JP2003074007A - Elastic pavement, and method for the same pavement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide elastic pavement technique suitable for construction at site for elastic pavement material using soft aggregate comprising fiber rubber in part of aggregate. SOLUTION: At the construction site, hard aggregate 32 of a Mohs' hardness of 7 or more and an average grain size of 1,000 μm or less is added by 5 wt.% or more to soft aggregate 31 (100 wt.%) comprising fiber rubber, and obtained mix is mixed and agitated with binder regulated to viscosity of 1-8 Pa.s (1000-8000 cPs) to be then fed to a bed 2 to be placed on it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-site construction pavement using a soft aggregate made of fibrous rubber which is excellent in safety and has good human sensation such as walking sensation and a pavement method thereof. . INDUSTRIAL APPLICABILITY The elastic pavement of the present invention is suitable for a roadway that requires a wide range and is difficult to slip when wet.

[0002]

2. Description of the Related Art An elastic pavement is constructed by laying an elastic pavement material containing a soft aggregate such as rubber and a binder as a main component on a base, and its structure is a porous structure having voids between the aggregates. Is. Therefore, this kind of elastic pavement provides a good walking feeling and a high level of safety when it falls, and also has drainage properties, so that it is difficult for puddles to form due to rain even when used outdoors.

Recently, as one of various research results, it has been reported that the elasticity and the porosity of the elastic pavement material reduce the noise during the running of the vehicle, which is practically used for the road. The conversion is coming to an end.

The construction method of the elastic pavement is roughly classified into a precast method and an on-site construction method. The former, that is, the precast method, is a method in which a block-shaped or panel-shaped elastic pavement made in advance at a factory is brought to the construction site and laid on the ground by pasting or laying with an adhesive. is there.

In the precast method, firstly, a pavement can be manufactured under the same conditions, and various physical property values such as flatness and water permeability can be uniformly controlled. Secondly, since it is already cured, it can be used immediately even if the curing time is waited for even through an adhesive.

On the other hand, the latter on-site construction method is a method of performing all the work on site. That is, at least the soft aggregate and the binder are mixed and stirred on site, placed on the ground, and then the construction surface is finished. This on-site construction method has a large area that can be constructed at one time, and a flat surface can be obtained to some extent by leveling with a squeegee or the like.

By the way, as a soft aggregate of the elastic pavement, fiber rubber (for example, width 1 to 5 mm, length 2 to 40)
It is also known as hijiki rubber or twisted rubber with a thickness of about mm. By using (1), it is possible to significantly improve the wear resistance of the surface of the elastic pavement when wet. There are also cases in which low noise and drainage can be achieved at the same time by controlling the press pressure during precasting of fibrous rubber.

[0008]

However, the precast method has the following drawbacks. That is,
First, since a seam is generated in each block body (press plate), a seam treatment is necessary, and a gap or a step is generated due to expansion and contraction due to heat.

Secondly, if the groundwork is not extremely flat, the surface becomes rattling and cannot be used as a road surface in practice. Therefore, the ground surface to be laid is also required to have high-precision flatness, and as a practical matter, a single construction unit is as long as several kilometers, which is unsuitable for vehicle running roads with complicated terrain such as curves and ups and downs. is there. For this reason, the elastic pavement for a vehicle running road must be a field construction method that can take a large construction area at one time and can be paved according to the topography.

However, when the fibrous rubber is mixed as an elastic aggregate with a binder on site, the following problems occur. That is, since the fibrous rubber has a complicated shape such as Hijiki, which is difficult to mix and stir with the binder, the mixed state becomes non-uniform. Therefore, it does not spread well on the ground surface, and it is difficult to obtain a flat and uniform road surface even if it is leveled with a squeegee or the like.

Therefore, the inventor of the present invention has found that even when fiber rubber is used as the soft aggregate, it can be applied on site by selecting the shape, material and blending ratio of the aggregate and the viscosity of the binder to be used. It has been found that the method can build elastic pavement with a flat and uniform surface.

