Asphalt mixture

Abstract

To provide an asphalt mixture which can exhibit stable performance even when asphalt recycled aggregates having different degrees of deterioration are used.SOLUTION: An asphalt mixture comprising a novel asphalt, an additive for regenerating and an asphalt regenerated aggregate, wherein the additive for regenerating comprises (I) an aliphatic amine having an aliphatic hydrocarbon group having 1 to 10 carbon atoms, (ii) an aliphatic amine having an aliphatic hydrocarbon group having 11 to 17 carbon atoms, and (iii) an aliphatic amine having an aliphatic hydrocarbon group having 18 or more carbon atoms.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an additive for regenerating asphalt mixtures and recycled asphalt aggregates. [Background technology]

[0002] BACKGROUND ART Asphalt pavements using asphalt compositions are used for paving roads, parking lots, freight yards, sidewalks, etc. because they are relatively easy to lay and require a short time from the start of paving work until traffic can begin. This asphalt pavement has a road surface formed from an asphalt mixture in which aggregate is bound with asphalt, and has good hardness and durability.

[0003] In recent years, from the viewpoint of reducing environmental impact and rising crude oil prices, asphalt pavement, which uses damaged asphalt pavement debris (recycled asphalt aggregate) as a new pavement material, has become increasingly popular.

[0004] Patent Document 1 discloses an asphalt mixture for obtaining asphalt pavement that is highly durable and can maintain its black color even after the road is opened to traffic. The asphalt mixture contains polyester resin, a compound having 8 or more carbon atoms and having a hydroxyl group or an amino group, asphalt, and aggregate, and the aggregate contains recycled asphalt aggregate. Patent Document 2 discloses, as a technology that enables wider use of reclaimed asphalt, an asphalt composition that contains reclaimed asphalt and an ester-functional rejuvenating agent, the reclaimed asphalt containing aggregate and an oxidized asphalt binder, and the rejuvenating agent is present in an amount effective to reduce the glass transition onset temperature of the oxidized asphalt binder by at least 5°C compared to the glass transition onset temperature of the oxidized asphalt binder that does not contain the rejuvenating agent. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-36018 [Patent Document 2] International Publication No. 2013 / 090283 Summary of the Invention [Problem to be solved by the invention]

[0006] Recycled asphalt aggregate requires the use of softening additives depending on the location of use and / or recovery. As the repeated use of recycled aggregate progresses and the ratio of recycled aggregate to be mixed tends to increase, the fluctuation in physical properties mentioned above becomes a significant issue, and improvement of this is necessary. The technology described in Patent Document 1 effectively acts on the fixed asphalt in recycled aggregate, resulting in pavement that is durable and has a black color, but it is not very effective on various recycled aggregates, and in particular, softening is insufficient. The technology described in Patent Document 2 can soften hard, deteriorated asphalt without impairing its necessary properties. However, this test was mainly conducted on extracted and plasticized deteriorated asphalt, and it is believed that the effect on asphalt fixed in recycled aggregate is insufficient.

[0007] The present invention relates to an asphalt mixture that can exhibit stable performance even when using recycled asphalt aggregate with different degrees of deterioration, and an additive for recycling recycled asphalt aggregate that can obtain such an asphalt mixture.

[0008] The present invention relates to the following [1] and [2]. [1] An asphalt mixture containing new asphalt, a regeneration additive, and recycled asphalt aggregate, wherein the regeneration additive includes (i) an aliphatic amine having an aliphatic hydrocarbon group with 1 to 10 carbon atoms, (ii) an aliphatic amine having an aliphatic hydrocarbon group with 11 to 17 carbon atoms, and (iii) an aliphatic amine having an aliphatic hydrocarbon group with 18 or more carbon atoms. [2] (i) aliphatic amines having an aliphatic hydrocarbon group with 1 to 10 carbon atoms, (ii) aliphatic amines having an aliphatic hydrocarbon group with 11 to 17 carbon atoms, and (iii) aliphatic amines having an aliphatic hydrocarbon group with 18 or more carbon atoms, an additive for recycling asphalt recycled aggregate, wherein the content of the aliphatic amine (i) is 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii); the content of the aliphatic amine (iii) is 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii); and the content of the aliphatic amine (ii) is 50 parts by mass or more and 95 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii).

[0009] The present invention provides an asphalt mixture that can exhibit stable performance even when using recycled asphalt aggregate with different degrees of deterioration, and an additive for recycling recycled asphalt aggregate that can obtain such an asphalt mixture. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Asphalt mixture] The asphalt mixture of the present invention contains a novel asphalt, a rejuvenation additive, and recycled asphalt aggregate, and the rejuvenation additive includes (i) an aliphatic amine having an aliphatic hydrocarbon group with 1 to 10 carbon atoms, (ii) an aliphatic amine having an aliphatic hydrocarbon group with 11 to 17 carbon atoms, and (iii) an aliphatic amine having an aliphatic hydrocarbon group with 18 or more carbon atoms.

