Asphalt additive composition

Abstract

To provide an asphalt additive composition capable of obtaining an asphalt pavement that has excellent paving properties and a good working environment during construction even when using recycled asphalt aggregate, and an asphalt mixture.SOLUTION: The asphalt additive composition includes a regeneration additive (A), the following compound (B), and the following compound (C). The compound (B) is a ketone compound having a 5- or 6-membered ring structure and having 10 to 16 carbon atoms, and the compound (C) is a compound that does not contain a ketone group and has a logP value of 4.0 or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an asphalt additive composition and an asphalt mixture. [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 odor suppressant that can achieve both deodorizing or masking effects and durability, and that contains a fragrance compound with a boiling point of less than 200°C at normal pressure and a solvent with a boiling point of 200°C or higher at normal pressure. Patent Document 2 discloses an asphalt composition that contains specific amounts of a styrene-butadiene-styrene copolymer (SBS) with a specific 25% toluene solution viscosity, a polycyclic diterpene with 20 carbon atoms and a carboxyl group, and a petroleum resin with a bromine number of 30 or less, with the remainder being composed of at least a base asphalt containing a specific amount of aromatic oil, as a technology for improving the storage stability, strength, and workability of asphalt compositions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent No. 7182575 [Patent Document 2] Japanese Patent No. 7167309 Summary of the Invention [Problem to be solved by the invention]

[0006] Depending on the composition of the original asphalt pavement, recycled aggregate may emit a rubbery odor due to the elastomers it contains, such as SBS, or an unpleasant odor due to the oxidation and deterioration of sulfur-based or hydrocarbon compounds, creating a poor working environment during construction.

[0007] Although the technology described in Patent Document 1 achieves a reduction in odors originating from asphalt, it is insufficiently effective against odors originating from specific compounds of additives for recycling. Although the technology described in Patent Document 2 achieves a sustained odor reduction effect derived from asphalt, the odor reduction effect is insufficient due to poor volatility. Furthermore, the effect on the rubber odor derived from degraded elastomers such as SBS is insufficient.

[0008] The present invention relates to an asphalt additive composition and asphalt mixture that can improve the pavement properties of the resulting asphalt pavement even when recycled asphalt aggregate is used, while also providing a good working environment during construction. [Means for solving the problem]

[0009] The present invention relates to the following [1] and [2]. [1] An asphalt additive composition comprising a reclaiming additive (A), the following compound (B) and the following compound (C). Compound (B): a ketone compound having a 5- or 6-membered ring structure and having 10 to 16 carbon atoms Compound (C): A compound that does not contain a ketone group and has a log P value of 4.0 or more. [2] An asphalt mixture comprising recycled asphalt aggregate, a recycling additive (A), the following compound (B), and the following compound (C). Compound (B): a ketone compound having a 5- or 6-membered ring structure and having 10 to 16 carbon atoms Compound (C): A compound that does not contain a ketone group and has a log P value of 4.0 or more. [Effects of the Invention]

[0010] According to the present invention, there are provided an asphalt additive composition and an asphalt mixture that can improve the pavement properties of the resulting asphalt pavement even when recycled asphalt aggregate is used, while also providing a good working environment during construction. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Asphalt additive composition] The asphalt additive composition of the present invention contains a regenerating additive (A), the following compound (B) and the following compound (C). Compound (B): a ketone compound having a 5- or 6-membered ring structure and having 10 to 16 carbon atoms Compound (C): A compound that does not contain a ketone group and has a log P value of 4.0 or more.

[0012] According to the asphalt additive composition of the present invention, even when the asphalt mixture uses recycled asphalt aggregate, it is possible to achieve both improved pavement properties of the resulting asphalt pavement and a good working environment during construction. In this specification, improved pavement properties mean that an asphalt pavement using an asphalt mixture has improved durability and workability compared to when the asphalt additive composition is not used, etc. The durability and workability of an asphalt pavement can be evaluated, for example, by the stability and void ratio measured from a Marshall test specimen, as shown in the examples described later. A good working environment during application means a working environment in which odors that impair workability during application are sufficiently reduced. The odors during application can be evaluated by a sensory test, as shown in the examples below.

