JP2001073252A - Mesh sheet for civil engineering and construction, excellent in impact resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a mesh sheet for civil engineering and construction excellent in handling, strength, interlocking faculty and impact resistance by satisfying a specified relation between fineness of fiber bundle and fineness of covering fiber covering circumference thereof. SOLUTION: This mesh sheet for civil engineering and construction is obtained by using fiber yarns satisfying the formula I>=-0.06 T+1,500, wherein T corresponds to fineness T (denier) of at least one direction fiber bundle consisting of 3,000-150,000 d multifilament or span yarn and I corresponds to fineness I (denier) of covering fiber consisting of 100-60,000 d multifilament or span yarn, covering the fiber bundle and having >=1.2 times longitudinal length per a unit based on the above fiber bundle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mesh sheet for civil engineering and construction used as a reinforcing and shielding material in the civil engineering and construction fields, and more particularly as a soil reinforcing material for landfill and embankment construction in the civil engineering field. The present invention relates to a useful mesh sheet for civil engineering and construction.

[0002]

2. Description of the Related Art Conventionally, as a field for soil reinforcement materials described in the preceding paragraph, there is a grid sheet known as a geogrid or a geotextile. Items particularly required for the lattice sheet include a strong utilization factor, an interlocking function, and impact resistance.

[0003] Various devices have been devised to increase the power utilization rate. In particular, in the case of a woven fabric, the cross section of the warp and the weft is devised so that the warp and the weft are each linear in order to increase the strength utilization rate of the fiber. However, since it is a woven fabric, the warp and the weft do not line up with each other at the intersection, because they go up and down,
The above objectives are not always achieved. Tissues such as leno weaves have similar problems for the above reasons. In view of the above, a configuration is proposed in this application in which the strands inserted by warp insertion and / or weft insertion are used as linearly as possible.

On the other hand, with respect to the interlocking function, a configuration is disclosed in Japanese Patent Application Laid-Open No. 4-327247, which is characterized by making the fiber aggregate as cylindrical as possible. With this configuration, the mesh holes per area are increased, and the interlocking effect due to the mesh is increased.

[0005]

The mesh sheet for civil engineering and construction is required to have impact resistance in addition to the above. In particular, when the sheet is used for civil engineering or embankment reinforcement, the sheet always receives an impact due to heavy equipment running. Accordingly, there has been a demand for a sheet having impact resistance due to heavy equipment traveling. The present invention has found a method for improving not only the strong utilization rate and the interlocking function required for civil engineering and construction but also the durability of heavy equipment during running. That is, a sheet that sufficiently satisfies the durability is provided.

[0006]

According to the mesh sheet for civil engineering and construction of the present invention, when the fiber convergence body is used for the sheet, the denier of the fiber convergence body in at least one direction is T denier,
When the coated fiber covering the outer periphery of the fiber converging body is I denier, I ≧ −0.06T + 1500 (1). If I is less than the formula (1), the required impact resistance cannot be obtained, which is not preferable.

[0007] As a gist of the present invention, a coated fiber is required on the outer peripheral portion of the fiber bundle. In order to cover the fiber convergence body with the fiber, a so-called sea core structure in which the fiber convergence body is wrapped with a larger number of fibers (multi-denier) than the fiber convergence body is also possible. However, other than this method, a structure in which the fiber bundle is inserted into the knitted fabric structure or a structure in which the fiber bundle is wound around the surface of the fiber bundle may be used. When the coated fiber uses a denier finer than the fiber bundle, the coated fiber present on the fiber bundle needs to be at least 1.2 times as long as the fiber bundle. If it is less than 1.2 times, the effect of covering by the covering fiber cannot be obtained, which is not preferable. It is preferably at least 1.3 times, more preferably at least 1.5 times.

The fiber converging body has a thickness of 3000 d to 150.
000d. When the thickness is 3000d or less, many strands must be arranged in order to obtain the required strength, and a desired mesh hole cannot be obtained. As the fiber converging body, 4500d or more is preferable.
In addition, the fiber convergence body may be thick to obtain the required strength. However, if it is too thick, the softness, which is a characteristic of the fiber mesh sheet, may be impaired or the basis weight may become heavy, which is not preferable. Preferably it is 135000d or less. Further, the coated fiber preferably has a length of 100 d or more and 6000 d or less.
If it is less than 100d, the impact resistance is reduced, which is not preferable. Preferably it is 200d or more. Thick coated fibers are preferred because of increased impact resistance, but too thick are not preferred because the softness characteristic of the fiber mesh sheet is impaired and the basis weight is increased. Preferably it is 5000d or less.

