JP2004100208A - Elastic paving material, and production method and quality evaluation method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an elastic paving material for the goal to a characteristic figure defined according to a practicality when preparing the elastic paving material, the elastic paving material having the characteristic figure and excellent in a low noise property and nonslip property, and a quality evaluation method for the elastic paving material. <P>SOLUTION: In the elastic paving material composed of a soft aggregate and a hard aggregate combined together, a sound pressure level measured from the front face of a tire when the tire is dropped from the vertical upper level of the elastic paving material is defined as A, and a sound pressure level measured from the front face of the tire when the tire is dropped from the vertical upper level of a dense graded asphalt is defined as B. In this time, a parameter obtained from the formula: (B-A)/B is at least 0.030 and a wet friction coefficient is made to be at least 0.45. By using an elastic paving material having the above characteristic figures, an elastic pavement road practically having a noise-resistant, nonslip, and good traveling propertry can be work-executed. <P>COPYRIGHT: (C)2004,JPO

Description

【００４４】
表１の結果に示されるように、音圧比（Ｂ−Ａ）／Ｂが０．０３０以上であり、かつ濡れ摩擦係数が０．４５以上である弾性舗装材（実施例１および２）は、実車試験による走行性および耐騒音性に優れている。これに対して、比較例１の舗装材は、音圧比（Ｂ−Ａ）／Ｂが０．０３０に達していないことから耐騒音性に問題があり、また比較例２の舗装材は濡れ摩擦係数が０．４５に達していないことから走行性に問題があり、いずれの舗装材も弾性舗装材として適当ではなかった。比較例３の舗装材もまた、音圧比（Ｂ−Ａ）／Ｂが０．０１７を示し、耐騒音性に問題を有していた。比較例４は、通常のアスファルト舗装であるが、音圧比（Ｂ−Ａ）／Ｂは０であり、騒音が高いことを示している。
【００４５】
なお、表１の結果から、実車騒音レベル（ｄＢ）と音圧比（Ｂ−Ａ）／Ｂとの関係をグラフで表すと、図２のとおり、両測定値には直線関係があり、高い相関関係を有する。すなわち、音圧比（Ｂ−Ａ）／Ｂが騒音レベルを評価するためのパラメータとして適当であることを示すものである。
【００４６】
【発明の効果】
上述のように、音圧比（Ｂ−Ａ）／Ｂが０．０３０以上であり、かつ濡れ摩擦係数が０．４５以上である弾性舗装材は、耐騒音性と走行性に優れており、車両走行用道路の舗装材として実用上、きわめて有利に使用できる。当該弾性舗装材で施工した道路は、濡れたときの滑り、目詰まり、あるいは道路の剥離損傷による耐久性などが改良されたものとなる。また、音圧比（Ｂ−Ａ）／Ｂは、騒音レベルを評価するために適しており、濡れ摩擦係数と共に、低騒音性で滑りにくい性能を有する弾性舗装材を試作するに際して、簡便なパラメータとして採用できる。
【図面の簡単な説明】
【図１】弾性舗装材の耐騒音性を測定するための装置を示す。
【図２】実車騒音レベル（ｄＢ）と、図１の騒音性測定装置を用いて測定した音圧比（Ｂ−Ａ）／Ｂとの関係を示すグラフである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an elastic pavement material, a method for producing the same and a method for evaluating the quality thereof, and more particularly, to the construction of an elastic pavement road in which the performance of reducing noise and preventing slippage when wet with water is balanced for roadways. A suitable elastic pavement.
[0002]
[Prior art]
The elastic pavement material is a pavement material obtained by binding an aggregate including a soft aggregate with a binder, and is a porous structure having a void inside the pavement material as a general structure. It is known that this void depends on the aggregate and binder used, and also varies depending on the method of construction and temperature conditions. The characteristic of the physical property of the elastic pavement material is that the elasticity is exhibited due to the material used (particularly, soft aggregate), so that a good walking feeling and high safety can be obtained. Further, since it is porous, it has a drainage property even when used for outdoor pavement, and has a feature that water hardly accumulates.
[0003]
Because of these features, elastic pavement materials have been widely used for various exercise facilities, sidewalks, and various pavements requiring elasticity. In addition, as a result of various research in recent years, the elasticity and porosity have reduced the noise when the vehicle is running, and the study as a pavement for roadway has begun, and at the stage of taking a step toward practical use. is there.