[0013] Although the detailed mechanism by which the effects of the present invention are obtained is unknown, part of it is thought to be as follows. In asphalt mixtures using recycled asphalt aggregate, the use of recycling additive (A) improves the pavement properties of the asphalt pavement. Compound (B) masks odors while controlling volatility in high-temperature working environments, and compound (C), which acts as a compatibilizer between recycling additive (A) and compound (B), achieves uniformity of the components, which is thought to result in a sustained masking effect.

[0014] <Recycling Additive (A)>

[0015] Regeneration additive (A) is a component derived from recycled asphalt aggregate to restore the properties of deteriorated asphalt. Regeneration additives with the following standard properties listed in the "Pavement Regeneration Handbook (2010 edition)" compiled by the Japan Road Association can be used as the regeneration additive (A). (Standard properties of recycling additives) Kinematic viscosity (60℃): 80mm 2 / s or more 1000mm 2 / s or less Flash point: 250°C or higher Viscosity ratio after thin film heating (60℃): 2 or less Thin film heating mass change rate: within ±3%

[0016] The kinematic viscosity (60°C) is measured in accordance with JIS K2283:2000. The flash point is measured in accordance with JIS K2207:2006. The viscosity ratio (60°C) after thin film heating and the thin film heating mass change rate are measured in accordance with JIS K2207:2006.

[0017] The regeneration additive (A) has a density of 0.95 g / cm3 from the viewpoint of uniform mixing with various materials in the asphalt mixture and suppressing material separation. 3 The density is measured in accordance with JIS K2249-4:2011.

[0018] Examples of the regeneration additive (A) include asphalt-based, petroleum lubricating oil-based, animal and vegetable oil-based, and asphalt emulsion-based regeneration additives, and asphalt-based or petroleum lubricating oil-based regeneration additives are preferred.

[0019] From the viewpoint of affinity for the regeneration effect of the recycled aggregate, the regeneration additive (A) preferably has a saturated content of 80% by mass or less, more preferably 50% by mass or less. "Saturates" refers to the ratio of saturated components when the recycling additive is separated into four components - saturated, aromatic, resin and asphaltene - and the content of each component is measured in accordance with the petroleum testing standard JPI-5S-70-2010 "Test method for asphalt composition analysis using TLC / FID method" established by the Japan Petroleum Institute, a public interest incorporated association.

[0020] From the viewpoint of the recycling effect of recycled aggregate, the recycling additive (A) preferably has an aromatic content of 50% by mass or more, more preferably 60% by mass or more. "Aromatic content" refers to the ratio of aromatic components when the recycling additive is separated into four components - saturated content, aromatic content, resin content, and asphaltene content - and the content of each component is measured in accordance with the petroleum testing standard JPI-5S-70-2010 "Test method for asphalt composition analysis using TLC / FID method" established by the Japan Petroleum Institute, a public interest incorporated association.

[0021] Commercially available products can be used as the recycling additive (A). Examples of commercially available recycling additives include "Reprovital 500" (manufactured by Idemitsu Kosan Co., Ltd.), "T-Revive" (manufactured by Takenaka Sangyo Co., Ltd.), "SR Recover" and "SR Bright" (all manufactured by Shinreki Kogyo Co., Ltd.).

[0022] <Compound (B)> The asphalt additive composition of the present invention contains compound (B), which is a ketone compound having a five- or six-membered cyclic structure and having 10 to 16 carbon atoms.

[0023] Compound (B) is a ketone compound that contains one carbonyl group (-(C=O)- group). The carbon atom of the carbonyl group is bonded to two adjacent carbon atoms. The compound (B) has 10 or more and 16 or less carbon atoms, preferably 11, 13, or 16, and more preferably 11 or 13.

