Geosynthetics

Abstract

Chapter 17 provides an introduction to geosynthetics. The description begins with definitions of the term, including those from ASTM and EN ISO standards, and the reasons for the explosion of geosynthetic materials in the civil engineering market. The next heading discusses the raw materials used in manufacturing geosynthetics, polypropylene (PP), polyethylene (PE), poly(vinyl chloride) (PVC), and polyester (polyethylene terephthalate—PET) being the most commonly used polymers. In specific applications, some geotextiles can incorporate natural biodegradable fibers. Manufacturing processes of geosynthetics are then discussed, including nonwoven, woven, and knitting methods. Subsequently, geosynthetic functions are described; hydraulic functions include filtration, drainage, and fluid(gas) barrier while mechanical functions are mainly separation, reinforcement, and protection. The next topic covers description of the most commonly available geosynthetics, i.e., geotextiles, geomembranes, geogrids, geonets, geocells, geofoams, geomats, geosynthetic clay liners, and geocomposites. At the end of the chapter, geosynthetics applications are kept in mind, including embankments on soft soils, erosion control, hydraulic landfills, railroads, roadways, and retaining walls. To finish the chapter, geosynthetic standards are very briefly discussed.