JP6731573B2 - Mixture for high performance type II pavement and high performance type II pavement - Google Patents

Description

TECHNICAL FIELD The present invention relates to a mixture for high-performance pavement type II and a high-performance type II pavement formed by using the mixture.

In recent years, as a technique for improving the drainage function and noise reduction function of an asphalt pavement, it is known to form a high-performance pavement type II pavement (hereinafter referred to as "high-performance type II pavement") on the surface layer. .. The high-performance type II pavement shows high drainage by making the surface of the surface layer have a texture depth equivalent to that of the porous asphalt mixture, and the inside of the surface layer is as dense as the crushed stone mastic asphalt mixture. A pavement body having high durability by having a structure having For example, Patent Document 1 discloses a high-performance type II pavement formed by rolling an asphalt mixture having a predetermined particle size range and a predetermined asphalt content.

The high-performance type II pavement is generally formed by using an asphalt mixture containing aggregate, asphalt, asphalt binder and the like (hereinafter referred to as “high-performance pavement type II mixture”). This high performance type II pavement mix is made to produce a certain amount of sag to form a high performance type II pavement. If the amount of sagging of the mixture for high-performance pavement type II is excessive, a desired high-performance type II pavement may not be obtained. In addition, the amount of sag increases as the temperature rises. For this reason, in the mixture for high-performance pavement type II, the upper limit of the mixing temperature of the mixture for high-performance pavement type II is set by the static sag test so that the amount of sag does not become excessive.

Here, the static sag test means "test method 249-2008 static sag test method of asphalt mixture" defined by East Japan Expressway, Central Japan Expressway, and West Japan Expressway. To do. This static sag test method is specifically carried out as follows, and is evaluated by the calculated adhesion loss amount. The smaller the adhesion loss amount, the smaller the sagging amount. First, a sieve with predetermined sieves is placed flat on the bottom surface of the vat, and after heating these, the target asphalt mixture is evenly spread on the sieve and cured at a predetermined temperature for 1 hour. Next, after removing the sieve and the asphalt mixture from the vat, the ratio of the amount of asphalt adhering to the vat divided by the mass of the asphalt mixture spread before the test is taken as the amount of adhesion loss.

By the way, in general, the above-mentioned mixture for high-performance pavement type II takes a long time from shipment to arrival at the site, or when it is installed in the cold season, the temperature tends to be lowered and it is difficult to install it on site. Therefore, in these cases, in order to be able to perform appropriate construction at the site, manufacture and ship at a high temperature in advance in anticipation of a temperature decrease, specifically, a mixture for high-performance pavement type II. It is preferable to manufacture and ship at a temperature close to the upper limit in the mixing temperature range defined in 1., for example, 175 to 185°C. However, when the mixture for high-performance pavement type II is manufactured and shipped at a high temperature, there is a problem that the viscosity of the asphalt contained in the asphalt mixture is lowered and sagging is likely to occur during manufacturing or construction.

On the other hand, conventionally, there is known a technique of adding a warming agent, which is a component that enables production and construction of an asphalt mixture at a lower temperature, to the asphalt mixture. The present technology can also be applied to a mixture for high-performance pavement type II. According to the technique of adding this warming agent, even when a temperature drop occurs in the mixture for high-performance pavement type II during transportation or construction, The warming action can impart sufficient workability to the high-performance pavement type II mixture. Here, the warming effect means an effect that enables the production and construction of the mixture for high-performance pavement type II at a lower temperature than in the case where no warming agent is added. As a plant mix type warming agent that mixes with the mixture for high-performance pavement type II by the time of shipment, a viscoelasticity adjusting warming agent that adjusts the viscosity of asphalt, causing a slight amount of foaming in the asphalt. There is known a foaming type warming agent to be used, and a lubricant type warming agent to enhance lubricity between asphalt and an aggregate coated with asphalt.