[0024] The 5- or 6-membered ring structure may have a double bond. Aromatic rings are not included. The 5- or 6-membered ring structure may be part of a fused ring. Examples of the five-membered ring structure include a cyclopentane ring, a cyclopentene ring, and a cyclopentadiene ring. Examples of the six-membered ring structure include a cyclohexane ring, a cyclohexene ring, a 1,3-cyclohexadiene ring, and a 1,4-cyclohexadiene ring. The carbon atom of the carbonyl group in the compound (B) may be either a carbon atom constituting a cyclic structure or a carbon atom outside the cyclic structure.

[0025] Specific examples of compound (B) include menthone (including stereoisomers such as l-menthone and d-menthone), damascenone (including stereoisomers such as α-damascenone, β-damascenone, and γ-damascenone), jasmone (including stereoisomers such as cis-jasmone and trans-jasmone), ionone (including structural isomers such as α-ionone, β-ionone, and γ-ionone), and 1-(2,3,8,8-tetramethyl-1,3,4,5,6,7-hexahydronaphthalen-2-yl)ethanone (also known as Iso E Super). The compound (B) can be used alone or in combination of two or more.

[0026] <Compound (C)> The asphalt additive composition of the present invention contains compound (C), which is a compound that does not contain a ketone group and has a log P value of 4.0 or more. The logP value is 4.0 or more, preferably 4.3 or more, more preferably 4.5 or more, and preferably 7.0 or less, more preferably 5.5 or less. The compound (C) may be a single compound or a mixture, and as long as the logP of the main component (80% by mass) constituting the compound (C) satisfies the above, various compounds may be contained within the range that does not affect the performance (odor).

[0027] The logP value is an index of the lipophilicity of a chemical substance, and refers to the logarithm of the octanol / water partition coefficient. It is specified in JIS Z7260-107:2000 (Measurement of partition coefficient (1-octanol / water) - Shake flask method). Specifically, it is the common logarithm of the partition coefficient P (n-octanol / water) between n-octanol and water. The logP value can be calculated from the structure of a compound. For example, the logP value of a compound can be calculated using CSLogP™, a logP estimation software from ChemSilico LLC, USA.

[0028] Compound (C) does not contain a ketone group. A ketone group refers to a carbonyl group (-C=O) in which a carbon atom is bonded to two other carbon atoms.

[0029] Specific examples of compound (C) include limonene (logP value: 4.83), β-pinene (logP value: 4.35), isopropyl myristate (logP value: 7.17), caryophyllene (logP value: 6.30), nerolidol (logP value: 5.58), cyclohexyl salicylate (logP value: 4.87), cis-3-hexenyl salicylate (logP value: 4.84), 1-dodecanol (logP value: 4.77), amyl salicylate (logP value: 4.57), isoamyl salicylate (logP value: 4.49), geranyl acetate (logP value: 4.48), neryl acetate (logP value: 4.48), 2-(tert-butyl)cyclohexyl acetate (logP value: 4.42), 4-(tert-butyl)cyclohexyl acetate (logP value: 4.42), and benzyl salicylate (logP value: 4.31).

[0030] <Asphalt additive composition> The asphalt additive composition of the present invention contains the above-mentioned recycling additive (A), the above-mentioned compound (B), and the above-mentioned compound (C), and by blending this with an asphalt mixture, it is possible to achieve both improved pavement properties of the resulting asphalt pavement and workability with reduced odor during construction, even when recycled asphalt aggregate is used. The compound (B) is a fragrance component, and the compound (C) is a component that acts as a compatibilizer between the regenerating additive and the fragrance component. In the asphalt additive composition of the present invention, the compound (B) is dissolved in the compound (C). The compound (A) may be mixed with the compounds (B) and (C) to form an integrated composition, or may be provided separately as a two-component composition.

