JP2005325536A - Asphalt material and asphalt pavement body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an asphalt material which enables a pavement to keep a flowing water speed of a surface higher and keep drainability longer. <P>SOLUTION: This asphalt material contains asphalt and a water repellent polymer with a mass equivalent to 5-40% of the mass of the asphalt. The water repellent polymer enhances water repellency of a surface of the asphalt material, and the asphalt material is equipped with a surface which allows the easy rolling of the water, that is, a surface which allows the easy and rapid movement of the water. This can bring about the pavement wherein the water flowing speed is kept higher on the surface and an asphalt surface in a void, and wherein the retention of particles is suppressed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an asphalt material and an asphalt pavement mainly applied to road pavement.

  Asphalt pavement on roads, porous pavements have been developed that are effective in reducing noise caused by traveling vehicles and suppressing glare caused by slipping during rainfall and light reflection at night. Such a pavement is formed with a high porosity in the surface layer, and has characteristics such that it easily disperses and absorbs energy that becomes sound, or allows water to pass from the surface toward the lower part. However, there is a problem that the surface layer voids, that is, the gaps, are easily clogged with earth and sand, dust, and the like, and thus the above-described functions, particularly the drainage function, are deteriorated. For this reason, various methods for removing dust, earth and sand that have entered the gaps in the pavement have been disclosed. For example, a method of supplying a foaming solution such as hydrogen peroxide water to drainage pavement and floating and collecting particles clogged by foaming (see, for example, Patent Document 1) or high-pressure water from the pavement surface. A method of ejecting particles in a pavement gap by spraying from below in directions intersecting each other downward (for example, see Patent Document 2), and a method of piercing a pavement surface of a steel material into a pavement surface to dig up particles and suck them together with air (For example, refer to Patent Document 3) In addition, there is a method of supplying water to the pavement and causing ultrasonic vibration to recover the clogged state of the particles and sucking it up with water (for example, refer to Patent Document 4). . However, these have to use chemicals and special equipment, and have to work every predetermined period, so the burden required for pavement maintenance is large. On the other hand, as another method for preventing clogging in drainage asphalt pavement, the gap between the drainage asphalt pavement surfaces includes an aggregate that is specified in a predetermined range in which the particle size of the aggregate is relatively small, and a resin. A method of filling a mixture to prevent particles from entering the voids (see, for example, Patent Document 5) is disclosed.

JP-A-6-33428 JP-A-8-165622 JP-A-6-81325 Japanese Patent Laid-Open No. 9-177022 Japanese Patent Laid-Open No. 11-293614

  However, if the space on the asphalt pavement surface is reduced by the filler, the water permeability, particularly the water flow rate, is reduced, and drainage may take time. In addition, the durability of the filler is likely to be smaller than that of asphalt pavement and may have to be refilled. In this case, however, the time required to occupy the road becomes longer compared to the above other removal methods. there is a possibility.

Therefore, an object of the present invention is to provide an asphalt material capable of forming a pavement in which the surface water velocity is maintained higher and the drainage performance is maintained longer.
In addition, another object of the present invention is to provide an asphalt pavement in which the surface water flow rate is maintained higher and the drainage performance is maintained longer.

As means for solving the above-mentioned problems, the first invention of the present invention provides an asphalt material containing asphalt and a water-repellent polymer that is 5% or more and 40% or less based on the mass of the asphalt.
According to the present invention, the asphalt material has a surface having high water repellency due to the water repellent polymer, and has a surface on which water easily rolls, that is, a surface on which water readily moves. Therefore, the flow velocity of the water flowing on the surface of the asphalt material is maintained fast, and as a result, the particles are less likely to stay on the surface due to the water force. Therefore, by using this asphalt material as an asphalt component in the drainage pavement, it is possible to obtain a pavement in which a faster water flow rate is maintained on the surface and the asphalt surface in the voids and particle retention is suppressed.