The pavement made of an elastic pavement material is expected to have a noise reduction effect of 10 dB (decibel) or more at a normal traveling speed (20 to 80 km / h) of a vehicle as compared with a normal asphalt pavement road surface. However, among roads nationwide, only 30% of roads (so-called human-friendly roads) have achieved an environmental standard with a noise level of up to 65 dB due to various measures. At present, noise reduction of about 5 dB is realized by drainage pavement and its improved type as compared with ordinary asphalt pavement, but this can only solve about 60% of the environmental standard. Moreover, it is known that the noise reduction effect is weakened due to clogging of the pavement or the like in such a method, and it can be said that it is completely insufficient as an actual countermeasure.
[0004]
It is said that the elastic pavement material can reduce noise by 10 dB or more as described above, and if the noise reduction is realized as such, the achievement rate of the environmental standard is 90% or more.
On the other hand, pavement made of elastic pavement material can reduce noise, but on the other hand, it is extremely slippery when the pavement becomes wet due to rain etc. because elastic materials such as crushed rubber and polyurethane are used as soft aggregates. (Slippage when wet), and a safety problem occurs. Further, in order to improve the slippage when wet, it is necessary to appropriately fill the hard aggregate, but there is a problem with the balance with the noise reduction effect.
[0005]
As conventional elastic pavement materials, for example, those described in the following Patent Documents 1 to 4 are known.
As a roadway elastic pavement material, an elastic pavement material obtained by mixing a granular low-hardness elastic aggregate having a difference in hardness of 10 or more and a granular organic high-hardness aggregate and binding with a resin binder is used. Is set to be effective for improving slip resistance, strength, and water permeability (Patent Document 1). Further, a water-permeable elastic pavement material in which an aggregate made of a vulcanized rubber chip is bonded with a urethane resin binder, the entire surface is polished so that the aggregate is exposed on the surface, and the porosity is 20 to 40% Is reported to be excellent in frictional force at the time of moistening (Patent Document 2).
[0006]
On the other hand, as a water-permeable elastic pavement method, when preparing a resin mortar using hard granular aggregate and soft elastic aggregate, it is known that the volume ratio of soft elastic aggregate is 25 to 75% (Patent) Reference 3). Further, in a pavement material formed by combining a hard material and a soft material with a binder resin, by mixing a large diameter (10 to 5 mm) and a small diameter (5 to 2.5 mm) as the hard aggregate, the adhesive strength is improved. It has been proposed to improve it (Patent Document 4). A porous elastic pavement comprising a vulcanized rubber chip, comprising an elastic pavement having a first layer having a high hardness as a road surface and a second layer having a low hardness under the first layer and having a porosity of 30 to 40%; It is known to evaluate pavement with wet skid performance, sound absorption performance, and the like (Patent Document 5).
[0007]
[Patent Document 1]
JP-A-2000-248503 (Claims 1 to 5, paragraph 0024, FIG. 1)
[Patent Document 2]
JP-A-2000-273809 (Claim 1, Example, Paragraph 0035)
[Patent Document 3]
JP-A-63-7404 (claims 1 and 2, lower right column of page 2, lower left column of page 4)
[Patent Document 4]
JP-A-8-165606 (Claim 1, paragraphs 0005 to 0008)
[Patent Document 5]
JP-A-2000-319808 (Claims, paragraphs 0073 to 0074)
[0008]
[Problems to be solved by the invention]
As described above, elastic pavement materials for various roadways have been proposed so far, but basically what kind of characteristics are provided when viewed from the viewpoint of noise resistance and slip resistance. There has not been enough research to see if it is practically satisfactory. In other words, since it is not yet well understood what quality standard should be set for the elastic pavement material, production by trial and error is required. Conventionally, it has been considered to increase the amount of elastic material and increase the porosity in order to realize a low noise elastic pavement that meets environmental standards. The problem is the lack of durability due to slippage, clogging, or road peeling damage.
[0009]
Therefore, an object of the present invention is to determine an evaluation characteristic value suitable for practical use in producing an elastic pavement material, and to have a method of manufacturing an elastic pavement material with the characteristic value as a target, and to have the characteristic value, An object of the present invention is to provide an elastic pavement material excellent in low noise and anti-slip properties, and a quality evaluation method for the elastic pavement material.