[0009] The fiber used in the present invention may be a filament yarn or a spun yarn. If both filament yarn and spun yarn can obtain the design strength suitable for this application,
There is no particular limitation. Metal fibers as well as synthetic fibers and natural fibers may be used. Synthetic fibers are preferred in terms of strength. For example, glass fiber, carbon fiber, aramid fiber, high-strength polyethylene fiber, and polyester fiber and nylon fiber are preferable in consideration of cost and strength.

The method of coating the fiber bundle with the covering fiber may be any method, but the method of covering the fiber bundle with the covering fiber or the method of inserting the fiber bundle into the ground structure of the knitted fabric to reduce the ground structure It is also possible to use a coated fiber (see FIG. 1).

As a structure satisfying the present invention, warp knitting and weft insertion can be mentioned. In this case, the ground structure is the coated fiber, and the inserted warp is the fiber converging body. As a ground organization, 100
Fibers of d or more and 6000 d or less are used. The warp inserted into this structure has a thickness of 3000d to 150,000d.
It is necessary to be. When the thickness is 3000d or less, it is necessary to arrange many warp strands in order to obtain necessary strength, and it is not possible to obtain a desired mesh hole. As a warp, 4500d or more is preferable. On the other hand, if the thickness is too large, the softness, which is a characteristic of the fiber mesh sheet, is impaired, and the weight per unit area is unfavorably increased. Preferably it is 135000d or less. In addition, the weft insertion yarn used in the present invention has a size of 3000d to 15d for the same reason.
0000d, more preferably 4500d to 135000
d. In addition, it is preferable that both the warp insertion yarn and the weft insertion yarn are independent strands. In addition, each strand may be subjected to sweet twist to enhance the convergence of the fibers in advance.

As a specific structure, a structure in which multifilament or spun yarn of ground texture is arranged as a chain yarn on both sides of a warp-insertion fiber converging body, or a multifilament or spun yarn of ground texture is warp-inserted fiber convergent A tissue which is disposed as a chain thread on both sides of the body and is disposed as a binding thread of a warp-inserted fiber converging body. By using this structure, the warp can be more converged, and the impact resistance and the mesh holes can be easily controlled, which is preferable.

The sheet of the present invention is more preferably processed with a resin. The resin processing may be performed at the strand stage before weaving or weaving, but it is more preferable to perform resin processing in a sheet shape after weaving. The resin to be used is not particularly limited, and may be any resin and processing conditions that do not significantly reduce the fiber's strong utilization rate.

The seat having the configuration of the present invention can reduce the rate of decrease in strength due to heavy equipment running, which is assumed particularly when used in civil engineering applications. In addition, by devising the knitted fabric structure and the fibers used, strong utilization rate,
A sheet suitable for this use can be obtained.

[0015]

The present invention will be described in more detail with reference to the following examples. The physical properties and evaluations in the examples were obtained as follows.

(Measurement) The distance between the strand and the adjacent strand was measured.

(Tensile Strength) The sample is set to a width of 20 cm with respect to the direction in which the sample is to be measured, and set on a chuck so that the chuck does not break.
The measurement was carried out at a pulling speed such that it became 20% / min.

(Amount of Coated Yarn) When the coated fibers were finer in denier than the fiber converging body, the coating ratio was determined. A strand having a predetermined length was cut out, and the coated fiber was taken out from the fiber bundle. From the length (H) of the coated fiber and the length (S) of the fiber bundle at this time, the amount of the coated yarn was determined by the following equation. Covered yarn amount = (H) / (S) In addition, due to the knitted fabric configuration, it was estimated that even when the coated fibers were not continuous, (H) was determined.