[0011] The asphalt mixture of the present invention exhibits stable performance even when recycled asphalt aggregates with different degrees of deterioration are used. In this specification, an asphalt mixture capable of exhibiting stable performance means that an asphalt pavement using the asphalt mixture has both excellent durability and flexibility. The durability of asphalt pavement can be evaluated, for example, by Marshall stability as shown in the examples below. The flexibility of asphalt pavement can be evaluated, for example, by flow value as shown in the examples below.

[0012] While the detailed mechanism by which the effects of the present invention are achieved is unclear, it is believed that the high softening effect is achieved by having an aliphatic hydrocarbon group with a specific carbon number that has a high affinity with asphalt derived from recycled aggregate and an amino group that has a high affinity with aggregate. Furthermore, because the amino group has high polarity and a high pH, ​​it has a high affinity with aggregated asphaltene, resulting in electrostatic charging properties. This also enhances the dispersing effect, and it is expected that extremely high functionality can be imparted to deteriorated asphalt. Furthermore, because it is composed of compounds with various alkyl chains, it is expected that it has a high affinity with asphalt of different degrees of deterioration, which is thought to be why it works effectively with various recycled aggregates and exhibits its effects without any fluctuation in physical properties.

[0013] <New asphalt> New asphalt is also called virgin asphalt or unused asphalt, and refers to asphalt that has never been used in asphalt pavement. As new asphalt, various asphalts can be used as long as they have no history of use in asphalt pavement. Examples include straight asphalt, which is petroleum asphalt for paving, as well as modified asphalt. Modified asphalts include blown asphalt and polymer-modified asphalt modified with polymeric materials such as thermoplastic elastomers and thermoplastic resins. Straight asphalt refers to the residual bitumen obtained by subjecting crude oil to atmospheric distillation or vacuum distillation. Blown asphalt refers to asphalt obtained by heating a mixture of straight asphalt and heavy oil and then oxidizing it by blowing air into it. The asphalt is preferably selected from straight asphalt and polymer-modified asphalt. From the viewpoint of the durability of asphalt pavement, polymer-modified asphalt is more preferred, while straight asphalt is more preferred from the viewpoint of versatility. As polymer-modified asphalt, asphalt modified with thermoplastic elastomers is more preferred. The modified asphalt is preferably a polymer-modified asphalt, more preferably a polymer-modified asphalt modified with a thermoplastic elastomer.

[0014] (thermoplastic elastomer) Examples of the thermoplastic elastomer in the polymer modified asphalt modified with a thermoplastic elastomer include styrene / butadiene block copolymers, styrene / butadiene / styrene block copolymers, styrene / butadiene random copolymers, styrene / isoprene block copolymers, styrene / isoprene / styrene block copolymers, styrene / isoprene random copolymers, ethylene / vinyl acetate copolymers, ethylene / acrylic acid ester copolymers, styrene / ethylene / butylene / styrene copolymers, styrene / ethylene / propylene / styrene copolymers, polyurethane-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, isobutylene / isoprene copolymers, polyisoprene, polychloroprene, synthetic rubbers other than those mentioned above, and at least one selected from natural rubber. The thermoplastic elastomer in the modified asphalt is preferably at least one selected from styrene / butadiene block copolymers, styrene / butadiene / styrene block copolymers, styrene / butadiene random copolymers, styrene / isoprene block copolymers, styrene / isoprene / styrene block copolymers, styrene / isoprene random copolymers, ethylene / vinyl acetate copolymers, and ethylene / acrylic acid ester copolymers. Among these, from the viewpoint of durability of asphalt pavement, 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, even more preferably at least one selected from styrene / butadiene random copolymer and styrene / butadiene / styrene block copolymer. From the viewpoint of durability and surface appearance of the asphalt pavement, the content of thermoplastic elastomer in the 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, even more preferably 10% by mass or less.

[0015] <Recycling additives> The asphalt mixture of the present invention contains a regeneration additive, which is a component for restoring the properties of deteriorated asphalt derived from recycled asphalt aggregate. The reclaiming additive includes (i) an aliphatic amine having an aliphatic hydrocarbon group with 1 to 10 carbon atoms (hereinafter also referred to as aliphatic amine (i)), (ii) an aliphatic amine having an aliphatic hydrocarbon group with 11 to 17 carbon atoms (hereinafter also referred to as aliphatic amine (ii)), and (iii) an aliphatic amine having an aliphatic hydrocarbon group with 18 or more carbon atoms (hereinafter also referred to as aliphatic amine (iii)). Furthermore, it is preferable that the aliphatic amines (i), (ii), and (iii) do not contain unsaturated components. In the regeneration additive, the total amount of monoamines and diamines in the aliphatic amines is preferably 90% by mass or more, more preferably 95% by mass or more.

[0016] (Aliphatic amine (i)) The aliphatic amine (i) is an aliphatic amine having an aliphatic hydrocarbon group having a carbon number of 1 to 10. The aliphatic amine (i) has an aliphatic hydrocarbon group having a carbon number of 1 to 10 and one or more amino groups.