[0012]

That is, according to the present invention, an aggregate composed of a soft aggregate and a hard aggregate, and a majority amount (50% by weight or more) of the fiber rubber is used as a binder at a construction site. In an elastic pavement constructed by being mixed with and being cast on a predetermined lower ground, the hard aggregate having a Mohs hardness of 7 or more and an average particle diameter of 1000 μm or less is 100% by weight of the soft aggregate. On the other hand, it is characterized by containing 5% by weight or more. The preferred average particle size of the hard aggregate is 150 to 800 μm.

According to this, the hard aggregate enters between the fibrous rubber (soft aggregate) and performs a smooth material function like a so-called "roller", so that it is mixed with the binder in the field construction. Property and stirring property are remarkably improved.
Furthermore, the leveling property and flatness at the time of placing are also improved.

The "average particle size" in the present invention is the average value of the mesh size when the aggregate particles are sieved with a mesh sieve, and when the variation in the particle size of the aggregates is made into a histogram. , The most frequently measured particle size. In addition, the base is a surface on which the elastic pavement of the present invention is applied, and it is preferable that the base is uniformly flat.

The hard aggregate is an inorganic material,
The binder has a viscosity of 1-8 Pa · s (1000-8
Since it is 000 cps), the binder can evenly enter between the aggregates and a uniform mixed state can be obtained.

That is, the binder is 1 Ps · s.
If it is less than (1000 cps), the viscosity may be too low, and the binder may droop and flow onto the substrate after being cast without being trapped between the aggregates. Conversely, 8 Pa · s (8
If it exceeds 000 cps), the viscosity is too high and the binder itself has a high binding force, so that the binder may not enter into the aggregates and may not be uniformly mixed.

The blending ratio (weight) of the aggregate and the binder is preferably 100: 12 to 100: 35. That is, when the compounding ratio is less than 100: 12, the construction is possible, but in order to improve the durability, it is necessary to apply a pressing pressure equivalent to that of the precast method, which makes the construction troublesome. Conversely, the mixing ratio is 100: 35
When it exceeds, the porosity of the paving material becomes small and the water permeability becomes low because the amount of the binder is large. Further, in some cases, unevenness may occur on the surface of the pavement due to curing of the resin, which is not preferable.

In order for the elastic pavement of the present invention to withstand a sufficient load as a road surface for running a vehicle, the surface hardness measured by a CS hardness meter in the cured state of the binder is 60 or more. preferable. Further, in consideration of traveling of a truck, turning back of a forklift, etc., in which a larger load is applied than in normal traveling, the hardness is more preferably 75 or more.

In order to minimize the risk of slipping during rain, etc., 60 km / wet in a wet state.
It is preferable that the dynamic friction coefficient of the surface measured by a DF tester (dynamic friction tester) is 0.4 or more during h running.

The present invention also includes a paving method for the above elastic pavement. That is, the pavement method of the present invention is a hard aggregate having a Mohs hardness of 7 or more and an average particle diameter of 1000 μm or less in the aggregate in which the soft aggregate made of fiber rubber occupies 50% by volume or more of the whole. 5% by weight or more with respect to 100% by weight of the above soft aggregate, and a step of placing an elastic pavement material obtained by mixing with a binder at the construction site on the groundwork.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described. FIG. 1 shows a schematic cross-sectional view of an elastic pavement in which a surface layer portion 30 made of the elastic pavement material 3 of the present invention is formed on a base material 2 laid on the roadbed 1 in advance. In the drawing, the base 2 and the surface layer portion 30 seem to be uniformly filled with the binder, but in reality, there are voids between the aggregates and at least the surface layer portion 30.
Has water permeability.

The base 2 may be, for example, asphalt / concrete, crushed stone, mortar, semi-flexible pavement, simple stabilizing treatment surface, and the like, and does not necessarily have to be a highly stabilized treatment surface, but is uniform. It is preferably a stabilized surface. Since the surface layer portion 30 of the foundation 2 is the elastic pavement material 3, the voids may be reduced as much as possible so as to increase the strength so as not to bend under repeated loads.

In this embodiment, the base 2 is provided on the roadbed 1 in advance. However, if the laying surface of the surface layer portion 30 is a uniformly stabilized surface as described above, the base 2 is used. The surface layer portion 30 may be directly constructed on the roadbed 1 without being provided.

