Asphalt mixture

Abstract

To provide an asphalt mixture for obtaining asphalt pavement which is excellent in durability such as water resistance and fatigue resistance, while using an asphalt recycled aggregate.SOLUTION: An asphalt mixture contains new asphalt, a polyester resin, an additive agent for recycling, and an asphalt recycled aggregate, wherein a solubility parameter (SP value) of the polyester resin is 11 (cal / cm3)1 / 2 or more and 12.5 (cal / cm3)1 / 2 or less.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an asphalt mixture.

Background Art

[0002] For paving roads such as motorways, parking lots, freight yards, and sidewalks, asphalt paving using an asphalt composition is carried out because it is relatively easy to lay and the time from the start of paving work to the start of traffic can be shortened. In this asphalt paving, since the road surface is formed by an asphalt mixture in which aggregates are bound with asphalt, the paved road has good hardness and durability.

[0003] In recent years, from the viewpoints of reducing environmental impact and rising crude oil prices, the use of damaged asphalt paving (asphalt recycled aggregates) as a new paving material has been increasingly popular.

[0004] Patent Document 1 discloses an asphalt mixture for obtaining an asphalt paving that is excellent in durability and can maintain blackness even after traffic opening, which contains a polyester resin (A), the following compound (B), asphalt, and aggregates, and the aggregates contain asphalt recycled aggregates. Patent Document 2 discloses an asphalt paving composition that enables the production of a recycled modified asphalt paving composition without a softening agent addition facility, has excellent solubility and dispersibility in asphalt, has high toughness and tenacity with respect to aggregates, and is also excellent in crack resistance and flow resistance, and contains (A) recycled aggregates obtained by recycling asphalt paving waste materials, (B) a copolymer latex mainly composed of styrene and butadiene containing a softening agent, and (C) new materials composed of new asphalt and / or new aggregates in respective predetermined amounts.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] While it is easy to ensure the same hardness and durability as conventional pavements for pavements using asphalt recycled aggregates, since the fixed phase of deteriorated asphalt and the exposed surfaces of aggregates are scattered in the asphalt recycled aggregates, aggregate adhesion becomes non-uniform, which affects various pavement physical properties adversely. In particular, since the deterioration of water resistance, stripping resistance, and fatigue resistance is related to the pavement life, improvement is strongly demanded. With the technology described in Patent Document 1, an asphalt pavement with excellent durability can be obtained. However, the improvement of the water resistance and stripping resistance of the pavement using asphalt recycled aggregates is insufficient. With the technology described in Patent Document 2, an asphalt pavement with excellent abrasion resistance can be obtained. However, the improvement of the aggregate adhesiveness of asphalt is limited, and the improvement of water resistance and stripping resistance is insufficient.

[0007] The present invention relates to an asphalt mixture for obtaining an asphalt pavement excellent in durability such as water resistance and fatigue resistance while using asphalt recycled aggregates.

Means for Solving the Problems

[0008] The present invention relates to the following [1]. [1] An asphalt mixture containing a novel asphalt, a polyester resin, a regenerating additive, and asphalt recycled aggregates, wherein the solubility parameter (SP value) of the polyester resin is 11 (cal / cm 3 ) 1 / 2 or more and 12.5 (cal / cm 3 ) 1 / 2 or less.

Effects of the Invention

[0009] According to the present invention, an asphalt mixture for obtaining an asphalt pavement excellent in durability such as water resistance and fatigue resistance can be provided while using asphalt recycled aggregate.

Mode for Carrying Out the Invention

[0010] [Asphalt mixture] The asphalt mixture of the present invention contains novel asphalt, a polyester resin, a regenerating additive, and asphalt recycled aggregate, and the solubility parameter (SP value) of the polyester resin is 11 (cal / cm 3 ) 1 / 2 or more and 12.5 (cal / cm 3 ) 1 / 2 or less. The inventors have found that an asphalt mixture for obtaining an asphalt pavement excellent in durability can be obtained while using asphalt recycled aggregate with an asphalt mixture having a predetermined composition. The asphalt pavement obtained by the asphalt mixture of the present invention is excellent in durability, particularly in peeling resistance and fatigue resistance, and cracks and rutting caused by repeated vehicle passage are suppressed.

[0011] In this specification, the higher the durability of the asphalt pavement, the more cracks and rutting occur in the asphalt pavement due to repeated vehicle passage, resulting in deterioration, and the longer the period during which repair is required. The durability of the asphalt pavement can be evaluated by, for example, the durability of asphalt concrete and the load-bearing capacity and fatigue resistance of asphalt mortar in a wheel tracking test shown in the examples described later.

[0012] Although the detailed mechanism by which the effects of the present invention are obtained is unknown, in the asphalt mixture of the present invention, by adding a polyester resin having a specific SP value, which has high affinity with asphalt derived from recycled aggregate whose oxidation deterioration has progressed and polarity has increased, the asphalt-aggregate interface is strengthened, and excellent durability, particularly water resistance, is considered to be achieved.

[0013] <New asphalt> New asphalt, also known as virgin asphalt or unused asphalt, means asphalt that has never been used for asphalt paving. As new asphalt, various types of asphalt can be used as long as it has never been used for asphalt paving. For example, in addition to straight asphalt, which is petroleum asphalt for paving, modified asphalt can be mentioned. Examples of modified asphalt include blown asphalt; polymer-modified asphalt modified with polymer materials such as thermoplastic elastomers and thermoplastic resins. Straight asphalt refers to residual asphalt substances obtained by subjecting crude oil to atmospheric distillation units, vacuum distillation units, etc. Also, blown asphalt means asphalt obtained by heating a mixture of straight asphalt and heavy oil and then blowing air into it for oxidation. The asphalt is preferably selected from straight asphalt and polymer-modified asphalt. From the perspective of the durability of asphalt paving, polymer-modified asphalt is more preferable, and from the perspective of versatility, straight asphalt is more preferable. As polymer-modified asphalt, asphalt modified with a thermoplastic elastomer is more preferable. The modified asphalt is preferably polymer-modified asphalt, and more preferably polymer-modified asphalt modified with a thermoplastic elastomer.