The second invention provides an asphalt material in which the water-repellent polymer in the first invention is silicone resin or silicone oil.
Silicone resin and silicone oil have good heat resistance, so, for example, using a conventional pavement method involving heating such as melting and mixing aggregates into asphalt, the surface water flow rate is higher, and particles on the surface Asphalt pavement can be obtained in which the retention of is suppressed.
A third invention provides an asphalt material further comprising an aggregate having an open particle size distribution in the first or second invention.
By using the asphalt material according to the present invention as a constituent material of asphalt pavement, it is possible to form an open grained pavement having a large porosity. Therefore, it is possible to construct an asphalt layer in which the cross-sectional area of the water flow path is large and the flow rate of the water is high, so that the drainage is good and the retention of particles is well suppressed and the drainage is maintained longer.

The fourth invention is prepared as an emulsion having water or an organic solvent as a dispersion medium and asphalt as a dispersoid. % Of asphalt material to be contained is provided.
Since this asphalt material has low viscosity and good fluidity, it can be easily mixed with other components and processed into solid asphalt by evaporating the dispersion medium. Easy to handle and process.
Moreover, 5th invention provides the asphalt material whose water-repellent polymer is silicon resin or silicon oil in 4th invention.
Silicone resin and silicone oil have good heat resistance, so that they can be used satisfactorily, for example, in the formation of a layer or when a high-temperature material is compacted on an asphalt material.

The sixth invention of the present invention provides an asphalt pavement formed by spreading a mixture containing the asphalt material of the first or second invention and aggregate.
The seventh invention of the present invention provides an asphalt pavement formed by spreading and mixing a mixture containing the evaporation residue of the asphalt material of the fourth or fifth invention and the aggregate.
In these asphalt pavements, water repellency is imparted to the surface of the pavement, and the water flow rate is maintained at a higher speed, so that drainage is quick. In addition, the uneven surface of the pavement surface is also provided with water repellency, and since the flow rate of water is maintained faster in these parts, dust and earth are easily swept away by water and are less likely to stay. . Therefore, the asphalt pavement according to the present invention has good drainage and is maintained for a longer time.
An eighth invention of the present invention provides the asphalt pavement according to the sixth or seventh invention, wherein the aggregate has an open particle size distribution.
According to the present invention, the asphalt layer formed by the mixture has continuous voids through which water can flow, so that the cross-sectional area of the water flow path is larger and water repellency is imparted to the surface. The water flow rate is kept faster. Therefore, the stay of dust, earth and sand that has entered the gap due to the water is suppressed, and the asphalt pavement has good drainage and is maintained for a longer time.
Furthermore, the ninth invention of the present invention provides an asphalt pavement comprising a layer containing an evaporation residue of the asphalt material of the fourth or fifth invention.
According to this invention, the layer containing the evaporation residue of the asphalt material has water repellency and can maintain the flow rate of water at a higher speed. Therefore, the accumulation of water on the upper surface of this layer is suppressed, and the asphalt pavement maintains a good flow rate of water in the asphalt pavement.

  According to the present invention, it is possible to provide an asphalt material capable of forming a pavement in which the surface water flow rate is maintained at a higher level and the drainage performance is maintained longer, and the surface water flow rate is maintained at a higher level and the water discharge performance is maintained. By providing an asphalt pavement that can be maintained for a longer time, it is possible to provide an asphalt pavement that has good drainage over a long period of time and that reduces the burden of maintenance.

The best mode for carrying out the present invention will be described in detail below.
The asphalt material according to the present invention contains asphalt and a water-repellent polymer.

  The asphalt used for the asphalt material is not particularly limited, and known asphalts such as straight asphalt, semi-blown asphalt, blown asphalt, Trinidad lake asphalt, solvent deasphalted asphalt, and petroleum resin can be used. Further, modified asphalt modified by adding a rubber material or a resin material to these asphalts can be used. For example, known asphalt containing rubber (modified asphalt in a narrow sense) in which at least one rubber material such as styrene / butadiene rubber, natural rubber, chloroprene rubber is added to straight asphalt or petroleum resin, or straight asphalt or petroleum resin to styrene Add at least one kind of known thermoplastic elastomer such as butadiene block copolymer, styrene / isoprene block copolymer, vinyl aromatic hydrocarbon / conjugated diene block copolymer such as styrene / ethylene / butylene block copolymer, etc. Asphalt containing thermoplastic elastomer (also referred to as a high viscosity binder) can be used.

