Geotextiles:Types and Advantages of Using Geotextiles

Geotextiles: A fast solution to improve soil conditions

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Geotextiles are used in the civil construction, especially in roads and fills to improve soil characteristics. The recent popularity of geotextiles makes a poor soil more manageable and making possible to build in places where otherwise would be impossible. Geotextiles are ideal materials for infrastructure works such as roads, harbors and many others.

Function of Geotextiles

Geotextiles are commonly used to improve soils over which roads, embankments, pipelines and earth retaining structures will be built.

Depending on the type of application, geotextiles can be open mesh type, warp-knitted structure, or with a closed fabric surface, such as a non-woven. It is also important to highlight that for use or proposed design, geotextiles will be specified based on the following criteria: separation, filtration, drainage, reinforcement, sealing and protection.

Geotextile Separation

When the geotextile is to be installed between two different soil materials, the separation criteria plays a very important role. In this case, the geotextile will separate and maintain separate dissimilar materials so the required soil characteristics could be obtained. The main purpose of this type of geotextile is that when water gets into the soil strata, the geotextile will prevent soils from mixing. In road construction, you might want to keep fine subgrade aggregate from coarse aggregates that are placed as the base course.

By doing this the drainage characteristics will be kept intact preventing the fine aggregate from filling the voids between the larger aggregate. These type of geotextile will have special thickness and permeability characteristics to prevent soil contamination and will allow water to flow in without damaging the strength and structural capacity of the road.

Geotextile Applications

Geotextiles can be used in the following applications To improve unpaved and paved roads in airport runways On landfills and stone base courses Beneath sidewalks and sand drainage layer Underneath parking lots and curb areas To improve green areas and recreational facilities Beneath retaining wall structures To improve soil underneath duct banks and pipe trenches.

Geotextile Filtration

Filtration geotextile characteristics are used to allow for water to move in both directions. These type of geotextiles can be woven or non-woven that will prevent fine aggregates to move between soil layers. To select the right application for your usage, you will need to examine and analyze the porosity and permeability of the geotextile being proposed. Remember that geotextiles can be used on both axis, vertical and horizontal. A properly porosity and permeable geotextile can help solve drainage problems around the house and roads and curbs. The geotextile promotes a lateral flow thereby dissipating the kinetic energy of the capillary rise of ground water.

Geotextile Reinforcement

When a geotextile is used to improve soil characteristics, it shall consider the following criteria: friction or movement restraint, support of loads and changes in bearing failure plane.

This is comparable to the function of rebar in concrete, that it is used to reinforce concrete. This is why geotextiles are used on embankments and roads being built over very poorly graded soils. It will allow also to have a steeper embankment built, although it is always recommended to have that information provided by the geotechnical engineer.

Geotextile Sealing

When a geotextile is impregnated with asphalt or other mixes it will turn into an impermeable fabric that will restrict the flow of liquids in both directions.it is important to highlight that this will only occur if the geotextile is a non-woven fabric as normally is used in road improvements projects. There are multiple options and types of geotextiles but the remember that always the suggestion needs to come from a soil expert based on the information gather from existing soil strata.