Japanese Patent No. 4069194

However, the mixture for high-performance pavement type II to which the viscoelasticity adjusting system warming agent is added is not mixed in the standard mixing temperature range of the mixture for high-performance pavement type II without adding the warming agent, particularly in the temperature range close to the upper limit. The viscosity of asphalt tends to decrease excessively. For this reason, in the mixture for high-performance pavement type II to which the viscoelasticity adjusting system warming agent is added, asphalt or asphalt mortar is excessively fluidized within the standard mixing temperature range, and the amount of sag tends to increase. Further, in the mixture for high-performance pavement type II to which the foaming type warming agent is added, the asphalt and the asphalt mortar components are excessively fluidized due to the bearing effect of bubbles, and the amount of sag tends to increase.

Therefore, in the case of the mixture for high-performance pavement type II to which the viscoelasticity adjusting system warming agent or the foaming system warming agent is added, the viscosity of asphalt is excessively lowered and the amount of sag is excessive within the standard mixing temperature range. There was a problem that it was easy to become.

The present invention has been made in view of the above circumstances, and the amount of sag of the asphalt mixture is small in the temperature range close to the upper limit in the standard mixing temperature range of the high-performance paving type II mixture without adding a warming agent. An object of the present invention is to provide a mixture for high-performance pavement type II to which a warming agent is added, and a high-performance type II pavement obtained by using the mixture.

High Performance Pavement II type mix according to the first aspect of the present invention, viewed contains and aggregate, asphalt, and lubricant system warm-agent, wherein the lubricating material based mesophilic agent polyoxyethylene The propylene glycol-based surfactant is characterized in that the lubricant-based warming agent is contained in an amount of 0.3 to 1.2% by mass based on 100% by mass of the asphalt .

The mixture for high-performance pavement type II according to the second aspect of the present invention comprises 93.9 to 95.1% by mass of the aggregate and 4% of the asphalt in 100% by mass of the total amount of the aggregate and the asphalt. It is characterized in that it is contained in an amount of 0.9 to 6.1% by mass.

The high-performance type II pavement according to the third aspect of the present invention is characterized by being obtained by using the mixture for high-performance type II pavement.

The high-performance paving type II mixture according to the present invention has a small amount of sag in the asphalt mixture in a temperature range close to the upper limit of the standard mixing temperature range of the high-performance paving type II mixture in which the warming agent is not added. Further, since the high-performance type II pavement according to the present invention uses the high-performance type II pavement mixture with a small amount of sag within the standard mixing temperature range, the workability is good.

5 is a graph showing a composite particle size distribution of the aggregate of Example 1. It is a graph which shows the amount of adhesion loss of the mixture for high-performance pavement type II when the amount of asphalt is the optimum amount of asphalt (OAC: Optimum Asphalt Content). It is a graph which shows the adhesion loss amount of the high performance pavement type II mixture when the amount of asphalt is OAC+0.5 mass %. It is a graph which shows the kinematic viscosity of the asphalt simple substance used by the mixture for high-performance pavement type II, and the asphalt which added the lubricant type|system|group warming agent which concerns on this invention to the said asphalt.

[Mixture for high performance pavement type II]
Hereinafter, the mixture for high-performance pavement type II of the present embodiment contains an aggregate, asphalt, and a lubricant-based warming agent.

(aggregate)
The aggregate contained in the mixture for high-performance pavement type II of the present embodiment is not particularly limited, and known aggregates can be used. Specifically, crushed stone, crushed stone, gravel, steel slag, sand, recycled aggregate, hard aggregate and the like can be used as the aggregate. The aggregate is preferably a mixture of those having various particle sizes. The aggregate has, for example, a sieve passing mass percentage in the nominal dimensions of the sieve of 19.0 mm, 13.2 mm, 4.75 mm, 2.36 mm, 0.6 mm, 0.3 mm, 0.15 mm, and 0.075 mm. , 100% by mass, 95 to 100% by mass, 30 to 38% by mass, 22 to 27% by mass, 17 to 21% by mass, 15 to 18% by mass, 10 to 13% by mass, and 9 to 11% by mass, respectively. The grain size range is In addition, this grain size range is the same as that described in East Japan Expressway Co., Ltd., Central Japan Expressway Co., Ltd. and West Japan Expressway Co., Ltd.

