JP6046408B2 - Vibration reduction pavement - Google Patents

Description

The present invention relates to a vibration reducing pavement using as a base layer a vibration reducing pavement asphalt mixture having high flexibility, vibration damping property, crack resistance, and plastic deformation resistance.

  The following materials have been proposed as materials with high flexibility used for asphalt pavement.

  Patent Document 1 discloses a pavement in which rubber chips and asphalt mortar are mixed.

  Patent Document 2 discloses an elastic pavement mixture in which asphalt, thermoplastic elastomer, stone powder, and aggregate are mixed.

  Patent Document 3 discloses an asphalt mixed object obtained by mixing an asphalt composition containing asphalt, a thermoplastic elastomer, process oil, and a ductile material, and an aggregate.

  Patent Documents 4 and 5 show asphalt compositions comprising asphalt, rubber and / or thermoplastic elastomer, mineral oil, and low molecular weight polyethylene or a phenyl ether compound having a specific substituent.

JP 2006-183271 A JP 2000-204262 A JP-A-2005-200355 JP 2003-3070 A JP 2003-192901 A

  Patent Document 1 has a problem that it is inferior in durability, such as scattering of rubber chips, because it is a pavement with many voids in which a single particle size rubber chip is bonded with asphalt mortar.

  Patent Document 2 has a problem that the viscosity of the asphalt mixture becomes high and the workability is poor because a large amount of a styrene thermoplastic elastomer that melts at 80 to 120 ° C. is blended.

  With respect to Patent Document 3, a special asphalt composition obtained by mixing asphalt, a thermoplastic elastomer, process oil, and a ductile material is used. Therefore, when producing an asphalt mixture, a dedicated asphalt composition for heating and storing is used. There has been a problem in that an asphalt tank or a special asphalt lorry vehicle for heating the asphalt composition and transferring it to the asphalt pipe of the asphalt mixture factory is required.

  Patent Documents 4 and 5 are both intended to improve mixing properties and storage stability, and require low-molecular-weight polyethylene or phenyl ether compounds having specific substituents, and have a low mineral oil content. Therefore, even if an asphalt mixture is produced using this as a binder, high flexibility, vibration damping, crack resistance, and plastic deformation resistance cannot be exhibited in a balanced manner.

  In other words, even a highly flexible asphalt mixture can be easily manufactured at a normal asphalt mixture factory, good workability can be obtained with normal construction machines, and it can withstand long-term use after construction. It is desirable that

Furthermore, as the basic properties of the highly flexible asphalt mixture used as the base layer of the vibration reducing pavement, it is desirable that the high flexibility, vibration damping property, crack resistance, and plastic deformation resistance can be exhibited in a balanced manner. .

The present invention has been made in view of such problems, and its object is to have high flexibility, vibration damping, and crack resistance, as well as plastic deformation resistance, which is a contradictory property to these. And it is providing the vibration reduction pavement which can be manufactured in a normal asphalt compound factory, and can obtain favorable workability with a normal construction machine.

To achieve the above object, the vibration relief pavement according to the present invention, the base layer of asphalt pavement, and aggregate, and polymer modified asphalt asphalt dispersed polymer continuous phase is formed in the polymer as characterized in that the contain 20 wt% 30 wt% based on the polymer modified asphalt, and a vibration relief paving highly flexible asphalt mixture pour point ing from -10 ° C. or less of mineral oil Yes.

Since the highly flexible asphalt mixture used in the present invention uses polymer-modified asphalt as a raw material, it can be easily manufactured in a normal asphalt mixture factory, and good workability can be obtained with a normal construction machine. It is done.

Then, using the high flexible asphalt mixture this to the base layer, since the high flexible asphalt mixture This has vibration damping, the vibration generated at the surface by passing vehicles attenuated by substrate, the roadside There is an effect to reduce the vibration to propagate. The high flexibility asphalt mixture of this, since the high cracking resistance, even if cracks are generated in the lower layer than the base layer, there is an effect capable of suppressing the substrate, and cracks in the surface layer to occur.

It is a graph which shows the measurement result of a loss factor. It is a graph which shows the addition amount of mineral oil, and the relationship of HIC. It is a graph which shows the relationship between the addition amount of mineral oil, and dynamic stability. It is a graph which shows the relationship between the pour point of mineral oil, and HIC. It is a graph which shows the relationship between the pour point of mineral oil, and a fracture | rupture strain.

Hereinafter, the polymer-modified asphalt, mineral oil, and aggregate used in the highly flexible asphalt mixture used in the present invention will be described, and then a method for producing this highly flexible asphalt mixture will be described.