[0010]
[Means for Solving the Problems]
The present inventors have made various studies in view of the above problems, and found that elastic pavement materials differing in noise reduction performance and wet slipperiness depending on the method of mixing, etc., even when the same pavement material is used. Was obtained. For such an elastic pavement material, the noise resistance and the slip resistance were evaluated by an actual vehicle test, and both the sound pressure level and the wet friction coefficient were adopted as measured values related to the evaluation. An appropriate reference value was identified. Furthermore, when an elastic pavement material was produced with the target of those characteristic values, a practically satisfactory elastic pavement material was successfully obtained, and the present invention was completed.
[0011]
That is, the present invention relates to the following elastic pavement, a method for producing the same, and a method for evaluating the quality of the elastic pavement.
1) In an elastic pavement obtained by combining at least a soft aggregate and a hard aggregate, the sound pressure level measured from the front of the tire when the tire is dropped vertically above the elastic pavement is A decibels, When the sound pressure level measured from the front of the tire when the tire is dropped vertically above the asphalt is B decibels, the parameter value obtained by the formula: (BA) / B is 0.030 or more;
An elastic pavement material having a coefficient of wet friction of 0.45 or more.
[0012]
2) The elastic pavement as described in 1) above, wherein the porosity of the pavement is 50% or less and the thickness is 5 to 40 mm.
3) A method of manufacturing an elastic pavement material in which 100 parts by weight of soft aggregate and 2 to 50 parts by weight of hard aggregate are combined with a binder having a weight of 1/3 to 1/10 of the weight of the aggregate. Having a step of mixing the binder in a plurality of times,
The mixing step includes: (1) a step of adding approximately half of the amount of the binder to the soft aggregate and mixing the mixture; (2) a half or less of the hard aggregate and a remaining amount after the step (1). And (3) additionally mixing the remaining amount of the hard aggregate with the remaining amount of the binder after the step (2) once or a plurality of times. From the elastic pavement material formed by adjusting the rolling pressure of the mixture,
The sound pressure level measured from the front of the tire when the tire was dropped vertically above the elastic pavement was A decibel, and the sound pressure level measured from the front of the tire when the tire was dropped vertically above the dense asphalt Is defined as B decibels, a parameter value obtained by the formula: (BA) / B is 0.030 or more, and a wet friction coefficient is 0.45 or more. Manufacturing method of elastic pavement material.
[0013]
4) The method for producing an elastic pavement material according to the above item 3), wherein the step of subdividing and additionally mixing the hard aggregate is performed three or more times.
5) The method for producing an elastic pavement material according to the above item 3), wherein the additional amount of the hard aggregate and the binder is approximately half the additional amount in the previous step, and the total number of additions is 4 with the number of additions being four.
6) The method for producing an elastic pavement according to 3) above, wherein the porosity of the pavement is adjusted to 50% or less and the thickness is adjusted to 5 to 40 mm.
[0014]
7) In an elastic pavement obtained by combining at least a soft aggregate and a hard aggregate, the sound pressure level measured from the front of the tire when the tire is dropped vertically above the elastic pavement is A decibels, When the sound pressure level measured from the front of the tire when the tire is dropped vertically above the asphalt is B decibels, the parameter value obtained by the formula: (BA) / B is 0.030 or more;
A quality evaluation method for an elastic pavement material, comprising selecting an elastic pavement material having a wet friction coefficient of 0.45 or more.
The elastic pavement material according to the present invention can be particularly advantageously used as a pavement material for a vehicle traveling road because of its excellent noise resistance and running property. However, it can be used for various exercise facilities, sidewalks, and various pavements requiring elasticity. Is also available.
The elastic pavement material is characterized in that the parameter value obtained by the above formula: (BA) / B is 0.030 or more, and the wet friction coefficient is 0.45 or more. In order for the parameter value to be large, the sound pressure level A needs to be small. From a correlation with an actual vehicle test, when this parameter value is 0.030 or more, it is practically a low noise level. means. This parameter value is more preferably 0.045 or more, but the upper limit is usually 0.1, and even if it is higher than this value, there is no significant difference from the viewpoint of practically reducing noise.
