JP4168324B2 - Composite sheet for civil engineering materials - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite sheet for civil engineering materials that has high strength and excellent filter characteristics and is particularly useful as a filter sheet for a concrete block mat.
[0002]
[Problems to be solved by the invention]
Conventionally, so-called block mats in which a large number of concrete blocks are fixed in a grid pattern on one surface of a filter sheet have been widely used for the purpose of preventing soil surface erosion. This block mat is lifted by grabbing both ends in the longitudinal direction by a heavy machine, and is laid directly on the embankment slope or the like. For this reason, the filter sheet is required to have enough strength to withstand the weight of the concrete block group, strength to withstand rough handling during construction, strength to withstand unevenness and protrusions on the laying surface, and the like.
[0003]
In response to these strict requirements, the use of a polypropylene short fiber nonwoven fabric reinforced with polyester long fibers arranged in the warp (longitudinal) direction has been proposed (for example, see Patent Document 1). The aim is to ensure the filter characteristics with polypropylene nonwoven fabric, mainly bearing the weight of the concrete block group that is applied at the time of construction with polyester long fibers arranged in the warp direction. And in the manufacturing method, a polypropylene short fiber web is laminated | stacked on the arranged polyester long fiber, and the needle punching is given. In order to finish the block mat, a concrete block is molded and placed on the polypropylene short fiber web side, and is fixed using the anchor effect of the polypropylene short fibers which are fuzzy.
[0004]
[Patent Document 1]
Japanese Examined Patent Publication No. 1-35106
According to this proposal, a filter sheet with improved warp strength can be obtained, but some problems remain as follows. That is, the warp strength in the warp direction is almost borne by the polyester long fibers, and the contribution rate of the polypropylene short fiber nonwoven fabric portion is small, so that the warp strength in the warp direction is not necessarily obtained as a whole. Further, since they are easily torn along the arranged polyester continuous fibers, they may be torn and damaged when twisted randomly during construction or caught on protrusions on the construction surface. Moreover, since the polypropylene short fiber which was fluff was easy to be pulled out, the sufficient anchor effect was not exhibited. In addition, in order to secure the strength of the polypropylene short fiber web itself and to make it into a non-woven fabric, and at the same time, in order to integrate the obtained polypropylene short fiber non-woven fabric and the polyester long fiber, a fairly dense needle punching is performed. The polyester filaments were cut by contact with the needle, and the warp strength was reduced.
[0006]
Therefore, in view of the above-mentioned problems of the prior art, the present inventor has earnestly provided a composite sheet for civil engineering materials in which warp direction tensile strength, tearing strength, concrete block fixing force and the like are significantly improved, and a method for producing the same. As a result of repeated studies, the present invention has been achieved.
[0007]
[Means for Solving the Problems]
That is, the present invention has the following configuration.
1. A composite sheet for civil engineering materials, in which a needle-punched long-fiber nonwoven fabric layer and a reinforcing layer composed of a group of filaments arranged vertically or horizontally are integrated by needling .
2. Civil engineering materials composite sheet of the first described the long-fiber nonwoven fabric ing from polyethylene terephthalate.
3. Civil engineering materials composite top sheet SL first described tensile strength of the filaments of the reinforcing layer is Ru der than 9 g / d.
4). Civil engineering materials for the composite sheet of the above Symbol first described civil engineering materials for the composite sheet is Ru filter sheet der of concrete block mat.
[0008]
Next, embodiments of the composite sheet for civil engineering materials according to the present invention will be described in detail based on the drawings.
[0009]
FIG. 1 shows an example of a particularly preferred embodiment of the present invention, in which a composite sheet 10 for civil engineering materials is subjected to needle punching which is polymerized on both sides of a reinforcing layer 14 composed of filament groups arranged vertically or horizontally. The long-fiber nonwoven fabric layer 12 is composed of two layers. And the long-fiber nonwoven fabric layer 12 and the reinforcement layer 14 are integrated by needling. However, since the fibers in the long-fiber nonwoven fabric layer 12 and the filaments in the reinforcing layer 14 are mixed by needling, the boundary between the two layers is not clear as schematically shown in this figure. Here, the longitudinal direction means the longitudinal direction of the civil engineering material composite sheet 10.
