KR20010064502A - Composite geogrid and preparation thereof - Google Patents

Abstract

PURPOSE: A composite geogrid manufacturing method is provided to manufacture a geogrid with low ductility to the direction of the woof and warp regardless of the size of the loads applied to a geogrid and functions as a stiffener excellently. CONSTITUTION: In a geogrid for the public work of a synthetic resinous sheet reinforced by a stiffener, a reinforced part(1) reinforced by many linear stiffeners(3) to the mechanical direction and a non-reinforced part(2) are alternately formed and many boring holes(4) are formed on the non-reinforced part to the mechanical direction regularly, wherein the reinforced part is used to the same direction of loads and the bored part connected to the reinforced part corresponds to a point of contact and is filled with sand, earth, rock, etc.

Description

Composite geogrid and preparation method thereof

The present invention relates to a geogrid for civil construction work in the form of a synthetic resin sheet reinforced with a reinforcing material, and more particularly, a composite geogrid with excellent strength, low elongation, and weather resistance, which combines the advantages of rigid geogrid and soft geogrid.

Polymer materials for civil construction are manufactured by various fiber shapes, extrusion, coating, etc., and are classified into woven and nonwoven geotextiles, geomembranes, geogrids, geonets, geomats, geomeshes, and geocomposites. .

Geogrid is a lattice-like material with holes of about 1 to 10 cm between ribs, and is used as reinforcement in the direction of load. Geogrids can vary in how they are constructed, connected, or joined.

Geogrid, which has a lattice structure in the light and weft direction, was developed in the 1980s and has been used in civil engineering. It has high tensile strength on the rib, which is required for strength, to strengthen the foundation and pavement of roads. It is being applied to slope reinforcement and reinforced earth retaining wall construction. In addition, geogrid has a higher tensile strength than geotextile, and its use is expanding as a substitute for the reinforcement field in which geotextiles have been applied. With the development of new civil construction methods, various types of geogrid products are available worldwide. Developed. The importance of the development and characteristics of geogrid suitable for the construction site is more important and the geogrid used as reinforcement for retaining wall, waste landfill, ground reinforcement, road construction should have high tensile strength, high shear strength and pullout resistance. .

Geogrids can be divided into rigid geogrids and soft geogrids according to the manufacturing method and form. In general, soft geogrids have a higher shear strength than rigid geogrids. In addition, flexible geogrids are frequently used in the construction of structures requiring high strength and low elongation. This is because rigid geogrids have low flexural stiffness and high strain rate, and are low in friction.

Rigid geogrids are made by passing a synthetic resin sheet through a perforation roller, drilling apertures and stretching in one or two directions. The manufactured rigid geogrid has elliptical holes and has a bending hardness value of 1,000 g · m or more. As the synthetic resin used for the rigid geogrid, polyolefin-based, polyvinyl chloride-based, and polyurethane-based resins are used.

Rigid geogrid is excellent in friction, drawing, chemical resistance and weather resistance, but when a load of 10 tons or more is added, there is a problem that the stability is lowered due to the high elongation in the inclined direction.

The flexible geogrid is supplied in the form of warp in the warp direction and the high-strength filament yarn in the warp direction of the band fabric in the form of weaving or knitted fabric, and the apertures are formed by crossing in the light and weft direction. It is coated with polyvinyl chloride, bitumen, coal tar, acrylic, latex, and rubber-based resins in order to impart and to strengthen the contact point at the point of binding of the weft yarn and to improve the resistance to sunlight and ultraviolet rays. Another reason for coating synthetic geogrid fabrics with synthetic resins is due to improved durability. Geogrid is important because it is necessary to maintain the initial properties of geogrid during its service life. Flexible geogrid has 1,000 g It has the following bending hardness values, and high strength polyester is mainly used as a weft yarn.

The flexible geogrid has excellent tensile and creep characteristics, but has a problem in that stability in the weft direction is lowered when a high load is added. In addition, in order to coat the synthetic resin for the flexible geogrid fabric, the synthetic resin must be dissolved in a suitable solvent. The manufacturing process of such soft geogrid is complicated and economically undesirable. For example, in the case of the flexible geogrid coated with polyvinyl chloride, about 40% of the plasticizer is added, and thus, the manufacturing cost is not cheap, and in the case of the latex coated soft geogrid, the manufacturing cost is expensive.

It is an object of the present invention to provide a geogrid with a low elongation in the warp and weft direction and excellent function as a reinforcing material regardless of the magnitude of the load added to the geogrid, and a method of manufacturing the same.

