JP2007247224A - Elastic paving material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastic paving material which excellently ensures slip resistance in a wet condition even after abrasion of a pavement surface. <P>SOLUTION: The elastic paving material contains an asphalt-based binder, rubber chips and/or rubber powder, and aggregate. The aggregate contains plastics waste, and its proportion to the entire elastic paving material falls in the range of 3 to 15 vol.%. The plastics waste is preferably formed of fiber reinforced plastics (FRP), and the asphalt-based binder preferably contains asphalt and an ethylene-vinyl acetate copolymer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an elastic pavement material, and more particularly to an elastic pavement material for improving slip resistance (wet μ) when wet.

  Conventionally, a low noise elastic pavement using a curable resin such as urethane or epoxy as a binder is known as a method of using vulcanized rubber in the form of powder or chips. In addition, elastic pavements in which rubber chips are mixed with these binders and press-molded are used on sidewalks, playgrounds, roadways, and the like.

  These elastic pavements using rubber chips have excellent effects such as shock absorption during walking and safety during falls due to the elasticity of the rubber chips, and since there are voids inside, in addition to drainage and breathability Therefore, it is also attracting attention as a functional elastic pavement material for reducing traffic noise in urban areas because it is effective in reducing noise generated on tires and road surfaces.

  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. 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

  As shown in Patent Documents 1 and 2 and the like, it is possible to solve the above-described problems such as curing time and recyclability by using a cooling and curing type asphalt binder. However, asphalt-based elastic pavement has a problem that slip resistance (wet μ) in a wet state decreases after the pavement surface wears due to friction with the tire. Therefore, it has been desired to realize a pavement that can obtain good wet slip resistance even after the pavement surface is worn due to aging.

  Accordingly, an object of the present invention is to provide an elastic pavement material that can satisfactorily ensure slip resistance in a wet state even after the pavement surface is worn out by solving the above problems.

  As a result of intensive studies, the present inventor has determined a predetermined amount of plastic waste such as fiber reinforced plastic (FRP) as well as natural aggregate such as stone and sand as usual asphalt-based elastic pavement aggregate. It has been found that by using a mixture in a ratio, it is possible to prevent a reduction in slip resistance when wet due to aging, and the present invention has been completed.

That is, the elastic paving material of the present invention is an elastic paving material containing an asphalt binder, a rubber chip and / or rubber powder, and an aggregate.
The aggregate contains plastic waste material, and the proportion of the plastic waste material in the elastic pavement material is in the range of 3% by volume to 15% by volume, preferably 5% by volume to 10% by volume. Is.

  In the present invention, as the plastic waste material, one made of fiber reinforced plastic can be suitably used. Further, as the asphalt binder, those containing asphalt and an ethylene vinyl acetate copolymer (EVA) are preferable, and it is particularly preferable to contain a wax and / or a silane coupling agent.

  According to the present invention, the above configuration can effectively suppress a decrease in wet μ due to abrasion of the pavement surface, and thereby, good slip resistance in a wet state even after aged use. It has become possible to realize an elastic pavement material that can be secured.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The elastic pavement material of the present invention contains an asphalt binder, rubber chips and / or rubber powder, and aggregate.

  In the present invention, the aggregate includes plastic waste, and the proportion of the plastic waste in the elastic pavement material is in the range of 3% to 15% by volume, preferably 5% to 10% by volume. It has the characteristics. As an aggregate of asphalt-based elastic pavement, natural aggregates such as cinnabar are usually used, but in the present invention, by replacing a predetermined amount of cinnabar as aggregate with plastic waste, It is possible to suppress a decrease in wet μ after wear, and it is possible to ensure excellent slip resistance when wet even after aged use. If the percentage of plastic waste is less than 3% by volume, the effect of suppressing the reduction of wet μ will be insufficient. On the other hand, if it exceeds 15% by volume, the binder viscosity will increase and the workability will deteriorate. However, the desired effect of the present invention cannot be obtained.