[0014] (Thermoplastic elastomer) As the thermoplastic elastomer in the polymer-modified asphalt modified with a thermoplastic elastomer, for example, styrene / butadiene block copolymer, styrene / butadiene / styrene block copolymer, styrene / butadiene random copolymer, styrene / isoprene block copolymer, styrene / isoprene / styrene block copolymer, styrene / isoprene random copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid ester copolymer, styrene / ethylene / butylene / styrene copolymer, styrene / ethylene / propylene / styrene copolymer, polyurethane-based thermoplastic elastomer, polyolefin-based thermoplastic elastomer, isobutylene / isoprene copolymer, polyisoprene, polychloroprene, at least one selected from synthetic rubbers other than the above, and natural rubber can be mentioned. As the thermoplastic elastomer in the modified asphalt, preferably, at least one selected from styrene / butadiene block copolymer, styrene / butadiene / styrene block copolymer, styrene / butadiene random copolymer, styrene / isoprene block copolymer, styrene / isoprene / styrene block copolymer, styrene / isoprene random copolymer, ethylene / vinyl acetate copolymer, and ethylene / acrylic acid ester copolymer. Among these, as the thermoplastic elastomer, from the viewpoint of the durability of asphalt pavement, 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, still more preferably at least one selected from styrene / butadiene random copolymer and styrene / butadiene / styrene block copolymer. The content of the thermoplastic elastomer in the polymer-modified asphalt is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably 10% by mass or less, from the viewpoints of the durability and surface appearance of the asphalt pavement.

[0015] <Polyester resin> The asphalt mixture of the present invention contains a polyester resin having a solubility parameter (SP value) of 11 (cal / cm 3 ) 1 / 2 or more and 12.5 (cal / cm 3 ) 1 / 2 or less. The polyester resin is a polycondensate of an alcohol component and a carboxylic acid component, including a structural unit derived from the alcohol component and a structural unit derived from the carboxylic acid component. The "structural unit derived from the alcohol component" means a structure obtained by removing a hydrogen atom from the hydroxy group of the alcohol component, and the "structural unit derived from the carboxylic acid component" means a structure obtained by removing a hydroxy group from the carboxy group of the carboxylic acid component. The "carboxylic acid component" is a concept including not only the carboxylic acid itself but also an anhydride that decomposes during the reaction to generate an acid and an alkyl ester of the carboxylic acid (for example, having 1 to 3 carbon atoms in the alkyl group). When the carboxylic acid component is an alkyl ester of the carboxylic acid, the number of carbon atoms of the carboxylic acid does not include the number of carbon atoms of the alkyl group that is the alcohol residue of the ester. Examples of the polyester resin include an amorphous polyester resin and a crystalline polyester resin, and an amorphous polyester resin is preferred. Whether the resin is crystalline or amorphous is determined by the crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the maximum peak temperature of endotherm in the measurement method described in the examples below (softening point (°C) / maximum peak temperature of endotherm (°C)). A crystalline resin is one with a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one in which no endothermic peak is observed, or if an endothermic peak is observed, the crystallinity index is less than 0.6 or more than 1.4. Hereinafter, the alcohol component and the carboxylic acid component will be described.

[0016] (Alcohol component) Examples of the alcohol component include aliphatic diols, alicyclic diols, aromatic diols, polyhydric alcohols with three or more valences, etc. These alcohol components can be used alone or in combination of two or more.

[0017] The aliphatic diol is preferably a linear or branched aliphatic diol having 2 or more and 12 or less carbon atoms in the main chain, more preferably a linear or branched aliphatic diol having 2 or more and 8 or less carbon atoms in the main chain. Also, the aliphatic diol is preferably a saturated aliphatic diol. Specific examples of the aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,10-decanediol, 1,12-dodecanediol.

[0018] Examples of the alicyclic diol include hydrogenated bisphenol A (2,2-bis(4-hydroxycyclohexyl)propane), an alkylene oxide adduct of hydrogenated bisphenol A, cyclohexanediol, cyclohexanedimethanol.

[0019] Examples of the aromatic diol include bisphenol A [2,2-bis(4-hydroxyphenyl)propane] and an alkylene oxide adduct of bisphenol A. Examples of the alkylene oxide adduct of bisphenol A include an alkylene oxide adduct of bisphenol A represented by the following formula (I).

[0020] [Chemical formula]

[0021] [In the formula, OR 1 and R 1 O is an alkylene oxide, R 1 is an alkylene group having 2 or 3 carbon atoms, x and y represent positive numbers indicating the average number of moles of alkylene oxide added, the sum of x and y is preferably 1 or more, more preferably 1.5 or more, and is preferably 16 or less, more preferably 8 or less, still more preferably 4 or less. ]

[0022] Examples of the alkylene oxide adduct of bisphenol A represented by the formula (I) include a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A. These alkylene oxide adducts of bisphenol A can be used alone or in combination of two or more.

[0023] The polyhydric alcohol having a valency of 3 or more is preferably a trihydric alcohol. Examples of the polyhydric alcohol having a valency of 3 or more include glycerin, pentaerythritol, trimethylolpropane, and sorbitol.

[0024] From the viewpoint of physical property adjustment, the alcohol component can further contain a monohydric aliphatic alcohol. Examples of the monohydric aliphatic alcohol include lauryl alcohol, myristyl alcohol, palmityl alcohol, and stearyl alcohol. These monohydric aliphatic alcohols can be used alone or in combination of two or more.

[0025] (Carboxylic acid component) Examples of the carboxylic acid component include aliphatic dicarboxylic acids, aromatic dicarboxylic acids, and polycarboxylic acids having 3 to 6 valences. These carboxylic acid components can be used alone or in combination of two or more.

[0026] Examples of the aliphatic dicarboxylic acid include those having a main chain carbon number of preferably 4 or more, and preferably 10 or less, more preferably 8 or less, still more preferably 6 or less, such as fumaric acid, maleic acid, oxalic acid, malonic acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, or anhydrides thereof, and alkyl esters thereof (for example, the alkyl group has 1 to 3 carbon atoms). Examples of the substituted succinic acid include dodecyl succinic acid, dodecenyl succinic acid, and octenyl succinic acid.

[0027] Examples of the aromatic dicarboxylic acid include phthalic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, or anhydrides thereof, and alkyl esters thereof (for example, the alkyl group has 1 to 3 carbon atoms). Among the above aromatic dicarboxylic acids, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred from the viewpoint of the durability of asphalt pavement.

[0028] The polycarboxylic acid having 3 to 6 valences is preferably a trivalent carboxylic acid. Examples of the polycarboxylic acid having 3 to 6 valences include trimellitic acid, 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, or acid anhydrides thereof.

