Geogrid and its applications

What is a geogrid?

Geogrid is a geosynthetic material that has a flat grid structure and is made using a special technology of weaving and fixing high-modulus synthetic fibers.

To increase adhesion to asphalt concrete, the fibers are impregnated with a bituminous emulsion. The material has a rigid frame, which provides high strength, thanks to which it successfully resists tensile stresses and is immune to external factors. Such a set of characteristics gives the pavement coating a long service life.

Purpose of geogrids

The geogrid distributes the load exerted on the road surface evenly, thereby protecting the asphalt from cracks and dents. It is also used during road repairs. The grid is placed on the damaged area, and new asphalt is laid on top, so the properties of the grid prevent old cracks from transferring to the new surface.

Road geogrid properties:

• Minimizes the likelihood of cracks and holes;

• Resists dynamic and static loads;

• Distributes the load over the entire surface;

• Keeps the location of the crushed stone layer on the same level;

• Performs drainage functions;

• Separates layers of pavement;

• Prevents slippage of the canvas;

• Extends the life of the roadway.

Due to the properties of the material, its use provides significant advantages in the construction and repair of roads. The duration of asphalting is reduced. Reducing the consumption of crushed stone and labor costs gives a positive economic effect. Among other things, the frequency of repairs is reduced.

Applications

First of all, the geogrid is intended for road construction, soil reinforcement, embankments and slopes. In addition to the main scope of use, the material is also used in railway and hydraulic engineering construction and in the improvement of household plots.

The scope is determined by the characteristics and classification of the geogrid. For example, the asphalt concrete grid, among other things, fixes and holds together the layers of pavement, and the soil grid reduces the consumption of bulk material by 40 percent.

Geogrid classification

An uniaxial grid has an elongated rectangular shape, it is characterized by high strength in the longitudinal direction. Such grid is used for reinforcing the soil and separating layers, it is also used in road construction.

Biaxial grids have strength both in the longitudinal and transverse directions, which enables them to be used in road construction and cope with dynamic and static loads more efficiently than a single-axis geogrid.

By material type

Fiberglass is made of fiberglass, has high strength and low elasticity, due to which it successfully prevents subsidence of the canvas and weakening of the base of the pavement. It is also often used in the upper layers of asphalt concrete.

Basalt is a grid of basalt, to enhance the properties of which, it is impregnated with a bituminous emulsion. This technology gives the grid increased strength and good adhesion. It is an environmentally friendly material and does not conduct electricity.

Polypropylene is a polypropylene geogrid is highly water resistant, and also has high strength and the ability to withstand mechanical stress. Successfully prevents the appearance of cracks and holes by absorbing dynamic effects on the web.

Polyestergeogrid is created from polyester threads, making it relatively cheap. Just like the basalt grid, it is additionally impregnated with a bituminous emulsion. This grid shows high resistance to external loads, which significantly increases the life of the roadway and, among other things, the material is relatively environmentally friendly. It is used in the construction of highways.

Polymergrid is made of polymers by extrusion. In practice, it demonstrates high physical and mechanical properties and successfully resists external influences, but is exposed to ultraviolet rays. Scope of application: construction of highways.

Compositegrid consists of several layers and can be made from different materials and in any combination.

Transport and storage

Appropriate storage and transportation of the geogrid is an important condition for achieving the best laying quality and preventing the formation of roadbed defects.

In the warehouse for storing the material, the relative humidity of the air should not exceed 80%, and the grid should be stored in a protective film. In order to avoid deformation of the material during storage, it is laid horizontally and parallel to each other, no more than seven rows in height. Geogrids and composites are transported by all types of covered transport in compliance with the transportation rules applicable to each type of transport.

Geogrid laying rules

To lay the geogrid on asphalt concrete, the first step is to prepare the base. For this purpose, the installation site is leveled and cleaned so that the grid lies flat. Then, to ensure the best adhesion and fixation of the grid, the bottom layer is treated with a bituminous emulsion.

Next, the geogrid itself is laid, and after the grid is laid, asphalt is slowly and carefully laid on top of it. It is important to ensure immobility and maintain the integrity of the grid in order to avoid bumps and distortions.

Geogrid mounting options:

• Laying over the entire width and length of the coating;

• Partial laying. This option is used during repairs, when it is necessary to patch cracks and potholes;

• Combined styling. With this option, the grid is laid in a continuous layer and, in addition, pieces of the grid are added to the joints and problem areas.

To achieve maximum efficiency and quality of the roadway, certain paving requirements must be observed:

• The breaking load of the geogrid should be at least 40 kN/m;

• The size of the cells is calculated by the formula, they should be 2-2.5 times the size of the crushed stone;

• The asphalt concrete mixture must comply with GOST 9128-97.

Conclusion

Geogrid is a material with a rigid frame designed to improve the quality and service life of pavement by evenly distributing loads over the entire surface. The main purpose of geogrids is to improve the physical and mechanical characteristics of the road. The grid prevents the roadbed from deformation, as well as the appearance of pits and cracks. In addition to the main purpose, the grid is used to reinforce embankments, slopes and various earthworks.

If the grid is laid in the inner layers of the roadway, it will perform reinforcing functions and will reduce the amount of crushed stone consumed by 40 percent. And when reinforcing the upper layers of asphalt with a geogrid, it will increase its performance, strength and service life.

By reducing repair costs, by improving the quality of the roadway, and reducing the amount of crushed stone used, the geogrid enables you to save significantly for each kilometer of the road under construction.