(Soil pull-out test) A soil pull-out tester was used as a testing machine. The soil was compacted at 80% using a sand density (roughness) with a relative density Dr = 87%. Vertical stress
The drawing was performed at 0.30 kgf / cm ² at a drawing speed of 1 mm / min. The test piece was 15 cm wide and 50 cm long. The maximum shear stress was determined from the maximum pull-out force of each sample. Maximum shear stress is 0.1kgf / c
If it is less than m2, the interlocking effect in the soil is small, and the soil may slide down during reclaiming or embankment reinforcement, which is not preferable.

(Impact Resistance Test) The sample was subjected to an impact using a servo pulser (model EHF-UG1-40L) manufactured by Shimadzu Corporation. The shock was applied under load control by applying a sine wave load of 0 to 10 kg / cm ² at 1 Hz and 200 times through a rectangular plate having a warp direction of 10 cm and a weft direction of 20 cm with respect to the sample.
The sample was fixed in a square of 40 cm, and positioned just in the center so that the above-mentioned rectangle hit. At the bottom of the sample, A4 was measured by the spring method shown in JIS K-6253.
0 / S hardness is 45mm at the bottom and JIS A-
S-30 (No.4 crushed stone) shown in 5001 will be spread 30mm. S-30 was spread over the sample by 30 mm. The test was performed by applying a rectangular pressure plate from above the crushed stone at the top of the sample. After the test, a sample was taken out and the tensile strength was measured by the method described above. The strength retention was determined from the strength before the test and the strength after the test. A sheet having a strength retention of 60% or less is not preferred as a sheet for this application.

(Example 1) Polyester yarn (11 1500d multifilaments bundled) as warp insertion yarn using a weft insertion type 9 gauge Raschel machine.
16500d was used. As the ground knitting yarn, 1000d of polyester multifilament was used. A chain stitch was made using 1000d of the ground knitting yarn, and a 16500d yarn was inserted into the loop as a warp insertion yarn. Further, a 9000d yarn was inserted in the weft direction. The intersection interval between the warp and the weft was 17 mm. The knitted fabric was processed with an acrylic resin to form a sheet. Soil pull-out test of this sheet,
When an impact resistance test was performed, both showed good values. Therefore, this sheet was suitable for this use.

(Example 2) Polyester yarn (28 1500d multifilaments bundled) as warp insertion yarn using a weft insertion type 9 gauge Raschel machine.
42000d was used. As the ground knitting yarn, 250 d of polyester multifilament was used. 1 of ground knitting yarn
A chain stitch was made using 000d, and a 42,000d yarn was inserted into the loop as a warp insertion yarn. Further, a 9000d yarn was inserted in the weft direction. The intersection interval between the warp and the weft was 17 mm. The knitted fabric was processed with an acrylic resin to form a sheet. When the sheet was subjected to a soil pull-out test and an impact resistance test, it showed good values in both cases. Therefore, this sheet was suitable for this use.

(Example 3) As a warp yarn, a yarn obtained by covering (120 T / m) with a polyester filament of 16500 d and a polyester filament of 1000 d was used. Using a 9 gauge Raschel machine, chain knitting was made using 250d of polyester multifilament as the ground knitting yarn, and the covered yarn was inserted into the loop as a warp insertion yarn. Further, a 9000d yarn was inserted in the weft direction. The intersection interval between the warp and the weft was 17 mm. The knitted fabric was processed with an acrylic resin to form a sheet. When the sheet was subjected to a soil pull-out test and an impact resistance test, it showed good values in both cases. Therefore,
This sheet was suitable for this application.

Example 4 A polyester multifilament yarn having a thickness of 1500 d was used as a chain yarn and a polyester multifilament having a thickness of 750 d was used as an insertion yarn, and 15 polyester yarns (15 1500 d multifilaments were bundled) as warps to be inserted. ) 22500d was used. Further, a 9000d yarn was inserted in the weft direction. The interval between the intersections of both the warp and the weft was 25 mm. The knitted fabric was processed with an acrylic resin to form a sheet. When the sheet was subjected to a soil pull-out test and an impact resistance test, it showed good values in both cases. Therefore, this sheet was suitable for this use.

(Comparative Example 1) A yarn was used in the same manner as in Example 1 except that 250 d of polyester multifilament was used as the ground knitting yarn. When an impact resistance test was performed on this sheet, the strength retention was 46%. From these results, this sheet was unfavorable for this application, because it was easily damaged by rolling and heavy machinery running during construction on site.