[0017] The aliphatic hydrocarbon group has 1 or more and 10 or less carbon atoms, preferably 6 or more, and more preferably 7 or more carbon atoms. The aliphatic hydrocarbon group may be either saturated or unsaturated, and may be either a straight-chain aliphatic hydrocarbon group or a branched aliphatic hydrocarbon group. The amino group may be a primary amino group, a secondary amino group, or a tertiary amino group.

[0018] Specific examples of the aliphatic amine (i) include caprylamine, octylamine, methyloctylamine, dimethyloctylamine, dimethyldecylamine, didecylmonomethylamine, and trioctylamine.

[0019] Examples of commercially available products of aliphatic amine (i) alone include "Farmin 08D", "Farmin DM0898", "Farmin DM1098", "Farmin M2-1095", "Farmin T-08", and "Lipomin 8D".

[0020] (Aliphatic amine (ii)) The aliphatic amine (ii) is an aliphatic amine having an aliphatic hydrocarbon group having a carbon number of 11 or more and 17 or less. The aliphatic amine (ii) has an aliphatic hydrocarbon group having a carbon number of 11 or more and 17 or less and one or more amino groups.

[0021] The aliphatic hydrocarbon group has 11 or more and 17 or less carbon atoms, preferably 12 or more and 16 or less carbon atoms. The aliphatic hydrocarbon group may be either saturated or unsaturated, and may be either a straight-chain aliphatic hydrocarbon group or a branched aliphatic hydrocarbon group. The amino group may be a primary amino group, a secondary amino group, or a tertiary amino group.

[0022] Specific examples of the aliphatic amine (ii) include laurylamine, dodecylamine, dimethyllaurylamine, dimethylmyristylamine, dimethylpalmitylamine, and dimethyldodecylamine.

[0023] Examples of commercially available products of aliphatic amine (ii) alone include "Farmin 20D," "Farmin DM2098," "Farmin DM2463," "Farmin DM2458," "Farmin DM4098," "Farmin DM6098," "Farmin DM6875," "Lipomin 12D," "Lipomin DM12D," and "Lipomin DM16D."

[0024] (Aliphatic amine (iii)) The aliphatic amine (iii) is an aliphatic amine having an aliphatic hydrocarbon group having at least 18 carbon atoms. The aliphatic amine (iii) has an aliphatic hydrocarbon group having at least 18 carbon atoms and one or more amino groups.

[0025] The aliphatic hydrocarbon group has 18 or more carbon atoms, preferably 22 or less, and more preferably 20 or less carbon atoms. The aliphatic hydrocarbon group may be either saturated or unsaturated, and may be either a straight-chain aliphatic hydrocarbon group or a branched aliphatic hydrocarbon group. The amino group may be a primary amino group, a secondary amino group, or a tertiary amino group.

[0026] Specific examples of the aliphatic amine (iii) include stearylamine, dimethylstearylamine, dimethylbehenylamine, beef tallow amine, beef tallow propylene diamine, and the like.

[0027] Examples of commercially available products of aliphatic amine (iii) alone include "Farmin 80S," "Farmin 86V," "Farmin DM8680," "Farmin DM8098," "Farmin DM2285," "Diamine R-86," "Diamine RRT," "Lipomin 18D," and "Lipomin DM22D."

[0028] In the aliphatic amine (i), aliphatic amine (ii), and aliphatic amine (iii), the "aliphatic hydrocarbon group" means an aliphatic hydrocarbon group directly bonded to an amino group. When an aliphatic amine compound has multiple aliphatic hydrocarbon groups, it is determined whether it belongs to aliphatic amine (i), aliphatic amine (ii), or aliphatic amine (iii) based on the aliphatic hydrocarbon group with the largest number of carbon atoms. For example, dodecyldimethylamine has two methyl groups with 1 carbon atom and a dodecyl group with 11 carbon atoms, and the aliphatic hydrocarbon group with the largest number of carbon atoms is the dodecyl group, so it belongs to aliphatic amine (ii).

[0029] (Aliphatic amine (i), (ii) and (iii) content) The content of the aliphatic amine (i) in the regeneration additive is preferably 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii). From the viewpoint of improving the pavement properties, the content is more preferably 0.7 parts by mass or more, even more preferably 0.9 parts by mass or more, and more preferably 39 parts by mass or less, even more preferably 20 parts by mass or less. The content of the aliphatic amine (ii) in the regeneration additive is preferably 50 parts by mass or more and 95 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii). From the viewpoint of improving the pavement properties, the content is more preferably 55 parts by mass or more, even more preferably 65 parts by mass or more, and more preferably 94 parts by mass or less, even more preferably 90 parts by mass or less. The content of the aliphatic amine (iii) in the regeneration additive is preferably 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii). From the viewpoint of improving the pavement properties, the content is more preferably 1 part by mass or more, even more preferably 2 parts by mass or more, and more preferably 35 parts by mass or less, even more preferably 30 parts by mass or less.

