JPH06158607A - High elastic modulus compound forming material for asphalt pavement reinforcement - Google Patents

Abstract

PURPOSE:To improve the effect of reinforcing material to control the crack of asphalt by using the reinforcing material which is covered with material sticking to the asphalt, and formed of the bundle of fiber including high elastic modulud fiber, and has the specified values of physical properties. CONSTITUTION:Fiber material 2 in which tensile elastic modulus is 20 to 200GPa, and breaking ductility is 10 to 20% is selected. For instance, polyacetal fiber. Next, another fiber 3, for instance nylon, is combinedly woven to form the compound forming body 1 of a woven cloth. The compound forming body 1 is then provided with an opening part 5 whose one side is shorter than 10mm in length. In this case, the thickness of the compound forming body 1 is 0.2 to 3mm, and the tensile elastic modulus per unit length is 50kg/mm. In addition, material closely adhesive to asphalt is previously coated on fiber material 2, or after the compound forming body 1 formed of woven cloth is processed, it is coated on the fiber material 2. The compound forming body 1 is buriedly provided in the asphalt. Thus effect to control cracking fluidization and track excavation of the asphalt pavement can be improved.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a reinforcing material for asphalt pavement. More specifically, the present invention relates to a high-modulus composite molded article for reinforcing asphalt pavement, which comprises a fiber bundle containing high-modulus fibers coated with a material that adheres to asphalt.

[0002]

2. Description of the Related Art Conventional asphalt paved roads are
It is constructed by forming an asphalt layer on the roadbed. However, in recent years, pavement cracks, fluidization, and rubbing have occurred on many roads due to the increase in vehicle loading weight and traffic volume, and road repairs such as overlays must be frequently carried out without waiting for their useful life. The problem is happening. Usually, cracking, fluidization, and rutting depend on the hardness of the asphalt used, so soft asphalt is used to prevent cracking, and hard asphalt is used to prevent fluidization and rutting. ing. Therefore, asphalt alone could not solve these problems at the same time. Conventionally, in order to solve such a problem,
Attempts have been made to stretch plastic stretch nets (geogrids), synthetic fiber woven or non-woven fabrics (geotextiles), wire mesh, etc. as reinforcement materials in the asphalt layer. However, since the conventional geogrids and geotextiles have a low tensile elastic modulus and a large elongation, the elongation strain of the asphalt in the loaded state cannot be sufficiently suppressed and the reinforcing effect is small. Further, since the wire netting has a high elastic modulus but is too small in elongation, it cannot absorb the impact, thus making the asphalt layer brittle.

Further, in order to realize the reinforcing effect, it is important to bond the asphalt and the reinforcing material. For geotextiles, conventionally, for this purpose, spraying of asphalt emulsion, tack coat agent, etc. on the reinforcing material and coating of the surface with a material that adheres to asphalt have been carried out, but conventional geotextiles are not always sufficient. No results have been obtained. As for the geogrid, since the base material has poor adhesiveness, sufficient adhesion has not been achieved even by such pretreatment and coating treatment. There is also a problem that if the reinforcing material is thick, interfacial peeling easily occurs due to bending stress and shear stress applied to the asphalt layer.

[0004]

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a composite molded article which has an excellent effect of suppressing cracking, fluidization and rutting of asphalt pavement and does not cause interfacial peeling. It was made for the purpose.

[0005]

Means for Solving the Problems The present inventor has conducted extensive studies to develop a reinforcing material having a good reinforcing effect on asphalt pavement, and as a result, a fiber having a specific tensile elastic modulus and elongation. It was found that the object can be achieved by using, as a reinforcing material, a composite molded article composed of a material, having a specific tensile elastic modulus and shape and high adhesiveness, and based on this finding, the present invention was completed. I arrived.

That is, according to the present invention, the tensile modulus of elasticity is 20 to 200 GP coated with a material that adheres to asphalt.
a, a composite molded article composed of a fiber bundle containing high elastic modulus fibers having a breaking elongation of 10 to 2%, wherein the length of one side of the opening of the composite molded article is less than 10 mm, and A high elastic modulus composite molded article for asphalt pavement reinforcement, which has a tensile elastic modulus (tensile elastic modulus x thickness) of 50 kg / mm or more and a composite molded body thickness of 0.2 to 3 mm. .