The water repellent polymer is a resin, oil or the like having water repellency, and is a polymer having a contact angle with water of more than 90 °. Examples of such a polymer include silicone resin, silicone oil, fluororesin, fluoro oil, wax-based resin, and wax-based oil, and these can be used alone or in combination. Specific examples include perfluoroalkylethyl acrylate such as poly (perfluorooctylethyl acrylate), polytetrafluoroethylene, polydimethylsiloxane, polyphenylmethylsiloxane, and paraffin.
The mixing form of the water-repellent polymer into the asphalt is not particularly limited, and is prepared, for example, by blending the water-repellent polymer oil into the asphalt powder or by melt-kneading the water-repellent polymer at a temperature at which the asphalt melts. The In the asphalt material prepared by melt-kneading, the water-repellent polymer is preferably a silicone resin or silicone oil that is stable even at the melting temperature of the asphalt.

  The blending amount of the water-repellent polymer is not particularly limited. For example, when it is 5% or more and 40% or less with respect to the asphalt mass, the strength due to the asphalt and the water repellency due to the water-repellent polymer are good. It is preferable because it has both. That is, when the water-repellent polymer is less than 5% with respect to the asphalt mass, it is difficult to obtain significant water repellency. On the other hand, when the water-repellent polymer exceeds 40% with respect to the asphalt mass, the strength of the asphalt, etc. Various properties will deteriorate.

  The asphalt composition thus prepared is an embodiment of the asphalt material according to the present invention. This asphalt material can be used in the same manner as known construction materials and civil engineering materials containing asphalt. The surface formed by this asphalt material has water repellency, and the flow rate of water flowing through the surface is made faster, so that the drainage is good. This asphalt material is particularly preferably prepared as a pavement material. For example, it can be used as a raw material for fillers such as fog seals, asphalt mixtures containing aggregates, and asphalt emulsions using water as a dispersion medium. it can.

Another form of the asphalt material according to the present invention is an asphalt mixture. The asphalt mixture contains asphalt, a water-repellent polymer and aggregate.
The aggregate can be a variety of known coarse aggregates and fine aggregates for road paving. Specifically, for example, natural coarse aggregate, crushed stone that is natural fine aggregate, earth and sand, blast furnace slag crushed stone that is steel slag, blast furnace water granulated slag fine aggregate, concrete lump, recycled recycled from asphalt waste Aggregates, aggregates produced from municipal waste incineration ash molten slag, etc. Moreover, mineral powder, for example, limestone, igneous rock, and the like are included as aggregates (also referred to as fillers) with smaller particle sizes.
The asphalt mixture can be prepared in the same manner as various known asphalt mixtures such as a dense particle size asphalt mixture, a coarse particle size asphalt mixture, an open particle size asphalt mixture, and a gap particle size asphalt mixture, except that it contains a water-repellent polymer. When the open-graded asphalt mixture is formed into a lump like pavement, it forms a porous body with a large specific surface area and many continuous voids that can come into contact with water. can get. That is, the aggregate to be mixed with the asphalt mixture is preferably an aggregate having an open particle size, and specifically, an open particle size distribution in which the passage through a 2.36 mm sieve is 15 to 30% in the synthetic particle size. Aggregates having are preferred.

  Also in the preparation of the asphalt mixture, it is preferable that the water-repellent polymer has good heat resistance in order to melt the asphalt. Although heating temperature changes with kinds etc. of asphalt, it is the range of 140 to 200 degreeC, for example, and a silicone resin and a silicone oil are easy to mix and favorable in heat resistance, and are preferable. The blending amount of the water-repellent polymer in the asphalt mixture is not particularly limited, but is particularly preferably 5% or more and 40% with respect to the asphalt mass in the open particle size asphalt mixture or gap particle size asphalt mixture. Within this range, preferable strength is ensured in road pavement, particularly the surface layer, and good water repellency is imparted.

  Another form of the asphalt material according to the present invention is an asphalt emulsion. The asphalt emulsion is an emulsion containing asphalt and a water repellent polymer as a dispersoid using water or an organic solvent in which asphalt is difficult to dissolve, such as toluene and xylene. In the asphalt emulsion, an emulsifier for emulsifying asphalt is mixed. The emulsifier is a so-called surfactant, and is at least one cationic, anionic, or nonionic surfactant, and is typically a cationic surfactant. Various amines, that is, primary to tertiary amines, polyamines, and ammonium salts can be used as the cationic surfactant. In addition, other substances may be appropriately added for pH adjustment. In the cationic asphalt emulsion, for example, an organic acid such as acetic acid, hydrochloric acid, amidosulfuric acid or the like can be added to form a well dispersed asphalt emulsion.