On the other hand, by setting the wet friction coefficient to 0.45 or more, the slip resistance, which is important as the performance of the elastic pavement material, is improved, and as a result, the running performance in terms of safety is improved. The slip resistance is better if the wet friction coefficient is 0.45 or more, and the larger the value is, the better it is 0.5 or more. However, from the viewpoint of durability, the value is 0.9 or less. It is desirable.
[0015]
The elastic pavement material of the present invention has a porosity of usually 50% or less, preferably 30 to 50%, more preferably 40 to 45%, and a thickness of 5 to 40 mm when paving. It is preferably adjusted to 15 to 25 mm from the viewpoint of cost.
The elastic pavement material according to the above item 1) has various parameters in production such that the parameter value obtained by the formula: (BA) / B is 0.030 or more and the wet friction coefficient is 0.45 or more. It is manufactured by selecting factors (soft aggregate, hard aggregate, binder type, blending ratio, blending method, etc.). As one of them, as described in the above items 3) to 6), a soft aggregate, a hard material and a binder are mixed at a specific mixing ratio and are prepared from pavement materials prepared by mixing them in plural times. It can be manufactured by selecting those satisfying the above two characteristic values.
[0016]
According to this manufacturing method, when a new soft aggregate, a hard aggregate or a binder is to be used, a quality target value is set, so that the quality change according to the compounding amount and the method of mixing can be easily performed. Therefore, it is not necessary to actually construct and evaluate the pavement, and the prototype work and the like can proceed very efficiently in terms of time and cost.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described in detail.
[Measurement of (BA) / B value and wet friction coefficient]
The (BA) / B value and the wet friction coefficient in the present invention are measured by the following methods.
Measurement of (BA) / B value This parameter value is measured by the following method using the measuring device of FIG.
[0018]
That is, a test specimen (50 cm × 50 cm × 5 cm thick) is placed on a nonwoven fabric laid on concrete in an anechoic chamber, and a tire (Public Works tire, non-directional rim) is placed vertically above (height: 650 mm). , 170 KPa), and the contact sound pressure at that time is recorded by a microphone (at a distance of 800 mm from the test object and at a height of 500 mm above the substrate at a distance of 800 mm from the test piece). When the sound pressure level when the test piece is an elastic pavement material is A decibel and the sound pressure level when the test piece is dense asphalt is B decibel, the sound pressure level is obtained by the formula: (BA) / B. The parameter value indicates the noise resistance of the elastic pavement material.
[0019]
This parameter value has a high correlation with the noise level in the actual vehicle test (see FIG. 2), and the larger this value is, the smaller the noise property of the elastic pavement material is. The elastic pavement material of the present invention is required to have this value of 0.030 or more, which ensures a low noise level in practical use.
・ Measurement of wet friction coefficient According to a known measurement method using a dynamic friction tester (DF tester), it is confirmed that a water film is formed on the test piece slowly by spraying water thereon, and the linear velocity of the tire rubber piece is increased to 90 km / h. While raising, the dynamic coefficient of friction (μ) is measured. The elastic pavement material of the present invention requires that the coefficient of wet friction when the linear velocity of the tire rubber piece is 60 km / h is 0.45 or more in this measurement method, whereby the running property from the safety aspect is good. Is guaranteed. The greater the wet friction coefficient, the higher the safety in running. On the other hand, the wear on the pavement surface increases, and the durability deteriorates. Therefore, it is usually preferably 0.9 or less.
[0020]
[material]
The soft aggregate elastic pavement material must include a soft aggregate material, which imparts elasticity to the pavement surface and has a low noise effect. Examples of the soft aggregate that can be selected in the present invention include various elastomers, and particularly, rubber and urethane foam can be used.
The rubber material may be either natural rubber or synthetic rubber, and may be a single rubber or a mixed rubber. Examples of the synthetic rubber include SBR, NBR, EPDM, BR and CR. Further, a rubber mixture of the above-mentioned rubber-containing material, for example, the above-mentioned rubber-coated material or the above-mentioned rubber-coated material can also be used. The soft material may be a newly manufactured soft material, but by using recycled rubber such as waste rubber or waste rubber, effective use of resources and cost reduction can be achieved.
[0021]
The shape of the soft aggregate is not particularly limited, such as a granular shape, an irregular mass, and a sword-like shape. Among them, the sword-like rubber is particularly advantageously used because the porosity can be easily adjusted to a predetermined value. In the case of a pulverized product, it is preferable that the cut surface has fluff.