[0030] The total content of the aliphatic amine (i) and the aliphatic amine (iii) in the regeneration additive is preferably 5 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii). In one embodiment of the present invention, the content of the aliphatic amine (i) is preferably 0.5 parts by mass or more and 40 parts by mass or less per 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii), from the viewpoint of improving pavement physical properties, and the content of the aliphatic amine (iii) is preferably 0.5 parts by mass or more and 40 parts by mass or less per 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii), from the viewpoint of improving pavement physical properties. More preferred ranges are the same as those described above. In another aspect of the present invention, the content of the aliphatic amine (i) is preferably 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii), and the content of the aliphatic amine (iii) is preferably 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii), and the content of the aliphatic amine (ii) is preferably 50 parts by mass or more and 95 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii).

[0031] (Other ingredients) The regenerating additive may contain other ingredients as long as they do not impair the effects of the present invention. Other components include ester compounds. The ester compound is, for example, an ester compound of a fatty acid derived from natural fats and oils, which are the raw material for fatty amines, with an alcohol.

[0032] The content of the ester compound in the regenerating additive is preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, and preferably 20 parts by mass or less, more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii).

[0033] (Method of manufacturing regenerating additives) The regenerating additive can be produced, for example, by mixing the aliphatic amine (i), the aliphatic amine (iii), and the aliphatic amine (iii). Furthermore, as the regenerating additive, aliphatic amine (i), aliphatic amine (iii), and commercially available products containing aliphatic amine (iii) can be used. In addition, by-products of industrial compound production can be used as recycling additives. For example, aliphatic amines can be produced using fatty acids and alcohols derived from natural fats and oils as raw materials. The obtained aliphatic amines are separated into main fractions by distillation, and aliphatic amines with specific carbon numbers are commercialized. On the other hand, by recovering the distilled pitch containing by-products as is, a mixture containing, for example, aliphatic amines with a distribution of carbon numbers and by-product ester compounds of fatty acids and alcohols can be obtained as a by-product, and this can be used as a recycling additive.

[0034] <Recycled asphalt aggregate> The asphalt mixture of the present invention contains recycled asphalt aggregate as an aggregate. Recycled asphalt aggregate is made by collecting used asphalt pavement, crushing it, and classifying it. The post-consumer asphalt pavement from which the recycled asphalt aggregate is derived contains asphalt and aggregate, and may contain other additives as needed.

[0035] The physical and chemical properties of the asphalt contained in recycled asphalt aggregate have deteriorated 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 asphalt's penetration, softening point, flexural strength, strain at break, asphalt composition, etc. Generally, asphalt in which the maltene fraction in asphalt has migrated to asphaltene and the penetration has decreased is often referred to as deteriorated 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.

[0036] The asphalt mixture from which the used asphalt pavement is derived contains aggregate. Examples of such aggregate include aggregates commonly used in asphalt mixtures for road paving, such as crushed stone, boulders, gravel, sand, and ceramics. The asphalt mixture from which the used asphalt pavement is derived may itself use recycled asphalt aggregate as the aggregate.

[0037] <New aggregate> The asphalt mixture of the present invention can contain new aggregate in addition to recycled asphalt aggregate. Specific examples of novel aggregates that can be used include crushed stone, boulders, gravel, sand, ceramics, etc. In addition, as aggregates, coarse aggregates with a particle size of 2.36 mm or more, fine aggregates with a particle size of 0.075 mm or more but 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, dune sand, mountain sand, sea sand, crushed sand, fine sand, screenings, crushed stone dust, silica sand, artificial sand, glass cullet, and foundry sand. The particle size of the coarse aggregate and fine aggregate is based on the sieve analysis test method specified in JIS A5001:2008.

[0038] Examples of fillers include sand, fly ash, calcium carbonate powder such as limestone powder, hydrated lime, etc. Among these, calcium carbonate powder is preferred from the viewpoint of improving the strength of the 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, and 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% cumulative volume (D 50 ) and can be measured using a laser diffraction particle size distribution analyzer.

[0039] As the aggregate, it is preferable to use a combination of coarse aggregate and fine aggregate. In this case, from the viewpoint of durability of the asphalt pavement, 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 is preferably 90 / 10 or less, more preferably 80 / 20 or less, even more preferably 70 / 30 or less.

[0040] <Content of each ingredient> From the viewpoint of the effects of the present invention, the content of the three components of the new asphalt, the asphalt derived from recycled aggregate, and the recycling additive in the asphalt mixture 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 more preferably 15% by mass or less, even more preferably 10% by mass or less.

[0041] In this specification, "asphalt derived from recycled aggregate" refers to asphalt contained in recycled asphalt aggregate. Asphalt derived from recycled aggregate is distinguished from new asphalt. Asphalt derived from recycled aggregate is sometimes called deteriorated asphalt. The content of asphalt derived from recycled aggregate in recycled asphalt aggregate can be measured by solvent extraction or loss on ignition. Typically, the asphalt content in recycled asphalt aggregate derived from used asphalt pavement is approximately 5.5% by mass. In the present invention, the content of asphalt derived from recycled aggregate is determined according to the method of measuring loss on ignition specified in AASHTO (American Association of State Highway and Transportation Officials) T 308-10 (2015). Because recycled asphalt aggregate is included as an aggregate, the amount of asphalt is calculated from the loss on ignition of the recycled asphalt aggregate and used in the mix calculation.