  The asphalt emulsion can be prepared by a known method. For example, an emulsifier is dissolved in water to prepare an aqueous emulsifier solution, and the asphalt in which the water-repellent polymer is dispersed and mixed, or the asphalt and the water-repellent polymer are separately added to the aqueous emulsifier solution dropwise while stirring. Can be prepared. The water repellent polymer may be added to a known asphalt emulsion with stirring at room temperature. The blending amount of asphalt in the asphalt emulsion is not particularly limited, but in the final asphalt material, that is, the asphalt material after adding various auxiliary materials, the evaporation residue is 50% or more and 80% or less. From the viewpoint of storage properties, it is preferable.

The blending amount of the water-repellent polymer in the asphalt material prepared in the asphalt emulsion is not particularly limited, but a range in which the strength required in the use environment is ensured is preferable. For example, a formulation suitable for use as a tack coat, prime coat, chip seal, or binder of a normal temperature asphalt mixture, when prepared into an asphalt emulsion, repels the residual evaporation in the final asphalt emulsion. It is preferable that it is 5% or more and 40% or less with respect to the evaporation residual mass which has asphalt other than an aqueous polymer as a main component. Within this range, the strength required for a tack coat, prime coat, binder, etc. is obtained, and good water repellency is imparted.
As an auxiliary material for the asphalt emulsion, for example, rubber can be preferably used, and the rubber-containing asphalt emulsion improved in properties by being mixed in the emulsion can be used favorably in road paving.

  Next, an asphalt pavement 1 according to an embodiment of the present invention is shown in FIGS. The asphalt pavement 1 is a drainage asphalt pavement having a known layer structure, and is formed by laminating a roadbed 3, a base layer 5, a tack coat 7 and a surface layer 9 in order from the bottom on a road floor 20. In the present embodiment, the surface layer 9 has water permeability.

The roadbed 3 has a known configuration, and may be a single layer or may be composed of two or more layers. For example, in a two-layer structure, the lower layer can be made of crusher run, steel slag, sand, etc., and the upper layer can be made of crushed stone.
The base layer 5 is a layer that uniformly transmits the load applied to the surface layer 9 to the roadbed 3. In the asphalt pavement, the base layer 5 is made of an asphalt material containing aggregate and asphalt. In the case of imparting water permeability to the base layer 5, it is preferable to use an asphalt material (asphalt mixture) containing the above-described water-repellent polymer, asphalt, and aggregate having an open particle size. The base layer 5 is typically formed by spreading a heated asphalt mixture.

The tack coat 7 is a layer that improves the adhesion between the base layer 5 and the surface layer 9. In this embodiment, the tack coat 7 further has a waterproof function for preventing water from flowing down to the base layer 5 and below. The tack coat 7 is a relatively thin layer formed by the asphalt composition. The asphalt material used for forming the tack coat 7 is typically an asphalt emulsion. In the form in which the surface layer 9 has water permeability as in this embodiment, the asphalt emulsion can be formed using the above-described asphalt emulsion. preferable. More preferably, it is formed by a rubber-containing asphalt emulsion containing a water repellent polymer. The tack coat 7 can be formed by applying or dispersing an asphalt emulsion on the surface of the base layer 5 in a layered form so as to be 0.3 to 0.6 L / m ² and drying.

  The surface layer 9 constitutes the uppermost part of the asphalt pavement, and the upper surface is formed flat. The surface layer 9 disperses the load applied from the upper surface of the pavement and transmits it to the lower portion, and exhibits moderate slip resistance with the tire and the like. Moreover, in this embodiment, it is set as the structure which can drain water from the upper surface of the surface layer 9, ie, the part other than a surface, typically a sewer can drain water from the upper surface of the surface layer 9, in this embodiment. The surface layer 9 is formed using an open-graded asphalt mixture which is one form of the asphalt material according to the present invention. That is, the surface layer 9 is formed by heating the asphalt mixture to a softened state and supplying it so that the amount per unit area on the tack coat 7 becomes uniform, and pressing and leveling by a known method such as a rolling roller. can do. The surface layer 9 preferably has a total porosity of 10% to 40% from the viewpoint of drainage and durability. More preferably, the total porosity is 15% or more and 30% or less.