Hard Aggregates Hard materials that can be selected in the present invention include natural stones, wood chips, walnuts, bamboo chips, shells, silica sand, artificial stones, slag, ceramic particles, and hard plastics. In particular, (1) a material having a very high microhardness, that is, a material having a Mohs hardness of 8 or more, preferably 10 or more, and (2) a material having a regular crystal lattice, for example, a ceramic material, is artificially manufactured. Ceramics are advantageously used.
[0022]
Due to the high hardness of the material (1), even when a high load is applied, the material itself does not deform and exhibits a strong frictional effect, and can increase resistance to a contacted object. In addition, the material (2) tends to break along the crystal lattice when worn, so that the effect of reducing the "slip when wet" when an elastic pavement material is formed is maintained. This is advantageous in that the water film is broken by the edge effect and a similar reduction effect can be expected.
[0023]
Further, when the materials (1) and (2) are used together, the synergistic effect not only reduces the slippage when wet from the beginning of use, but also has excellent abrasion resistance and causes fracture along the crystal lattice plane, Slip prevention when wet can be maintained for a long time.
As the ceramic material, a material belonging to an abrasive or an abrasive is used, and an artificial product is preferable from the viewpoint of uniformity and cost. The feature of this material lies in the regularity of the crystal lattice.
[0024]
The elastic pavement material including the hard aggregate of the above (1) and (2) facilitates leveling work, compaction work, and stirring work in pavement work. Work becomes extremely easy.
When the hardness of hard aggregate is represented by (new) Mohs hardness, which is a representative value of scratch hardness, it is generally desired that the hardness be 8 or more (for example, Verilia, titania, zirconia, mullite, spinel, It is more preferable that the hardness is 10 or more (for example, alumina, chromium oxide, silicon carbide, some titanium carbide, and silicon nitride). In particular, materials that are industrially used as artificial abrasives can be advantageously used in terms of cost and performance, but examples thereof include brown alumina, white alumina, pink alumina, crushed alumina, artificial emery, alumina zirconia, Black silicon carbide, green silicon carbide and the like. Any one of the hard aggregates may be used, or two or more hard aggregates may be used in combination.
[0025]
The particle size of the hard material can be appropriately selected in consideration of the purpose of use and the like. For example, by setting the thickness to 500 μm or less, the formation of the microtexture is facilitated and the resistance is increased, and by setting the thickness to 300 μm or less, the exposed surface area of the hard aggregate increases, and the effect of addition such as slip prevention is reduced. Become noticeable.
Binder The binder that can be selected in the present invention mainly includes a resin-based binder as in the related art. Examples include polyurethane resin, epoxy resin, acrylic resin, polyester resin, methacrylic resin, acrylic emulsion, asphalt emulsion, and the like. Among these, a curable resin material or a soft thermoplastic polymer which is soft and has excellent weather resistance and water resistance is preferably used. In particular, when various properties such as adhesion and workability are taken into consideration, a one-component moisture-curable polyurethane is most preferable. For example, a relatively high tensile strength of 10 MPa or more increases the friction coefficient when wet. It can be used advantageously.
[0026]
Others In addition to the soft aggregate, the hard aggregate and the binder, the elastic pavement of the present invention may optionally contain other materials and additives, if necessary, such as a pigment and a weathering stabilizer. , Antioxidants, extenders, oils, plasticizers, catalysts (organic or inorganic compound catalysts, metal catalysts) and the like.
[Blending ratio and manufacturing method]
The elastic pavement material of the present invention is an elastic pavement material obtained by combining at least a material containing a soft aggregate and a hard aggregate, and the parameter value obtained by the above formula: (BA) / B is 0.030. And a wet friction coefficient of 0.45 or more. In the production of the elastic pavement material, the types and the proportions of the soft aggregate, the hard aggregate and the binder are determined so as to have the above-mentioned characteristics.
[0027]
Therefore, as described above, the ratio of the hard aggregate is 2 to 50 parts by weight with respect to 100 parts by weight of the soft aggregate, and the binder is in the range of 1/3 to 1/10 of the weight of the aggregate. , Select the blending ratio. The hard material, when present in the vicinity of the surface layer of the elastic pavement, tends to exhibit the effect of its addition. However, the effect starts to appear when the content is 2 parts by weight or more with respect to 100 parts by weight of the soft material, and the effect starts when the content is 4 parts by weight or more. When the amount is more than 10 parts by weight, by covering the exposed portion of the soft aggregate, the slip when wet is further reduced. On the other hand, if it exceeds 50 parts by weight, the function of low noise as an elastic pavement decreases.