[0042] From the viewpoint of the effects of the present invention, the content of the recycling additive in the asphalt mixture of the present invention is preferably 5 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, and more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, per 100 parts by mass of the total content of the three components: new asphalt, asphalt derived from recycled aggregate, and recycling additive.

[0043] Furthermore, from the viewpoint of the effects of the present invention, the content of the recycling additive in the asphalt mixture is preferably 3 parts by mass or more, more preferably 4 parts by mass or more, and even more preferably 5 parts by mass or more, per 100 parts by mass of asphalt derived from recycled aggregate, and from the viewpoint of maintaining workability, it is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less.

[0044] From the viewpoint of the effects of the present invention, the content of aggregate in the asphalt mixture is preferably 50% by mass or more and 99% by mass or less, more preferably 75% by mass or more, even more preferably 80% by mass or more, and more preferably 98% by mass or less, even more preferably 96% by mass or less. The content of recycled asphalt aggregate in the asphalt mixture is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, from the viewpoint of reusing waste asphalt pavement materials, and is preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, from the viewpoint of achieving both durability and flexibility.

[0045] In the present invention, the aggregate content refers to the total content of recycled asphalt aggregate and optionally contained new aggregate. The aggregate content includes the content of asphalt derived from recycled aggregate. When the aggregate contains new aggregate, the content of new aggregate is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, and preferably 80 parts by mass or less, more preferably 75 parts by mass or less, per 100 parts by mass of the total content of asphalt recycled aggregate and new aggregate, from the viewpoint of reusing waste asphalt pavement, and the content of asphalt recycled aggregate is preferably 15 parts by mass or more, more preferably 25 parts by mass or more, per 100 parts by mass of the total content of asphalt recycled aggregate and new aggregate, from the viewpoint of reusing waste asphalt pavement, and is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, from the viewpoint of reusing waste asphalt pavement, and is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, from the viewpoint of reusing waste asphalt pavement,

[0046] Examples of suitable aggregate blends for asphalt mixtures include the following (1) to (3): (1) Fine-graded asphalt containing 30% to less than 45% by volume of coarse aggregate, 30% to 50% by volume of fine aggregate, and 5% to 10% by volume of asphalt composition. (2) An example of an asphalt mixture is dense-graded asphalt containing 45% to less than 70% by volume of coarse aggregate, 20% to 45% by volume of fine aggregate, and 3% to 10% by volume of asphalt composition. (3) Porous asphalt containing 70% to 80% by volume of coarse aggregate, 10% to 20% by volume of fine aggregate, and 3% to 10% by volume of asphalt composition. The asphalt mixing ratio in conventional asphalt mixtures containing aggregate and asphalt is usually determined according to the optimal amount of asphalt determined from the "Mix Design of Asphalt Compositions" described in the "Guidelines for Pavement Design and Construction" published by the Japan Road Association, a public interest incorporated association. In the present invention, the above-mentioned optimum amount of asphalt corresponds to the total amount of asphalt and polyester resin. However, it is not necessary to be limited to the method described in the "Guidelines for Pavement Design and Construction" and other methods may be used to determine the amount of asphalt.

[0047] [Asphalt mixture manufacturing method] The method for producing an asphalt mixture of the present invention includes a step of mixing novel asphalt, a regeneration additive, and recycled asphalt aggregate under heated conditions. In the mixing step, new asphalt, the regeneration additive, and the recycled asphalt aggregate can be mixed simultaneously or in any order. From the viewpoint of durability and flexibility of the asphalt pavement, the regeneration additive is preferably mixed with the recycled asphalt aggregate simultaneously with or after the new asphalt. Mixing under heated conditions is preferably carried out in an embodiment using heated recycled asphalt aggregate. When the asphalt mixture contains new aggregate in addition to recycled asphalt aggregate, the recycled asphalt aggregate and the new aggregate can be mixed together to achieve the above-mentioned content, for example. Specific methods for producing asphalt mixtures include conventional methods for producing asphalt mixtures known as the plant mix method and the premix method. Both methods involve adding new asphalt and the above-mentioned regenerating additive to heated aggregate. Examples of addition methods include the premix method, in which the new asphalt and the above-mentioned regenerating additive are dissolved in advance, and the plant mix method, in which the new asphalt is added to heated aggregate and then the above-mentioned regenerating additive is added simultaneously or in any order. Of these, the plant mix method is preferred from the viewpoint of demonstrating asphalt performance. More specifically, in the method for producing an asphalt mixture, preferably, in the mixing step, (i) Add new asphalt to heated aggregate and mix to obtain a mixture, and then add and mix the above-mentioned regenerating additive; (ii) Adding and mixing the new asphalt and the above-mentioned rejuvenating additive simultaneously to the heated aggregate; or (iii) Add and mix the pre-heated mixture of new asphalt and the above-mentioned regenerating additive to the heated aggregate. Among these, the method (i) is preferred for the mixing step.

[0048] The heating temperature is preferably 160°C or higher, more preferably 165°C or higher, and even more preferably 170°C or higher, from the viewpoint of improving durability through sufficient mixing, and is preferably 350°C or lower, more preferably 250°C or lower, and even more preferably 200°C or lower, from the viewpoint of performance stability.

