[2019] Best guide on Geotextile

Geotextile

Geotextile is a porous fabric made from geosynthetic material. Geotextile is used with many geotechnical materials to enhance their physical property. Easy to use, ability to resist differential settlement, drainage system, etc are the properties which make geotextile the more versatile material.

Introduction - What is Geotextile? (Definition)

Geotextiles are rapidly growing material as the nomenclature of geo-synthetics which can be made either from the natural fibres or from synthetic materials.

These are basically porous or permeable fabrics which are used with geotechnical materials (Soil or rock) as an integral part of a structure or system.

Geotextiles and geostrips are the most common nomenclature of geosynthetics.

Nowadays geotextiles are preferred over many construction materials because of the following Function-

• Ease and speed of construction.
• The ability to provide a viable solution to difficult construction problems.
• Can withstand differential settlement.

Uses of geotextile

Geotextiles are used in the wide area of construction such as -

1. construction-

• Concrete floor
• roofs
• Foundation
• Roof garden

2. Railway works-

•   Separation
•  Drainage
•  Reinforcement

3. Roadworks-

• Temporary roads
• Road widening
• parking area
• Railways
• Airport
• permanent roads

Other than that geotextile has a huge influence on erosion control.

Types of geotextile to be used in erosion control depend upon the type of erosion.

1. Beach erosion- Using synthetic fibre on the beach may harm the living things of the beach. So natural product like straw or coir is recommended.
2. Soil erosion- Woven, coir or non-woven geotextiles could be used.
3. Water erosion- Using non-woven geotextile will help to absorb excess water.
4. Wind erosion- The use of woven geotextile allows water and wind to pass through it but will protect the sediment.

Types of geotextiles

According to the data of ASTM, geotextiles are the type of permeable sheets of synthetic fibres like polyamide, polyethene, polyester etc.

Natural fibres and Synthetic fibres are the two most primary division of Geotextiles.

Natural fibres further can be classified into three parts-

1. jute grids
2. paper grids
3. wood shavings

Further classification of synthetic fibres is shown below

Non-woven material is divided into three parts

1. mechanically bonded
2. chemically bonded
3. thermally bonded

The woven material is classified as follows-

1. monofilament
2. multi filament
3. silt filament

One basic question that may come to your mind is that What is the difference between woven and non-woven geo-textiles?

Here I discussed the major significant difference between woven and non-woven material-

1. The woven materials are manufactured with a process of weaving narrow strips of film together to form a large piece.
On the other end, non-woven geotextiles are manufactured by banding with needle punching, chemically, or entangling fibres of plastic.

2. The advantage of woven material is that these are capable of resisting the high load which makes it suitable for roadways etc.

Similarly, nonwoven geotextiles are excellent at filtration and drainage, makes it ideal for uses of erosion control, drainage fabric etc.

I hope the classification of geotextile might be clear to you now.

If you want more detailed guide to the types of geotextile, comment below.

Function of geotextile

Okay, let me clear this first. 

don't get confused with the terms 'geosynthetic' and 'geotextile' materials.

Geotextile is just a part of geosynthetic material which is gaining high popularity due to its function.

Now I will give a detailed explanation about all the major functions of geotextile.

1. Separation

Well, you may hear of geosynthetic reinforced soil wall which is currently trending in the construction industry.

It helps to prevent multiple soil layers from mixing with each other. 

These techniques are useful for constructing retaining wall where the main moto is to provide separation between different soil layers.

Again geotextiles can be used as a waterproof material which will prevent cracks in existing asphalt pavements.

To know more about the use of geo-synthetic please go through geosynthetic reinforced soil

2. Drainage

Whenever we are required to eliminate excess water from the existing soil structure, drainage should be provided.

Drainage helps to prevent damage which may cause due to excess water flows through the underground.

Using nonwoven material is most suitable as it has a superior drainage quality.

Due to this quality nonwoven geotextile can also be used for

• drainage trenches
• drainage pipe
• surface drain

3. Protection

As I mentioned earlier that geotextile materials are useful for controlling erosion.

The type of geotextile should be selected depends upon the types of erosion.

For example,
in case of beach erosion, jute grid is useful as it is a completely natural product. Similarly, woven fabric is suitable for erosion caused by wind.

4. Reinforcement

Actually, The purpose of reinforcing any materials is to provide extra strength to that material. 

And surprisingly it is observed that some forms of geotextile have high soil fabric friction coefficient and high tensile strength. 

This characteristic makes it ideal to be used in reinforced earth structures.

Mainly heavy geotextiles are the best choice for this purpose.

Using geotextiles as reinforcing agent ensures better load distribution for heavyweight and high modulus of fabrics.

Another reason for using geotextile in road construction is geotextile fabric helps to spread the load in the wider area which decreases the magnitude of the load.

Fabrics are mainly placed under tension zone.

The types of reinforcement used are-

1. geotextiles
2. metal strips
3. geogrids

5. Filtration

Geotextiles are permeable in nature.

The filtration process is directly linked with the drainage process. During the drainage process of water, some amount of fine particle gets coagulated at the inlet of drainage.

This will effectively reduce the rate of the draining system.

By using geotextile cable (such as needle punched geotextile) we can prevent the coagulation of soil particle without reducing its permeability.

Woven or non-woven geo fabrics can be used in this process.

Uses of geotextiles in Road Construction

Because of the variety of useful quality, geotextile is widely acceptable and unavoidable material in civil engineering or in the construction industry.

The basic advantages that geotextiles provide are

• Easy to use and handle
• helps in the economical design
• Enhance the strength and stability
• reduction of differential settlings
• Increases the service life of roadways.

It is also considered because this fully preserves the properties of road construction materials.

This protects the foundation course and prevents the penetration of soil subgrade and aggregates.

Uses of geotextile membrane in soil stabilization

By applying the soil stabilization process we can enhance the physical properties, the shear strength of soil.

It is observed that the shear strength and bearing capacity of soil can be enhanced by reinforcing the foundation soil.

As geomembranes or heavy geotextiles are good in taking tension load, this can be used as a reinforcing agent.

Geotextiles help to reduce the effect of lateral deformation of soils.

By using geogrids or geomembrane, load carrying capacity can be increased effectively.

Learn more about Ground improvement techniques

Use of geotextiles in Railway works

The three main objectives of providing geomaterials are-

1. Reinforcement
2. separation
3. water drainage

Well in case of rail foundation geotextiles separate the subgrade level and ballast at intervals. It helps to prevent mixing of two layers from with each other.

The deformation caused by the huge dynamic load of the train could be a serious problem. 

Thus by using geotextile, we can keep the stress level low by distributing the total load over a wide area.

It also provides surface and subsurface drainage by drainage action. This action keeps the subgrade level dries which further helps to improve its shear parameters.

Conclusion

Over the last decade, geotextile is raising its popularity thanks to the function and versatility of geotextile.

From railworks to road construction geotextile is widely acceptable.

Must read for you: properties of concrete