[0028]
The mixing ratio of the soft aggregate, the hard aggregate, and the binder is finally set to the above ratio, but in the step of preparing the elastic pavement material, the hard aggregate and the binder are mixed in plural times. This mixing step includes: (1) a step of adding a binder to the soft aggregate by adding approximately half of the above amount, and mixing; (2) a half or less of the hard aggregate and a residual amount after the (1) step. A step of additionally mixing less than half the amount of the binder; and (3) a step of additionally mixing the remaining amount of the hard aggregate and the remaining amount of the binder after the step (2) once or a plurality of times. I do.
[0029]
The final mixture thus obtained is compacted and adjusted to a porosity of usually not more than 50%, and a test for measuring the parameter values and the wet friction coefficient determined by the above formula: (BA) / B is performed. The body is molded and a pavement material having a characteristic value of 0.030 or more and 0.45 or more is selected.
[Construction method of pavement]
The elastic pavement material of the present invention is mainly used for construction of a low-noise, non-slip pavement on a pavement for running a vehicle. As the construction method, (1) a method of directly laying a mixture of a soft aggregate and a hard aggregate with a binder on a foundation (base), and rolling and then hardening; (2) a block body once In principle, any method of laying the elastic pavement material formed on the base material on the base material can be adopted.
[0030]
In the block body in the above (2), it is preferable that one piece is 30 cm or more, and it is more preferable that one piece is 50 cm or more in consideration of productivity, while it is preferable that the piece is smaller than 200 cm square in consideration of workability. A groove-shaped pattern or the like may be formed on the block body. Of the above two construction methods, the method (1), that is, on-site construction, is often more desirable. The reason is that it is easy to cope with construction such as unevenness, inclination, and curve of the base.
[0031]
For the formation of the groundwork, an intermediate layer made of asphalt or concrete is provided on a crushed stone layer in which crushed stones are spread to a specified thickness, the surface is leveled sufficiently, the levelness is increased, and the primer is treated. I do. Next, the elastic pavement material according to the present invention is laid, rolled, and then cured to perform elastic pavement. In this case, in the blending / mixing process, the same small blending is performed as when the elastic pavement material is selected.
[0032]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
In the production of the following elastic pavement material, the following soft aggregate, hard aggregate and binder were used.
<Soft aggregate>
Rubber chip (1): EPDM and SBR blended rubber chip ("3KA" manufactured by Sumitomo Rubber Industries, average particle size 3 mm or less)
Rubber chip (2): blended rubber chip of EPDM and SBR (“1KA” average particle size of 3 to 5 mm manufactured by Sumitomo Rubber Industries)
Rubber chip (3): "Hijiki rubber FR24" manufactured by Sumitomo Rubber Industries
<Hard aggregate>
(1) Silica: "Silica Sand No. 7" manufactured by Sumitomo Rubber Industries
(2) Alumina abrasive: "C60" manufactured by Riken Corundum
<Binder>
MDI one-component curable urethane resin (“Grip coat GB0007” manufactured by Sumitomo Rubber Industries)
Example 1
An elastic pavement material obtained by combining 100 parts by weight of a rubber chip (3) as a soft aggregate and 32 parts by weight of "Silica Sand No. 7" as a hard aggregate with 32 parts by weight of a binder "GB0007" is produced by the following process. did.
[0033]
[1] 100 parts by weight (total amount) of rubber chips (2) were put into a universal stirring tree, and a half of the above-mentioned binder (16 parts by weight) was mixed therein while being put into it to obtain a uniform mixture.
[2] To this, １ ／ of the hard aggregate “silica sand” (16 parts by weight) is added, and 量 of the remaining binder (5 parts by weight) is added and mixed well to obtain a uniform mixture. And
[0034]
[3] To the mixture obtained in the above [2], 残 量 amount of the remaining hard aggregate “silica sand” (8 parts by weight) and 残 量 amount of the remaining binder (2.5 parts by weight). Add and mix well.
[4] To the mixture obtained in the above [3], 8 parts by weight of the remaining hard aggregate “silica sand” was added in two portions, and 2.5 parts by weight of the remaining binder was added and mixed well. .