[0031] In the asphalt additive composition, the ratio of the mass of the compound (B) to the mass of the compound (C) [(B) / (C)] is preferably 2 / 98 or more and 80 / 20 or less, more preferably 30 / 70 or more, even more preferably 50 / 50 or more, and more preferably 4 / 96 or less, even more preferably 3 / 97 or less.

[0032] Furthermore, the content of the compound (B) relative to the total mass of the recycling additive (A), the compound (B) and the compound (C) is preferably 0.1 mass% or less, more preferably 0.09 mass% or less, and even more preferably 0.08 mass% or less.

[0033] Compounds that fall under compound (B) are not included in compound (C). The asphalt additive composition of the present invention may also contain other components as long as the effects of the present invention are not impaired.

[0034] [Asphalt mixture] The asphalt mixture of the present invention contains recycled asphalt aggregate, a recycling additive (A), the following compound (B) and the following compound (C). Compound (A): a compound having 8 or more carbon atoms and having a carboxyl group, a hydroxyl group, an amide group, or an amino group Compound (B): a ketone compound having a 5- or 6-membered cyclic structure and having 10 to 16 carbon atoms Compound (C): A compound that does not contain a ketone group and has a log P value of 4.0 or more.

[0035] The asphalt mixture of the present invention contains the regeneration additive (A), the above-mentioned compound (B) and the above-mentioned compound (C), i.e., the above-mentioned asphalt additive composition, and therefore can provide an asphalt pavement with improved pavement properties even while using recycled asphalt aggregate, and also has reduced odor and excellent workability during pavement construction.

[0036] <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.

[0037] 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.

[0038] 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.

[0039] <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.

[0040] 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.

[0041] 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.

[0042] <New asphalt> The asphalt mixture of the present invention can contain new asphalt, which is also called virgin asphalt or unused asphalt, and means 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.

[0043] (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.

[0044] <Content of each ingredient> From the viewpoint of the effects of the present invention, the content of the three components of asphalt derived from recycled aggregate, recycling additive (A), and optionally contained new asphalt 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.

[0045] 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.

[0046] From the viewpoint of the effects of the present invention, the total content of the above-mentioned recycling additive (A), compound (B) and compound (C) in the asphalt mixture of the present invention is 2 parts by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, per 100 parts by mass of asphalt derived from recycled aggregate, and from the viewpoint of maintaining the pavement properties, it is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less.

[0047] Furthermore, from the viewpoint of the effects of the present invention, the content of the recycling additive (A) in the asphalt mixture is preferably 3 parts by mass or more, more preferably 6 parts by mass or more, and even more preferably 10 parts by mass or more, per 100 parts by mass of the total amount of the two components, the asphalt derived from recycled aggregate and the recycling additive (A), and from the viewpoint of maintaining workability, it is preferably 60 parts by mass or less, more preferably 40 parts by mass or less, even more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less.

[0048] 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 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, from the viewpoint of achieving both durability and flexibility.

[0049] 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,

[0050] 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.

[0051] [Asphalt mixture manufacturing method] The method for producing an asphalt mixture of the present invention includes a step of mixing recycled asphalt aggregate, the above-mentioned regeneration additive (A), the above-mentioned compound (B), and the above-mentioned compound (C) (hereinafter also referred to as "asphalt additives") under heated conditions. Optionally, new asphalt, new aggregate, etc. can be used. In the mixing step, the components can be mixed simultaneously or in any order. When new asphalt is used in combination, from the viewpoint of durability and flexibility of the asphalt pavement, the asphalt 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 called plant mix methods, premix methods, etc. Among these, the plant mix method is preferred from the viewpoint of exerting asphalt performance.

[0052] 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.

[0053] [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.

[0054] 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]

[0055] In the following examples and comparative examples, parts and percentages are by mass unless otherwise specified.