[0010]
This composite sheet 10 for civil engineering materials is not only reinforced by the reinforcing layer 14, but also the excellent tensile strength and tear strength of the long-fiber nonwoven fabric layer 12 contribute, and particularly the longitudinal strength and tear strength are exceptional. Has been enhanced. Moreover, the feature of the long-fiber nonwoven fabric that it is thinner than the short-fiber nonwoven fabric remains. Further, since the needle-punched long fiber nonwoven fabric layer 12 is used, fluff-like or loop-like fibers protrude from the sheet surface. Moreover, since the long fiber nonwoven fabric layer 12 and the reinforcement layer 14 are integrated by needling, both do not peel.
[0011]
A block mat can be manufactured by adhering a concrete block to the composite sheet 10 for civil engineering material. That is, the ready-mixed concrete is placed in a concrete block mold, and the civil engineering material composite sheet 10 is laid and bonded thereon. Then, the mold may be removed after curing. Since the composite sheet 10 for civil engineering materials is thin, handling becomes easy and thick winding can be achieved, and the manufacturing cost can be reduced as compared with the related art. Fluffy or loop-like fibers protruding from the surface of the civil engineering material composite sheet 10 are embedded in the concrete block, and the concrete block is firmly fixed to the civil engineering material composite sheet 10 by the anchor effect thereof.
[0012]
The obtained block mat inherits the excellent physical properties of the composite sheet 10 for civil engineering materials as it is, the tensile strength sufficient to bear the weight of the concrete block group, various deformation stresses applied during construction, Has sufficient tear strength to withstand unevenness. And since the fluff or loop-shaped protruding fiber which functions as an anchor is a long fiber, it is difficult to come out, and the anchor effect is enhanced more than before, and the fixing force of the concrete block is particularly enhanced.
[0013]
FIG. 2 shows an example of a particularly preferred method for producing the composite sheet for civil engineering materials according to the present invention. That is, two long-fiber nonwoven fabrics 13 that have been needle-punched in advance are prepared, and needling is performed while supplying filament groups 15 that are arranged vertically or horizontally between them. The filament group 15 may be in the form of a sheet that has been pre-beamed or woven, or may be fed directly from a creel stand. Further, the needling may be performed in two upper and lower directions, or may be performed in either one direction.
[0014]
The reason why the long-fiber nonwoven fabric 13 previously needle punched is used is to avoid the filament group 15 from being cut or damaged by needling as much as possible. For example, if a long fiber web that is not needle punched is used, high density needling must be performed in order to ensure the physical properties of the long fiber nonwoven fabric and the necessary amount of fuzz. As a result, the filament group 15 is significantly damaged by the needle, and the reinforcing effect of the reinforcing layer 14 is greatly impaired. By using a needle-punched non-woven fabric that has been needle punched in advance, the minimum needling required for integration can be suppressed, and damage to the filament group 15 can be greatly reduced. However, the method for producing a composite sheet for civil engineering materials according to the present invention is not limited to using a needle-punched long fiber nonwoven fabric in advance, using a long fiber web, a weakly heat-bonded long fiber nonwoven fabric, or the like, The needle-punched long fiber nonwoven fabric layer 12 can also be formed by needling when integrated with the filament group 15.
[0015]
Moreover, the integration means of the long fiber nonwoven fabric layer 12 and the reinforcement layer 14 is not specifically limited. Sinter lamination, extrusion sand lamination, quilting, adhesion, etc. can avoid filament damage due to needling. However, the integration by needling is particularly preferably performed because it is easy to ensure the water permeability required for the filter sheet of the block mat and it can be integrated at a low cost.
[0016]
The reinforcing layer 14 is composed of a group of filaments arranged vertically or horizontally. Since the block mat is lifted and constructed at both ends in the longitudinal direction, the tensile strength in the longitudinal direction is regarded as the most important. For this reason, as the reinforcing layer 14, the presence of filament groups arranged in the vertical direction is unavoidable, and in order to achieve this with the minimum amount and the lowest cost, the reinforcing layer 14 is composed of only the filament groups arranged in the vertical direction. It is preferable to do this. However, since the composite sheet 10 for civil engineering materials that is such a reinforcing layer 14 is naturally not reinforced in the tensile strength in the transverse direction or tearing strength in the longitudinal direction, troubles such as breakage due to messy handling during construction. May occur. If a fabric such as a woven fabric in which filament groups are arranged not only in the vertical direction but also in the horizontal direction is used for the reinforcing layer 14, the tensile strength in the horizontal direction and the tearing strength in the vertical direction can be improved, and the occurrence of these troubles can be suppressed.