[5] The above mixture was rolled to adjust the porosity to 40.5% to obtain an elastic pavement material.
[0035]
A 50 cm × 50 cm × 5 cm (thickness) shape of this paving material was used as a test piece.
Example 2
An elastic pavement material obtained by combining 100 parts by weight of a rubber chip (3) as a soft aggregate and 20 parts by weight of “alumina abrasive” as a hard aggregate with 27 parts by weight of a binder “GB0007” is the same as in Example 1. In the compounding step, an elastic pavement material having a porosity of 48% was obtained in a work procedure in which each material was divided and added. A 50 cm × 50 cm × 5 cm (thickness) shape of this paving material was used as a test piece.
[0036]
Comparative Example 1
100 parts by weight of a rubber chip (1) as a soft aggregate, 24 parts by weight of a binder “GB0007”, and 50 parts by weight of a “silica sand” as a hard aggregate are put into a universal stirring tree once in this order, and are thoroughly stirred and uniformly mixed. After preparing such a mixture, it was rolled and adjusted to a porosity of 35% to obtain an elastic pavement material. A 50 cm × 50 cm × 5 cm (thickness) shape of the paving material was used as a test piece.
[0037]
Comparative Example 2
100 parts by weight of a rubber chip (2) as a soft aggregate, 24 parts by weight of a binder "GB0007", and 32 parts by weight of a "silica sand" as a hard aggregate are put into a universal stirring tree all at once in this order. After preparing such a mixture, it was rolled and adjusted to a porosity of 35% to obtain an elastic pavement material. A 50 cm × 50 cm × 5 cm (thickness) shape of the paving material was used as a test piece.
[0038]
Comparative Example 3
100 parts by weight of a rubber chip (1) as a soft aggregate, 27 parts by weight of a binder "GB0007", and 95 parts by weight of alumina abrasive grains as a hard aggregate are put into a universal stirring tree all at once in this order. After preparing the mixture, it was rolled and adjusted to a porosity of 18% to obtain an elastic pavement material. A 50 cm × 50 cm × 5 cm (thickness) shape of the paving material was used as a test piece.
[0039]
Comparative Example 4
Dense asphalt (ISO road surface) was used for sound pressure level B measurement.
Evaluation test <Sound pressure ratio and wet friction coefficient measurement>
On-site construction was performed using the elastic pavement material having a shape of 50 cm × 50 cm × 5 cm (thickness) obtained in the above Examples and Comparative Examples, and after curing for one week, a uniform surface layer was obtained. With respect to this elastic pavement material, the parameter value (sound pressure ratio) and the wet friction coefficient (μ) of the equation: (BA) / B were measured by the methods described above. The wet friction coefficient was represented by a value when the linear velocity of the tire rubber piece was 60 km / h. Table 1 shows the measurement results.
[0040]
<Real vehicle test>
Using the elastic pavement material obtained in the above Examples and Comparative Examples, a paved road surface having a width of 3.6 m, a thickness of 3 cm, and a length of 50 m was produced, and an actual vehicle (Toyota Corolla vehicle, rim 4.53, tires were civil engineering) The running performance and the noise performance were evaluated by a feeling test using a standard longitudinal groove rib tire at an air pressure of 170 KPa). Table 1 shows the results.
-Drivability The professional driver ran on a motorcycle and evaluated the safety during braking and handling according to the following criteria.
[0041]
：: Safe as on asphalt road surface.
○: There is no safety problem during running.
Δ: Anxiety remains during running.
×: Danger is felt.
・ Noise-resistance The coasting noise (running off the engine and passing the road surface at a constant speed) when driving a four-wheeled vehicle is heard 7.5 m away from the microphone at a height of 1.2 m. Was evaluated.
[0042]
A: Anyway, it is quiet.
○: It is much quieter than asphalt road surface.
Δ: Quiet compared to asphalt road surface.
×: There is almost the same noise as the asphalt road surface.