[0049] [Paving method] The asphalt mixture of the present invention is suitable for paving, and examples of paving applications include roads, parking lots, and the like. The paving method includes a step of applying the asphalt mixture to a paving target to form an asphalt pavement layer. The asphalt pavement layer is usually a base layer or a surface layer, and is preferably a surface layer from the viewpoint of improving resistance to deflection and cracking.

[0050] From the viewpoint of improving resistance to flexure and cracking, 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, even more preferably 5.5 cm or less. 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, even more preferably 3 cm or less. The asphalt mixture may be compacted and applied in the same manner using known construction machinery. When used as a heated asphalt mixture, the compaction temperature is preferably 100°C or higher, more preferably 120°C or higher, and even more preferably 130°C or higher, from the viewpoint of improving the deflection resistance and crack resistance of the asphalt pavement, and is preferably 200°C or lower, more preferably 180°C or lower. [Example]

[0051] Various physical properties were measured and evaluated by the following methods. In the following examples and comparative examples, parts and percentages are by mass unless otherwise specified.

[0052] (1) Gas chromatographic measurement conditions (Gas chromatograph measuring device) Gas chromatograph (GC): Agilent 6850 (Agilent Technologies) Gas chromatograph column (for standard analysis): DB-17HT (Agilent Technologies, inner diameter 0.25 mm, film thickness 0.15 μm, length 15 m) (Measurement conditions) Carrier gas: Helium, 3.6 mL / min Injection conditions: 300°C, split ratio 1 / 50 Detection conditions: FID method, 350°C Column temperature conditions: 60°C for 12 seconds, then increase the temperature at 30°C / min to 350°C and hold for 1 minute

[0053] A calibration curve of retention time was prepared using various amines with known structures as standards, and each component in the measurement sample was assigned and quantified based on its retention time and peak area. Specifically, a calibration curve was prepared using the following various amines as standards, and the values ​​were used to assign and quantify each compound in the measurement sample. Decyldimethylamine, didecylmethylamine, and tridecylamine were used as standards for aliphatic amines (i) having an aliphatic hydrocarbon group with 1 to 10 carbon atoms ("C1-C10" in the table). As standards of aliphatic amines (ii) having an aliphatic hydrocarbon group with 11 to 17 carbon atoms ("C11-C17" in the table), dodecyldimethylamine, didodecylmethylamine, hexadecyldimethylamine, and dihexadecylmethylamine were used. Octadecyldimethylamine and dioctadecylmethylamine were used as standards for aliphatic amines (iii) having an aliphatic hydrocarbon group with 18 or more carbon atoms ("C18 or more" in the table). Regarding ester compounds, when the number of alkyl carbon atoms is the same as that of the dialkylmethylamines, their structures were inferred from the fact that they tend to be detected 0.3 to 0.4 minutes later in retention time. Specifically, for example, the peak of decyl decyl ester of decylic acid is detected about 0.4 minutes after that of didecylmethylamine.

[0054] Manufacturing Example 1 The regenerating additive A1 was obtained by separating by-products from the production of dimethylamines such as dimethyloctylamine, dimethylpalmitylamine, and dimethyllaurylamine using aliphatic alcohols as raw materials. Regeneration additive A1 is a mixture of several types of aliphatic amines and fatty acid esters. Table 1 shows the carbon number distribution of the aliphatic amines and the content of fatty acid esters in the mixture, as determined by gas chromatography.

[0055] Manufacturing Example 2 A by-product from a different lot from that in Production Example 1 was separated to obtain a recycling additive A2. Regeneration additive A2 is a mixture of several types of aliphatic amines and fatty acid esters. Table 1 shows the carbon number distribution of the aliphatic amines and the fatty acid ester content in the mixture, as determined by gas chromatography.

[0056] Manufacturing Example 3 The trade names "Farmin DM1098" (dimethyloctylamine, manufactured by Kao Corporation), "Farmin DM4098" (dimethylmyristylamine, manufactured by Kao Corporation), and "Farmin DM8098" (dimethylstearylamine, manufactured by Kao Corporation) were mixed in a ratio of Farmin DM1098:Farmin DM4098:Farmin DM8098 = 4% by mass:94% by mass:2% by mass to obtain regeneration additive A3. The alkyl representative compositions (%) of Farmin DM1098, Farmin DM4098 and Farmin DM8098 are as follows: Farmin DM1098; C8:C10:C12=1:97:2 Farmin DM4098; C12:C14:C16=2:97:1 Farmin DM8098; C16:C18=2:98 The carbon number distribution of the aliphatic amines and the content of fatty acid esters in the mixture were determined by gas chromatography and are shown in Table 1.

[0057] Example 1-1 (1) Preparation of asphalt mixture 15 kg of aggregate having the composition (I) shown below, heated to 165°C, was placed in an asphalt mixer and mixed for 60 seconds at 165°C. Next, 328 g of straight asphalt 60-80 (manufactured by Mitsubishi Corporation Energy Corporation) and 50 g of Additive A1 obtained in Production Example 1 were added, and the mixture was mixed for 2 minutes in the asphalt mixer to obtain an asphalt mixture.