(Comparative Example 2) Polyester yarn (five 500d multifilaments bundled) 25 as warp insertion yarn using a weft insertion type 9 gauge Raschel machine
00d was used. As the ground knitting yarn, 1000d of polyester multifilament was used. 100 of ground knitting yarn
A chain stitch was made using 0d, and a 2500d yarn was inserted into the loop as a warp insertion yarn. Further, a 2500d yarn was inserted in the weft direction. The interval between the intersections of both the warp and the weft was 3 mm. The knitted fabric was processed with an acrylic resin to form a sheet. The sheet was subjected to a soil pull-out test to find that it was 0.12 kgf / cm ² , which was not preferable. In addition, when an impact resistance test was performed, the strength retention was 38%.
%, Which was also undesirable. If the fiber converging body is made thinner in this manner, it is necessary to reduce the interval between the intersections in order to obtain the strength required for civil engineering and building sheets, and a configuration inevitably resulting in a smaller mesh size occurs. For this reason, the soil pull-out property is reduced, and at the same time, the impact resistance is also reduced. This sheet was not preferred for this application.

(Comparative Example 3) A yarn was used in the same manner as in Example 3 except that a yarn having been covered (42 T / m) with a polyester filament of 1000 d was used. When an impact resistance test was performed on this sheet, the strength retention was 55%. From these results, this sheet was unfavorable for this application, because it was easily damaged by rolling and heavy machinery running during construction on site.

[0028]

According to the present invention, it is possible to provide a mesh sheet excellent in handleability, excellent in strength required for civil engineering construction materials, excellent in interlocking function (pullability in soil), and excellent in impact resistance. Was.

[Brief description of the drawings]

FIG. 1 is an enlarged schematic view of a mesh fabric according to Examples 1 to 3 of the present invention.

FIG. 2 is an enlarged schematic view of a mesh fabric according to a fourth embodiment of the present invention.

[Explanation of symbols]

1: warp, 2: weft, 3: ground structure, 4: ground structure (tied yarn), 5: ground structure (chain knitting yarn)

 ──────────────────────────────────────────────────続 き Continued on front page F term (reference) 4L036 MA05 MA33 MA35 PA46 RA24 UA07 4L048 AA34 AA48 AB01 AB07 AB19 AC09 BA01 BA02 CA00 CA01 DA30 DA31 DA41

Claims (7)

[Claims] 1. A fiber yarn having a fiber fineness (T denier) of at least one direction and a fineness (I denier) of a covering fiber covering an outer periphery of the fiber convergence body satisfying the following formula (1): A mesh sheet for civil engineering with excellent impact resistance, characterized by the following features: I ≧ −0.06T + 1500 (1) 2. The civil engineering building with excellent impact resistance according to claim 1, wherein the length of the coated fiber per unit in the longitudinal direction is at least 1.2 times the length of the fiber convergent body. Mesh sheet. 3. The thickness of the fiber converging body is 3000d or more and 15 or more.
2. The multi-filament yarn or spun yarn having a thickness of 100 d or more and 4,000 d or less and having a thickness of 100 d or more and 6000 d or less. 3. Mesh sheet. 4. The mesh sheet for civil engineering and construction having excellent impact resistance according to claim 1, wherein the covering fiber is formed by covering a fiber converging body. 5. A multifilament or spun yarn of 100d or more and 6000d or less is used as a ground structure, a warp-inserted fiber bundle of 3000d to 150,000d is used as a warp, and a weft-inserted fiber bundle of 3000d to 150,000 is used as a weft. 5. The method according to claim 1, wherein
The described mesh sheet for civil engineering and construction. 6. The mesh sheet for civil engineering and construction according to claim 5, wherein the multifilament or spun yarn having the ground structure is arranged as a chain yarn on both sides of the warp-inserted fiber converging body. 7. A multifilament or spun yarn having a ground structure is arranged as a chain yarn on both sides of a warp-insertion fiber converging body, and is arranged as a binding yarn of the warp-insertion fiber converging body. Item 6. The mesh sheet for civil engineering and construction according to Item 5.