  The plastic waste material used in the present invention is not particularly limited, and wastes of various plastic molded products can be used. Specifically, for example, fiber reinforced plastic (FRP) is preferable. Can be used. Moreover, as the remainder other than the plastic waste material among the aggregates in the present invention, conventional natural aggregates and the like can be used. Specifically, for example, natural aggregates such as river gravel and river sand, crushed stone, slag, Examples include recycled aggregates such as concrete and glass. In particular, it is preferable to use dredged sand or the like in combination with plastic waste.

  Moreover, it is preferable to mix 5 volume% or more of fine aggregates with a particle size of 0.5 mm or less with respect to the coarse aggregate with a particle size of 0.5-30 mm normally. The coarse aggregate mainly forms a porous structure in order to obtain water permeability, and a hard aggregate having a sharp shape like a crushed stone that meshes with each other to form a gap is suitable. On the other hand, the fine-grained aggregate adheres to the surface of the large-sized coarse-grained aggregate and brings about an anti-slip action (polishing effect like sandpaper) on the tire or the like. About the plastic waste material which concerns on this invention, it grind | pulverizes, for example to a particle size of 1-3000 micrometers, Preferably about 10-1000 micrometers, and uses it as an aggregate.

  In the elastic pavement material of the present invention, the amount of aggregate excluding plastic waste is 5 to 40% by volume, preferably about 10 to 30% by volume. If the proportion of the aggregate in the elastic pavement material is less than 5% by volume, the strength is not sufficient, while if it exceeds 40% by volume, sufficient elasticity and bass effect cannot be obtained.

  The asphalt binder used in the present invention is not particularly limited as long as it contains at least asphalt, and preferably contains asphalt and an ethylene vinyl acetate copolymer (EVA).

  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.

  Moreover, as EVA, what can be obtained in markets, such as EV210ET (made by Mitsui DuPont Chemical Co., Ltd.), EVA720, EVA680, EVA710 (made by Tosoh Corporation), can be used conveniently, for example. The vinyl acetate unit in EVA is preferably 10% by weight or more in order to enhance the adhesion to rubber. The durometer A hardness in accordance with EVA JIS K7215 is preferably 70 or more from the viewpoint of strength. The amount of EVA in the asphalt binder can be preferably 30 to 80 parts by weight with respect to 20 to 70 parts by weight of asphalt.

  The asphalt binder according to the present invention preferably further contains a wax. By adding wax to the asphalt-based binder, it is possible to improve workability and suppress a decrease in storage elastic modulus at high temperatures, and to obtain the effect of improving the resistance to rubbing of the resulting pavement.

  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 about 10 to 20% by weight.

  Furthermore, it is preferable to contain a silane coupling agent in the asphalt-based binder, and this also provides adhesion to the stone surface, so that 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.

  The proportion of the asphalt binder in the elastic pavement material of the present invention can be about 10 to 35% by volume.

  The material of the rubber chip and / or rubber powder is not particularly limited, and natural rubber, isoprene rubber, styrene-butadiene rubber, butyl rubber, ethylene-propylene rubber, or the like can be used. Such rubber can be obtained from used waste materials such as rubber tires, weather strips, hoses, etc., unnecessary end materials generated during molding, molding defects, and the like.

  The proportion of rubber in the elastic pavement material of the present invention is preferably 20 to 70% by volume. If this proportion is less than 20% by volume, the effect as an elastic pavement is not sufficient. On the other hand, if it exceeds 70% by volume, sufficient physical properties for application to asphalt pavement cannot be obtained, which is not preferable.

  The oil used for mixing the above components constituting the elastic pavement material 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 material of the present invention comprises asphalt and optionally blended with the remaining compound such as EVA, wax, silane coupling agent, aggregate, rubber chip and / or rubber powder at an appropriate temperature, for example, It can be obtained by mixing at about 150 to 200 ° C. 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 preferable to pre-mix EVA and rubber chips and / or rubber powder, and then mix the remaining compound, so that the rubber can be effectively protected from heat.