[0056] The regenerating additive (A), compound (B) and compound (C) used are shown below. <Recycling Additive (A)> Regeneration additive (A1): Product name "Reprovital 500", manufactured by Idemitsu Kosan Co., Ltd. Regeneration additive (A2): Product name "T-Revive", manufactured by Takenaka Sangyo Co., Ltd.

[0057] <Compound (B)> Compound (B1): A mixture of cis-jasmone, β-damascenone, and β-ionone Compound (B2): cis-Jasmone Compound (b1): cis-3 hexenol

[0058] <Compound (C)> Compound (C1): Limonene, log P value: 4.83 Compound (C2): β-pinene, log P value: 4.35 Compound (C3): isopropyl myristate, log P value: 7.17 Compound (c1): hexyl acetate, log P value: 2.83 Compound (c2): propylene glycol, log P value: -0.78

[0059] <Other ingredients> Methyldihydrojasmonate (MDJ), logP value: 2.98

[0060] Production Example 1 Asphalt Additive Composition (1) A mixture of cis-jasmone, β-damascenone, and β-ionone (compound (B1)) was added dropwise to methyl dihydrojasmonate, followed by stirring at 100 rpm for approximately 1 minute. The mass ratio of each component was cis-jasmone:β-damascenone:β-ionone:MDJ = 75:7:15:3. Furthermore, the mixture of cis-jasmone, β-damascenone, β-ionone and MDJ was added dropwise to limonene (compound (C1)), and then the mixture was stirred at 100 rpm for about 1 minute. Next, a regenerating additive (A1) (trade name "Reprovital 500", manufactured by Idemitsu Kosan Co., Ltd.) was added and the mixture was left to stand overnight. The resulting mixture was used as asphalt additive composition (1). The mass ratio of the components was reclaiming additive (A): compound (B): compound (C) = 99:0.05:0.95.

[0061] Production Example 2 Asphalt Additive Composition (2) Asphalt additive composition (2) was obtained in the same manner as in Production Example 1, except that the mass ratio of the components was 99:0.1:0.9 (recycling additive (A):compound (B):compound (C)).

[0062] Production Example 3 Asphalt Additive Composition (3) Asphalt additive composition (3) was obtained in the same manner as in Production Example 1, except that the mass ratio of the components was set to 99.5:0.05:0.45:recycling additive (A):compound (B):compound (C).

[0063] Production Example 4 Asphalt additive composition (4) Asphalt additive composition (4) was obtained in the same manner as in Production Example 1, except that the mass ratio of the components was 99.5:0.1:0.4 (recycling additive (A):compound (B):compound (C)).

[0064] Production Example 5 Asphalt Additive Composition (5) An asphalt additive composition (5) was obtained in the same manner as in Production Example 1, except that cis-jasmone (compound (B2)) was used instead of compound (B1).

[0065] Production Example 6 Asphalt Additive Composition (6) An asphalt additive composition (6) was obtained in the same manner as in Production Example 1, except that a regeneration additive (A2) (trade name "T-Revive", manufactured by Takenaka Sangyo Co., Ltd.) was used instead of the regeneration additive (A1).

[0066] Production Example 7 Asphalt Additive Composition (7) An asphalt additive composition (7) was obtained in the same manner as in Production Example 1, except that β-pinene (compound (C2)) was used instead of compound (C1).

[0067] Production Example 8 Asphalt additive composition (8) An asphalt additive composition (8) was obtained in the same manner as in Production Example 1, except that isopropyl myristate (compound (C3)) was used instead of compound (C1).

[0068] Production Example 9 Asphalt additive composition (9) Asphalt additive composition (9) was obtained in the same manner as in Production Example 1, except that the mass ratio of the components was 90:0.5:9.5 (recycling additive (A):compound (B):compound (C)).

[0069] Production Example 10 Asphalt additive composition (10) An asphalt additive composition (10) was obtained in the same manner as in Production Example 1, except that the mass ratio of the components was 99:0.5:0.5 (recycling additive (A):compound (B):compound (C)).