[0017]
The material and thickness of the fibers constituting the long-fiber nonwoven fabric layer 12 are not particularly limited, and polypropylene, polyamide, polyester, and the like are preferably used. Among them, polyethylene terephthalate and poly, which are excellent in strength, chemical resistance, and weather resistance, are used. Polyesters such as trimethylene terephthalate and polybutylene terephthalate are particularly preferably used. Moreover, it is preferable that the thickness of a constituent fiber shall be 1d-10d.
[0018]
The reinforcing layer 14 is composed of a high-strength filament group. In order to facilitate handling and to reduce damage during needling, the filament is preferably not used as a single yarn but as a bundling yarn for non-twisting, additional twisting or twisting. As the strength of the filament increases, it can carry a larger concrete block, so that it can be used as a block mat for severe environments that receive rough waves. Alternatively, if the strength of the filament increases, the number of filaments can be reduced, so that damage to the filament due to needling for integration can be reduced. As a result of many experiments, the present inventors have found that when a filament having a tensile strength of 9 g / d or more is used, particularly practical effects as described above can be obtained.
[0019]
Examples of the filament having a tensile strength of 9 g / d or more include high-strength polyethylene terephthalate, p-aramid, polyarylate, ultrahigh-strength polyethylene, PBO, PBZT, and the like. Any of these filaments has a low elongation, and if it is a block mat, it does not deform so much even if the weight of the concrete block is applied, so that it can be laid more orderly.
[0020]
The polymerization of the long fiber nonwoven fabric layer 12 and the reinforcing layer 14 is not limited to three layers, and may be any number of layers. The civil engineering material composite sheet 10 illustrated in FIG. 3 includes two layers of one long-fiber nonwoven fabric layer 12 and one reinforcing layer 14.
[0021]
Moreover, the composite sheet 10 for civil engineering materials of this invention should just be polymerized at least with the long fiber nonwoven fabric layer 12 and the reinforcement layer 14, and may be comprised including the short fiber nonwoven fabric. The civil engineering material composite sheet 10 illustrated in FIG. 4 includes three layers of a long fiber nonwoven fabric layer 12, a reinforcing layer 14, and a short fiber nonwoven fabric layer 16.
[0022]
As mentioned above, although the composite sheet for civil engineering materials concerning the present invention and its manufacturing method have been described in detail, the present invention is not limited to the above cited / illustrated examples, the configuration and shape of the composite sheet for civil engineering materials, and the long fiber nonwoven fabric layer. The structure of the reinforcing layer and the constituent fibers can be implemented in variously modified, modified, and modified forms based on the knowledge of those skilled in the art without departing from the spirit of the present invention.
[0023]
Examples of the present invention are described in detail below.
[0024]
【Example】
Example 1
A composite sheet 10 for civil engineering material having the configuration shown in FIG. 1 was obtained by the same manufacturing method as shown in FIG. As the long-fiber nonwoven fabric 13, needle-punched polyethylene terephthalate spunbond (manufactured by Toyobo Co., Ltd., product number ODS160, basis weight 160 g / m ² ) was used. In addition, as the filament group 15, a filamentary filament in which two polyethylene terephthalate filaments of 1500d to 288f (manufactured by Toyobo Co., Ltd.) are twisted and arranged in a lengthwise (longitudinal direction) at a density of 22/5 cm is used. It was. The tensile strength of the filament was 9.2 g / d. A polyester filament group arranged in the warp direction between two long-fiber nonwoven fabrics 13 is guided and needled at a density of 80 / cm ² , and the composite sheet 10 for civil engineering materials shown in FIG. Got. The basis weight of this composite sheet 10 for civil engineering materials was 470 g / m ² , the longitudinal tensile strength was 410 kgf / 5 cm, and the water permeability coefficient in the vertical direction was 1.1 × 10 ⁻¹ cm / sec.