A primer may be applied to the underlayer 2 in order to prevent peeling at the joint surface with the surface layer portion 30. As the primer, for example, uncured urethane or epoxy is applied, and the surface layer portion 30 is applied before they are completely cured.
Is preferably constructed.

The elastic paving material 3 is made of a soft aggregate 31 made of fiber rubber (also known as hijiki rubber or twisted rubber).
And the Mohs hardness is 7 or more, and the average particle size is 10
The hard aggregate 32 having a size of 00 μm or less is included, and these aggregates are bonded by a binder. In this embodiment, the soft aggregate 31 occupies a majority amount (50% by volume or more) of the whole aggregate, and the hard aggregate 32 is 100% by weight of the soft aggregate.
To 5% by weight or more.

As the soft aggregate 31, natural rubber, SB
Applicable as long as it has basically rubber elasticity such as a single substance or a mixture of various rubber materials such as R, NBR, EDPM, BR and CR, or an aggregate covered with these rubber materials, various elastomers such as urethane, etc. Is.

The soft aggregate 31 may be a newly manufactured one, or may be a recycled product or a waste material. As long as the shape is fiber-like as described above, the particle size and the aspect ratio can be appropriately selected according to the specifications of the construction surface.

Further, a granular chip rubber prepared separately as the soft aggregate 31 may be further added, which further improves the mixing property of the materials.

The hard aggregate 32 has the above-mentioned Mohs hardness of 7
Inorganic materials such as stones, sands, clays, metal powders and various ceramics, which satisfy the above conditions and have an average particle diameter of 1000 μm or less, are preferable, but a more preferable average particle diameter is 150 to It is 800 μm.

The mixing ratio of the soft aggregate 31 and the hard aggregate 32 may be 5% by weight or more of the hard aggregate 32 (100% by weight) with respect to the soft aggregate 31 (a more preferable embodiment). When the average particle diameter of the hard aggregate 32 is 150 μm, the lower limit of mixing is, by weight ratio, soft aggregate: hard aggregate = 10.
It is 0: 8. On the contrary, when the average particle size is 1000 μm, the upper limit of mixing is soft aggregate: hard aggregate = 100: 4 by weight ratio.
It is 0.

In the present invention, there is no particular lower limit to the average particle size of the soft aggregate 32, but it is also possible to use, for example, an average particle size of 30 μm. In this case, the compounding weight ratio is soft aggregate: hard aggregate = 100. : 5 should be set. Further, the average particle size may be less than 30 μm, and by adjusting the viscosity of the binder to be small, for example, even with 1 μm, some effect can be obtained.

However, the particle size of the hard aggregate 32 is 10
If it is extremely larger than 00 μm, the mixed state tends to be uneven, and it is difficult to obtain a uniform road surface.

As the binder, a resin binder is preferably used. For example, one-component urethane, two-component urethane, epoxy resin, acrylic resin, or various emulsions can be used.

The viscosity of the binder is 1 to 8 Pa · s (1
000 to 8000 cps) is preferable. That is, when the binder is 1 Pa · s (100
If it is less than 0 cps), the viscosity may be too low, and the binder may not be trapped between the aggregates after casting and may flow down onto the substrate. Conversely, 8 Pa · s (8000 cp
If it exceeds s), the viscosity is too high and the binder itself has a high binding force, so that it may not enter into the aggregates and may not be uniformly mixed, which is not preferable.

In this embodiment, the elastic paving material 3 is
It is mainly composed mainly of an aggregate and a binder, but in addition to this, organic / inorganic fibers, resin pieces, pigments, etc. may be appropriately added, and various solvents, antioxidants, and weather resistance agents. Additives such as, or lead-based or tin-based catalysts may be added, and can be appropriately selected depending on the specifications of the elastic pavement 3 to be constructed.

Mixing ratio of aggregate and binder (weight)
Is blended so as to satisfy the range of aggregate: binder = 100: 12 to 100: 35. That is, when the compounding ratio is less than 100: 12, the construction is possible, but in order to improve the durability, it is necessary to apply a pressing pressure equivalent to that of the precast method, which makes the construction troublesome. On the other hand, if the mixing ratio exceeds 100: 35, the amount of the binder is large, so that the porosity of the paving material becomes small, and the water permeability may become low, which is not preferable.