(asphalt)
As the asphalt contained in the mixture for high-performance pavement type II of the present embodiment, known asphalt that is usually used for the mixture for high-performance pavement type II can be used. Specifically, petroleum asphalt, polymer-modified asphalt, or the like can be used as the asphalt. Here, the polymer-modified asphalt is an asphalt in which rubber or a thermoplastic elastomer is used alone or in combination.

(Lubricant-based warming agent)
As the lubricant-based warming agent contained in the mixture for high-performance pavement type II of the present embodiment, a known lubricant-based warming agent can be used. Among them, the lubricant-type warming agent consisting of an ether type nonionic surfactant does not easily deteriorate its function as a lubricant even if an acid, an alkali or an inorganic salt is present in the mixture for high performance pavement type II. Therefore, it is preferable. Among the lubricant-based warming agents composed of ether type nonionic surfactants, the lubricant-based warming agents composed of polyoxyethylene polyoxypropylene glycol-based surfactants and polyoxyethylene distyrenated phenyl A lubricant-based warming agent composed of an ether-based surfactant is preferable because it has a low foaming property. Furthermore, among the lubricant-based warming agents consisting of ether type nonionic surfactants, the lubricant-based warming agents consisting of polyoxyethylene polyoxypropylene glycol-based surfactants are more effective because of their large warming effect. preferable. As the lubricant-based warming agent composed of this polyoxyethylene polyoxypropylene glycol-based surfactant, for example, Semi Hot Support (registered trademark) manufactured by Nippon Road Co., Ltd. is used. The semi-hot support is a white flake solid at room temperature and has a melting point of 53°C and a flash point of 279°C.

The mixture for high-performance pavement type II according to the present embodiment is composed of the above-mentioned aggregate, asphalt, and lubricant-based warming agent.

(Amount of lubricant medium warming agent)
In the mixture for high-performance pavement type II of the present embodiment, the lubricant-based warming agent is usually 0.3 to 1.2% by mass, preferably 0.5 to 1.0% by mass, relative to 100% by mass of asphalt. %, more preferably 0.6 to 0.8% by mass. When the blending amount of the lubricant-based warming agent is within the above range, the sag amount of the asphalt mixture in the temperature range close to the upper limit in the standard mixing temperature range of the high performance pavement type II mixture of the present embodiment is high. Few.

On the other hand, if the blending amount of the lubricant-based warming agent is less than 0.3% by mass, the warming effect is not sufficiently exhibited. Further, if the amount of the lubricant-based medium temperature agent added exceeds 1.2% by mass, the medium temperature warming action is not improved so much as compared with the case of 1.2% by mass or less, which is not economical.

(Amount of aggregate and asphalt)
In the mixture for high-performance pavement type II of the present embodiment, 93.9 to 95.1% by mass of aggregate and 4.9 to 6.1% of asphalt are usually contained in the total amount of aggregate and asphalt of 100% by mass. Mass% is included. It is preferable that the amount of the aggregate and the asphalt compounded is within the above range, since the standards specified by East Japan Expressway Co., Ltd., Central Japan Expressway Co., Ltd. and West Japan Expressway Co., Ltd. are satisfied.

(Optimal amount of asphalt)
In the high performance pavement type II mixture of the present embodiment, OAC is usually 4.9 to 6.1 mass %. When the optimum amount of asphalt of the mixture for high-performance pavement type II of the present embodiment is within the above range, the mixture for high-performance pavement type II is a standard mixture of the mixture for high-performance pavement type II without adding a warming agent. The amount of sag of the asphalt mixture is small in the temperature range close to the upper limit of the temperature range. The optimum amount of asphalt can be determined by conducting a test in accordance with the "Design Guidelines, First Pavement Edition" issued by East Japan Expressway Co., Ltd., Central Japan Expressway Co., Ltd. and West Japan Expressway Co., Ltd. Is calculated.

It should be noted that, in the case of the mixture for high-performance pavement type II, in which a conventional viscoelasticity adjusting type warming agent or a foaming type warming agent is added, when the composition of asphalt in the asphalt mixture becomes a little larger than the optimum asphalt amount (OAC), the sagging The amount tends to be excessive. On the other hand, in the high performance pavement type II mixture of the present embodiment, even if the composition of the asphalt in the asphalt mixture is larger than the optimum asphalt amount (OAC), the amount of sag is small and the amount of sag is stable. high.