The present invention will be described in detail below. In the present invention, the tensile elastic modulus is 20 to 200 GPa, preferably 30 to 200 GPa, and more preferably 40 to 200 GPa.
It is in the range of Pa and has an elongation of 10 to 2%, preferably 8 to
The fiber material in the range of 2%, more preferably 6 to 3% is effectively used in that it has a high elastic modulus and an appropriate elongation. When the tensile modulus is 20 GPa or less, the expansion and contraction of asphalt (commonly known as asphalt concrete) containing crushed stone is not sufficient, and when the elongation is 10% or more, it stretches better than the asphalt concrete, so the reinforcing effect is small and below 2%, it becomes asphalt. It is not preferable because it absorbs little shock.

Examples of the fiber material effective in the present invention include polyacetal fiber, aromatic polyamide fiber, polyvinyl alcohol fiber, glass fiber, carbon fiber,
Examples include wholly aromatic polyester fibers, high molecular weight polyethylene fibers, polypropylene fibers and the like. Of these, polyacetal fibers, aromatic polyamide fibers, polyvinyl alcohol fibers, and glass fibers are preferable because they have the above-mentioned tensile elastic modulus and elongation in appropriate ranges and high heat resistance. Polyacetal fiber has a tensile modulus of 20 to 60 GP
A having an elongation of 10 to 4% is preferable. Also, two or more kinds of these fiber materials can be used.

In the present invention, a woven fabric or the like obtained by molding these fiber materials is usually used. For example, a woven fabric can be obtained by rolling a textile material on a loom. In this case, it is preferable to interweave fibers having a normal tensile elastic modulus (20 GPa or less) in addition to the high elastic modulus fibers. The interwoven structure facilitates the woven fabric forming process of the high elastic modulus fiber, imparts the softening property to the woven fabric, and has the effect that the adhesive for asphalt adhesion is uniformly attached to the woven fabric.
Preferable examples of such fibers for interweaving include nylon, polyester, cellulose and polyethylene.

The size of the opening of the composite molded article according to the present invention is required to have a side length of less than 10 mm. The inventor has already found that a net-shaped molded article for reinforcing asphalt pavement using a high elastic modulus fiber (Japanese Patent Application No. 2-406472).
However, the present invention finds that by further reducing the size of the opening of the reticulated molded body, a very stable effect can be obtained particularly for fluidization and rut control of asphalt pavement. I was able to. Also,
A stable effect was also obtained for crack suppression. It is considered that the reason for this is that by laying a high elastic modulus composite molded body having a small opening, the load is alleviated and averaged, and crack propagation is shielded on average. The size of the opening can be made as small as possible so that the asphalt can permeate, but due to the restrictions on the processing of the woven fabric, the size of the opening can be 0.
It is preferably 5 mm or more.

The composite molded article of the present invention is required to have a tensile elastic modulus per length of 50 kg / mm or more. Preferably 100 kg / mm or more, more preferably 2
It is better to set it to 00 kg / mm or more. It has been found that this is the performance required of the reinforcement to prevent cracking and flow failure of asphalt concrete. here,
The tensile modulus of elasticity per length is defined by the tensile modulus of elasticity in cross section of the composite molded article including the opening times the thickness of the composite molded article. If this value is 50 kg / mm or less, the reinforcing effect is not sufficient. Further, the higher this value is, the higher the reinforcing effect is, but the upper limit thereof is usually 2400 kg / mm, though it depends on the tensile elastic modulus of the fiber material used. The value of the tensile elastic modulus per length can be adjusted by the amount of the fiber material having the tensile elastic modulus in the above range.

The thickness of the composite molded article of the present invention is 0.2 to 3 m.
m. A range of 1-2 mm is usually suitable. A molded product having a thickness of 0.2 mm or less may be cut due to scratches during the laying work, and a molded product having a thickness of 3 mm or more is stiff and unfavorable for laying workability and laying condition. The composite molded article of the present invention having these physical properties and structure is coated with a material that adheres to asphalt. At this time, it is preferable that the fibrous material as the substrate and the covering material have higher adhesive strength.
For this reason, it is preferable that the fiber material having poor adhesive strength be appropriately pretreated. For example, a stretched product of polyacetal can be made into a fibrous material having good adhesion to a coating material by modifying the surface with resorcin or a mixture of resorcin and a resorcin-formaldehyde condensate (Japanese Patent Laid-Open No. 64-236242). Gazette).

