JPH0317303A - Surface longer body consisting of polyoxymethylene fiber body - Google Patents

Abstract

PURPOSE:To make it possible to lay a longer surface body as a reinforcing material on a road, soil, etc., by forming polyoxymethylene fiber bodies having the tension elastic modulus higher than a specific value into the longer surface body of thermoplastic resin. CONSTITUTION:Five polyoxymethylene fiber bodies with 0.5mm of the external diameter and having the tension elastic modulus higher than 20GPa, such as 40GPa, are arranged in a row, and they are formed into a surface longer body of thermoplastic resin such as vinyl chloride resin by a grid process. It is laid on a road, concrete and soil. According to the constitution, the generation of cracks in the road can be prevented, and the road life can be extended.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a planar elongated body made of a polyoxymethylene filament and a thermoplastic resin, which is suitable for reinforcing materials such as asphalt, concrete, and soil. .

[Conventional technology]

Various fiber materials are used as reinforcing materials for asphalt, concrete, and soil. An example of using fiber as a reinforcing material for asphalt mixture is JP-A-52-892.
Publication No. 14 discloses a method for paving an asphalt road, which is characterized by embedding a braided network made of fibers in asphalt mixture. This publication describes that a braided network made of fibers is buried in order to prevent the asphalt mixture from cranking or sinking. However, nylon/polyester fibers are preferred as the material for the Hewei fibers used here.
It is said that the fibers have a density of 5,000 denier or more and can be used to create net fabrics as they are. In this case, the reinforcing effect of the asphalt mixture is small because the tensile modulus of the synthetic fiber itself is low. ↓ When using such synthetic fibers, there is a slight effect on cracking, but especially in the summer Because the tensile modulus of the fiber is low, it is not effective in preventing ruts on asphalt. Furthermore, since the net fabric is formed from the aggregate of Hewei fibers itself, the filaments are exposed as they are on the surface of the rope, making it easy for the fibers to break, and when laying on asphalt, the tensile strength of the fibers decreases due to abrasion and catching. There were drawbacks that often occurred. As an example of another reinforcing material, Japanese Patent Application Laid-Open No. 11472/1983 discloses a glass fiber roving cloth with a special weave for use in reinforcing asphalt. This reinforcing material also uses glass fiber that is easy to break, so single threads break during installation.
There are some drawbacks that make it difficult to work with.

Similar mesh or grids made of resin are used for soil as well. For example, there is Netron's ``Tensar.'' This is a grid made of l-axis/bi-axis stretched body of Hekai resin, and is used for soil reinforcement. However, the tensile strength of the stretched portion of this grid of Gokai fibers is only 0. 4 GPa, and the tensile modulus is also quite low. Therefore, it was necessary to use it for a long time before it could be used for soil reinforcement. Currently, there are few materials suitable for reinforcing asphalt, concrete, and soil.

[Problem to be solved by the invention]

The present invention provides a material that is effective for reinforcing asphalt, concrete, and soil, and that causes less damage to fibers when laid.

[Means for Solving the Problems] The present invention is a planar elongated body in which a plurality of polyoxymethylene filaments having a tensile modulus of elasticity of 20 GPa or more are arranged in parallel and embedded and integrated in a thermoplastic resin.

The present invention is characterized in that it is a planar elongated body made of polyoxymethylene filaments. That is, the planar elongated body according to the present invention is one in which polyoxymethylene filaments are integrated with a thermoplastic resin.

The planar elongated body of the present invention itself has high tensile strength and high tensile modulus, so it can be used as it is or as a mesh body for asphalt, concrete, and soil reinforcement applications, such as woven fabric, knitted fabric,
It can be used by processing into nets, grids, honeycombs, etc. In this case, the reticular body may have any shape, but a grid is particularly preferred.

In the present invention, it is essential to use polyoxymethylene striae. In the case of a polyoxymethylene filament, since it is in the form of a monofilament, it has stiffness and can be stretched at a high magnification, making it relatively easy to increase the tensile modulus of the filament. As reinforcement for asphalt mixture, it has the advantage that it can be installed on roads without pulling both ends of the net.

For other synthetic fibers, especially fine denier fibers,
Because there is no waist, when laying the finished net on the road,
The disadvantage is that tension must be applied to both ends of the net to stretch it. However, in the case of polyoxymethylene filaments, since they are stiff, they can be laid very easily in the form of a flat plate on roads, and the construction work can proceed quickly.

It is essential that the polyoxymethylene filament used here has a tensile modulus of 20 GPa or more.

Polyoxymethylene striatum is, for example, disclosed in Japanese Patent Application Laid-open No. 60183.
It is obtained by the method disclosed in Japanese Patent No. 122.

This is a method in which an unstretched polyoxymethylene body is shaped and then stretched 10 times or more while being continuously heated and pressurized in a heating medium. Tensile modulus is important in determining the reinforcement performance of asphalt. Particularly at high temperatures in the summer, asphalt softens and a tensile modulus of elasticity of 2QGPa or more is required to prevent rutting.

Particularly preferably, the tensile modulus is 400 Pa, and the larger the tensile modulus, the greater the effect.