[0058] <Aggregate Composition (I)> No. 6 crushed stone 30.0 parts by mass No. 7 crushed stone 8.0 parts by mass Crushed sand 3.0 parts by mass River sand 6.0 parts by mass Mountain sand 3.0 parts by mass Recycled aggregate (1) 50.0 parts by mass Passed mass%: Sieve size 15 mm: 100% by mass Sieve size 10 mm: 82.9% by mass Sieve size 5 mm: 58.1% by mass Sieve size 2.5 mm: 39.8% by mass Sieve size 1.2 mm: 28.4% by mass Sieve size 0.6 mm: 15.9% by mass Sieve size 0.3 mm: 8.4% by mass Sieve size 0.15mm: 2.6% by mass

[0059] The asphalt content (asphalt derived from recycled aggregate) in 7.5 kg of recycled asphalt aggregate (1) was 412 g. The asphalt content derived from recycled aggregate was determined according to the method specified in AASHTO T 308-10 (2015). The content of the recycled additive in the asphalt mixture was 12 parts by mass per 100 parts by mass of the total content of asphalt derived from recycled aggregate. The penetration value of the asphalt derived from recycled aggregate was 7. The penetration value was measured according to the procedure of JIS K 2207:1996 for asphalt extracted in accordance with "G028 Asphalt Extraction Test Method" in the "Pavement Survey and Test Method Handbook (2019 Edition)" (compiled by the Japan Road Association).

[0060] (2) Measurement of Marshall stability and flow value 1.2 kg of the resulting asphalt mixture was weighed and cylindrical specimens were prepared using a Marshall test compactor (manufactured by Nakajima Gihan Co., Ltd., "Automatic Asphalt Compaction Device"). The specimens were gradually cooled to room temperature and demolded using a demolding machine. Four asphalt specimens were prepared. The demolded cylindrical specimen was immersed in a constant temperature water tank at 60°C for 30 minutes, and then subjected to a Marshall stability test in accordance with "B001 Marshall Stability Test Method" in the "Pavement Survey and Test Method Handbook (2019 Edition)" (compiled by the Japan Road Association, a public interest incorporated association), and the Marshall stability (kN) of asphalt specimen 1 was measured. In addition, the specimen was crushed at a speed of 50 mm / min, and the displacement (1 / 100 cm) from the viewpoint of the slope of the displacement to the maximum load was taken as the flow value. Table 1 shows the average values ​​of Marshall stability (kN) and flow value (1 / 100 cm) measured for four asphalt specimens. The Marshall stability is the maximum load required to break an asphalt specimen, and the higher the value, the more durable the asphalt pavement. The higher the flow value, the better the flexibility and crack resistance of the asphalt pavement at the operating temperature.

[0061] Example 1-2 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 50 g of Additive A2 obtained in Production Example 2 was used instead of 50 g of Additive A1. Asphalt specimens were produced using the obtained asphalt mixture, and the Marshall stability and flow value were measured in the same manner as in Example 1-1. The results are shown in Table 1.

[0062] Examples 1-3 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 50 g of Additive A3 obtained in Production Example 3 was used instead of 50 g of Additive A1. Asphalt specimens were produced using the obtained asphalt mixture, and Marshall stability and flow value were measured. The results are shown in Table 1.

[0063] Comparative Example 1-1 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 50 g of Additive A1 was not used. Asphalt specimens were produced using the obtained asphalt mixture, and the Marshall stability and flow value were measured in the same manner as in Example 1-1. The results are shown in Table 1.

[0064] Comparative Example 1-2 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 50 g of the following additive a1 was used instead of 50 g of the reclaiming additive A1. Asphalt specimens were produced using the obtained asphalt mixture, and the Marshall stability and flow value were measured in the same manner as in Example 1-1. The results are shown in Table 1. Additive a1: Product name "T-Revive" (a mixture of petroleum hydrocarbons, manufactured by Takenaka Sangyo Co., Ltd.)

[0065] Comparative Examples 1-3 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 50 g of the following additive a2 was used instead of 50 g of additive A1. Asphalt specimens were produced using the obtained asphalt mixture, and Marshall stability and flow value were measured in the same manner as in Example 1-1. The results are shown in Table 1. Additive a2: Trade name "Farmin DM6098" (dimethyl palmitylamine, manufactured by Kao Corporation) The typical alkyl composition (%, catalog value) of Farmin DM6098 is as follows: Farmin DM6098; C14:C16:C18=1:98:1

[0066] [Table 1]

[0067] Example 2-1 (1) Preparation of asphalt mixture 15 kg of aggregate having the composition (II) shown below, heated to 165°C, was placed in an asphalt mixer and mixed for 60 seconds at 165°C. Next, 412 g of straight asphalt 60-80 (manufactured by Mitsubishi Corporation Energy Co., Ltd.) and 18 g of the additive A1 were added, and the mixture was mixed for 2 minutes in the asphalt mixer to obtain an asphalt mixture.