[0070] Production Example 11 Asphalt additive composition (11) An asphalt additive composition (11) was obtained in the same manner as in Production Example 1, except that compound (C1) was not used and the mass ratio of the components was set to regeneration additive (A): compound (B): compound (C) = 99.9:0.1:0.

[0071] Production Example 12 Asphalt additive composition (12) An asphalt additive composition (12) was obtained in the same manner as in Production Example 1, except that hexyl acetate (compound (c1)) was used instead of compound (C1).

[0072] Production Example 13 Asphalt additive composition (13) An asphalt additive composition (13) was obtained in the same manner as in Production Example 1, except that propylene glycol (compound (c2)) was used instead of compound (C1).

[0073] Production Example 14 Asphalt additive composition (14) An asphalt additive composition (14) was obtained in the same manner as in Production Example 1, except that cis-3 hexenol (compound (b1)) was used instead of compound (B1).

[0074] Example 1 (1) Preparation of pseudo-asphalt recycled aggregate 15 kg of aggregate with the composition shown below, heated to 180°C, was placed in an asphalt mixer and mixed for 60 seconds at 180°C. Next, 820 g of modified type II asphalt (product name "HR Binder", manufactured by Toa Road Industry Co., Ltd.) was added, and the mixture was mixed in the asphalt mixer for 2 minutes. The resulting asphalt mixture was spread and filled into a stainless steel tray, and then cured in a high-temperature drying oven at 120°C for 48 hours to obtain artificially deteriorated pseudo-asphalt recycled aggregate. The asphalt content of the simulated recycled asphalt aggregate was 5.2% by mass. The penetration of the asphalt extracted from the simulated recycled asphalt aggregate according to the method specified in AASHTO T 308-10 (2015) was 30. The penetration was measured according to JIS K2207:2006.

[0075] <Aggregate composition> No. 6 crushed stone 40.0 parts by mass No. 7 crushed stone 13.0 parts by mass Crushed sand 10.0 parts by mass River sand 22.0 parts by mass Mountain sand 10.0 parts by mass Stone powder (calcium carbonate) 5.0 parts by mass Passed mass%: Sieve size 15 mm: 100% by mass Sieve size 10 mm: 88.7% by mass Sieve size 5 mm: 60.5% by mass Sieve size 2.5 mm: 42.6% by mass Sieve size 1.2 mm: 29.9% by mass Sieve size 0.6 mm: 19.8% by mass Sieve size 0.3 mm: 11.5% by mass Sieve size 0.15mm: 6.2% by mass

[0076] (2) Preparation of asphalt mixture 1.3 kg of simulated recycled asphalt aggregate heated to 180° C. was placed in a frying pan. Then, the asphalt additive composition (1) described in Production Example 1 was added, and the mixture was mixed at 180° C. for 120 seconds. The content of the recycling additive (A) in the asphalt mixture was 15 parts by mass per 100 parts by mass of the content of asphalt derived from recycled aggregate.

[0077] (3) Measurement of Marshall stability 1.2 kg of the resulting asphalt mixture was weighed and a cylindrical specimen was made using a Marshall test compactor ("Automatic Asphalt Compaction Device" manufactured by Nakajima Gihan Co., Ltd.). The specimen was gradually cooled to room temperature and demolded using a demolding machine. 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 using a Marshall loading device (manufactured by Nakajima Gihan Co., Ltd.) in accordance with "B001 Marshall Stability Test Method" in the "Pavement Survey and Testing Method Handbook (2019 Edition)" (compiled by the Japan Road Association, a public interest incorporated association), to measure the Marshall stability (kN) of asphalt specimen 1. Marshall stability is the maximum load required to destroy an asphalt specimen, and the higher the value, the more durable the asphalt pavement. The results are shown in Table 1.