As a material which adheres to asphalt, a material having a solubility parameter value (SP value) close to that of asphalt [8-9 (cal / cm ³ ) ^1/2 ] is selected. As such, resorcin-formaldehyde condensate, resorcin-formaldehyde-latex aged product, asphalt, petroleum resin, styrene-butadiene copolymer, hydrogenated styrene-butadiene copolymer, rubber, wax, soft polyvinyl chloride, Polyvinyl acetate, modified polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, polyurethane, modified polyurethane, polyvinyl alcohol, modified polyvinyl alcohol , And modified polyamides, and compositions thereof are suitable examples.

The coating with the above-mentioned coating material can be carried out, for example, by a method of coating a woven fabric with a fiber material and then coating it, or a method of using a fiber material coated in advance. The form of coating with the coating material is, for example, impregnation of the coating material, coating, film lamination, or the like, and is appropriately selected depending on the material. In addition, if the above-mentioned asphalt is coated with a film made of a material that adheres to the above asphalt, the asphalt reinforcing effect is further stabilized, and the tackiness of the coating when using asphalt as the coating is prevented. However, the shape retention of the composite molded article is improved and the laying workability is improved, which is preferable. Such a film is preferable in terms of adhesion because it easily melts at the temperature of ascon during construction and dissolves in asphalt.

Next, the present invention will be described with reference to the accompanying drawings. FIG. 1 is a preferred example of the composite molded article of the present invention. In FIG. 1, 1 is a plain weave of a fiber material, which is then coated with a material that adheres to asphalt. A composite molded body created by
Reference numeral 2 is a high elastic modulus fiber constituting the composite molded body, 3 is a fiber used for interwoven, 4 is a covering material that adheres to asphalt, and 5 is an opening of the composite molded body.

[0016]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples. In addition, in the following examples, polyvinyl alcohol fibers were prepared by gel-drawing high-molecular weight polyvinyl alcohol. The value of the tensile elastic modulus per length was adjusted by the amount of the fiber material used. A composite molded body composed of various fibers used in the examples was prepared as follows.

[0017]

Example 1 [Composite molded product of polyvinyl alcohol fiber] Polyvinyl alcohol fiber having a tensile elastic modulus of 20 GPa and a breaking elongation of 10% and a nylon tire cord were woven together to form a woven fabric having 5 mm square openings. After applying Kachicoat S [trade name of Nikki Chemical Industry Co., Ltd.], which is an asphalt-based coating material, a polyethylene film is adhered onto the coating and the thickness of 1.5 mm per length as shown in Table 1 is applied. A composite molded body having a tensile modulus shown in FIG. 1 was prepared.

[0018]

Example 2 [Composite molded article of polyacetal fiber] Tensile elastic modulus 30G
Pa, a 0.5 mm diameter polyacetal fiber having a breaking elongation of 8% [Tenac SD Asahi Kasei Kogyo Co., Ltd.] and nylon tire cords were alternately woven to form a woven fabric having 5 mm square openings. Ethylene-vinyl acetate copolymer [Suntech EVA Asahi Kasei Kogyo Co., Ltd. trademark]
The composite molded body shown in FIG. 1 having a tensile elastic modulus per length as shown in Table 1 having a thickness of 1.5 mm was prepared by coating with.

[0019]

Example 3 [Composite molded article of aromatic polyamide fiber] Tensile elastic modulus 70
An aromatic polyamide fiber having a GPa and a breaking elongation of 4.4% (trademark of Technora Teijin Ltd.) and a nylon tire cord were used to form a woven fabric having 5 mm square openings, and then coated with montan wax. The composite molded body shown in FIG. 1 having a tensile elastic modulus per length as shown in Table 1 having a thickness of 1.5 mm was prepared.

[0020]

Example 4 [Glass Fiber Composite Molded Product] A glass fiber having a tensile modulus of elasticity of 70 GPa and a breaking elongation of 4% and a nylon tire cord were used to make a woven cloth having 5 mm square openings, and then 10% of asphalt. , Petroleum resin 10%, Montan wax 80
%, And a film made of polyethylene and an ethylene-vinyl acetate copolymer [Suntec S film (trademark, manufactured by Asahi Kasei Kogyo Co., Ltd.)] is coated on the mixture to give a thickness of 1.5 mm as shown in Table 1. A composite molded body having a tensile modulus of elasticity per length was prepared.

[0021]

[Comparative Example 1] The following fluidization and rut digging suppression test conducted without using a reinforcing material was set as Comparative Example 1.

[0022]

Comparative Example 2 A composite molded body was prepared in the same manner as in Example 2 except that the openings of the woven cloth were 30 mm square.

[0023]

[Comparative Example 3] The following crack generation suppression test conducted without using a reinforcing material was set as Comparative Example 3.