The present inventors have combined the extrusion process for producing rigid geogrid and the weaving process for producing soft geogrid to manufacture geogrid, which has the advantages of both rigid geogrid and soft geogrid, and has high strength, low elongation and excellent weatherability with improved geogrid. It has been found that the present invention can be efficiently manufactured with productivity, thus completing the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows a preferable example of the composite geogrid of this invention.

2 is a manufacturing process chart showing an example of a preferred manufacturing method of the composite geogrid of the present invention.

Description of the main parts of the drawing

1: reinforcement part 2: non-reinforcement part

3: linear reinforcing material 4: perforation

According to the present invention, in the geogrid for civil construction workers in the form of a synthetic resin sheet reinforced with a reinforcing material, a plurality of linear reinforcing materials are formed in an alternating reinforcement part and a non-reinforcing part are alternately formed in the machine direction, and the plurality of perforations in the machine direction are Provided is a composite geogrid, characterized in that formed at regular intervals.

In addition, according to the present invention, in the method of manufacturing a geogrid for civil construction work in the form of a synthetic resin sheet reinforced with a reinforcement, a plurality of linear reinforcement in the machine direction by passing through the extrusion die in a state arranged in a plurality of rows at a predetermined interval Method of manufacturing a composite geogrid comprising forming a synthetic resin sheet formed by alternating reinforcement portions and non-reinforcement portions, and punching the non-reinforcement portions at predetermined intervals in the machine direction to form a plurality of holes, followed by cooling and winding. This is provided.

Hereinafter, the present invention will be described in more detail.

It will be described with reference to Figure 1 showing a preferred example of the composite geogrid of the present invention.

The composite geogrid of the present invention is formed with alternating reinforcement portions 1 and non-reinforcement portions 2, in which a plurality of linear reinforcements 3 are reinforced in the machine direction, and a plurality of perforations 4 in the machine direction in the non-reinforcement portions. It is characterized in that formed at regular intervals. Here, the reinforcement part is used in the same direction as the load is applied, and the perforated part connected to the reinforcement part corresponds to a contact point and is a part filled with sand, soil, rock, and the like.

The above-mentioned composite geogrid has a number of ribs per unit area of 15 to 50 / m 2, a weight of 150 to 1,000 g / m 2, a wide tensile strength of 5 to 300 kN / m and a single rib strength of 0.5 to 1.5 kN / m. The contact strength is preferably 20 to 60 kN / m, the limit creep strength is 19 to 65 kN / m, and the long term design strength is 10 to 35.

In the composite geogrid of the present invention, the reinforcing material is to use a high-strength polyester filament yarn, glass fiber, steel wire (mild steel or hard steel wire) or Kevler yarn as a reinforcing material to have the properties and performance described above. desirable.

In addition, in the composite geogrid of the present invention, it is preferable to use a polyethylene resin, a polypropylene resin, a polyvinyl chloride resin, or an acrylonitrile-butadiene-styrene copolymer resin in order to enhance the protection and morphological stability of the internal linear reinforcement.

The geogrid of the present invention forms a synthetic resin sheet in which a plurality of linear reinforcing members are reinforced in a machine direction and a non-reinforcing part is alternately formed by passing an extrusion die in a state in which a plurality of strands are arranged in a plurality of rows at predetermined intervals. After punching the non-reinforcement part at a certain interval in the machine direction to form a plurality of holes, punching the non-reinforcement part at a certain distance in the machine direction to form a plurality of holes, and then cooled by water-cooling or air-cooling. It can manufacture.

2 is a manufacturing process chart showing an example of a preferred manufacturing method of the composite geogrid of the present invention. Hereinafter, a method of manufacturing a composite geogrid will be described in detail with reference to FIG. 2.

In the preparation process, the reinforcing material is mounted on a creel, and then spliced or coalesced to arrange a plurality of strands of reinforcement in a plurality of rows at predetermined intervals. The reinforcement in the arranged state passes through an extrusion die to form a synthetic resin sheet in which a plurality of linear reinforcements are reinforced in the machine direction and non-reinforcement portions are alternately formed. At this time, the extrusion die is preferably T-dies, the capacity of the extruder (extrusion amount per unit time) is 100kg / hr ~ 400kg / hr, the temperature of the extruder is preferably 130 ~ 220 ℃. In addition, the line speed of the extruder is preferably 0.5 to 5 m / min.