[0029] From the perspective of physical property adjustment, the carboxylic acid component can further contain a monovalent aliphatic carboxylic acid. Examples of the monovalent aliphatic carboxylic acid include monovalent aliphatic carboxylic acids having 12 to 20 carbon atoms such as lauric acid, myristic acid, palmitic acid, stearic acid, and alkyl (having 1 to 3 carbon atoms) esters of these acids. These monovalent aliphatic carboxylic acids can be used alone or in combination of two or more.

[0030] (Constituent unit derived from polyethylene terephthalate) The polyester resin can contain a constituent unit derived from ethylene glycol and a constituent unit derived from terephthalic acid, both of which are derived from polyethylene terephthalate. Polyethylene terephthalate may contain a small amount of components such as butanediol and isophthalic acid in addition to the constituent units derived from ethylene glycol and terephthalic acid. Polyethylene terephthalate is preferably recycled polyethylene terephthalate. When the polyester resin contains a constituent unit composed of ethylene glycol and terephthalic acid derived from polyethylene terephthalate, the "constituent unit derived from the alcohol component" includes the constituent unit derived from ethylene glycol derived from polyethylene terephthalate, and the "constituent unit derived from the carboxylic acid component" includes the constituent unit derived from terephthalic acid derived from polyethylene terephthalate.

[0031] (Molar ratio of the constituent unit derived from the carboxylic acid component to the constituent unit derived from the alcohol component) The molar ratio of the constituent unit derived from the carboxylic acid component to the constituent unit derived from the alcohol component [carboxylic acid component / alcohol component] is preferably 0.6 or more, more preferably 0.7 or more, still more preferably 0.8 or more, and preferably 1.5 or less, more preferably 1.3 or less, still more preferably 1.1 or less.

[0032] The polyester resin may be a polyester resin modified to such an extent that its properties are not substantially impaired. Specifically, examples of the modified polyester resin include polyester resins grafted or blocked with phenol, urethane, epoxy, etc. by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, etc. Preferred modified polyester resins include urethane-modified polyester resins obtained by extending a polyester resin with a polyisocyanate compound.

[0033] From the viewpoint of improving performance by imparting affinity with asphalt and aggregates derived from recycled aggregates, the polyester resin has a solubility parameter (SP value) of 11 (cal / cm 3 ) 1 / 2 or more and 12.5 (cal / cm 3 ) 1 / 2 or less. From the same viewpoint, the SP value of the polyester resin is preferably 11.1 (cal / cm 3 ) 1 / 2 or more, more preferably 11.2 (cal / cm 3 ) 1 / 2 or more, and preferably 12.2 (cal / cm 3 ) 1 / 2 or less, more preferably 11.8 (cal / cm 3 ) 1 / 2 or less. In this specification, the solubility parameter (SP value) is the solubility parameter according to the Fedors method. Specifically, it is calculated by the method described in POLYMER ENGINEERING AND SCIENCE, FEBRUARY, 1974, Vol. 14, No. 2, ROBERT F. FEDORS. (pages 147 to 154). The SP value of the polyester resin can be adjusted by the raw material monomer composition, molecular weight, catalyst amount, or reaction conditions of the polyester resin.

[0034] The softening point of the polyester resin is preferably 85°C or higher, more preferably 95°C or higher, still more preferably 100°C or higher, and preferably 160°C or lower, more preferably 140°C or lower, still more preferably 120°C or lower, from the viewpoint of the durability of the asphalt pavement. The softening point of the polyester resin can be measured by the method described in the Examples. Note that the softening point can be adjusted by the raw material monomer composition, molecular weight, catalyst amount, or reaction conditions.

[0035] <Additive for regeneration> The additive for regeneration is a component for restoring the properties of deteriorated asphalt derived from asphalt recycled aggregates. As the additive for regeneration, an additive for regeneration having the following standard properties described in "Pavement Recycling Handbook (2010 Edition)" edited by the Japan Road Association can be used. (Standard properties of the additive for regeneration) Kinematic viscosity (60°C): 80 mm 2 / s or more and 1000 mm 2 / s or less Flash point: 250°C or higher Viscosity ratio after thin film heating (60°C): 2 or less Mass change rate after thin film heating: within ±3%

[0036] Note that 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 after thin film heating (60°C) and the mass change rate after thin film heating are measured in accordance with JIS K2207:2006.

[0037] From the viewpoint of suppressing the uniform mixing property with various materials of the asphalt mixture and material separation, the density of the additive for regeneration is 0.95 g / cm 3 or higher. The density is measured in accordance with JIS K2249-4:2011.

[0038] Examples of the additive for regeneration include asphalt-based, petroleum lubricating oil-based, animal and vegetable oil-based, asphalt emulsion-based additives for regeneration, etc., and preferably asphalt-based or petroleum lubricating oil-based additives for regeneration.

[0039] From the viewpoints of the regeneration effect of recycled aggregates and the affinity with polyester, the saturated component of the additive for regeneration is preferably 80% by mass or less, more preferably 50% by mass or less. The "saturated component" is the constituent ratio of the saturated component when the additive for regeneration is separated into four constituent components of saturated component, aromatic component, resin component and asphaltene component in accordance with the petroleum test-related standard JPI-5S-70-2010 "Test Method for Asphalt Composition Analysis by TLC / FID Method" defined by the Society of Petroleum Engineers of Japan, and the content of each component is measured.

[0040] From the viewpoints of the regeneration effect of recycled aggregates and the affinity with polyester, the aromatic component of the additive for regeneration is preferably 50% by mass or more, more preferably 60% by mass or more. The "aromatic component" is the constituent ratio of the aromatic component when the additive for regeneration is separated into four constituent components of saturated component, aromatic component, resin component and asphaltene component in accordance with the petroleum test-related standard JPI-5S-70-2010 "Test Method for Asphalt Composition Analysis by TLC / FID Method" defined by the Society of Petroleum Engineers of Japan, and the content of each component is measured.

[0041] Commercially available products can be used as the additive for regeneration. Examples of commercially available products of the additive for regeneration include "Repro Vital 500" (manufactured by Idemitsu Kosan Co., Ltd.), "T-Revive" (manufactured by Takenaka Corporation), "SR Recover", "SR Bright" (manufactured by Shinreki Kogyo Co., Ltd.), etc.

[0042] <Asphalt recycled aggregate> The asphalt mixture of the present invention contains asphalt recycled aggregate as an aggregate. The asphalt recycled aggregate is obtained by collecting a used asphalt pavement, crushing and classifying it. The used asphalt pavement from which the asphalt recycled aggregate is derived contains asphalt and aggregate, and may contain other additives as required.