[0043]
[Table 1]

[0044]
As shown in the results in Table 1, the elastic pavement material having a sound pressure ratio (BA) / B of 0.030 or more and a wet friction coefficient of 0.45 or more (Examples 1 and 2) Excellent runnability and noise resistance in actual vehicle tests. On the other hand, the pavement material of Comparative Example 1 has a problem in noise resistance because the sound pressure ratio (BA) / B does not reach 0.030, and the pavement material of Comparative Example 2 has wet friction. Since the coefficient did not reach 0.45, there was a problem in running properties, and none of the pavement materials was suitable as an elastic pavement material. The pavement material of Comparative Example 3 also had a sound pressure ratio (BA) / B of 0.017, and had a problem in noise resistance. Comparative Example 4 is a normal asphalt pavement, but the sound pressure ratio (B−A) / B is 0, indicating that the noise is high.
[0045]
From the results in Table 1, when the relationship between the actual vehicle noise level (dB) and the sound pressure ratio (BA) / B is represented by a graph, as shown in FIG. Have a relationship. That is, it indicates that the sound pressure ratio (BA) / B is appropriate as a parameter for evaluating the noise level.
[0046]
【The invention's effect】
As described above, an elastic pavement material having a sound pressure ratio (BA) / B of 0.030 or more and a wet friction coefficient of 0.45 or more has excellent noise resistance and running properties, It can be used very effectively in practical use as a paving material for running roads. The road constructed with the elastic pavement material has improved durability due to slippage when wet, clogging, or peeling damage of the road. Further, the sound pressure ratio (BA) / B is suitable for evaluating the noise level, and is a simple parameter when a trial production of an elastic pavement material having low noise and non-slip performance together with a wet friction coefficient is performed. Can be adopted.
[Brief description of the drawings]
FIG. 1 shows an apparatus for measuring the noise resistance of an elastic pavement.
FIG. 2 is a graph showing a relationship between an actual vehicle noise level (dB) and a sound pressure ratio (BA) / B measured using the noise measurement device of FIG.

Claims (7)

In an elastic pavement material combining at least soft aggregate and hard aggregate,
The sound pressure level measured from the front of the tire when the tire was dropped vertically above the elastic pavement was A decibel, and the sound pressure level measured from the front of the tire when the tire was dropped vertically above the dense asphalt Is B decibels, the parameter value obtained by the formula: (BA) / B is 0.030 or more,
An elastic pavement material having a coefficient of wet friction of 0.45 or more. The elastic pavement material according to claim 1, wherein the porosity of the pavement material is 50% or less and the thickness is 5 to 40 mm. In a method for manufacturing an elastic pavement material in which 100 parts by weight of soft aggregate and 2 to 50 parts by weight of hard aggregate are combined with a binder of 1/3 to 1/10 of the weight of the aggregate, the hard aggregate and the binder are combined. Having a step of mixing in a plurality of times,
The mixing step includes: (1) a step of adding approximately half of the amount of the binder to the soft aggregate and mixing the mixture; (2) a half or less of the hard aggregate and a remaining amount after the step (1). And (3) additionally mixing the remaining amount of the hard aggregate with the remaining amount of the binder after the step (2) once or a plurality of times. From the elastic pavement material formed by adjusting the rolling pressure of the mixture,
The sound pressure level measured from the front of the tire when the tire was dropped vertically above the elastic pavement was A decibel, and the sound pressure level measured from the front of the tire when the tire was dropped vertically above the dense asphalt Is defined as B decibels, a parameter value obtained by the formula: (BA) / B is 0.030 or more, and a wet friction coefficient is 0.45 or more. Manufacturing method of elastic pavement material. 4. The method for producing an elastic pavement material according to claim 3, wherein the step of subdividing and additionally mixing the hard aggregate is performed three times or more. 4. The method for manufacturing an elastic pavement material according to claim 3, wherein the additional amount of the hard aggregate and the binder is approximately half the additional amount in the previous step, and the total number of additions is four. The method for producing an elastic pavement material according to claim 3, wherein the porosity of the pavement material is adjusted to 50% or less and the thickness is adjusted to 5 to 40 mm. In an elastic pavement material combining at least soft aggregate and hard aggregate,
The sound pressure level measured from the front of the tire when the tire was dropped vertically above the elastic pavement was A decibel, and the sound pressure level measured from the front of the tire when the tire was dropped vertically above the dense asphalt Is B decibels, the parameter value obtained by the formula: (BA) / B is 0.030 or more,
A quality evaluation method for an elastic pavement material, comprising selecting an elastic pavement material having a wet friction coefficient of 0.45 or more.

Images