Degradable geotextiles

Geotextiles may be woven, nonwoven, or knitted. AH types, woven, nonwoven, or knitted, are susceptible to degradation owing to the effects of ultraviolet light and water. Thus stabilizing agents are added to the base polymeric material to lessen the effects of exposure to ultraviolet light and water. 

High performance fibers are generally characterized by remarkable unit tensile strength and resistance to heat, flame, and chemical agents that normally degrade conventional fibers. Applications include uses in the aerospace, biomedical, civil engineering, constmction, protective apparel, geotextiles, and electronic areas. 

Figure 9.2 Schematic prediction of strength of a polyester geotextile subjected to slow degradation by hydrolysis (based on information from [6])...

Synthetic spun fabrics these materials may also be sold as "landscape fabrics" or occasionally "geotextiles," for long-term weed control. They allow water to permeate through them into the soil, but can degrade where exposed to the sun, so cover with a loose mulch to protect them from the light. 

Geotextiles are available as mats, textiles, webs, nets, grids, and sheets. When retention of the contained material is desired synthetic polymers such as polypropylenes, polyesters, nylons, PEs, and PVCs are used because they resist rapid degradation. When only shortterm retention is needed natural materials such as cotton are used. Geotextiles are not always made from fibers, but include film materials such as PE and polypropylene sheets used to retain moisture but retard weed growth in gardens. 

Horrocks AR. Degradation of Polymers in Geomembranes and Geotextiles. In Hamidi SH, Amin MB, Maadhah AG, editors. London New York Marcel Dekker 1992. p. 433-505. 

For the geotextile to provide an effective reinforcement function, it should have not only a high tensile strength, but also a high tensile modulus so that its resistance to tensile loads generated within the soil occurs at sufficiently small strains to prevent excessive movement of the reinforced soil structure. It is self-evident that decreases in these properties with time (i.e. creep behaviour) must be low, and that the polymers used should have resistance to degradation by the soil. An estimate of the anticipated reduction in strength can be determined from an analysis of creep strain versus time plots for various stress levels and a suitable reduction factor applied. 

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