[0043] Note that the asphalt contained in the asphalt recycled aggregate has deteriorated in its physical and chemical properties compared to the fresh asphalt due to the influence of environmental factors such as heat and light. The physical and chemical properties of asphalt can be evaluated by measuring the penetration, softening point, bending strength, strain at break, asphalt composition, etc. of the asphalt. Generally, asphalt in which the maltene fraction in the asphalt has migrated to asphaltene and the penetration has decreased is often called deteriorated asphalt. However, even if the penetration of the recycled asphalt is equivalent to that of the fresh asphalt, it may not be able to exhibit the same performance as the fresh asphalt due to changes in other properties.

[0044] The asphalt mixture derived from the used asphalt pavement contains aggregates. Examples of such aggregates include aggregates commonly used in asphalt mixtures for road pavements, such as crushed stones, cobblestones, gravel, sand, and ceramics. Also, the asphalt mixture itself derived from the used asphalt pavement may use asphalt recycled aggregate as an aggregate.

[0045] <Fresh aggregate> The asphalt mixture of the present invention can contain fresh aggregates in addition to the asphalt recycled aggregate. As specific fresh aggregates, for example, crushed stones, cobblestones, gravel, sand, ceramics, etc. can be arbitrarily selected and used. Also, 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 and less than 2.36 mm, and fillers with a particle size of less than 0.075 mm can be used. Examples of the coarse aggregates include crushed stones with a particle size range of 2.36 mm or more and less than 4.75 mm, crushed stones with a particle size range of 4.75 mm or more and less than 12.5 mm, crushed stones with a particle size range of 12.5 mm or more and less than 19 mm, and crushed stones with a particle size range of 19 mm or more and less than 31.5 mm. Examples of the fine aggregates include river sand, hill sand, mountain sand, sea sand, crushed sand, fine sand, screenings, crushed stone dust, silica sand, artificial sand, glass cullet, and foundry sand. The particle sizes of the coarse aggregate and the fine aggregate are values based on the sieving test method specified in JIS A5001:2008.

[0046] Examples of the filler include calcium carbonate powder such as sand, fly ash, and limestone powder, and slaked lime. 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 still more preferably 0.02 mm or less. Here, the average particle size means the average particle size (D 50 ) at 50% volume accumulation, and can be measured with a laser diffraction particle size distribution analyzer.

[0047] It is preferable to use both the coarse aggregate and the fine aggregate as the aggregate. In this case, from the viewpoint of the durability of the asphalt pavement, the mass ratio of the coarse aggregate to the fine aggregate is preferably 10 / 90 or more, more preferably 15 / 85 or more, still more preferably 20 / 80 or more, and preferably 90 / 10 or less, more preferably 80 / 20 or less, and still more preferably 70 / 30 or less.

[0048] <Content of each component> From the viewpoints of the miscibility with the recycled aggregate and polyester and the adjustment of the void ratio of the specimen composed of them, the contents of the three components of the novel asphalt, the asphalt derived from the recycled aggregate, and the additive for recycling in the asphalt mixture are preferably 1% by mass or more, more preferably 3% by mass or more, still more preferably 4% by mass or more, and preferably 20% by mass or less, more preferably 15% by mass or less, and still more preferably 10% by mass or less.

[0049] From the perspective of achieving both durability and flexibility, the content of the novel asphalt is preferably 20% by mass or more, more preferably 30% by mass or more, and preferably 60% by mass or less, more preferably 50% by mass or less, among the three components of the novel asphalt, the asphalt derived from recycled aggregates, and the additive for recycling. From the perspective of achieving both durability and flexibility, the content of the asphalt derived from recycled aggregates is preferably 30% by mass or more, more preferably 40% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less, among the three components of the novel asphalt, the asphalt derived from recycled aggregates, and the additive for recycling. In this specification, "the asphalt derived from recycled aggregates" means the asphalt contained in the asphalt recycled aggregates. The asphalt derived from recycled aggregates is distinguished from the novel asphalt. The asphalt derived from recycled aggregates may also be referred to as deteriorated asphalt. The content of the asphalt derived from recycled aggregates in the asphalt recycled aggregates can be measured by the solvent extraction method or the loss on ignition method. Usually, the content of the asphalt contained in the asphalt recycled aggregates derived from the used asphalt pavement is approximately 5.5% by mass. In the present invention, the content of the asphalt derived from recycled aggregates is determined by the loss on ignition measurement in accordance with the method specified in AASHTO (American Association of State Highway and Transportation Officials; American Association of State Highway and Transportation Officials) T 308-10 (2015). Since the asphalt recycled aggregates are included as aggregates, the amount of asphalt is determined from the loss on ignition of the asphalt recycled aggregates and used for the compounding calculation.

[0050] From the perspective of improving the durability of asphalt pavement, the content of the regenerating additive in the asphalt mixture of the present invention is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, based on 100 parts by mass of the total amount of the three components of fresh asphalt, asphalt derived from recycled aggregates, and the regenerating additive, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, still more preferably 10 parts by mass or less from the perspective of maintaining workability.

[0051] Also, from the same perspective, the content of the regenerating additive in the asphalt mixture is preferably 3 parts by mass or more, more preferably 6 parts by mass or more, still more preferably 10 parts by mass or more, based on 100 parts by mass of the total amount of the two components of asphalt derived from recycled aggregates and the regenerating additive, and is preferably 60 parts by mass or less, more preferably 40 parts by mass or less, still more preferably 30 parts by mass or less, still more preferably 20 parts by mass or less from the perspective of maintaining workability.

[0052] From the perspective of improving the durability of asphalt pavement, the content of the polyester resin in the asphalt mixture of the present invention is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 7 parts by mass or more, based on 100 parts by mass of the total amount of the three components of fresh asphalt, asphalt derived from recycled aggregates, and the regenerating additive, and is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less from the perspective of maintaining flexibility.

[0053] From the perspective of achieving both durability and flexibility, the content of the aggregate in the asphalt mixture is preferably 50% by mass or more, more preferably 75% by mass or more, still more preferably 80% by mass or more, and is preferably 99% by mass or less, more preferably 98% by mass or less, still more preferably 96% by mass or less. The content of the asphalt recycled aggregate in the asphalt mixture is preferably 10% by mass or more, more preferably 15% by mass or more, still more preferably 20% by mass or more from the viewpoint of recycling waste asphalt pavement materials, and is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less from the viewpoint of achieving both durability and flexibility.