[Polymer modified asphalt]
The polymer-modified asphalt used in the highly flexible asphalt mixture used in the present invention is obtained by adding a polymer such as a thermoplastic elastomer as a modifier to straight asphalt. In the present invention, a polymer in which asphalt is dispersed and a polymer continuous phase is formed is used. A polymer continuous phase is formed when there is a large amount of polymer added and there is an asphaltene rich phase (asphalt is the main component) in the polymer rich phase (polymer is the main component), and the polymer is in the form of a continuous phase. It is what.

Examples of polymer-modified asphalt in which a polymer continuous phase is formed are described in the pavement design and construction guideline (2008 edition) published by the Japan Road Association, where there is generally a large amount of heavy vehicle traffic. The polymer modified asphalt type III used for the asphalt mixture applied to the above, and the polymer modified asphalt type H generally used for the porous asphalt mixture can be suitably used. More specifically, H type, H type-F, III type, III type-W
, Type III-WF can be used.

[mineral oil]
The mineral oil used in the highly flexible asphalt mixture used in the present invention improves the softness of the polymer-modified asphalt at normal and low temperatures without destroying the polymer continuous phase of the polymer-modified asphalt and has high flexibility. It is added to improve the workability of the asphalt mixture. As an example of the mineral oil, an industrial lubricating oil mainly composed of petroleum hydrocarbons having a pour point of −10 ° C. or lower can be suitably used. If the pour point of the mineral oil is higher than −10 ° C., the impact absorbability and the flexibility are lowered as described later.

Further, ore Monoyu can be either be those additives in a single product of a petroleum hydrocarbon is added. The mineral oil is not limited to industrial lubricating oil as long as it satisfies the pour point.

  The content of mineral oil is preferably 10 wt% to 30 wt% with respect to the polymer-modified asphalt. As will be described later, if it is less than 10 wt%, the softness of the polymer-modified asphalt cannot be improved, and the flexibility, vibration damping, crack resistance, and workability of the highly flexible asphalt mixture are lowered. On the other hand, if it exceeds 30 wt%, the polymer continuous phase of the polymer-modified asphalt is destroyed and the softening point is lowered, and the plastic deformation resistance of the highly flexible asphalt mixture is lowered, so that the flow resistance cannot be ensured.

[aggregate]
Aggregates used in the highly flexible asphalt mixture used in the present invention are aggregates conventionally used in asphalt mixtures such as crushed stone, sand and stone powder, and are not limited to specific ones.

[Manufacture of highly flexible asphalt mixture]
In the case of producing a highly flexible asphalt mixture used in the present invention , a polymer modification in which asphalt is dispersed in an aggregate heated to 150 to 220 ° C. and a polymer heated to 150 to 200 ° C. to form a polymer continuous phase. A predetermined amount of mineral oil having a pour point of −10 ° C. or less is added to and mixed with the fine asphalt. Alternatively, a polymer modified asphalt in which asphalt is dispersed in a polymer heated to 150 to 200 ° C. in advance to form a polymer continuous phase and a mineral oil having a pour point of −10 ° C. or less are mixed in a predetermined ratio, and You may mix with the aggregate heated to 150-220 degreeC by the predetermined | prescribed ratio. These mixing procedures can be arbitrarily selected depending on the working environment, and may be performed in either order as long as the temperature during mixing is within the above range.

The polymer-modified asphalt is roughly classified into two types: a polymer continuous phase formed and an asphalt continuous phase formed. Among them, the polymer-modified asphalt of the highly flexible asphalt mixture used in the present invention is characterized in that a polymer continuous phase is used.
Therefore, positive Rimmer those using polymer modified asphalt H type as Example 1 as an example of polymer modified asphalt continuous phase is formed, the polymer asphalt continuous phase polymer the continuous phase is not formed is formed As a modified asphalt example, the one using the polymer modified asphalt type II is referred to as Comparative Example 1, and the one using the straight asphalt 60-80 used for ordinary asphalt pavement as the comparative example 2, Various test results on the asphalt mixture using these binders will be described below.

[Example 1]
[Physical properties of the binder]
A binder physical test was conducted using Example 1 as a polymer-modified asphalt H type and a binder obtained by mixing 15 wt% of a mineral oil having a pour point of −30 ° C. with respect to the polymer-modified asphalt H type. Moreover, the physical test of the binder was done also about the comparative example 1 and the comparative example 2 which are shown below. The test results are shown in Table 1.

