Polymeric membranes or sheets, commonly referred to as geosynthetics, are used for structural reinforcement in a number of applications including retaining walls, constructed slopes, roadways, and reinforced granular load transfer platforms. In these applications, geosynthetics experience load simultaneously in each principal material direction. These types of loads influence the load-strain properties typically in beneficial ways as compared to material response observed in uniaxial loading.

Biaxial testing devices apply loads simultaneously in each principal direction of the material and can duplicate the types of loads seen in field applications. Biaxial tests have been developed for materials used for fabric buildings and roofing systems, however only limited studies have been performed on geosynthetics. Montana State University has recently built a load frame for biaxial loading of geosynthetics. This research will use this device to examine the biaxial response of an array of geosynthetics. This data is needed to examine the suitability of various numerical models for describing biaxial load response and for providing linear elastic material properties pertinent to field loading conditions.

The broader impacts of this project include generating information that will impact industry, engineering practice and education by: i) promoting the use of a sustainable construction material, ii) providing a means of assessing material response leading to optimization of geosynthetic manufacturing processes, and iii) supporting a graduate student who will take ownership of the testing program.