Next, a method of forming the surface layer portion 30 will be described. The construction method of the present invention is a so-called on-site construction method in which the elastic pavement material 3 is mixed at the construction site, is supplied onto the base 2, is leveled, and then pressed. According to this on-site construction method, it is possible to promptly deal with unevenness (unevenness), slope, curve, etc. of the roadbed 1 and the foundation 2.

First, the elastic pavement 3 is prepared by charging an aggregate prepared by mixing the soft aggregate 31 and the hard aggregate 32 in a predetermined weight ratio and at least a binder sufficient to bond the aggregates to the stirrer. Mix. The stirrer may be of an engine type or a motor type, and may be a stirrer such as a so-called mortar mixer in which stirring blades are rotated to mix.

Next, the agitated elastic pavement material 3 is sprayed (supplied) onto the base 2 preferably uniformly, and the surface thereof is leveled to form the surface layer portion 30 (leveling step). Examples of the paving material spraying construction machine include rubber chip construction machines P700 and P200 manufactured by Sumitomo Rubber Co., Ltd., which have a squeegee that scrapes the surface of the elastic paving material to even the surface. When high-precision flatness is required, it is preferable to reciprocate the squeegee in parallel with the base 2.

Next, in the pressing step, the surface layer portion 30 obtained in the leveling step is pressed by a predetermined pressing means so as to have a uniform density. It is preferable to use a pressure roller as the pressing means. The rolling operation may be carried out as many times as necessary before the binder is hardened.

Instead of the pressure roller, a pressing plate set to a predetermined surface pressure may be placed on the surface layer portion 30. In some cases, a rotating disk or the like may be brought into contact with the pavement surface under pressure. It should be noted that, particularly when a pressing plate is used, if the binder is dragged before being cured, a part of the surface layer portion 30 may be peeled off and unevenness may be formed, so be careful.

The curing of the binder can be promoted by performing a heating step of heating the surface layer portion 30 between the leveling step and the pressing step, or simultaneously with the pressing step. By using the heating roller or the heating pressing plate, the heating step and the pressing step can be performed at the same time.

In order for the elastic pavement thus obtained to withstand a sufficient load as a road surface for running a vehicle, the hardness of the surface measured by a CS hardness meter in the cured state of the binder is 60 or more. Preferably there is. If the hardness is less than 60, the pavement surface is soft and the vehicle may lose its posture and become unstable.

In order to minimize the risk of slippage during rain, etc., a DF tester (dynamic friction
The dynamic friction coefficient of the surface measured by a tester) is preferably 0.4 or more.

In this embodiment, the surface layer portion 30 is constructed by the on-site construction method, but it may be constructed by the precast method. That is, it is possible to manufacture only the surface layer portion 30 in advance outside the site such as a factory, bring it to the construction site, and lay it on the base 2 by pasting or laying it down.

[0046]

EXAMPLES Next, specific examples of the present invention will be examined together with comparative examples. First of all, as a preparatory work, open-grained asphalt is spread on a roadbed to a predetermined thickness and leveled, cement milk is poured in to form a base made of semi-flexible pavement for one week, and the surface is leveled by polishing etc. And Sumitomo Rubber Industries, Ltd. primer C918B
Was treated with a primer.

Then, before curing the primer, a surface layer portion made of the elastic pavement material of Examples 1 to 4 and Comparative Examples 1 to 4 below was formed by on-site construction. In each of the examples, soft aggregate (aggregate) has hijiki rubber (Sumitomo Rubber Industries, Ltd. hijiki rubber FR24: approximate width 2 to 4 and length 2 to 40 mm).
(Screen mesh: 2 mm stop, 4 mm pass)) was used. As the hard aggregate (aggregate), silica sand manufactured by Sumitomo Rubber Industries, Ltd. was used. A one-component curing type urethane resin (GB0007 manufactured by Sumitomo Rubber Industries, Ltd.) was used as the resin binder.