[0054] In the present invention, the aggregate content is the total content of the asphalt recycled aggregate and optionally included new aggregate. Note that the content of asphalt derived from the recycled aggregate is included in the aggregate content. When the aggregate includes new aggregate, the content of the 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 in 100 parts by mass of the total content of the asphalt recycled aggregate and the new aggregate from the viewpoint of achieving both the use of the asphalt recycled aggregate and excellent pavement physical properties. The content of the asphalt recycled aggregate is preferably 15 parts by mass or more, more preferably 25 parts by mass or more in 100 parts by mass of the total content of the asphalt recycled aggregate and the new aggregate from the viewpoint of recycling waste asphalt pavement materials, and is preferably 60 parts by mass or less, more preferably 50 parts by mass or less from the viewpoint of achieving both the use of the asphalt recycled aggregate and excellent pavement physical properties.

[0055] Preferable blending examples of the aggregate in the asphalt mixture include the following (1) to (3). (1) Fine-grained asphalt containing 30% by volume or more and less than 45% by volume of coarse aggregate, 30% by volume or more and 50% by volume or less of fine aggregate, and 5% by volume or more and 10% by volume or less of an asphalt composition. (2) An example of the asphalt mixture is, for example, dense-grained asphalt containing 45% by volume or more and less than 70% by volume of coarse aggregate, 20% by volume or more and 45% by volume or less of fine aggregate, and 3% by volume or more and 10% by volume or less of an asphalt composition. (3) Porous asphalt containing 70% by volume or more and 80% by volume or less of coarse aggregate, 10% by volume or more and 20% by volume or less of fine aggregate, and 3% by volume or more and 10% by volume or less of an asphalt composition. Regarding the mixing ratio of asphalt in a conventional asphalt mixture containing aggregate and asphalt, it is usually used in accordance with the optimum asphalt amount obtained from the "Mix Design of Asphalt Composition" described in the "Pavement Design and Construction Guidelines" issued by the Japan Road Association, a public interest incorporated foundation. In the present invention, the above optimum asphalt amount corresponds to the total amount of asphalt and polyester resin. However, it is not necessary to be limited to the method described in the "Pavement Design and Construction Guidelines", and it may be determined by other methods.

[0056] [Method for manufacturing asphalt mixture] The method for manufacturing the asphalt mixture of the present invention includes a step of mixing a novel asphalt, a polyester resin, a regenerating additive, and an asphalt recycled aggregate under heating conditions. In the mixing step, the novel asphalt, the polyester resin, the regenerating additive, and the asphalt recycled aggregate can be mixed simultaneously or in any order. From the viewpoints of the durability and flexibility of the asphalt pavement, preferably, the polyester resin and the regenerating additive are mixed with the novel asphalt simultaneously or after the novel asphalt and then with the asphalt recycled aggregate. The mixing under heating conditions is preferably an embodiment using heated asphalt recycled aggregate. When the asphalt mixture contains a novel aggregate in addition to the asphalt recycled aggregate, the asphalt recycled aggregate and the novel aggregate can be mixed and used, for example, so as to have the above content. Specific methods for manufacturing the asphalt mixture include methods for manufacturing asphalt mixtures such as the conventional plant mix method and the premix method. All of them are methods of adding a novel asphalt, a polyester resin, and a regenerating additive to heated aggregate. Examples of the adding method include the premix method in which the novel asphalt, the polyester resin, and the regenerating additive are dissolved in advance, or the plant mix method in which the novel asphalt is added to the heated aggregate and then the polyester resin and the regenerating additive are introduced simultaneously or in any order. Among these, from the viewpoint of exhibiting asphalt performance, the plant mix method is preferable. More specifically, in the step of mixing the asphalt mixture, preferably, (i) After adding and mixing the novel asphalt to the heated aggregate to obtain a mixture, adding and mixing the polyester resin and the recycling additive; (ii) Simultaneously adding and mixing a salt of the novel asphalt, the polyester resin, and the recycling additive to the heated aggregate, or (iii) Adding and mixing a mixture of the novel asphalt, the polyester resin, and the recycling additive, which has been pre-heated and mixed, to the heated aggregate. Among these, the method (i) is preferred for the mixing step.

[0057] From the viewpoint of improving durability by sufficient mixing, the heating temperature is preferably 160 °C or higher, more preferably 165 °C or higher, still more preferably 170 °C or higher. And from the viewpoint of performance stability, it is preferably 350 °C or lower, more preferably 250 °C or lower, still more preferably 200 °C or lower. Also, from the viewpoint of efficiently and uniformly dispersing the polyester resin and the recycling additive in the asphalt and exerting the asphalt performance, the mixing time is preferably 0.1 hour or longer, more preferably 0.5 hour or longer, still more preferably 1.0 hour or longer, still more preferably 1.5 hours or longer, and preferably 10 hours or shorter, more preferably 7 hours or shorter, still more preferably 5 hours or shorter, still more preferably 3 hours or shorter.

[0058] The method for preparing the mixture is not particularly limited, but preferably includes a step of heating and melting the novel asphalt, adding the polyester resin, the recycling additive, and, if necessary, other additives, and stirring and mixing with a commonly used mixer until each component is uniformly dispersed. Examples of commonly used mixers include homomixers, dissolvers, paddle mixers, ribbon mixers, screw mixers, planetary mixers, vacuum countercurrent mixers, roll mills, twin-screw extruders, and the like.

[0059] The asphalt mixture of the present invention may be used as a heated asphalt mixture substantially free of water. Alternatively, an emulsifier and water may be added to the asphalt mixture to form an asphalt emulsion, and aggregates and the like may be added thereto to be used as a normal-temperature asphalt mixture. Asphalt, polyester resin, and mixtures of the above polyester resins are preferably substantially free of water from the viewpoint of exhibiting asphalt performance.

[0060] There are no particular restrictions on the method for producing the asphalt mixture when it is used as a heated asphalt mixture, and it may be produced by any method. Usually, it may be carried out according to the method for producing an asphalt mixture containing aggregates and an asphalt composition.

[0061] [Method for constructing road pavement] The asphalt mixture of the present invention is suitable for road pavement. The method for constructing road pavement of the present invention preferably includes a step of constructing the asphalt mixture of the present invention on a road or the like to form an asphalt pavement layer. The asphalt pavement layer is usually the base layer or the surface layer of the road, and is preferably the surface layer of the road from the viewpoint of exhibiting the effect of durability.

[0062] In the road pavement method, the asphalt mixture may be compacted in the same manner as a normal asphalt mixture using the same construction machinery configuration. The compaction temperature of the asphalt mixture when used as a heated asphalt mixture is preferably 100°C or higher, more preferably 120°C or higher, still more preferably 130°C or higher, and preferably 200°C or lower, more preferably 180°C or lower, still more preferably 170°C or lower, from the viewpoint of exhibiting asphalt performance.

