JP2008002200A - Elastic pavement material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastic pavement material using an asphalt-based binder which enhances construction performance by improving the blending of the binder so as to reduce the 180°C-viscosity of the binder while maintaining pavement strength to a certain extent. <P>SOLUTION: This elastic pavement material contains the asphalt-based binder containing asphalt, rubber, and an aggregate. The asphalt-based binder contains an ethylene-methacrylic acid copolymer. Preferably, the quantity of the ethylene-methacrylic acid copolymer blended in the asphalt-based binder is in a range of 30-80 wt.%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an elastic pavement, and more particularly, to an elastic pavement using a thermoplastic binder.

  Conventionally, as a low-noise pavement for reducing traffic noise, there is a porous drainage pavement in which a gap is provided inside the pavement using a large particle size aggregate. Also known is a low noise elastic pavement using vulcanized rubber in powder or chip form and using a curable resin such as urethane or epoxy as a binder.

  Among them, elastic pavement using rubber chips has excellent effects such as shock absorption during walking and safety during falls due to the elasticity of rubber chips, and since it has voids inside, it has drainage and breathability. In addition, it has excellent sound absorption and is therefore effective in reducing noise generated on tires and road surfaces. Therefore, it is attracting attention as a functional elastic pavement for reducing traffic noise in urban areas.

  However, when a curable resin such as urethane is used as a binder, there is a problem in that when the applied pavement is recycled, it cannot be reused by heating or the like like asphalt. In addition, because curing is slow at room temperature, it takes about 1 to 2 days for curing time, and there is a problem that traffic must be restricted during that time. It was difficult and had economic problems.

On the other hand, the present applicant has examined various types of elastic pavement using asphalt as a binder that can be constructed in a short time and can be recycled at low cost instead of conventional curable binders such as urethane and epoxy. An elastic pavement material using an ethylene vinyl acetate copolymer (EVA), which is a thermoplastic resin, as a binder together with asphalt has been proposed (for example, Patent Documents 1 and 2).
Japanese Patent Application No. 2004-38513 Japanese Patent Application No. 2005-004509

  However, in the asphalt-based elastic pavement using EVA as a binder together with asphalt, the binder has a high viscosity of 180 ° C. in order to ensure the strength of the pavement, and thus has a problem of poor workability. .

  Therefore, an object of the present invention is to improve the workability by reducing the 180 ° C. viscosity of the binder while maintaining the pavement strength to some extent by improving the binder composition in the elastic pavement material using the asphalt binder. To provide a body.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by using ethylene methacrylic acid copolymer (EMAA) instead of EVA as the thermoplastic resin added to the asphalt binder. Thus, the present invention has been completed.

That is, the elastic pavement of the present invention is an elastic pavement containing an asphalt binder containing asphalt, rubber, and aggregate.
The asphalt binder contains an ethylene methacrylic acid copolymer.

  In the present invention, the blending amount of the ethylene methacrylic acid copolymer in the asphalt binder is preferably in the range of 30 to 80% by weight. Further, as the ethylene methacrylic acid copolymer, those having a melt flow rate in the range of 50 to 1000 g / 10 min are preferable.

  According to the present invention, the above configuration can reduce the 180 ° C. viscosity of the binder while maintaining the pavement strength to some extent, thereby realizing an elastic pavement with improved workability. It became.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The elastic pavement of the present invention contains an asphalt binder, rubber, and aggregate, and is characterized by containing an ethylene methacrylic acid copolymer (EMAA) together with asphalt in the asphalt binder. Have As a resin to be added to asphalt, by using EMAA instead of EVA that has been used in the past, it maintains the desired pavement strength and prevents the binder from becoming too high in viscosity at 180 ° C. It became possible to realize.

  The blending amount of EMAA in the asphalt binder is preferably in the range of 30 to 80% by weight. If the amount of EMAA is less than this range, the strength cannot be maintained. On the other hand, if it is more than this range, the workability deteriorates, which is not preferable. As such EMAA, for example, Nukurel (registered trademark) N1050H, N1110H (both manufactured by Mitsui DuPont Polychemical Co., Ltd.) can be appropriately selected and used. In the present invention, among them, EMAA having a melt flow rate in the range of 50 to 1000 g / 10 min can be suitably used.

