materials Review Polymer Geogrids: A Review of Material, Design and Structure Relationships Mohammad Al-Barqawi 1,†, Rawan Aqel 1,†, Mark Wayne 2,† , Hani Titi 1,† and Rani Elhajjar 1,*,† 1 College of Engineering & Applied Science, University of Wisconsin-Milwaukee, 3200 N Cramer St, Milwaukee, WI 53211, USA;
[email protected] (M.A.-B.);
[email protected] (R.A.);
[email protected] (H.T.) 2 Tensar International, Alpharetta, GA 30009, USA;
[email protected] * Correspondence:
[email protected] † All authors have contributed equally to this article. Abstract: Geogrids are a class of geosynthetic materials made of polymer materials with widespread transportation, infrastructure, and structural applications. Geogrids are now routinely used in soil stabilization applications ranging from reinforcing walls to soil reinforcement below grade or em- bankments with increased potential for remote-sensing applications. Developments in manufacturing procedures have allowed new geogrid designs to be fabricated in various forms of uniaxial, biaxial, and triaxial configurations. The design flexibility allows deployments based on the load-carrying capacity desired, where biaxial geogrids may be incorporated when loads are applied in both the principal directions. On the other hand, uniaxial geogrids provide higher strength in one direction and are used for mechanically stabilized earth walls. More recently, triaxial geogrids that offer a more quasi-isotropic load capacity in multiple directions have been proposed for base course reinforcement. The variety of structures, polymers, and the geometry of the geogrid materials provide engineers and designers many options for new applications. Still, they also create complexity in terms of selection, characterization, and long-term durability. In this review, advances and current understanding of Citation: Al-Barqawi, M.; Aqel, R.; Wayne, M.; Titi, H.; Elhajjar, R.