  In the asphalt pavement 1, when water is supplied to the pavement surface due to rain or the like, the water penetrates into the surface layer 9. That is, as shown in FIG. 2, since the surface layer 9 is an open grained pavement, it has innumerable voids 10 extending from the surface to the bottom. Accordingly, the water adhering to the surface of the surface layer 9 reaches the bottom of the surface layer 9, that is, the surface of the tack coat 7 through the gap 10 as indicated by an arrow A. At this time, since the entire surface of the asphalt mixture is covered with a molten component, that is, a mixture of asphalt and a water-repellent polymer, the surface of the surface layer 9 and the surface of the void 10 have water repellency. The flow rate can be maintained higher. Therefore, water quickly flows down in the surface layer 9 due to its own weight. For this reason, drainage is good and water is quickly drained even in heavy rain. Therefore, in this asphalt pavement 1, the occurrence and increase of water pools can be suppressed, and the occurrence of tire slip due to water, dazzling due to headlights during rainfall at night, and the occurrence of splashing due to the jumping up of the tire can be satisfactorily suppressed. .

  Further, when water flows down, dust, earth and sand having a particle size smaller than the width of the gap 10 enter the gap 10 due to the water force. When dust and earth and sand stay and accumulate inside the gap 10, the flow path of water is blocked. However, since the surface layer 9 is unlikely to have a low water flow rate due to the water repellency of the surface, dust and earth and sand are well swept away by water and do not easily stay in the gap 10. Therefore, the pavement has a drainage function that lasts for a long time.

  Moreover, since the tack coat 7 is formed of an asphalt material containing a water-repellent polymer in the present embodiment, this surface is likely to move at a higher flow rate of water. Accordingly, the water flowing down from the surface layer 9 at a higher flow rate is discharged to the outside, in FIG. 2, up to the sewage channel 22 (see arrow B in FIG. 2) while maintaining a good speed. Therefore, good drainage is achieved even in the case of heavy rain, and flooding can be suppressed. Also on the tuck coat 7, the drainage is kept longer because accumulation of dust, earth and sand, etc. is suppressed by a faster flow rate of water.

  Moreover, the asphalt mixture containing a water repellent polymer has improved peelability on the surface. For this reason, in the rolling compaction process when constructing the asphalt pavement, adhesion of the asphalt mixture to the roller or plate compactor that contacts the asphalt mixture is reduced. Therefore, conventionally, it is possible to reduce the amount of sprinkling water for preventing the asphalt mixture from adhering to the roller or the like in the compacting step. In particular, in a porous asphalt mixture with high water permeability, water of water sprinkles into the interior and the asphalt mixture may be cooled and fixed in an insufficiently compacted state. Then, the asphalt pavement which can be compacted efficiently with a smaller amount of water spray, achieves a desired compacted state and is excellent in strength and durability.

The present invention is not limited to the above embodiment. For example, in a form in which water permeability, that is, drainage is imparted to the base layer 5, a prime coat provided as appropriate between the base layer 5 and the roadbed 3 is obtained by drying the asphalt material according to the present invention, particularly an asphalt emulsion. The material is preferably used. In this case, similarly to the tack coat 7 for the surface layer 9, the flow rate of water in the lower part of the base layer 5 is maintained at a higher speed to suppress water accumulation in the base layer 5, and the flow rate of water in the base layer 5. Can be maintained in a faster state. When water permeability is imparted to the base layer 5 or lower layers, the coat positioned above the water permeable layer such as the tack coat 7 and the prime coat has an asphalt emulsion of 0.3 L / m ² or less. It is preferable to apply by spreading etc. by thickness. The coat formed in this manner is preferable because it has a water flow path and can maintain a high flow rate, so that the water can flow better in the lower layer.
In addition, in the form where the surface layer 9 is a water-permeable pavement as in the above-described embodiment, when the surface layer 9 and the tack coat 7 are both formed from the asphalt material according to the present invention, the asphalt pavement 1 It is preferable that the water flow rate in the water permeable portion can be maintained at a higher speed, but the surface layer 9 or the tack coat 7 may be formed of different asphalt materials. Also in this case, the state where the flow rate of water is higher in the portion according to the present invention is maintained, and thereby the decrease in the flow rate of water in the other portion can be suppressed, thereby improving drainage and reducing clogging. The effect is obtained.
Moreover, the asphalt emulsion which is one form of the asphalt material according to the present invention may be used as a binder or a chip seal in a room temperature asphalt mixture in addition to a tack coat and a prime coat. Even in this form, the water repellency of the surface of the asphalt composite or the chip-sealed surface is improved, and the water flow rate is maintained at a higher speed, so that the drainage is improved and a well-drained pavement is obtained. It is done. In addition, dust and dirt that become dirt on the pavement are likely to be washed away on the shoulders of the road by a faster flow rate of water.