Hereinafter, the present invention will be described in more detail with reference to examples.
(Comparative Example 1)
40 parts by weight of straight asphalt (25 ° C. penetration 60 to 80), 50 parts by weight of EVA (EV210ET, manufactured by Mitsui DuPont Polychemical Co., Ltd.), and Fischer-Tropsch wax (FT100, manufactured by Nippon Seiki Co., Ltd.) 10 parts by weight and 0.5 parts by weight of an amino silane coupling agent (KBM603, manufactured by Shin-Etsu Silicone Co., Ltd.) were mixed and stirred at 180 ° C. to prepare an asphalt binder.

  25% by volume of the obtained asphalt-based binder, 55% by volume of rubber powder (particle size 2 to 5 mm), and 20% by volume of mixed dredged sand (particle size 0.01 to 2 mm) as an aggregate are mixed, and a mixer The mixture was put in and stirred at room temperature for 5 minutes. Thereafter, this was filled into a mold and cured for 2 to 3 days to produce a rectangular parallelepiped test body having dimensions of 50 × 50 × 2.5 cm, and used as an elastic pavement material sample of Comparative Example 1.

(Examples 1-3)
Comparative example except that a part of the mixed cinnabar as aggregate was replaced with plastic waste (FRP chips, particle size 10 to 2000 μm) at the ratio shown in Table 1 below (volume ratio to the entire elastic paving material). In the same manner as in Example 1, elastic paving material samples of Examples 1 to 3 were produced.

(DFT measurement)
For each of the obtained samples, the sliding tester (accelerated wear tester) shown in FIG. 1 (manufactured by Nakajima Technical Sales, loading load 50 kg, tire 11: tire for small truck, rotation speed of table 10: 17 rpm (free), tire 11 was worn using a dynamic friction tester (DFT), and a wet resistance μ was measured. In the illustrated testing machine, the sample 1 is placed on a disk-shaped table 10 and the tire 11 is rotated in a fixed position while a load of 50 kg is applied via the arm 12 that fixes the tire 11. The table 10 is rotated to wear a position having a radius of 15 cm on the sample 1 as a measurement position by DFT. Table 1 below shows the results of DFT measurement performed under each condition of the table rotation speed of 1, 500, 1000, and 2000.

  As shown in Table 1 above, in the elastic pavement materials of Examples 1 to 3 in which the predetermined ratio of the aggregate is replaced by FRP from conventional cinnabar sand, the wear pavement surface after the slip test is also good. It was confirmed that wet μ was secured. In contrast, in Comparative Example 1 in which only the cinnabar sand is used as the aggregate, the initial wet μ is high, but it can be seen that the wet μ is greatly reduced with wear.

It is the schematic which shows the accelerated abrasion tester used in the Example.

Explanation of symbols

1 Elastic pavement material sample 10 Table 11 Tire 12 Arm

Claims (6)

In an elastic pavement material containing an asphalt binder, rubber chips and / or rubber powder, and aggregates,
The elastic pavement material characterized in that the aggregate contains plastic waste material, and the proportion of the plastic waste material in the elastic pavement material is in the range of 3 vol% to 15 vol%.   The elastic pavement material according to claim 1, wherein the plastic waste material is made of fiber reinforced plastic.   The elastic pavement material according to claim 1 or 2, wherein the asphalt binder contains asphalt and an ethylene vinyl acetate copolymer.   The elastic pavement material according to claim 3, wherein the asphalt binder further contains a wax.   The elastic pavement material according to claim 3 or 4, wherein the asphalt binder further contains a silane coupling agent.   The elastic pavement material according to any one of claims 1 to 5, wherein a ratio of the plastic waste material in the elastic pavement material is in a range of 5 vol% to 10 vol%.

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