  In Comparative Example 1, the polymer modified asphalt H type is replaced with a binder obtained by mixing 15 wt% of a mineral oil having a pour point of −30 ° C. with respect to the polymer modified asphalt H type. This uses polymer-modified asphalt type II, which is used for anti-flow resistance measures. Since the polymer-modified asphalt type II has a small amount of polymer added to the asphalt, the polymer-rich phase exists in the asphaltene-rich phase, and the asphalt is in the form of a continuous phase.

  In Comparative Example 2, straight asphalt 60 used for ordinary asphalt pavement is used in place of a polymer-modified asphalt H type and a binder obtained by mixing 15 wt% of mineral oil having a pour point of −30 ° C. with respect to the polymer-modified asphalt H type. ~ 80 is used.

  From Table 1, it can be seen that Example 1 has an extremely high penetration compared to Comparative Example 1 and Comparative Example 2, and has a higher softening point than Comparative Example 1 and Comparative Example 2. Therefore, it is considered that the asphalt mixture using Example 1 in which the polymer continuous phase is formed as a binder has excellent flexibility and crack resistance compared to Comparative Example 1 and Comparative Example 2, and has flow resistance. It is done.

[Example 2]
[Properties of highly flexible asphalt mixture]
After the binders of Example 1, Comparative Example 1 and Comparative Example 2 shown in Table 1 were mixed with the aggregate, a dense asphalt mixture having a maximum particle size of 13 mm generally used for the surface layer of asphalt pavement was manufactured. This was compacted, a specimen was prepared, and various tests were performed. The bending test was conducted in accordance with “Pavement Survey / Test Method Handbook B005”.

The test results are shown in Table 2. In general, a dense asphalt mixture having a maximum particle size of 13 mm is excellent in water resistance and resistance to cracking.
Here, in the preparation of the specimen according to Example 2, the binder amount is 5.5%, the blending ratio of the aggregate is as shown in Table 3, and the aggregate particle size is as shown in Table 4. .

  From the bending test results in Table 2, the dense asphalt mixture using the binder of Example 1 has a bending strain that is about 4 times larger than that when the binder of Comparative Example 1 or Comparative Example 2 is used. It turns out that it is excellent in the property and crack resistance.

  Further, from the results of the Marshall test shown in Table 2, the dense-graded asphalt mixture using the binder of Example 1 has almost the same stability and flow value as those of Comparative Example 2 used for ordinary asphalt pavement. From the results of the tracking test, the dense asphalt mixture using the binder of Example 1 has a dynamic stability that is an index of plastic deformation resistance, which is used as a measure against flow resistance in asphalt pavement where there is a large amount of heavy vehicle traffic. Although it is lower than that in the case of using Example 1, it is higher than in the case of using Comparative Example 2, so that it can be seen that it has sufficient plastic deformation resistance.

[Example 3]
[Shock absorbency of highly flexible asphalt mixture]
The binder of Example 1, Comparative Example 1, and Comparative Example 2 shown in Table 1 and the aggregate were mixed to produce a coarse asphalt mixture having a maximum particle size of 20 mm, which is generally used for a base layer of asphalt pavement. Later, this is compacted, a specimen is prepared, and a pavement road surface elasticity test (pavement survey and test method manual S026-1) and a HIC test (ASTM F-1292-99) are performed, and shock absorption is achieved. evaluated. The coarse particle size asphalt mixture having a maximum particle size of 20 mm is generally excellent in properties such as flow resistance.

The test results are shown in Table 5. The GB coefficient represents impact absorbability. The smaller the value, the higher the impact absorbency. The SB coefficient represents the resilience, and the smaller the value, the lower the resilience. Gmax represents the maximum deceleration of impact, and HIC is a measure of impact strength. The smaller the value, the higher the impact absorption.
Here, in the preparation of the specimen according to Example 3, the binder amount is 4.9%, the blending ratio of the aggregate is as shown in Table 6, and the aggregate particle size is as shown in Table 7. .

From Table 5, the coarse-grained asphalt mixture using the binder of Example 1 has a GB coefficient of 8 to 11% smaller than that of the binder of Comparative Example 1 or Comparative Example 2, and the SB coefficient is also 6 to 8 % Small, it can be seen that the impact absorption is high and the impact resilience is also low.
In addition, the coarse-grained asphalt mixture using the binder of Example 1 has a lower Gmax and HIC than the case of using the binder of Comparative Example 1 or Comparative Example 2, and thus it is understood that the impact absorption is high. .