[0068] <Aggregate Composition (II)> No. 6 crushed stone 30.0 parts by mass No. 7 crushed stone 8.0 parts by mass Crushed sand 3.0 parts by mass River sand 6.0 parts by mass Mountain sand 3.0 parts by mass Recycled aggregate (2) 50.0 parts by mass Passed mass%: Sieve size 15 mm: 100% by mass Sieve size 10 mm: 91.2% by mass Sieve size 5 mm: 55.0% by mass Sieve size 2.5 mm: 36.3% by mass Sieve size 1.2 mm: 29.1% by mass Sieve size 0.6 mm: 21.2% by mass Sieve size 0.3 mm: 14.2% by mass Sieve size 0.15mm: 8.0% by mass

[0069] The asphalt content of 7.5 kg of recycled asphalt aggregate (2) was 360 g. The asphalt content of recycled asphalt aggregate was determined according to the method specified in AASHTO T 308-10 (2015). The content of the recycled additive in the asphalt mixture was 12 parts by mass per 100 parts by mass of the total content of asphalt derived from recycled aggregate. The penetration value of the asphalt derived from recycled aggregate was 22. Penetration value was measured according to the procedure of JIS K 2207:1996 for asphalt extracted in accordance with "G028 Asphalt Extraction Test Method" in the "Pavement Survey and Testing Methods Handbook (2019 Edition)" (compiled by the Japan Road Association).

[0070] (2) Measurement of Marshall stability and flow value The resulting asphalt mixture was used to prepare an asphalt specimen, and the Marshall stability and flow value were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0071] Examples 2-2 to 2-3, Comparative Examples 2-2 to 2-3 An asphalt mixture was obtained in the same manner as in Example 2-1, except that the additives shown in Table 2 were used instead of 18 g of Additive A1. Asphalt specimens were produced using the obtained asphalt mixture, and the Marshall stability and flow value were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0072] Comparative Example 2-1 An asphalt mixture was obtained in the same manner as in Example 1-1, except that 18 g of Additive A1 was not used. Asphalt specimens were produced using the obtained asphalt mixture, and the Marshall stability and flow value were measured in the same manner as in Example 1-1. The results are shown in Table 2.

[0073] [Table 2]

[0074] As shown in Comparative Example 1-1, the effects of existing recycling additives on recycled aggregate that has deteriorated significantly are insufficient, particularly in terms of plasticization and fluidization. When a single amine compound is used as a recycling additive, a desired effect can be obtained, as shown in Comparative Example 1-2. However, as shown in Comparative Example 2-2, for example, when recycled aggregate that has not deteriorated is used, the softening effect is excessive, and the desired pavement properties are not achieved, resulting in an insufficient effect from the viewpoint of stability of the recycling additive's effect. The recycling additive of the present invention acts stably on recycled aggregates with a wide range of deterioration levels, so sufficient pavement properties can be ensured even when recycled aggregates of various origins are used in asphalt mixtures. Therefore, the use of the recycling additive of the present invention can be expected to improve the quality stability of asphalt mixtures containing recycled aggregates.

Claims

1. An asphalt mixture comprising a novel asphalt, a regeneration additive, and recycled asphalt aggregate, wherein the regeneration additive includes (i) an aliphatic amine having an aliphatic hydrocarbon group having 1 to 10 carbon atoms, (ii) an aliphatic amine having an aliphatic hydrocarbon group having 11 to 17 carbon atoms, and (iii) an aliphatic amine having an aliphatic hydrocarbon group having 18 or more carbon atoms.

2. The asphalt mixture according to claim 1, wherein the content of the aliphatic amine (i) is 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii), and the content of the aliphatic amine (iii) is 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii).

3. The content of the aliphatic amine (ii) is 50 parts by mass or more and 95 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii). Asphalt mixture according to claim 1 or 2.

4. The regeneration additive further contains an ester compound, and the content of the ester compound is 1 part by mass or more per 100 parts by mass of the total content of the aliphatic amine (ii) and the aliphatic amine (iii). Asphalt mixture according to claim 1 or 2.

5. The content of the regenerating additive is 5 parts by mass or more and 30 parts by mass or less per 100 parts by mass of the total amount of the new asphalt, the asphalt derived from recycled aggregate, and the regenerating additive. Asphalt mixture according to claim 1 or 2.

6. (i) an aliphatic amine having an aliphatic hydrocarbon group having 1 to 10 carbon atoms, (ii) an aliphatic amine having an aliphatic hydrocarbon group having 11 to 17 carbon atoms, and (iii) an aliphatic amine having an aliphatic hydrocarbon group having 18 or more carbon atoms, An additive for recycling asphalt recycled aggregate, wherein the content of the aliphatic amine (i) is 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii); the content of the aliphatic amine (iii) is 0.5 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii); and the content of the aliphatic amine (ii) is 50 parts by mass or more and 95 parts by mass or less, relative to 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii).

7. 7. The additive for recycling asphalt recycled aggregate according to claim 6, further comprising an ester compound, wherein the content of the ester compound is 1 part by mass or more per 100 parts by mass of the total content of the aliphatic amine (i), the aliphatic amine (ii), and the aliphatic amine (iii).

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