(Production method)
The mixture for high-performance pavement type II according to this embodiment is produced, for example, as follows. First, the aggregate is heated and the aggregate is weighed. Next, after dry-mixing the aggregate, a predetermined amount of asphalt is sprayed and wet-mixed. When a predetermined amount of the lubricant-based warming agent is added to this, the mixture for high-performance pavement type II of the present embodiment is obtained. In addition, it is preferable that the lubricant-based medium temperature agent is added during wet mixing.

[High-performance type II pavement]
The high-performance type II pavement of the present embodiment is obtained by using the above-mentioned mixture for high-performance type II pavement. Specifically, the high-performance type II pavement of the present embodiment is a surface layer of the high-performance type II pavement produced using the mixture for the high-performance type II pavement.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Example 1]
(Preparation of mixture for high performance pavement type II)
<Aggregate>
An aggregate having the synthetic particle size distribution shown in Table 1 and FIG. 1 was prepared.

<Asphalt>
Polymer-modified type II asphalt (manufactured by Nichireki Co., Ltd., trade name Polyphalt SS) was prepared.

<Asphalt mixture>
When a blending design using the above aggregate and the above asphalt was made in advance, it was found that the OAC (optimal amount of asphalt) was 5.0%. Therefore, a predetermined amount of the aggregate was weighed and then dry-mixed, and a predetermined amount of the asphalt having an OAC of 5.0% was added thereto, and wet mixing was performed. That is, 5 parts by mass of asphalt was added to 95 parts by mass of aggregate.

Next, in a mixture of aggregate and asphalt, a lubricant-based warming agent, Nippon Hot Road Co., Ltd. lubricant-based warming agent Semi Hot Support (registered trademark) (polyoxyethylene polyoxypropylene glycol-based surfactant , A white flake solid at room temperature, a melting point of 53° C., a flash point of 279° C.) was added to 0.7 part by mass of 100 parts by mass of asphalt in the mixture, and wet mixing was performed. Was obtained. Table 2 shows the composition of the high performance pavement type II mixture.

<Static sag test>
Regarding the obtained mixture for high-performance pavement type II, the NEXCO test method, Part 2 asphalt pavement-related test method stipulated by East Japan Expressway Co., Ltd., Central Japan Expressway Co., Ltd. and West Japan Expressway Co., Ltd. Method 249-2008 A static sag test was carried out using the "Static sag test method for asphalt mixture".
This static sag test method was specifically carried out as follows. First, on the flat bottom surface of the bat, a sieve having a mesh of 4.5 mm and a diameter of 19 cm made of a metal mesh using a metal wire of φ0.5 mm was placed flat. Next, after heating the vat and the sieve to the test temperature, the asphalt mixture prepared by mixing was quickly spread evenly on the sieve and cured at the test temperature for 1 hour. Then, after sieving and removing the asphalt mixture was the percentage obtained by dividing the mass M _B of the asphalt mixture mass M _L deposit adhered was leveled laid before testing the butt adhesion loss amount (wt%). The test temperature was set at three points of 175°C, 180°C, and 185°C within the manufacturer's recommended temperature range for the asphalt used, and a static sag test was performed at each test temperature. FIG. 2 shows the result of the static sag test.
In East Japan Expressway Co., Ltd., Central Japan Expressway Co., Ltd. and West Japan Expressway Co., Ltd., the standard value is 4% by mass or less of the static sag adhesion loss rate, which is the same as the adhesion loss amount.

[Comparative Example 1]
A mixture for high performance pavement type II was obtained in the same manner as in Example 1 except that the lubricant medium warming agent semi-hot support was not added. Table 2 shows the composition of the high performance pavement type II mixture.
A static sag test was performed on the obtained mixture for high-performance pavement type II in the same manner as in Example 1. FIG. 2 shows the result of the static sag test.
The kinematic viscosity of the asphalt used in the mixture for high-performance pavement type II and the asphalt obtained by adding a warming agent to the asphalt was measured at about 120 to 190°C. FIG. 4 shows the measurement results of kinematic viscosity.

