The NTPEP Geosynthetics committee oversees a product evaluation and facility audit program to help the state DOTs effectively approve geosynthetic products.
Geosynthetics are materials manufactured from various types of polymers used to enhance, augment and make possible cost effective environmental, transportation and geotechnical engineering construction projects. They are used to provide one or more of the following functions: separation, reinforcement, filtration, drainage and liquid barrier. They are classified into two broad categories: geotextiles and geogrids.
Geotextiles are typically defined as flexible, textile-like fabrics of controlled permeability used to provide all of the above functions, except liquid barrier, in soil, rock and waste materials. It should be noted that natural fibre geotextiles (e.g. using jute) are manufactured in some parts of the world and these products are also considered to fall within the geotextile classification. Standard geotextile types (AASHTO M288 geotextile categories) are covered by the committee’s Geotextiles Work Plan.
Geogrids are generally described as stiff or flexible polymer grid-like sheets with large apertures used primarily as reinforcement of slopes and retaining walls and highway base course. NTPEP is not currently working with highway base course applications. Geogrids and high-strength geotextiles for slope and wall reinforcing applications are covered by the committee’s REGEO Work Plan.
The growth of these geosynthetic materials in Transportation, Geotechnical and Environmental related applications has been dramatic. Total use and sales of these materials are regularly increasing at rates of 10% to 20% per year in each of the above categories. (Source: International Geosynthetics Society, IGS)