  In the elastic pavement of the present invention, the asphalt binder is not particularly limited except for blending EMAA with asphalt, and the other blending components are among the commonly used materials. Can be appropriately selected and used.

  The asphalt that can be used in the present invention is not particularly limited, and conventional asphalt, for example, straight asphalt, semi-blown asphalt, blown asphalt, asphalt emulsion, cutback added with tar, pitch, oil, etc. Examples include asphalt and recycled asphalt. These can be used alone or in combination of two or more. The asphalt may be decolorized asphalt. In this invention, the suitable compounding quantity of the asphalt in an asphalt-type binder exists in the range of 20 to 70 weight%.

  Moreover, it is preferable to mix | blend a wax with an asphalt-type binder. By adding wax to the asphalt-based binder, the workability can be improved and the decrease in storage elastic modulus at high temperatures can be suppressed, and the effect of improving the resistance to rubbing of the resulting elastic pavement can be obtained. .

  Such wax is not particularly limited, and any of natural wax and synthetic wax such as petroleum wax can be used. For example, paraffin wax, microcrystalline wax, liquid paraffin wax, paraffinic synthetic wax, polyethylene wax And hydrocarbon waxes, but are not limited to these. Such waxes may be used alone or in combination of two or more. The wax used in the present invention preferably has a softening point of 80 ° C. or higher and 160 ° C. or lower, particularly 90 ° C. or higher and 130 ° C. or lower. Further, the penetration at 25 ° C. is preferably 20 or less, more preferably 8 or less. The blending amount of the wax in the asphalt binder is preferably 10 to 20% by weight.

  Moreover, it is preferable that the asphalt binder further contains a silane coupling agent. This also provides the adhesion of the stone surface, so that the durability can be further enhanced. As the silane coupling agent, those available in the market can be used as appropriate, and are not particularly limited, but among them, amino-based silane coupling agents are suitable. For example, Shin-Etsu Chemical Co., Ltd. KBM603, KBM903, etc. made from) can be used conveniently. The blending amount of the silane coupling agent in the asphalt binder is preferably about 0.2 to 5% by weight.

  In addition, other thermoplastic elastomers can be added to the asphalt binder, for example, in order to improve strength and the like. Examples of such other thermoplastic elastomers include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), and styrene-ethylene-butylene-styrene copolymer (SEBS). One type or a combination of two or more types can be appropriately selected and used. The compounding quantity of these other thermoplastic elastomers can be about 10-50 weight% with respect to all the binders, for example. Further, in order to improve the workability, about 1 to 40% by weight of low molecular weight petroleum resin may be contained in the asphalt binder.

  Aggregates are not particularly limited, and natural aggregates such as quartz sand, which has been used for paving, and recycled aggregates such as river gravel and river sand, crushed stone, slag, concrete, glass, FRP, etc. Material can be used. The stone, sand, etc. used for this aggregate are intended to ensure the strength and wear resistance of the completed pavement and to be exposed on the surface to obtain an anti-slip action (polishing effect like sandpaper). The stone materials preferably have a function of meshing with each other to disperse the load. For this reason, a sharp object such as a crushed stone is suitable. Further, it is preferable to mix 5% by volume or more of fine aggregate having a particle size of 0.5 mm or less with respect to coarse aggregate having a particle size of 0.5 to 30 mm. Coarse-grained aggregates form a porous structure, and those having a sharp shape like a crushed stone that are meshed with each other to form a gap are suitable. On the other hand, the fine-grained aggregate adheres to the surface of the large-sized coarse-grained aggregate and provides an anti-slip effect on the tire or the like.

  The material used for the present invention is not particularly limited, and natural rubber, isoprene rubber, styrene-butadiene rubber, butyl rubber, ethylene-propylene rubber, and the like can be used. Specifically, rubber chips and rubber powder obtained from used waste materials such as rubber tires, weather strips, hoses, etc., unnecessary end materials generated during molding, molding defects, and the like can be suitably used.

  The elastic pavement of the present invention may comprise 10 to 35% by weight of the asphalt binder and 65 to 90% by weight of a mixture of aggregate and rubber. Moreover, the porosity of the elastic pavement of the present invention is preferably about 20 to 40%.

