Geotextiles functions

Geotextile function Tensile strength Elongation Chemical resistance Biode- gradability Flexibility Friction property Interlock Tear resistance Penetration Puncture resistance... 

Staple, slit film and multifilament yarns used to make a fabric will have open spaces between the fibres, but these are very small in size and may be neglected when considering the geotextile functionalities. 

Table 11.3 Geotextile function versus CBR value (Koerner, 2012)...

Fabrics perform one or more function in each installation generally there is one primary function. The five basic primary functions have been identified as separation, stabili2ation, reinforcement, filtration, and drainage. When the geotextile is impregnated with an impermeable material such as an asphaltic... 

Separation. In this function, the geotextile serves to separate two dissimilar materials (Fig. 3), eg, two different soils, landfill material and the native soil, stone material and subgrade sod, old and new pavement, foundation sods and various types of wads, or one of many other similar situations. In some instances, it is difficult to distinguish between the separation and stabilization functions because in both situations the geotextde is serving as a separator. However, in stabilization some additional phenomena occur. 

In separation, the primary function of the geotextile is to prevent intrusion of one material into another in order to prevent contamination of either material by the other. In the case of an aggregate being placed over a firm foundation soil, the purpose is to maintain the drainage integrity of the aggregate wall application is similar. In landfill application, the purpose is to prevent intrusion of waste material into the leachette collector system. 

Even though separation may not be the primary function for which the geotextile is installed, in almost every case the geotextile does perform as a separator. For the separation function, the physical properties of concern are primarily strength-related, including wide width, puncture resistance, and tear resistance. 

In order for it to perform the reinforcement function, the geotextile must be allowed to deform to develop its strength. When stabilization of a site occurs, there is consolidation of the soil, and with tbis comes deformation of the geotextile. Due to the deformation of the geotextile, strength is required to ensure that a site failure does not occur, ie, there can be a reinforcement component in the stabilization process. 

The functions of geotextiles can generally be broadly classified into four categories, as discussed below ... 

Giroud" has identified other functions of geotextiles and the definitions of these functions are given below. 

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