Then, a hard aggregate (aggregate), which has been granulated for each example, is blended with the soft aggregate at a predetermined blending ratio, and a resin binder adjusted to have a predetermined viscosity is added for each example, The mixture was uniformly stirred with a universal stirrer. Width of the agitated mixture is 1 m with a construction machine (Sumitomo Rubber Co., Ltd. rubber chip construction machine P200)
× On-site construction with a length of 25 m and a thickness of 20 mm, followed by curing for 1 week to obtain a uniform surface layer portion. With respect to this surface layer portion, the following evaluation tests 1 to 3 were carried out.

Mixing / stirring ability Can the materials be uniformly mixed and stirred? Also, visually confirm whether the binder can be uniformly dispersed in the aggregate. As for the evaluation, ◎ means very good, ○ means good, and △ means slightly bad.
And the defect was rated at four levels of x. : Leveling and pavement When the material is placed, whether the material is laid out easily and finished easily is evaluated by a questionnaire survey of workers. In the evaluation, ⊚ is very good, ∘ is good, Δ is slightly bad, and × is bad. : Pavement flatness Whether or not the pavement surface was flat was judged by walking on the pavement surface and running the vehicle. In the evaluation, the very flatness was ⊚, the flatness was ∘, the unevenness (unevenness) was slightly felt, and the large unevenness (unevenness) was ×.

Example 1 [Aggregate] Hijiki rubber [Aggregate] Silica Sand No. 3 (maximum particle size: 1680 μ)
m, average particle size: 840 μm) [Binder] One-component urethane (viscosity: 6500 cps) [Compounding weight ratio] Aggregate: Aggregate: Binder = 100:
30:27 [Mixing and stirring property] ○ [Surface leveling and paving property] ○ to △ [Pavement flatness] △ [Comprehensive evaluation] ○

Example 2 [Aggregate] Hijiki rubber [Aggregate] Silica Sand No. 4 (maximum particle size: 1190μ)
m, average particle size: 590 μm) [Binder] One-component urethane (viscosity: 6500 cps) [Compounding weight ratio] Aggregate: Aggregate: Binder = 100:
30:27 [Mixing and stirring] ○ [Laying and paving] ○ [Pavement flatness] △ [Comprehensive evaluation] ○

Example 3 [Aggregate] Hijiki Rubber [Aggregate] Silica Sand No. 6 (maximum particle size: 300 μm,
Average particle size: 105 μm) [Binder] One-component urethane (viscosity: 6500 cps) [Compounding weight ratio] Aggregate: Aggregate: Binder = 100:
30:27 [Mixing and stirring] ○ [Laying and paving] ○ [Flatness of paving] ○ [Comprehensive evaluation] ○

Example 4 [Aggregate] Hijiki Rubber [Aggregate] Silica Sand No. 6 (maximum particle size: 300 μm,
Average particle size: 105 μm) [Binder] One-component urethane (viscosity: 3500 cps) [Compounding weight ratio] Aggregate: Aggregate: Binder = 100:
30:27 [Mixing and agitation] ◎ [Surface leveling and paving] ◎ to ○ [Pavement flatness] ◎ to ○ [Comprehensive evaluation] ◎ to ○

<Comparative Example 1> [Aggregate] Hijiki rubber [Aggregate] None [Binder] One-component urethane (viscosity: 11000 cp)
s) [Compound weight ratio] Aggregate: Aggregate: Binder = 100:
0:27 [Mixing and stirring] x [Laying and paving] x [Pavement flatness] x [Comprehensive evaluation] x

Comparative Example 2 [Aggregate] Hijiki rubber [Aggregate] None [Binder] One-component urethane (viscosity: 6500 cps) [Compounding weight ratio] Aggregate: Aggregate: Binder = 100:
0:27 [Mixing and stirring] △ [Laying and paving] × [Flatness of paving] △ [Comprehensive evaluation] △

Comparative Example 3 [Aggregate] Hijiki rubber [Aggregate] None [Binder] One-component urethane (viscosity: 2500 cps) [Compound weight ratio] Aggregate: Aggregate: Binder = 100:
0:27 [Mixing and stirring] ○ to △ [Laying and paving] △ [Paving flatness] △ [Comprehensive evaluation] △

<Comparative Example 4> [Aggregate] Hijiki rubber [Aggregate] Silica Sand No. 1 (maximum particle size: 3360 μ)
m, average particle size: 2380 μm) [Binder] One-component urethane (viscosity: 6500 cps) [Compounding weight ratio] Aggregate: Aggregate: Binder = 100:
30:27 [Mixing and stirring property] X [Surface leveling and paving property] △ to X [Pavement flatness] △ [Comprehensive evaluation] ×

For reference, Table 1 shows specifications and evaluation results of Examples 1 to 4 and Comparative Examples 1 to 4 described above.