  The oil used for mixing the above components constituting the elastic pavement is not particularly limited. For example, among petroleum oils composed of three compositions of an aromatic ring, a naphthene ring, and a paraffin chain, the ring analysis result is 36. Aromatic oils having an aromatic carbon content of at least% can be suitably used.

  The elastic pavement of the present invention is obtained by mixing asphalt, EMAA and a blend of the remaining compound such as wax as desired, aggregate and rubber at a suitable temperature, for example, about 150 to 200 ° C. Obtainable. The mixing method in this case is not particularly limited, and any method that can uniformly mix these may be used. In this case, it is preferred to pre-mix EMAA and rubber and then mix the remaining blend, which can effectively protect the rubber from heat.

Hereinafter, the present invention will be described in more detail with reference to examples.
EMAA or EVA having the physical property values shown in Table 1 below is made from wax (Nippon Seiki Co., Ltd., FT100), amino-based silane coupling agent (Shin-Etsu Silicone, KBM603) and asphalt (25 ° C penetration) 60-80) and the formulations shown in Table 2 below, and the mixture was stirred at 180 ° C. to prepare binders of Examples and Comparative Examples.

＊１）メルトフローレート（ＭＦＲ）；ＪＩＳ Ｋ ７２１０に準拠
＊２）ＪＩＳ Ｋ ７２０６に準拠
＊３）ＥＶＡ：ＥＶＡ６２５（東ソー（株）製）
＊４）ＥＭＡＡ（１），（２）：Ｎ１０５０Ｈ，Ｎ１１１０Ｈ（三井デュポンポリケミカル社製）

* 1) Melt flow rate (MFR); compliant with JIS K 7210 * 2) compliant with JIS K 7206 * 3) EVA: EVA625 (manufactured by Tosoh Corporation)
* 4) EMAA (1), (2): N1050H, N1110H (Mitsui DuPont Polychemical Co., Ltd.)

<180 ° C viscosity measurement>
About each binder, 180 degreeC viscosity measurement was performed on 20 rpm conditions with the measuring apparatus (BROOKFIELD DV-II + VISCOMETER jig | tool NO.27 ((phi) 12 mm x 40 mm)) shown in FIG. In the figure, reference numeral 1 denotes a binder, and reference numeral 11 denotes a jig.

<Normal temperature fracture strength>
A sample having a size of 4 × 4 × 16 mm (4 × 4 × 16 mm) by a mold using a mixture of 25% by weight of the binder of each Example and Comparative Example and 75% by weight of a 75/25 mixture of rubber and silica sand. (Porosity 20%) was produced. As shown in FIG. 2, the sample 2 is placed on a pair of support bars 12 arranged at an interval of 10 cm, and the central portion of the sample 2 is pressed from above with a pressing bar 13 at a speed of 10 mm / min. Then, the breaking strength at room temperature was measured. In addition, if the normal temperature fracture strength is 686 N (70 kgf) or more, it can be said that the strength is sufficient for pavement.
These results are also shown in Table 2 below.

  As shown in Table 2 above, the binders of Examples 1 and 2 each have a low viscosity of 180 ° C., and by blending EMAA in place of EVA in the asphalt binder, while maintaining the strength to some extent, It was confirmed that the workability could be greatly improved.

It is the schematic which shows the measuring apparatus of the 180 degreeC viscosity in an Example. It is explanatory drawing which shows the measuring method of the normal temperature fracture strength in an Example.

Explanation of symbols

1 Binder 2 Elastic Pavement Sample 11 Jig 12 Support Bar 13 Press Bar

Claims (3)

In an elastic pavement containing an asphalt binder including asphalt, rubber, and aggregate,
An elastic pavement, wherein the asphalt binder contains an ethylene methacrylic acid copolymer.   The elastic pavement according to claim 1, wherein the blending amount of the ethylene methacrylic acid copolymer in the asphalt binder is in the range of 30 to 80% by weight.   The elastic pavement according to claim 1 or 2, wherein a melt flow rate of the ethylene methacrylic acid copolymer is in a range of 50 to 1000 g / 10 min.

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