  In addition, the asphalt surface layer formed by mixing the asphalt material according to the present invention with an aggregate having a dense particle size distribution does not have water permeability, but the surface has a higher water flow rate and adheres to the road surface due to rainfall or the like. The water to flow quickly flows toward the shoulder. For this reason, compared with the pavement by a normal dense particle size asphalt mixture, drainage is improved and a pavement with good drainage is obtained. In addition, dust, dirt and sand that become dirt on the pavement are likely to be washed away on the shoulders of the road by rain due to faster water flow rates, and a self-cleaning function is expected.

(Measurement of flow rate and residual water in asphalt composition)
Rubber-containing cationic asphalt emulsion Cathizole GM (manufactured by Nichireki Co., Ltd., evaporation residue 50% by weight) and silicon oil SH200-50EG (manufactured by Toray Dow Corning Silicone Co., Ltd.) 10% (evaporation residue) Asphalt emulsion was prepared by mixing and stirring at room temperature so as to be 20 wt% with respect to the minute). Next, an asphalt emulsion was applied to the inside of a ridge made by splitting a pipe made of vinyl chloride having an inner diameter of 10 cm and a length of 1 m so as to be 0.5 L / m ² to obtain a sample. Obtained.
A sample was prepared in the same manner for the rubber-containing cationic asphalt emulsion to which no silicone oil was added, and Comparative Example 1 was obtained.

  After measuring the weight of each sample, with the asphalt emulsion coated surface of the sample facing up, one end is fixed to be 2 cm higher than the other end, and water is dropped at a predetermined flow rate 5 cm above the held end. A water tank with a cock was installed. From this water tank, water was dropped into the sample at 25 cc / sec for 10 seconds, and the time until the water reached the lower end of the sample (flowing time) was measured. Further, the weight of each sample was measured after 60 seconds had elapsed from the end of dropping, and the difference from the initial weight was determined (remaining amount of water). The results are shown in Table 1.

結果から明らかなように、シリコン樹脂を含む実施例１における水の流下時間は、シリコン樹脂を含まない比較例１に比して約半分であった。このことから、実施例１の表面では、水が転がりやすく、より速い流速で移動できることが明らかとなった。また、流下可能な水が全て流下したと考えられる滴下終了６０秒後の水の残存量が、実施例１では、比較例１に比して約２ｇ少ないことから、実施例１では、水の流下が促進され、水はけが良いことが明らかとなった。

As is clear from the results, the water flow time in Example 1 containing the silicon resin was about half that of Comparative Example 1 not containing the silicon resin. From this, it became clear that on the surface of Example 1, water easily rolls and can move at a higher flow rate. In addition, in Example 1, the remaining amount of water 60 seconds after the completion of dropping, which is considered to have flowed all the water that can flow down, is about 2 g less than that in Comparative Example 1. It became clear that drainage was promoted and drainage was good.