[0024]

Comparative Example 4 A polyester cloth for tire cord having a tensile modulus of elasticity of 10 GPa and a breaking elongation of 15% was used to prepare a woven fabric having 30 mm square openings, and then coated with Toughprene [trademark of Asahi Kasei Kogyo KK]. And the thickness is 1.5 mm,
A composite molded body having a tensile elastic modulus per length of 20 kg / mm was prepared. [Fluidization / Rubbing prevention test] A wheel tracking tester was used under the following conditions.

Composite molded product (co-test product size: 30 cm square)
Is buried at the boundary between the upper layer of 3 cm thick ascon and the lower layer of 5 cm thick askon at the center, and the total load is 70 k.
g, wheel load 8 tons, ground pressure 6.4 kg / cm ² , running speed 21 reciprocations / min, no traverse, test temperature 60 ° C, test time 60 ° C, the final deformation, deformation rate and dynamic stability The degree was measured. The deformation rate was a value in 45 minutes to 60 minutes. The asphalt mixture of the surface layer and the lower layer used in the experiment is the surface layer type I of Japan Highway Public Corporation and has the following composition. Types of asphalt Straight asphalt 60/80 Composition of aggregate Mixture ratio (%) No. 6 crushed stone 39 No. 7 crushed stone 18 Screening 17 Coarse sand 13 Fine sand 9 Stone powder 4 Test results are shown in Table 1.

[0026]

[Table 1]

The above test was carried out three times, and stable test results were obtained. Further, a composite molded body was prepared in the same manner as in Example 2 except that the openings of the woven cloth were 8 mm square, and the above-mentioned test was conducted. The same was true for the final deformation amount, deformation rate, and dynamic stability. The result was obtained. [Crack generation suppression test] The test was performed under the following conditions using a wheel tracking tester.

Composite molded product (co-test product size: 30 cm square)
Is embedded at the boundary between the upper layer ascon of 3 cm in thickness and the lower layer of ascon in 5 cm divided in the center, and the load is 100 k.
The wheel tracking test (WT test) was carried out at g, a running distance of 22.8 cm, and a running speed of 21 reciprocations / minute, and the time until a crack penetrates the upper layer ascon was compared with the following comparative example. The comparison was made based on Comparative Example 3. Also,
The asphalt mixture of the surface layer and the lower layer used in the experiment is the surface type I of the Japan Highway Public Corporation and has the same composition as in the case of the fluidization / rut resistance control test. The test results are shown in Table 2.

[0029]

[Table 2]

The above test was carried out three times, and stable test results were obtained.

[0031]

INDUSTRIAL APPLICABILITY The composite molded article of the present invention has a remarkable effect on fluidization, rut control, and crack control of asphalt pavement and is excellent in lightness as a fiber material, flexibility, and laying workability. It is useful as a reinforcing material for roads.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the structure of a composite molded body that is an example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite molded body of this invention 2 High elastic modulus fiber which comprises a composite molded body 3 Fiber used for interweaving 4 Covering material which adheres to asphalt 5 Opening of composite molded body

Claims (3)

[Claims] 1. A tensile elastic modulus of 20 to 200 GPa and a breaking elongation of 10 to 2 coated with a material that adheres to asphalt.
% Of the fiber having a high elastic modulus, the length of one side of the opening of the composite molded body is less than 10 mm, and the tensile elastic modulus per length of the composite molded body (tensile elastic modulus x
Thickness) is 50 kg / mm or more and the thickness is 0.2 to 3 mm, a high elastic modulus composite molding for asphalt pavement reinforcement. 2. The high elastic modulus fiber according to claim 1 is at least one fiber selected from polyacetal fiber, aromatic polyamide fiber, polyvinyl alcohol fiber, glass fiber and carbon fiber. A high-modulus composite molding for asphalt pavement reinforcement. 3. The asphalt-adhesive material according to claim 1, wherein the resorcin-formaldehyde condensate, resorcin-formaldehyde-latex aged product, asphalt, petroleum resin, styrene-butadiene copolymer, hydrogenated styrene-butadiene co-polymer. Coalesced, rubber, wax,
Polyethylene, soft polyvinyl chloride, polyvinyl acetate,
Modified polyvinyl acetate, ethylene-vinyl acetate copolymer,
Polyvinylidene chloride, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, polyurethane, modified polyurethane, polyvinyl alcohol, modified polyvinyl alcohol, and modified polyamide, and compositions thereof A high modulus composite molding for asphalt pavement reinforcement, characterized by: