsu Kosan Co., Ltd.) was used instead of 8.7 g of polyoxyethylene alkylamine (1) (10 parts by mass per 100 parts by mass of the total amount of asphalt derived from recycled asphalt aggregate and recycling additive). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 2-1. The results are shown in Table 4.

[0104] Comparative Example 2-3 An asphalt mixture was obtained in the same manner as in Example 2-1, except that 13.8 g of the recycling additive "ReproVital 500" (trade name, manufactured by Idemitsu Kosan Co., Ltd.) was used instead of 8.7 g of polyoxyethylene alkylamine (1) (15 parts by mass per 100 parts by mass of the total amount of asphalt derived from recycled asphalt aggregate and recycling additive). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 2-1. The results are shown in Table 4.

[0105] Comparative Example 2-4 An asphalt mixture was obtained in the same manner as in Example 2-1, except that 8.7 g of polyoxyethylene alkylamine (7) shown in Table 3 was used instead of 8.7 g of polyoxyethylene alkylamine (1). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 2-1. The results are shown in Table 4.

[0106] Comparative Example 2-5 An asphalt mixture was obtained in the same manner as in Example 2-1, except that 8.7 g of "Farmin 20D" (trade name, manufactured by Kao Corporation; laurylamine) was used instead of 8.7 g of polyoxyethylene alkylamine (1). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 2-1. The results are shown in Table 4.

[0107] Comparative Example 2-6 An asphalt mixture was obtained in the same manner as in Example 2-1, except that "Farmin DM4098" (trade name, manufactured by Kao Corporation; dimethyl myristylamine) was used instead of polyoxyethylene alkylamine (1). Asphalt specimens were prepared using the obtained asphalt mixture, and the Marshall stability and porosity were measured in the same manner as in Example 2-1. The results are shown in Table 4.

[0108] [Table 4]

[0109] As shown in Examples 2-1 to 2-8, the asphalt mixture of the present invention exhibits high Marshall stability and low porosity, and therefore can exhibit excellent physical properties even when using recycled asphalt aggregate that has deteriorated to an advanced degree. Examples 2-1, 2-4, and 2-5 showed particularly excellent reduction in porosity, while Example 2-8 showed relatively low performance improvement, indicating that compounds with approximately 10 moles of oxyethylene added were particularly effective. This is because the interaction between the deteriorated asphalt and the aggregate in the recycled asphalt aggregate was best controlled. Conversely, a higher number of added moles resulted in excessive polarity, significantly disrupting this balance. Furthermore, compounds with higher effectiveness were found to be more effective in improving both porosity and stability. This is thought to be because fluidizing the solidified binder in the recycled asphalt aggregate improved workability and hardness.

Claims

1. An asphalt mixture comprising an amine compound represented by the following formula (I) and recycled asphalt aggregate. 【Chemistry 1】 [In the formula, R ａ represents an alkyl group having 20 or less carbon atoms. R ｂ and R ｃ independently represent an alkyl group having 6 or more and 22 or less carbon atoms, or -(R ｄ O) Ｘ -H. R ｄ is an alkylene group having 2 or more and 4 or less carbon atoms, and x is the average number of moles of oxyalkylene groups added. When R ｂ and R ｃ are -(R ｄ O) Ｘ -H, the total average number of moles of oxyalkylene groups added is 20 or less.]

2. The asphalt mixture according to claim 1, wherein the amine compound represented by formula (I) above comprises one or more selected from dialkylmethylamine represented by formula (II) below and polyoxyethylene alkylamine represented by general formula (III) below. 【Chemistry 2】 [In the formula, R １ and R ２ This independently represents an alkyl group having 6 to 22 carbon atoms. 【Transformation 3】 [In the formula, R ３ [where 'a' represents an alkyl group with 20 or fewer carbon atoms, and 'b' represents the average number of moles of oxyethylene groups added, where a + b is 20 or less.]

3. The aforementioned R １ and R ２ The asphalt mixture according to claim 2, wherein the average number of carbon atoms of the alkyl group represented is 8 or more and 22 or less.

4. The aforementioned R ３ The asphalt mixture according to claim 2, wherein the number of carbon atoms in the alkyl group represented by is 12 or more.

5. The asphalt mixture according to claim 2, wherein a + b is 2 or more and 15 or less.

6. The asphalt mixture according to claim 1, wherein the recycled asphalt aggregate is a deteriorated recycled asphalt aggregate with a penetration degree of 25 or less of the extracted asphalt.

7. The asphalt mixture according to claim 1, wherein the recycled asphalt aggregate is contained in an amount of 60 parts by mass or more per 100 parts by mass of the total mass of the asphalt mixture.

8. The asphalt mixture according to claim 1, further comprising novel asphalt.

9. The asphalt mixture according to claim 1, further comprising a novel aggregate.

10. The asphalt mixture according to claim 1, wherein the content of the amine compound represented by formula (I) is 3 parts by mass or more and 50 parts by mass or less, based on a total of 100 parts by mass of asphalt and the amine compound represented by formula (I) in the recycled asphalt aggregate.

11. A method for producing an asphalt mixture, comprising the step of mixing an amine compound represented by the following formula (I) and recycled asphalt aggregate. 【Chemistry 4】 [In the formula, R ａ R represents an alkyl group with 20 or fewer carbon atoms. ｂ and R ｃ These are independently alkyl groups having 6 to 22 carbon atoms, or -(R ｄ O) Ｘ - Represents H. R ｄ R is an alkylene group having 2 to 4 carbon atoms, and x is the average number of moles of oxyalkylene groups added. ｂ and R ｃ ga- (R ｄ O) Ｘ If it is -H, the total average number of moles of oxyalkylene groups added is 20 or less.

12. A method for producing an asphalt mixture according to claim 11, wherein the amine compound represented by the above formula (I) comprises one or more selected from dialkylmethylamine represented by the following formula (II) and polyoxyethylene alkylamine represented by the following general formula (III). 【Transformation 5】 [In the formula, R １ and R ２ This independently represents an alkyl group having 6 to 22 carbon atoms. 【Transformation 6】 [In the formula, R ３ [where 'a' represents an alkyl group with 20 or fewer carbon atoms, and 'b' represents the average number of moles of oxyethylene groups added, where a + b is 20 or less.]

13. The method for producing an asphalt mixture according to claim 11, wherein the recycled asphalt aggregate is a deteriorated recycled asphalt aggregate with a penetration degree of 25 or less of the extracted asphalt.

14. A recycling additive for recycled asphalt aggregate, comprising an amine compound represented by the following formula (I). 【Transformation 7】 [In the formula, R ａ R represents an alkyl group with 20 or fewer carbon atoms. ｂ and R ｃ These are independently alkyl groups having 6 to 22 carbon atoms, or -(R ｄ O) Ｘ - Represents H. R ｄ R is an alkylene group having 2 to 4 carbon atoms, and x is the average number of moles of oxyalkylene groups added. ｂ and R ｃ ga- (R ｄ O) Ｘ If it is -H, the total average number of moles of oxyalkylene groups added is 20 or less.

15. The additive for recycling recycled asphalt aggregate according to claim 14, wherein the amine compound represented by the above formula (I) comprises one or more selected from dialkylmethylamine represented by the following formula (II) and polyoxyethylene alkylamine represented by the following general formula (III). 【Transformation 8】 [In the formula, R １ and R ２ This independently represents an alkyl group having 6 to 22 carbon atoms. 【Chemistry 9】 [In the formula, R ３ [where 'a' represents an alkyl group with 20 or fewer carbon atoms, and 'b' represents the average number of moles of oxyethylene groups added, where a + b is 20 or less.]

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