[Comparative example 2]
Instead of adding 0.7 parts by mass of the lubricant-based warming agent semi-hot support to 100 parts by mass of the asphalt in the mixture, 5 parts of the viscoelasticity adjusting system warming agent was added to 100 parts by mass of the asphalt in the mixture. A high performance pavement type II mixture was obtained in the same manner as in Example 1 except that 0.0 part by mass was added. Table 2 shows combinations of asphalt and warming agent used in producing the mixture for high-performance pavement type II.
A static sag test was performed on the obtained mixture for high-performance pavement type II in the same manner as in Example 1. FIG. 2 shows the result of the static sag test.

[Comparative Example 3]
Instead of adding 0.7 parts by mass of the lubricant-based warming agent semi-hot support to 100 parts by mass of the asphalt in the mixture, the same effect as the foaming system warming agent is added to 100 parts by mass of the asphalt in the mixture. A high performance pavement type II mixture was obtained in the same manner as in Example 1 except that the foam door asphalt technique in which 2.0 parts by mass of the obtained water was added was used. Table 2 shows combinations of asphalt and warming agent used in producing the mixture for high-performance pavement type II.
A static sag test was performed on the obtained mixture for high-performance pavement type II in the same manner as in Example 1. FIG. 2 shows the result of the static sag test.

[Example 2]
A high performance pavement type II mixture was obtained in the same manner as in Example 1 except that the amount of asphalt in the asphalt mixture was changed to 5.5% by mass of OAC+0.5% by mass. Table 2 shows the composition of the high performance pavement type II mixture.
A static sag test was performed on the obtained mixture for high-performance pavement type II in the same manner as in Example 1. FIG. 3 shows the result of the static sag test.

[Comparative Example 4]
A high performance pavement type II mixture was obtained in the same manner as in Comparative Example 1 except that the amount of asphalt in the asphalt mixture was changed to 5.5% by mass of OAC+0.5% by mass. Table 2 shows the composition of the high performance pavement type II mixture.
A static sag test was performed on the obtained mixture for high-performance pavement type II in the same manner as in Example 1. FIG. 3 shows the result of the static sag test.

[Comparative Example 5]
A high performance pavement type II mixture was obtained in the same manner as in Comparative Example 2 except that the amount of asphalt in the asphalt mixture was changed to 5.5% by mass of OAC+0.5% by mass. Table 2 shows combinations of asphalt and warming agent used in producing the mixture for high-performance pavement type II.
A static sag test was performed on the obtained mixture for high-performance pavement type II in the same manner as in Example 1. FIG. 3 shows the result of the static sag test.

[Comparative Example 6]
A high performance pavement type II mixture was obtained in the same manner as in Comparative Example 3 except that the amount of asphalt in the asphalt mixture was changed to 5.5% by mass of OAC+0.5% by mass. Table 2 shows the composition of the high performance pavement type II mixture.
A static sag test was performed on the obtained mixture for high-performance pavement type II in the same manner as in Example 1. FIG. 3 shows the result of the static sag test.

The following facts were found from FIGS. 2 and 3.
First, the mixture for high-performance pavement type II containing no warming agent (Comparative Examples 1 and 4) has an adhesion loss amount of 2 to 175°C, 180°C, and 185°C in the case of OAC (Comparative Example 1). Although it is 4% by mass or less, the amount of adhesion loss at 175° C., 180° C., and 185° C. in the case of OAC+0.5% by mass (Comparative Example 4) rises to about 4% by mass, which is a reference value, or more. From these results, the mixture for high-performance pavement type II containing no warming agent is relatively hard to sag in the case of OAC (Comparative Example 1), but may easily sag due to an increase in the amount of asphalt than OAC. Do you get it.

Secondly, the mixture for high-performance pavement type II (Examples 1 and 2) containing the lubricant-based warming agent was used in the case of OAC (Example 1) and in the case of OAC+0.5% by mass (Example 2). In both cases, the adhesion loss amount at 175° C., 180° C., and 185° C. is extremely low at approximately 1 mass% or less. From these results, it can be seen that the mixture for high-performance pavement type II containing the lubricant-based warming agent is extremely resistant to sagging and that the sagging resistance is stably expressed without being affected by the increase in the amount of asphalt. Do you get it.

