Geosynthetics is a popular and widely used product in modern civil engineering projects. Polypropylene, nylon, pvc, and other synthetic materials are used to make geosynthetics. These are being used in a number of novel civil engineering construction projects.
Reinforcement, separation, drainage, filtration and moisture barrier, seepage control, foundations, and pavements are just a few of the common applications. A number of advantages linked with geosynthetic application in various civil engineering tasks can be credited to its success and growing popularity.
Types of Geosynthetics
Geosynthetics are generally classed based on the material they are made of. The four major types of geosynthetics are discussed more below.
Geotextiles
Geotextiles are any permeable textile material utilised as an integral part of a man-made project, structure, or system with foundation, soil, rock, earth, or any geotechnical engineering related material.
These are synthetic polymeric materials that are made up of woven or non-woven fabrics and are used for a variety of purposes including separation, drainage, filtration, and reinforcing. Geotextiles can also be used to increase the stability of soil.
Geogrids
Geogrids are relatively strong materials with large openings (10 to 50 mm) that allow them to interlock with the surrounding soil, rock, earth, or any other geotechnical material.
High dimensional stability and tensile modulus at very low elongation are also their prime characteristics.
When used with suitably sized aggregate infill, geogrids provide reinforcement, stabilisation, and even filtration.
They can be utilised to improve the bearing capacity of soil or in road pavements.
Geomembranes
Geomembranes are a type of continuous membrane and barrier made of asphaltic, polymeric, or a combination of the two. These are the materials that have a low enough permeability to limit fluid migration in geotechnical engineering-related man-made projects or structures.
Geocomposites
Geocomposites are made up of a variety of materials such as geotexites, geogrids and geomembranes. Other materials may also be used in addition to these combinations.
The best properties of several types of geosynthetics are combined in geocomposites so that the materials combined action provides optimal performance in a given environment.
Advantages of Using Geosynthetics
- For a variety of purposes, they can be an excellent substitute for scarce and expensive traditional construction materials like cement and steel.
- They could be quite valuable, or even the only option, in certain of the bad site conditions.
- They are simple to use and install.
- They have shown to be cost-effective in large-scale applications.
- They are more resistant to atmospheric weathering than other reinforcing materials (such as steel).
- They also have the benefit of being useful in environmental conservation projects.
Application of Geosynthetics in Construction Industry
Because of its unique benefits, geosynthetics are increasingly being used in civil engineering. Geosynthetics have shown to be one of the most adaptable and cost-effective materials for ground alteration. Some of the most common geosynthetic applications are described below.
To Protect Geomembrane Lining
Geotextiles can be used to protect the geomemebrane (Synthetic liner) from installation and design stresses on one or both sides. In both hazardous and non-hazardous waste dumps, such lining systems are gaining favour.
They take the place of sand/clay protective layers. Geotextiles are also extensively utilised in waste disposal plants. They serve as fluid transmission and/or relief layers, respectively.
Steep Slope Reinforcement
By replacing a standard flat slope with a steep reinforced slope in highway building, highways can be enlarged without requiring additional right-of-way. This makes land use more efficient.
The quantity of usable land inside a given area is enhanced in private developments without the expenditure of a typical retaining wall.
Reinforced Embankment
If the foundation soils beneath the embankment are too weak to allow for the building of an embankment to the requisite height, geosynthetic-reinfored embankments can save money compared to traditional methods such as soil displacement and stabilising berms. Geotextiles or geogrids can both be used for this purpose.
Subgrade Stabilization
When building roads over weak soils, a geosynthetic can improve load carrying capacity and prevent rutting. Under construction traffic, the geosynthetic acts as a separation barrier, preventing fill from punching into the subgrade.
The subgrade will be able to reach its full bearing capacity, and the fill will be able to effectively disperse traffic loads. If necessary, the geosynthetic can also offer filtration and drainage.
Additional roadbed filtration, lateral permeability strength and modulus increase, subgrade and ballast separation may all be possible with geosynthetics utilised beneath railway tracks.
Asphalt Overlay
A geotextile, which is placed between the old and new asphalt layers, serves to prevent reflective cracking and extend the life of the overlay. The tack coat sprayed on the previous pavement’s surface is absorbed by the geotextile, forming a permanent moisture barrier.
The geosynthetic creates a barrier that protects the subgrade from water infiltration and subgrade deterioration. When compared to traditional repaving procedures, pavement service life is extended, maintenance expenses are lowered and costly resurfacing is postponed significantly.
By providing a flexible stress relieving layer between the pavement and the overlay, the pavement overlay fabric or geogrid-asphalt system and also delays the formation of reflecting cracks in the overlay.
Erosion Control
- In ditches, channels, and slopes, three-dimensional erosion control mats are employed to develop a reinforced truf. The mats entangle with the root and stem network of vegetation, considerably increasing flow resistance.
- A concrete forming technique could be a more cost-effective alternative to stone rip-rap. Water-permeable, double-layer woven fabric is commonly used to make the mats.
- Geotextiles are used as an interface to prevent soil erosion through the rip-rip armouring layer. In place of a traditional graded aggregate filter, the geotextile is used.