[0078] (4) Measurement of porosity <Porosity measurement> The void ratio of the asphalt specimen M-1 was calculated from its air and water weight 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 Test Methods Handbook (2019 Edition)" (compiled by the Japan Road Association, a public interest incorporated association).

[0079] Specifically, the porosity was calculated according to the following formula. Porosity = 100 × {1 - (specimen bulk density) / (theoretical maximum density)} Each physical property used to calculate the porosity was calculated according to the following formula. Bulk density of specimen = (mass in air) / (surface dry mass - mass in water) Theoretical maximum density=2.458 The surface dry weight is the mass of the test specimen after it has been immersed in water for 3 minutes and then the surface has been wiped.

[0080] By measuring the void ratio under the same conditions, the workability of the asphalt mixture can be evaluated. The results are shown in Table 1.

[0081] (5) Evaluation of deodorizing (masking) effect The deodorizing (masking) effect was evaluated based on the following five-point scale when the asphalt mixture was prepared (in the table, when heated and mixed) and when the Marshall stability was measured (in the table, when cooled and demolded). The sensory evaluation was carried out by a panel of five experts who agreed to use the following criteria for evaluation. The score given by the largest number of panel members was used as the final score. 5. High masking effect, high-quality, pleasant fragrance 4: High masking effect, but no good fragrance 3: High masking effect, but the fragrance is too strong and somewhat unpleasant 2: The masking effect is uneven, and the odor caused by the deterioration of rubber in the asphalt remains. 1: No effect The results are shown in Table 1.

[0082] Examples 2 to 10, Comparative Examples 2 to 5 Asphalt mixtures were prepared in the same manner as in Example 1, except that asphalt additive compositions (2) to (14) shown in Table 1 were used instead of asphalt additive composition (1). Preparation, Marshall stability measurement, void volume measurement, and deodorizing (masking) effect evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

[0083] Comparative Example 1 An asphalt mixture was prepared in the same manner as in Example 1, except that the regeneration additive (A1) was used instead of the asphalt additive composition (1). Preparation, Marshall stability measurement, void volume measurement, and deodorizing (masking) effect evaluation were performed in the same manner as in Example 1.

[0084] [Table 1]

[0085] The asphalt additive composition of the present invention achieves both improved pavement properties and a good working environment during construction in asphalt mixtures using recycled asphalt aggregate. In particular, when the content of compound (C) relative to the total mass of the recycling additive (A), compound (B), and compound (C) is within a predetermined range, particularly excellent pavement properties are achieved.

Claims

1. An asphalt additive composition comprising a regenerating additive (A), the following compound (B) and the following compound (C). Compound (B): a ketone compound having a 5- or 6-membered cyclic structure and having 10 to 16 carbon atoms. Compound (C): A compound containing no ketone group and having a log P value of 4.0 or more

2. The asphalt additive composition according to claim 1, wherein the compound (B) is one or more selected from the group consisting of menthone, damascenone, jasmone, ionone, and 1-(2,3,8,8-tetramethyl-1,3,4,5,6,7-hexahydronaphthalen-2-yl)ethanone.

3. The asphalt additive composition according to claim 1, wherein the ratio of the mass of the compound (B) to the mass of the compound (C) [(B) / (C)] is 2 / 98 or more and 80 / 20 or less.

4. 2. The asphalt additive composition according to claim 1, wherein the rejuvenation additive (A) is an asphalt-based or petroleum lubricating oil-based rejuvenation additive having an aromatic content of 50% by mass or more.

5. The content of the compound (C) relative to the total mass of the regeneration additive (A), the compound (B), and the compound (C) is 0.1 mass% or less. The asphalt additive composition according to claim 1.

6. An asphalt mixture comprising recycled asphalt aggregate, a recycling additive (A), the following compound (B), and the following compound (C). Compound (B): a ketone compound having a 5- or 6-membered cyclic structure and having 10 to 16 carbon atoms. Compound (C): A compound containing no ketone group and having a log P value of 4.0 or more

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