Thirdly, the mixture for high-performance pavement type II containing the viscoelasticity adjusting system warming agent (Comparative Examples 2 and 5) was OAC (Comparative Example 2) and OAC+0.5% by mass (Comparative Example 5). In Table 1, the amount of adhesion loss is larger than that of the mixture for high-performance pavement type II containing no warming agent (Comparative Examples 1 and 4). Therefore, it has been found that the mixture for high-performance pavement type II containing the viscoelasticity adjusting system warming agent is more likely to sag than the mixture for high-performance pavement type II containing no warming agent. Further, from FIGS. 2 and 3, in the high-performance pavement type II mixture (Comparative Examples 2 and 5) containing the viscoelasticity adjusting system warming agent, the temperature increased and the amount of asphalt increased compared to OAC. It turned out to be very easy to sag.

Fourthly, in the case of OAC (Comparative Example 3) and OAC+0.5% by mass, the high performance pavement type II mixture containing water (comparative examples 3 and 6) containing the same effect as the foaming warming agent is obtained. In (Comparative Example 6), the amount of adhesion loss is larger than that of the mixture for high-performance pavement type II containing no warming agent (Comparative Examples 1 and 4). Therefore, it has been found that the mixture for high-performance pavement type II containing water, which has the same effect as the foaming type warming agent, is more likely to sag than the mixture for high-performance pavement type II containing no warming agent. Further, from FIGS. 2 and 3, the high performance pavement type II mixture containing water (comparative examples 3 and 6), which has the same effect as the foaming warming agent, has a higher temperature and a higher asphalt content than OAC. It has been found that the increase in the amount increases the tendency to sag.

From the results of Examples 1 and 2 and Comparative Examples 1 to 6, it was found that the mixture for high-performance pavement type II (Examples 1 and 2) containing the lubricant-based warming agent was most useful for preventing sagging. It was

[Examples 3 to 5]
A mixture containing asphalt and a lubricant-based medium temperature agent semi-hot support was prepared without adding an aggregate, and the kinematic viscosity was measured. As the asphalt, the same polymer-modified type II asphalt as in Example 1 was used. The amount of the lubricant-based medium temperature agent semi-hot support added was 0.4 parts by mass (Example 3), 0.8 parts by mass (Example 4), and 1 with respect to 100 parts by mass of the polymer-modified type II asphalt. 2 parts by mass (Example 5). Table 3 shows the composition of asphalt. FIG. 4 shows the measurement results of kinematic viscosity.

As shown in FIG. 4, the kinematic viscosity of asphalt used in the mixtures for high-performance pavement type II of Examples 3 to 5 containing a lubricant-based warming agent and the high performance of Comparative Example 1 containing no warming agent. The kinematic viscosity of the asphalt used in the pavement type II mixture is located almost on the same straight line on a semilogarithmic graph. Therefore, the asphalt used in the mixture for high-performance pavement type II (Examples 3 to 5) containing the lubricant-based warming agent is the same as the mixture for high-performance pavement type II containing no warming agent (Comparative example 1). It has been found that it has similar properties to the asphalt used and that the lubricant-based warming agent does not modify the asphalt.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to these, and various modifications can be made within the scope of the gist of the present invention.

The mixture for high-performance pavement type II according to this embodiment can be used as a raw material for the surface layer of an asphalt pavement road such as a highway. The high-performance type II pavement according to the present embodiment can be used as a surface layer of an asphalt pavement road such as a highway.

Claims (3)

Aggregate,
Asphalt,
A lubricant-based medium temperature agent,
Only including,
The lubricant-based warming agent is a polyoxyethylene polyoxypropylene glycol-based surfactant,
The mixture for high-performance pavement type II, wherein the lubricant-based warming agent is contained in an amount of 0.3 to 1.2% by mass relative to 100% by mass of the asphalt . Claim 1, characterized in the total amount 100 mass% of the aggregate and asphalt, the aggregate from 93.9 to 95.1 wt%, said asphalt is contained 4.9 to 6.1 wt% The mixture for high-performance pavement type II according to 1. A high-performance type II pavement obtained by using the mixture for high-performance pavement type II according to claim 1 or 2 .

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