In the case of polyoxymethylene filaments, there is a certain correlation between the stretching ratio and the tensile modulus and tensile strength. That is, the tensile modulus of polyoxymethylene of 20 GPa is the tensile strength of about 1. 3
GPa, and a tensile modulus of 40 GPa corresponds to a tensile strength of approximately 1. Equivalent to 7 GPa. Therefore, in the case of a polyoxymethylene filament, a high tensile modulus also means a high tensile strength. The tensile strength and tensile modulus of the polyoxymethylene filament according to the present invention are clearly different from those of the Gakkai resin used in conventional grids. This means that the reinforcing material using polyoxymethylene filaments has a large reinforcing effect with the same basis weight, and it is possible to reduce the date with the same reinforcing effect. The date here refers to the weight (g/rd) of the net-like body, and the smaller the date, the lighter it is. The outer diameter of the polyoxymethylene strands used here is usually 0. Preferably, the thickness is 1 mm or more. Although the outer diameter is not related to the tensile modulus, it is preferable for the outer diameter to be somewhat large in terms of the stiffness of the filament.

A grid processing method will be described as an example of processing polyoxymethylene filaments into a net-like body, but other woven fabrics, knitted fabrics, and net-like bodies can also be manufactured by the same method.

As a method of processing polyoxymethylene filaments into a grid, an aggregate of several to several tens of polyoxymethylene filaments is constructed as a planar elongated body. This planar elongated body is in the shape of a belt or string. The planar elongated body has a width of 4 to 40 nm and a thickness of about 1 to 10 m. In this case, as a method of giving shape to the planar elongated body, there is a method of arranging polyoxymethylene filaments in parallel and then coating them with a thermoplastic resin. In the present invention, the thermoplastic resin is preferably a resin having a temperature up to about the melting point of the polyoxymethylene filament, and is particularly preferably in the form of a planar elongated body formed by melt extrusion. Preferred thermoplastic resins include vinyl chloride, polyethylene, and polypropylene. In particular, from the viewpoint of reinforcing performance, it is preferable to use a material that does not contain too many impurities other than polyoxymethylene filaments, that is, a material in which the proportion of thermoplastic resin used is small, since the tensile modulus as a whole does not decrease. As an example of a preferable form, for example, the wire diameter is 0.5 to 1.5 f.
There is a method of assembling 3 to 30 pieces of fIII1 to form a planar elongated body.

As a method of forming a grid, there is a method of arranging a large number of planar elongated bodies in parallel to form a grid. Since it is a grid, the planar elongated bodies are arranged at distances in the vertical and horizontal directions, and the number of open holes in the grid is at least 1 cd.
The space should be empty, particularly preferably 2 cd or more. It is preferable to have this size of openings because the aggregate will penetrate into the openings of the asphalt and the planar elongated body will be integrated from the top and bottom while containing the aggregate. When processing grids from a planar elongated body, the intersections of the grids may or may not be joined. This has good adhesion between the planar elongated body made of polyoxymethylene filaments and asphalt,
This is because when actually embedded in asphalt mixture, the grid will be integrated regardless of whether or not there is adhesion at the grid intersection points. however,
It is preferable that the intersection points of the grid are joined to some extent because the form of the grid is stable and the grid is easier to handle as a whole.

The planar elongated body of the present invention is particularly suitable as a reinforcing material for asphalt mixture for roads.

Asphalt mixture is commonly used for road paving and consists of asphalt, aggregate, filler, and other additives. As aggregate used for asphalt, crushed stone having a particle size of approximately 13 to 20 fflI1 in outer diameter is generally used.

Roads to which the reinforcing material of the present invention can be applied may be any of temporary roads for general construction, access roads, and full-scale roads. In particular, it can be applied to temporary roads, and by taking advantage of the road's ability to prevent ruts and cracks after temporary construction, it is possible to reduce maintenance later on.

〔Example〕

The present invention will be explained in more detail, but the present invention is not limited to this example.

Example 1 An example in which the planar elongated body according to the present invention is used for reinforcing asphalt mixture is shown. A wheel tracking test was conducted to evaluate the reinforcing properties of asphalt mixture, and the thermal stability (OS
) was used for comparative evaluation. The samples used in the test were manufactured as follows.

The tensile modulus is 40 GPa and the outer diameter is 0. A planar elongated body was manufactured by arranging five 5 mm polyoxymethylene filaments in parallel and integrating them with vinyl chloride resin. The tensile strength of this planar elongated body was about 150 kg, which was almost comparable to the total tensile strength of the polyoxymethylene strands.

A planar elongated body with a grid of 35 ff III pitch and 30 ci square grid was used, and this grid was placed in the center of an asphalt mixture having a thickness of IOcI. As the asphalt mixture, dense-grained Ascon (l3) manufactured by Asphalt Paving Kaname X (@Japan Road Association) was used. As a comparative example, the tensile modulus of polyoxymethylene filament is 15G.
A similar planar body manufactured using a low tensile modulus of Pa (Comparative Example 1) and a commercially available polyester nonwoven fabric (date 150 kg/rrf) were used. (Comparative Example 2).

Test conditions were 60°C and solid tire ground pressure 6.4kg.
/CTa at 42 times/min, and the number of times in lffITI1 modified Surma was defined as DS. Therefore, the larger the DS value, the greater the effect on rutting prevention. The results are shown in Table I. From Table 1, it can be seen that the DS of the products using polyoxymethylene filaments is improved.

Table 1 [Effects of the Invention] By laying the planar elongated body made of the polyoxymethylene filament of the present invention on roads, concrete, or soil, for example, on roads, ruts and cracks caused by the passage of vehicles, etc. It is possible to prevent the occurrence of such problems and extend the life of the material, and in the case of soil, it is highly effective in reinforcing embankments.

Claims (1)

[Claims] 1. A planar long body made by embedding and integrating a plurality of polyoxymethylene filaments having a tensile modulus of elasticity of 20 GPa or more in parallel in a thermoplastic resin.