Examples

[0063] The physical property values of resins and the like were measured and evaluated by the following methods. [Measurement method] (1) Softening point of polyester resin Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating a 1 g sample at a heating rate of 6 °C / min, a load of 1.96 MPa was applied by a plunger and extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. The plunger descent amount of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was defined as the softening point.

[0064] (2) Molecular weight of the polyester resin The weight average molecular weight was determined by gel permeation chromatography (GPC) method according to the following method. (i) Preparation of sample solution The sample was dissolved in chloroform at 40 °C so that the concentration became 0.5 g / 100 mL. Then, this solution was filtered using a PTFE type membrane filter "DISMIC-25JP" (manufactured by Toyo Roshi Kaisha, Ltd.) with a pore size of 0.20 μm to remove insoluble components, and used as the sample solution. (ii) Molecular weight measurement Using the following measuring device and analytical column, chloroform was used as the eluent and flowed at a flow rate of 1 mL per minute, and the column was stabilized in a constant temperature bath at 40 °C. 200 μL of the sample solution was injected there and the measurement was carried out. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. The calibration curve at this time included several types of monodisperse polystyrenes (A-500 (5.0×10 2 ), A-1000 (1.01×10 3 ), A-2500 (2.63×10 3 ), A-5000 (5.97×10 3 ), F-1 (1.02×10 4 ), F-2 (1.81×10 4 ), F-4 (3.97×10 4 ), F-10 (9.64×10 4 ), F-20 (1.90×10 5 ), F-40 (4.27×10 5 ), F-80 (7.06×10 5 ), F-128 (1.09×10 6 )) manufactured by Tosoh Corporation were used as standard samples. The values in parentheses indicate the molecular weights. Measuring device: "HLC-8320GPC" (manufactured by Tosoh Corporation) Analysis column: "TSKgel Super HZM" + "TSKgel Super H-RC" × 2 (manufactured by Tosoh Corporation)

[0065] (3) Solubility parameter (SP value) of polyester resin The solubility parameter (SP value) of the polyester resin was determined according to the calculation method of Fedors.

[0066] (4) Asphalt content in asphalt recycled aggregate The asphalt content in the asphalt recycled aggregate was determined according to the method specified in AASHTO T 308-10 (2015).

[0067] Production Example 1 (Polyester Resin A1) Among the raw material monomers shown in Table 1, the alcohol component and terephthalic acid were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydration tube, a reflux condenser, and a nitrogen inlet tube. Under a nitrogen atmosphere, the amounts of tin(II) bis(2-ethylhexanoate) and gallic acid shown in Table 1 were added. The temperature was raised to 235°C over 3 hours in a mantle heater and held at 235°C for 5 hours, and then a vacuum reaction was carried out at 8.0 kPa for 1 hour. After cooling to 180°C, alkenyl succinic anhydride was added, the temperature was raised to 210°C over 2 hours, held at 210°C for 1 hour, and a vacuum reaction was carried out at 8.3 kPa. The reaction was continued until the softening point shown in Table 1 was reached to obtain the target polyester.

[0068] Production Example 2 (Polyester Resin A2) Among the raw material monomers shown in Table 1, the alcohol component, terephthalic acid, and polyethylene terephthalate (PET) were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydrating tube, a downward condenser, and a nitrogen inlet tube. Under a nitrogen atmosphere, the amount of tin(II) bis(2-ethylhexanoate) shown in Table 1 was added, and the temperature was raised to 235°C over 3 hours in a mantle heater. After reaching 235°C, it was held for 5 hours. After visually confirming that the PET particles had disappeared from the reaction product, it was cooled to 180°C. After cooling to 180°C, alkenyl succinic anhydride was added, the temperature was raised to 210°C over 2 hours, held at 210°C for 1 hour, and after performing a pressure reduction reaction at 8.3 kPa, the reaction was carried out until the softening point shown in Table 1 was reached to obtain the target polyester.

[0069] Production Example 3 (Polyester Resin A3) Among the raw material monomers shown in Table 1, the alcohol component, terephthalic acid, and polyethylene terephthalate (PET) were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydrating tube, a downward condenser, and a nitrogen inlet tube. Under a nitrogen atmosphere, the amount of tin(II) bis(2-ethylhexanoate) shown in Table 1 was added, and the temperature was raised to 210°C over 3 hours in a mantle heater. After reaching 210°C, it was held for 7 hours. After visually confirming that the PET particles had disappeared from the reaction product, adipic acid was added, the temperature was raised to 235°C over 2 hours, held at 235°C for 1 hour, and after performing a pressure reduction reaction at 8.3 kPa, the reaction was carried out until the softening point shown in Table 1 was reached to obtain the target polyester.

[0070] Production Example 4 (Polyester Resin A4) The raw materials shown in Table 1 were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydrating tube, a downward condenser, and a nitrogen inlet tube. Under a nitrogen atmosphere, the amount of tin(II) bis(2-ethylhexanoate) shown in Table 1 was added, and the temperature was raised to 235°C over 3 hours in a mantle heater. After reaching 235°C, it was held for 5 hours. After visually confirming that the PET particles had disappeared from the reaction product, a pressure reduction reaction was carried out at 8.3 kPa, and then the reaction was carried out until the softening point shown in Table 1 was reached to obtain the target polyester.

[0071] Production Example 5 (Polyester Resin A5) The raw materials shown in Table 1 were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydration tube, a downward condenser, and a nitrogen inlet tube. Tin(II) bis(2-ethylhexanoate) in the amount shown in Table 1 was added under a nitrogen atmosphere, and the temperature was raised to 140°C over 1 hour in a mantle heater. After reaching 140°C, it was held for 6 hours, and then further raised to 210°C over 6 hours and reacted for 1 hour. After visually confirming that the PET pellets had disappeared from the reaction product, a vacuum reaction was carried out at 8.3 kPa, and then the target polyester was obtained.

[0072] Production Example 6 (Polyester Resin A6) The raw materials shown in Table 1 were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydration tube, a downward condenser, and a nitrogen inlet tube. Tin(II) bis(2-ethylhexanoate) in the amount shown in Table 1 was added under a nitrogen atmosphere, and the temperature was raised to 140°C over 1 hour in a mantle heater. After reaching 140°C, it was held for 6 hours, and then further raised to 210°C over 6 hours and reacted for 1 hour. After visually confirming that the PET pellets had disappeared from the reaction product, a vacuum reaction was carried out at 8.3 kPa, and then the target polyester was obtained.

[0073] Production Example 7 (Polyester Resin a1) Among the raw material monomers shown in Table 1, the alcohol component and polyethylene terephthalate (PET) were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydration tube, a downward condenser, and a nitrogen inlet tube. Tin(II) bis(2-ethylhexanoate) in the amount shown in Table 1 was added under a nitrogen atmosphere, and the temperature was raised to 235°C over 3 hours in a mantle heater. After reaching 235°C, it was held for 5 hours. After visually confirming that the PET pellets had disappeared from the reaction product, it was cooled to 180°C. After cooling to 180°C, alkenyl succinic anhydride was added, and the temperature was raised to 210°C over 2 hours and held at 210°C for 1 hour. After carrying out a vacuum reaction at 8.3 kPa, the reaction was carried out until the softening point shown in Table 1 was reached, and the target polyester was obtained.

[0074] Production Example 8 (Polyester Resin a2) Among the raw material monomers shown in Table 1, the alcohol component and terephthalic acid were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a dehydration tube, a downflow condenser, and a nitrogen inlet tube. Under a nitrogen atmosphere, tin(II) bis(2-ethylhexanoate) and gallic acid in the amounts shown in Table 1 were added. The temperature was raised to 235°C over 3 hours in a mantle heater, held at 235°C for 5 hours, and then a vacuum reaction was carried out at 8.0 kPa for 1 hour. After cooling to 180°C, alkenyl succinic anhydride was added, the temperature was raised to 210°C over 2 hours, held at 210°C for 1 hour, and a vacuum reaction was carried out at 8.3 kPa. The reaction was continued until the softening point shown in Table 1 was reached to obtain the target polyester.

[0075] Production Example 9 (Polyester Resin a3) The raw materials shown in Table 1 were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a downflow condenser, and a nitrogen inlet tube. Under a nitrogen atmosphere, tin(II) bis(2-ethylhexanoate) in the amount shown in Table 1 was added. The temperature was raised to 235°C over 3 hours in a mantle heater and held for 7 hours after reaching 235°C. After a vacuum reaction was carried out at 8.3 kPa, the reaction was continued until the softening point shown in Table 1 was reached to obtain the target polyester.

[0076]

Table 1

[0077] Example 1-1a Measurement of Pavement Physical Properties of Asphalt Concrete <Preparation of Asphalt Concrete Specimen> 7.5 kg of aggregates heated to 165°C (see the following for the composition of the aggregates) were placed in an asphalt mixer and mixed at 165°C for 60 seconds. Next, 316 g of straight asphalt (60 - 80) (manufactured by Mitsubishi Corporation Energy Co., Ltd.) and 62 g of regenerative additive B1 (trade name "Repro Vital 500", manufactured by Idemitsu Kosan Co., Ltd.) were added and mixed in the asphalt mixer for 1 minute. Next, 79 g of the polyester resin A1 obtained in Production Example 1 was added and mixed in the asphalt mixer for 2 minutes. After heat-curing the obtained asphalt mixture at 165°C for 1 hour, it was quickly filled into a mold of 300 × 300 × 50 mm, and using a roller compactor (manufactured by Iwata Kogyosho Co., Ltd.), 25 rotation pressure treatments were performed at a temperature of 150°C and a load of 0.44 kPa to prepare an asphalt concrete specimen M-1a.

[0078] <Composition of Aggregates> 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 Asphalt recycled aggregate: 50.0 parts by mass Passing mass %: Sieve size 15 mm: 100 mass % Sieve size 10 mm: 82.9 mass % Sieve size 5 mm: 58.1 mass % Sieve size 2.5 mm: 39.8 mass % Sieve size 1.2 mm: 28.4 mass % Sieve size 0.6 mm: 15.9 mass % Sieve size 0.3 mm: 8.4 mass % Sieve size 0.15 mm: 2.6 mass %

[0079] The asphalt content in 7.5 kg of the asphalt recycled aggregate was 411 g. Therefore, the total content of the novel asphalt, asphalt derived from recycled aggregates, and the recycling additive in the asphalt mixture was 789 g, and the total amount of the novel asphalt, asphalt derived from recycled aggregates, and the recycling additive in the asphalt mixture was 5.0% by mass. The content of polyester resin A1 in the asphalt mixture was 10 parts by mass with respect to 100 parts by mass of the total content of the novel asphalt, asphalt derived from recycled aggregates, and the recycling additive. Also, the content of the recycling additive B1 in the asphalt mixture was 15 parts by mass with respect to 100 parts by mass of the total content of the asphalt derived from recycled aggregates.

[0080] <Measurement of rutting amount (wheel tracking test)> The asphalt concrete specimen was immersed in warm water set at 60°C in a 60°C constant temperature chamber, and using a wheel tracking tester (manufactured by Iwata Kogyosho Co., Ltd., load 1716 N, iron wheel width 47 mm, linear pressure 291.5 N / cm), the wheel was reciprocated on the specimen at a speed of 15 reciprocations / min, and the displacement amount at the time of 1,250 reciprocations of the passing number was measured and taken as the rutting amount (mm). Other measurement conditions were in accordance with the "B003 Wheel Tracking Test" described in the "Pavement Survey and Test Method Handbook" published by the Japan Road Association, a public interest incorporated foundation. Note that the rutting amount in the wheel tracking test is an index of the durability of the asphalt pavement. The results are shown in Table 2.

[0081] <Measurement of the flow inflection point> In the graph showing the relationship between the rutting amount obtained in the wheel tracking test and the passing number, an inflection point appears where the rutting amount suddenly turns to an increase. At this time, the intersection of the respective regression lines for the portions where the slopes are linear with the ratio of rutting before and after the inflection point being substantially constant was defined as the flow inflection point, and the passing number [times] indicated was obtained. The results are shown in Table 2.

[0082] Examples 1-2a to 1-6a An asphalt specimen was prepared in the same manner as in Example 1-1a, except that the polyester resin A1 was changed to the polyester resins A2 to A6 obtained in Production Examples 2 to 6 shown in Table 2, and the rutting excavation amount and the flow inflection point were evaluated. Example 2-1a An asphalt concrete specimen was prepared in the same manner as in Example 1-3a, except that the regenerating additive B1 was changed to the regenerating additive B2 (trade name: "T-Revive", manufactured by Takechiku Industries Co., Ltd.), and the rutting excavation amount and the flow inflection point were evaluated. Comparative Example 1-1a An asphalt concrete specimen was prepared in the same manner as in Example 1-1a, except that the polyester resin A1 was not added, and the rutting excavation amount and the flow inflection point were evaluated. Comparative Examples 1-2a to 1-4a An asphalt concrete specimen was prepared in the same manner as in Example 1-1a, except that the polyester resin A1 was changed to the polyester resins a1 to a3 obtained in Production Examples 7 to 9 shown in Table 1, and the rutting excavation amount and the flow inflection point were evaluated. Comparative Example 2-1a An asphalt concrete specimen was prepared in the same manner as in Example 2-1a, except that the polyester resin A3 was not added, and the rutting excavation amount and the flow inflection point were evaluated. Comparative Example 2-2a An asphalt concrete specimen was prepared in the same manner as in Example 2-1, except that the polyester resin A1 was changed to the polyester resin a1 obtained in Production Example 7 shown in Table 1, and the rutting excavation amount and the flow inflection point were evaluated.

[0083]

Table 2

[0084] Example 1-1b Measurement of Pavement Physical Properties of Asphalt Mortar <Preparation of Asphalt Mortar Specimen> 230 g of the powder fraction that passed through a 0.6 mm sieve of the asphalt recycled aggregate was heated in an oven at 180°C, and 2.8 g of the recycling additive resin B1 (trade name “Repro Vital 500”, manufactured by Idemitsu Kosan Co., Ltd.) and 1.9 g of the polyester resin A1 obtained in Production Example 1 were added and mixed using a medicine spoon. After uniformly mixing, it was filled into a mold of 24 × 24 × 200 mm. After naturally cooling to room temperature, it was demolded to obtain an asphalt mortar specimen M-1b.

[0085] The asphalt content in 230 g of the asphalt recycled aggregate was 18.9 g. Therefore, the total content of the asphalt derived from the recycled aggregate and the recycling additive in the asphalt mortar was 8.2% by mass. The content of the polyester resin A1 in the asphalt mortar was 10 parts by mass with respect to 100 parts by mass of the total content of the asphalt derived from the recycled aggregate and the recycling additive. Also, the content of the recycling additive B1 in the asphalt mortar was 15 parts by mass with respect to 100 parts by mass of the total content of the asphalt derived from the recycled aggregate.

[0086] <Measurement of load-bearing capacity> Using an electric measuring stand (MX2-5000, manufactured by Imada Co., Ltd.), a three-point bending test jig (BT-5000N, manufactured by Imada Co., Ltd.), and a digital force gauge (ZTS-5000N, manufactured by Imada Co., Ltd.), a three-point bending test was carried out on the asphalt mortar specimen under the following conditions. Span 75 mm Head speed 10 mm / min A load-displacement curve was created, and the load at the inflection point (also called the breaking point) was taken as the load-bearing capacity [N]. The results are shown in Table 3.

[0087] <Measurement of fatigue resistance> The test was carried out using the fracture sample obtained in the above measurement of the load-bearing capacity. In the load-displacement curve, the load value at a displacement of 0.3 mm was determined. Using this load value as the upper limit of the device load, a three-point bending test jig (BT-5000N, manufactured by IMADA Co., Ltd.) was used to conduct repeated bending tests under the following conditions. Span length 75 mm Head speed 10 mm / min After standing still for 1 second at the set load, return to the origin at a head speed of 300 mm / min The number of bending cycles until the sample was completely broken was measured. The average value of 4 times was taken as the fatigue resistance [cycles]. The results are shown in Table 3.

[0088] Examples 1-2b to 1-6b Asphalt mortar specimens were prepared in the same manner as in Example 1-1b, except that polyester resin A1 was changed to polyester resins A2 to A6 obtained in Production Examples 2 to 6 shown in Table 3, and the load resistance and fatigue resistance were measured. Example 2-1b Asphalt mortar specimens were prepared in the same manner as in Example 1-3b, except that the regenerating additive B1 was changed to regenerating additive B2 (trade name "T-Revive", manufactured by Takeuchi Sangyo Co., Ltd.), and the load resistance and fatigue resistance were measured. Comparative Example 1-1b Asphalt mortar specimens were prepared in the same manner as in Example 1-1b, except that polyester resin A1 was not added, and the load resistance and fatigue resistance were measured. Comparative Examples 1-2b to 1-4b Asphalt mortar specimens were prepared in the same manner as in Example 1-1b, except that polyester resin A1 was changed to polyester resins a1 to a3 obtained in Production Examples 7 to 9 shown in Table 1, and the load resistance and fatigue resistance were measured. Comparative Example 2-1b Asphalt mortar specimens were prepared in the same manner as in Example 2-1b, except that polyester resin A3 was not added, and the load resistance and fatigue resistance were measured. Comparative Example 2-2b Asphalt mortar specimens were prepared in the same manner as in Example 2-1b, except that polyester resin A1 was changed to polyester resin a1 obtained in Production Example 7 shown in Table 1, and the load resistance and fatigue resistance were measured.

[0089]

Table 3

[0090] Examples 1-1b to 1-6b have a higher load-bearing value and a greater number of bending cycles of fatigue resistance for the asphalt mortar specimens compared to Comparative Examples 1-1b to 1-4b. Also, Examples 1-1a to 1-6a have a smaller amount of rutting excavation and a greater number of currency cycles corresponding to the flow bending point in the asphalt concrete specimens compared to Comparative Examples 1-1a to 1-4a. From these results, it can be seen that the asphalt mixture of the present invention is excellent in durability while using asphalt recycled aggregates. Similarly, for Examples 2-1a and 2-1b as well, it can be said that they are excellent in durability while using asphalt recycled aggregates compared to Comparative Examples 2-1a to 2-2a and Comparative Examples 2-1b to 2-2b.

Claims

Claim 1 An asphalt mixture containing a novel asphalt, a polyester resin, a regenerating additive, and asphalt recycled aggregate, wherein the solubility parameter (SP value) of the polyester resin is 11 (cal / cm 3 ), 1 / 2 or more and 12.5 (cal / cm 3 ), 1 / 2 or less. Claim 2 The asphalt mixture according to claim 1, wherein the softening point of the polyester resin is 160°C or lower. Claim 3 The asphalt mixture according to claim 1 or 2, wherein the polyester resin has a structural unit derived from an alcohol component and a structural unit derived from an acid component, and the acid component contains one or more aromatic carboxylic acids. Claim 4 The asphalt mixture according to any one of claims 1 to 3, wherein the asphalt is straight asphalt or modified asphalt.

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