(Measurement of moisture residue in asphalt mixture)
Straight asphalt (60/80) (produced by Showa Shell Sekiyu KK) and modifier Toughback Super (produced by Oari Construction Co., Ltd.) mainly composed of styrene-butadiene block copolymer in a mass ratio of 88 The modified asphalt (high-viscosity binder) mixed at a ratio of 12 to the above-described silicon oil and aggregate containing No. 6 crushed stone, sand, and stone powder were melt-kneaded at a blending ratio shown in Table 2. That is, the asphalt melted at 185 ° C., the aggregate heated to 185 ° C., and the water-repellent polymer were put into an asphalt mixer with a heating apparatus heated to 180 ° C. so as to be 8 kg. Mixed for 2 seconds.
Next, a predetermined amount of the kneaded asphalt mixture was taken and filled into a cylindrical mold having a diameter of 101.6 mm. Thereafter, one of the circular end faces was placed facing upward, and a hammer having a circular flat end face (heated to 150 ° C.) and a mass of 4.5 kg was freely dropped from a height of 457 mm 50 times and compacted. Next, the opposite end face was compacted in the same manner. After cooling to room temperature, the asphalt mixture was removed from the mold using a pusher device to obtain a sample having a diameter of 101.6 mm and a height of 63.5 ± 1.3 mm. Three samples were prepared for each of Example 2 and Comparative Example 2.

About each obtained sample, the porosity was calculated | required with the following method according to "Pavement test method manual" 5-3-6 "Density test method of water-permeable asphalt mixture" ((Japan) Japan Road Association).
1) The sample diameter and thickness were measured with calipers, and the sample volume V ₀ was calculated.
2) The air mass A of the sample was measured.
3) was A / _{V 0} and sample density _{D m.}
4) The mixture density D ₁ (theoretical maximum density) when the porosity was 0 was calculated from the density and composition of the materials used, and the total porosity v _v was calculated according to the following equation.
v _v = (1−D _m / D ₁ ) × 100 (%)
About Example 2 and Comparative Example 2, the simple average of each sample was calculated | required and it was set as the porosity of Example 2 and Comparative Example 2. The results are shown in Table 3.

In addition, for each of the obtained samples, according to the following method according to “Pavement Test Method Handbook (provisional test method)” 1-1-4T “Continuous Porosity Measurement Method” (Japan Road Association), the following method is used. Asked. The continuous porosity is the volume% of continuous voids that are actually effective for the flow of air and moisture.
1) The diameter and thickness of each sample were measured with a caliper, and the sample volume V ₀ was calculated.
2) The air mass A of the sample was measured.
3) The sample was left in room temperature water for about 1 minute to completely expel bubbles, and then the weight C of the sample in water was measured.
4) the value obtained by subtracting the water weight C from the air mass A and the volume V ₁ of the independent voids between aggregates (void are closed), it was calculated continuous porosity v _c by the following equation.
v _c = (V ₀ −V ₁ ) / V ₀ × 100 (%)
About Example 2 and Comparative Example 2, the simple average of each sample was calculated | required and it was set as the continuous porosity of Example 2 and Comparative Example 2, respectively. The results are shown in Table 3.

Moreover, in order to confirm the ease of moisture removal in the voids of the sample, the moisture residual ratio was measured by the following method.
Calculated by the following equation 1) sample volume V ₀ obtained by the above method and the continuous porosity v _c, the water mass W ₀ in a sample when the expelling bubbles completely on standing samples at room temperature water did. However, a is the density of water at room temperature.
W ₀ = V ₀ × v _c / 100 × a
2) After leaving the sample in room temperature water for about 1 minute to completely expel the bubbles, the sample is pulled up into the shrine to allow the water in the sample to flow down naturally, after 5, 10, 30, 60 minutes. The air mass _Bn was measured.
3) The value obtained by subtracting the air mass A of the sample from the air mass B _n was used as the amount of water W _n in the sample at each measurement time, and the water residual rate w _v at each measurement time was calculated by the following equation.
w _v = W _n / W ₀ × 100 (%)
For Example 2 and Comparative Example 2, the simple average of the moisture residual rate at each measurement time of each sample was taken as the moisture residual rate at each measurement time of Example 2 and Comparative Example 2. The results are shown in Table 3.