[0025]
Example 2
As the filament group 15, a bundle of filaments obtained by twisting two 1200d-1170f ultra-high-strength polyethylene filaments (manufactured by Toyobo Co., Ltd., Dyneema) in a longitudinal direction (longitudinal direction) at a density of 7 / 5cm. The composite sheet 10 for civil engineering material was manufactured on the same conditions as Example 1 except having used. The tensile strength of the filament was 30 g / d. The obtained composite sheet 10 for civil engineering material had a basis weight of 360 g / m ² , a longitudinal tensile strength of 430 kgf / 5 cm, and a water permeability coefficient in the vertical direction of 3.5 × 10 ⁻¹ cm / sec.
[0026]
【The invention's effect】
According to the composite sheet for civil engineering materials according to the present invention, a reinforcing layer comprising a group of filaments arranged vertically or vertically and horizontally is provided. Therefore, the block mat using this as a filter sheet sufficiently withstands the weight of the concrete block. High vertical (longitudinal) strength can be obtained.
[0027]
In addition, according to the composite sheet for civil engineering materials according to the present invention, since the needle punched long fiber nonwoven fabric layer is provided, the excellent tensile strength and tear strength of the long fiber nonwoven fabric layer contribute to the tensile strength. And tearing strength is significantly increased. Further, based on the feature of the long-fiber nonwoven fabric that is thinner than the short-fiber nonwoven fabric, the handling property is improved and thick winding can be achieved, thereby reducing the manufacturing cost of the block mat.
[0028]
In addition, the block mat using the composite sheet for civil engineering materials according to the present invention inherits the excellent physical properties of the composite sheet for civil engineering materials as it is, and has a tensile strength sufficient to bear the weight of the concrete block group, and during construction. A tear strength sufficient to withstand such various deformation stresses and unevenness of the construction surface is provided. Further, the fluff or loop-shaped protruding fibers formed by the needle punch are long fibers, so that they are difficult to come out, and a higher anchoring effect than the conventional one is obtained, so that the fixing force of the concrete block is particularly enhanced.
[0029]
In particular, by integrating the long-fiber nonwoven fabric layer and the reinforcing layer by needling, excellent water permeability can be easily ensured, and the integration processing cost can be reduced.
[0030]
In particular, by using a reinforcing layer composed only of vertically arranged filament groups, the longitudinal tensile strength that can sufficiently withstand the weight of the concrete block when used in a block mat can be obtained with a minimum amount and a minimum cost. .
[0031]
In particular, by using a long fiber nonwoven fabric made of polyethylene terephthalate, it is possible to obtain a composite sheet for civil engineering materials that is further superior in strength, chemical resistance, weather resistance, and the like.
[0032]
In particular, by using a filament having a tensile strength of 9 g / d or more, a high-load type block mat having a large concrete block can be manufactured, or the number of filaments can be reduced. Damage to the filament is reduced, and a lightweight and high-strength composite sheet for civil engineering materials can be obtained.
[0033]
In addition, according to the method for manufacturing a composite sheet for civil engineering materials according to the present invention, a long-fiber nonwoven fabric pre-punched with needles and a filament group arranged vertically or vertically and horizontally are integrated by needling. It is possible to greatly reduce the damage to the filament group by minimizing the needling required for conversion.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an example of a composite sheet for civil engineering materials according to the present invention.
FIG. 2 is a perspective view schematically showing an example of a method for producing a composite sheet for civil engineering materials according to the present invention.
FIG. 3 is a cross-sectional view showing another example of a composite sheet for civil engineering materials according to the present invention.
FIG. 4 is a cross-sectional view showing another example of a composite sheet for civil engineering materials according to the present invention.
[Explanation of symbols]
10: Composite sheet for civil engineering material 12: Long fiber nonwoven fabric layer 13: Long fiber nonwoven fabric 14: Reinforcing layer 15: Filament group 16: Short fiber nonwoven fabric layer

Claims (4)

A composite sheet for civil engineering materials, in which a needle-punched long-fiber nonwoven fabric layer and a reinforcing layer composed of a group of filaments arranged vertically or horizontally are integrated by needling . Civil engineering materials composite sheet according to claim 1, wherein the long-fiber nonwoven fabric ing from polyethylene terephthalate. The tensile strength of the filaments of the reinforcing layer is Ru der than 9 g / d 請 Motomeko 1 civil engineering materials composite sheet according. Civil engineering materials for the composite sheet of civil engineering materials for the composite sheet is 請 Motomeko 1, wherein Ru filter sheet der of concrete block mat.

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