Geogrid definition and classification

Definition of Geogrid: a two-dimensional grid or a three-dimensional grid screen with a certain height by thermoplastic or molding a polymer such as polypropylene or polyvinyl chloride. When used as a civil engineering project, It is called a geogrid.

1. Geogrid

Geogrid is a major geosynthetic material with unique properties and efficacy compared to other geosynthetics. Geogrids are often used as reinforcements for reinforced earth structures or as composite materials. Geogrid is divided into four categories: plastic geogrid, steel geogrid, Fiberglass Geogrid and Glass Fiber geogrid.

(1) Plastic geogrid

The plastic geogrid is a square or rectangular polymer mesh which is formed by stretching, and may be uniaxially stretched or biaxially stretched according to the direction of stretching in the manufacture. It is punched on a extruded polymer sheet (mostly polypropylene or high density polyethylene) and then subjected to oriented stretching under heating. The unidirectionally stretched grid is stretched only along the length of the sheet, while the biaxially stretched grid is formed by continuing to stretch the unidirectionally stretched grid in a direction perpendicular to its length.

Since the polymer of the plastic geogrid is realigned and oriented along with the heating extension process, the bonding force between the molecular chains is strengthened, and the strength is improved. Its elongation is only 10% to 15% of the original board. If an anti-aging material such as carbon black is added to the geogrid, it can have good durability such as acid resistance, alkali resistance, corrosion resistance and aging resistance.

(2) Steel plastic geogrid

The steel-plastic geogrid is made of high-strength steel wire (or other fiber), specially treated, with polyethylene (PE), and other additives, and it is extruded into a composite high-strength tensile strip with rough pressure on the surface. The pattern is a high-strength reinforced geotechnical belt. The single belt is formed by longitudinal or transverse spacing at a certain interval or by clamping, and is welded by a fusion welding technique of special strengthening bonding to form a reinforced geogrid.

(3) Glass fiber geogrid

The glass fiber geogrid is a geosynthetic material made of glass fiber and made of a certain weaving process. It is a geocomposite material which is made of a special coating process to protect the glass fiber and improve the overall performance. The main component of glass fiber is: silicon oxide, which is an inorganic material. Its physical and chemical properties are extremely stable, and it has high strength, high modulus, high wear resistance and excellent cold resistance, no long-term creep; thermal stability. Good property; the mesh structure makes the aggregate interlock and limit; improve the load-bearing capacity of the asphalt mixture. Because the surface is coated with special modified asphalt, it has two-fold composite performance, which greatly improves the wear resistance and shearing capacity of the geogrid.

Sometimes combined with self-adhesive pressure-sensitive adhesive and surface asphalt impregnation, the grid and asphalt pavement are tightly integrated into one. Due to the increased interlocking force of the earth and stone in the geogrid grid, the friction coefficient between them increases significantly (up to 08 to 10), and the pull-out force of the geogrid embedded in the soil is due to the gap between the grid and the soil. The frictional bite force is strong and significantly increased, so it is a good reinforcement material. At the same time, the geogrid is a kind of plastic flat net material with light weight and certain flexibility. It is easy to cut and connect on site, and can also overlap and overlap. It is easy to construct and does not require special construction machinery and professional technicians.

(4) Polyester Fiber warp geogrid

The polyester fiber warp-knitted geogrid is made of high-strength polyester fiber. The warp-knitted oriented structure, the warp and weft yarns in the fabric are not bent with each other, and the intersections are combined with high-strength fiber filaments to form a firm joint point, giving full play to its mechanical properties, high-strength polyester fiber warp knitting geogrid The grid has high tensile strength, small elongation force, large tear strength, small difference in longitudinal and transverse strength, resistance to ultraviolet aging, abrasion resistance, corrosion resistance, light weight, strong interlocking force with soil or gravel, and reinforcement of soil. Shearing and reinforcing improve the integrity and load of the soil and have a significant effect.