この結果によれば、実施例２と比較例２とは、それぞれほぼ同じ連続空隙率を有しているが、その水分残留率は実施例２の方が小さく、排水機能が高いことが明らかとなった。また、シリコン樹脂を含有する実施例２と比較例２との水分残留率の差は、時間が経過するほど大きくなることから、実施例２のアスファルト混合物の空隙中における水の流速の方が比較例２のアスファルト混合物の空隙中における水の流速よりも速いことが明らかとなった。このことから、実施例２におけるアスファルト混合物は、水はけがよいことがわかった。

According to this result, Example 2 and Comparative Example 2 each have substantially the same continuous porosity, but it is clear that the water residual ratio is smaller in Example 2 and the drainage function is higher. became. Moreover, since the difference of the water | moisture-content residual ratio of Example 2 containing a silicone resin and the comparative example 2 becomes so large that time passes, the direction of the water flow rate in the space | gap of the asphalt mixture of Example 2 is compared. It was found that the flow rate of water in the voids of the asphalt mixture of Example 2 was faster. From this, it was found that the asphalt mixture in Example 2 had good drainage.

(Measurement of clogging in asphalt mixture)
Using the same asphalt mixture as in Example 2, the mold was filled with the asphalt mixture so that the sample size was 101.6 mm in diameter and 100 ± 2 mm in height, and compacted in the same manner as in Example 2. The sample of Example 3 was obtained without demolding. Three samples having a diameter of 101.6 mm and a height of 100 ± 2 mm were prepared. Further, three samples of Comparative Example 3 were prepared in the same manner as Example 3 using an asphalt mixture having the same composition as Comparative Example 2.

1) The mass of the sample before the test was measured. Further, the porosity of each sample was measured in the same manner as in Example 2 except that the mass of the mold was subtracted.
2) 10 g of sand whose particle size was adjusted to 0.3 mm or less was added to 1000 g of water and suspended water prepared by stirring was allowed to flow from one end of the mold to the other end of each sample. Thereafter, the sample was dried in a drying furnace heated to 60 ° C. for 24 hours, and the mass of each sample was measured to determine the mass increment from the mass before the test. Dividing this mass increment by the area of the circular end face of the sample, the mass increase per unit area (1 m ² ) (g / m ² , converted to 10 cm in thickness) is obtained, and the simple average of the mass increase in the three samples is calculated It was set as the clogging amount in Example 3 and Comparative Example 3.
3) After flowing the same suspension water to the sample after the test in the same manner, the mass increment was determined in the same manner to determine the mass increase from before the test.
The results are shown in Table 4.

この結果によれば、実施例３の連続空隙率が比較例３の連続空隙率よりも低かったにもかかわらず、目詰まり量の増加は、１回目、２回目とも実施例３の方が比較例３より低かった。特に、実施例３では、１回目の後２回目の流下のみに依存する目詰まり量の増分も比較例３より少なく、目詰まりしにくい状態が持続することが明らかとなった。

According to this result, although the continuous porosity of Example 3 was lower than the continuous porosity of Comparative Example 3, the increase in the amount of clogging was compared with Example 3 both in the first time and the second time. Lower than Example 3. In particular, in Example 3, the increase in the amount of clogging that depends only on the second flow after the first time is also smaller than that in Comparative Example 3, and it has become clear that clogging is difficult.

1 is a schematic cross-sectional view of an embodiment of an asphalt pavement according to the present invention. It is an expanded sectional view showing the surface layer portion of the asphalt pavement according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Asphalt pavement 3 Subbase 5 Base layer 7 Tack coat 9 Surface layer 10 Cavity 20 Subgrade 22 Sewer

Claims (9)

  An asphalt material comprising asphalt and a water-repellent polymer that is 5% or more and 40% or less based on the mass of the asphalt.   The asphalt material according to claim 1, wherein the water repellent polymer is a silicone resin or silicone oil.   The asphalt material according to claim 1 or 2, further comprising an aggregate having an open particle size distribution.   It is prepared as an emulsion having water or an organic solvent as a dispersion medium and asphalt as a dispersoid, and the water-repellent polymer is 5% by weight to 40% by weight with respect to the evaporation residue other than the water-repellent polymer. Asphalt material contained in   The asphalt material according to claim 4, wherein the water-repellent polymer is a silicone resin or silicone oil.   An asphalt pavement formed by spreading and leveling a mixture containing the asphalt material according to claim 1 or 2 and an aggregate.   An asphalt pavement formed by spreading and mixing a mixture containing the evaporation residue of the asphalt material according to claim 4 and an aggregate.   The asphalt pavement according to claim 6 or 7, wherein the aggregate has an open particle size distribution. An asphalt pavement comprising a layer containing an evaporation residue of the asphalt material according to claim 4 or 5.

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