[Example 4]
[Vibration damping of highly flexible asphalt mixture]
After producing the asphalt mixture by mixing the binder and aggregate of Example 1, Comparative Example 1 and Comparative Example 2 shown in Table 1, this was compacted to produce a specimen having a two-layer structure, Based on “JIS G 0602 Vibration Damping Characteristics Test Method for Damping Steel Sheet”, a loss factor, which is an index of vibration damping, was measured at 20 ° C. to evaluate the vibration damping. The loss factor measurement results are shown in FIG. Note that the greater the value of the loss coefficient, the higher the vibration damping property.

Here, in the production of the specimen according to Example 4, the surface layer is a dense-graded asphalt mixture used binder ratio Comparative Examples 1, the base layer of the actual Example 1 binder, the binder of Comparative Example 1, and Comparative Example 2 A coarse-grained asphalt mixture using each of the above binders. The types of specimens are as shown in Table 8.

  From FIG. 1, in the case of A in which the coarse particle size asphalt mixture using the binder of Example 1 was applied to the base layer, the coarse particle size using the binder of Comparative Example 1 of B or Comparative Example 2 of C as the base layer Compared to the case where the asphalt mixture is applied, the vibration damping property is high since it is about 4 times larger.

  From the test results of Examples 2 to 4 above, the asphalt mixture using the binder of Example 1 in which the polymer continuous phase is formed is more than the one using the binder of Comparative Example 1 or Comparative Example 2, It was confirmed that the object of the present invention is to exhibit the high flexibility, vibration damping, crack resistance, and plastic deformation resistance in a well-balanced manner.

  Next, the optimum amount of mineral oil added to the polymer-modified asphalt and the results of tests conducted to confirm the desired pour point of the mineral oil will be described below.

[Example 5]
[Additional amount of mineral oil and properties of the mixture]
A dense asphalt mixture having a maximum particle size of 13 mm, which is generally used for the surface layer of asphalt pavement, is produced by changing the amount of mineral oil added in the same amount of binder and aggregate as in Example 2, and then compacting the mixture. A specimen was prepared, and an HIC test (ASTM F-1292-99) and a wheel tracking test were performed. The test results are shown in FIGS.

From FIG. 2, it can be seen that HIC tends to decrease as the amount of mineral oil added increases, and tends to decrease particularly when the amount added is 10 wt% or more. The smaller the value of the HIC, the higher the shock absorption . In particular, when the addition amount is 20 wt% or more, the HIC is 600 or less, and a very high shock absorption is obtained.

FIG. 3 shows that the dynamic stability tends to decrease as the amount of mineral oil added increases. When the addition amount of mineral oil is 30 wt% or less, the dynamic stability is 500 or more, and a dense particle size asphalt mixture using straight asphalt 60 to 80 which is a general asphalt mixture shown in Comparative Example 2 in Table 2 (13 ) And the necessary plastic deformation resistance can be ensured.
Therefore, it is desirable that the amount of mineral oil added to the base layer is 20 wt% to 30 wt%.

[Example 6]
[Pour point of mineral oil and properties of mixture]
A dense asphalt mixture having a maximum particle size of 13 mm generally used for the surface layer of asphalt pavement is produced by changing the pour point of mineral oil with the same binder amount and aggregate blending ratio as in Example 2, and then compacting this. A specimen was prepared, and an HIC test (ASTM F-1292-99) and a bending test were performed. The test results are shown in FIGS.

  From FIG. 4, it can be seen that HIC tends to increase when the pour point of mineral oil is higher than −10 ° C. The smaller the value of HIC, the higher the impact absorbability. Therefore, when the pour point of mineral oil is higher than −10 ° C., the impact absorbability decreases.

FIG. 5 shows that the breaking strain tends to decrease as the pour point of the mineral oil increases, and in particular, tends to decrease when the pour point becomes higher than −10 ° C. The larger the value of the breaking strain, the better the flexibility. Therefore, when the pour point of the mineral oil is higher than −10 ° C., the flexibility is lowered.
Therefore, it is desirable that the pour point of the mineral oil is −10 ° C. or lower.

From the results of Example 5 and Example 6, when using a highly flexible asphalt mixture for the base layer, the amount of mineral oil added to the polymer-modified asphalt is preferably 20 wt% to 30 wt%, It was also confirmed that the pour point of the mineral oil is desirably -10 ° C or lower.

Claims (1)

The base layer of the asphalt pavement includes 20 wt% to 30 wt% of the aggregate , the polymer-modified asphalt in which asphalt is dispersed in the polymer to form a polymer continuous phase, and the polymer-modified asphalt, vibration mitigation paving, characterized in that the pour point is constituted by a vibration relief paving highly flexible asphalt mixture ing from -10 ° C. or less of mineral oil.

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