After the extrusion process, the synthetic resin sheet goes through a punching process to form a plurality of holes by punching the non-reinforcement part at a certain interval in the machine direction, and then cooled and cut by water cooling or air cooling by passing through a cooling bath to form a complex type. It can be made of geogrid.

Hereinafter, the advantages and features of the present invention will be described through examples. However, the present invention is not limited by the following examples.

Geogrid physical properties were measured by the following measurement methods.

* Weight per unit area: ASTM D 5261

* Wide tensile strength: ASTM D 4595

* Single rib strength: GRI Test Method GG1

* Contact Strength: GRI Test Method GG2

* Limit creep strength: ASTM D 5262

* Long-term Design Strength: GRI Test Method GG4

<Example 1>

According to the manufacturing method of the present invention, a high strength polyester filament yarn of 1,000 denier / 60 ply yarn was used as a reinforcing material, and polyolefin resin was used as a synthetic resin. The temperature of the extruder at this time was 195 degreeC, and the line speed was 1.5 m / min. A hole having a diameter of 40 to 70 mm was punched out by a punching machine and cooled by water cooling to prepare a composite geogrid.

The number of ribs per unit area, weight per unit area, wide tensile strength, single rib strength, contact strength, limit creep strength, and long-term design strength of the manufactured composite geogrid are shown in Table 1.

<Comparative Example 1>

Rigid geogrids were prepared by a conventional method for producing rigid geogrids using polyolefin resins.

The number of ribs per unit area, weight per unit area, wide tensile strength, single rib strength, contact strength, limit creep strength, and long-term design strength of the fabricated rigid geogrids are shown in Table 1.

<Comparative Example 2>

A flexible geogrid was prepared by a conventional method of producing a flexible geogrid using 3,000 denier high-strength polyester filament yarn and a polyolefin resin.

The number of ribs per unit area, weight per unit area, wide tensile strength, contact strength, limit creep strength, and long-term design strength of the manufactured flexible geogrids are measured and shown in Table 1.

division Number of ribs per unit area Weight per unit area (g / ㎡) Wide tensile strength (kN / m) Single rib strength (kN / m) Contact strength (kN / m) Limit creep strength (kN / m) Long term design strength (kN / m) Example 1 34 410 30.5 0.75 48.4 43.2 24.2 Comparative Example 1 27 360 13.8 0.51 43.6 35.4 14.3 Comparative Example 2 50 430 24 0.48 21.3 41.7 20.1

As shown in the above embodiment, the composite geogrid of the present invention has wider tensile strength, single rib strength, contact strength, limit creep strength and long-term design strength than the conventional rigid geogrid and soft geogrid, so It is a new and useful invention that can be applied to reinforcement of layers, reinforcement of banks and slopes, and reinforcement soil retaining wall construction to exhibit excellent performance, and has a relatively high tensile strength compared to existing geogrid products.

Claims (5)

In the geogrid for civil construction work in the form of a synthetic sheet reinforced with a reinforcement material, a plurality of linear reinforcement members are alternately formed with a reinforcement portion and a non-reinforcement portion reinforced in a machine direction, and a plurality of perforations are formed at regular intervals in the non-reinforcement portion with a machine direction. Hybrid geogrid, characterized in that. The composite geogrid according to claim 1, wherein the reinforcing material is a high strength polyester filament yarn, glass fiber, steel wire (mild steel and hard wire) or Kevlar yarn. The composite geogrid according to claim 1, wherein the synthetic resin is polyethylene resin, polypropylene resin, polyvinyl chloride resin or acrylonitrile-butadiene-styrene copolymer resin. 2. The composite geogrid according to claim 1, wherein the number of ribs per unit area of the composite geogrid is 15 to 50 / m 2, the weight per unit area is 150 to 1,000 g / m 2, the broad tensile strength is 5 to 300 kN / m, and the single rib strength is 0.5 to 5. A composite geogrid comprising 1.5 kN / m, contact strength 20 to 60 kN / m and limit creep strength. In the method of manufacturing geogrid for civil construction work in the form of a synthetic sheet reinforced with a reinforcement, a reinforcement portion in which a plurality of linear reinforcements are reinforced in a machine direction by passing the extrusion die with the reinforcement arranged in a plurality of rows at predetermined intervals. And forming a plurality of holes by punching the non-reinforcing portion at a predetermined interval in the machine direction, and cooling and winding the composite geogrid.