[0059]

[Table 1]

The above Examples 1 to 4 and Comparative Examples 1 to 4 are a part of the present invention, and various other studies were conducted. As a result, the following findings were obtained.

According to Examples 1 to 4 and Comparative Example 4, by adding the hard aggregate to the soft aggregate, the hard aggregate penetrates between the soft aggregates and functions as a so-called "roller". Each evaluation improves. However, the average particle size is 1000μ
When it exceeds m, the evaluation is gradually lowered.

According to Examples 3 and 4, the smaller the particle size of the hard aggregate is less than 500 μm, the more significantly the evaluation is improved.

According to Comparative Examples 1 to 3, when the hard aggregate is not added, the viscosity of the binder is low, and the larger the amount, the better the mixed state can be obtained. As a result, if the binder viscosity is 5 Pa · s (5000 cps) or less and the range of aggregate: binder = 100: 20 to 100: 35, it can withstand on-site construction.

When the hardness of the surface of the elastic pavement is 60 or more in the CS hardness tester, the pavement surface has sufficient proof strength for running the vehicle, is stable during walking and running the vehicle, and is stable on the pavement surface. Hard to crack.

If the dynamic friction coefficient of the surface of the elastic pavement in the DF tester when running 60 km / h when the pavement surface is wet is 0.4 or more, the pavement surface is not slippery and safe in both walking and vehicle running. Is obtained. The dynamic friction coefficient of the pavement surface finished in Example 3 was 0.48.

[0066]

As described above, according to the present invention,
An aggregate in which a majority of the fibers (50% by weight or more) is occupied by fibrous rubber has a Mohs hardness of 7 or more, and
Hard aggregates with an average particle size of 1000 μm or less are used as soft aggregates 10.
By adding 5% by weight or more to 0% by weight, the hard aggregate enters between the soft aggregates, fulfills a smooth material function like a so-called "roller", and is conventionally not suitable for on-site construction. Elastic pavement made of rubber can be installed on site.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an elastic pavement of the present invention.

[Explanation of symbols]

1 roadbed 2 groundwork 3 elastic paving material 30 Surface layer 31 Soft aggregate 32 hard aggregate

Claims (6)

[Claims] 1. An aggregate composed of a soft aggregate and a hard aggregate, the majority of which (50% by volume or more) is occupied by fibrous rubber, is mixed with a binder at a construction site, and is cast on a predetermined lower ground. In the elastic pavement constructed as described above, the Mohs hardness is 7 or more, and the average particle size is 1000.
An elastic pavement characterized by containing 5% by weight or more of hard aggregate having a size of not more than μm with respect to 100% by weight of the soft aggregate. 2. The hard aggregate is an inorganic material, and the binder has a viscosity of 1 to 8 Pa · s (1000 to 800).
The elastic pavement according to claim 1, which is 0 cps). 3. The elastic pavement according to claim 1, wherein the compounding ratio (weight) of the total aggregate and the binder is 100: 12 to 100: 35. 4. In the cured state of the binder, C
The elastic pavement according to any one of claims 1 to 3, wherein a surface hardness measured by an S hardness meter is 60 or more. 5. The dynamic friction coefficient of the surface measured by a DF tester when running at 60 km / h in a wet state is 0.
The elastic pavement according to any one of claims 1 to 4, which is 4 or more. 6. A soft aggregate comprising fibrous rubber occupying 50% by volume or more of the total, and a hard aggregate having a Mohs hardness of 7 or more and an average particle diameter of 1000 μm or less is used as the soft bone. 5% by weight or more based on 100% by weight of the material, and a step of placing an elastic pavement material obtained by mixing with a binder at a construction site on a predetermined lower ground. Paving method.