ABSTRACT
Inclusion of geosynthetic reinforcements within the granular base layer has been shown to substantially improve the overall performance and life of pavements. This effect has been demonstrated in several applications, and the mechanisms through which such an improvement can be achieved have been clearly described for the past 40 years by many authors. However, because of the complexity of the reinforcement mechanisms, quantifying this effect, either in terms of increased design life or reduction of the pavement thickness, is not simple. Because of this, available design methods still rely heavily on empirical test results from large scale lab tests or field trials. The growing need for a sustainable use of plastic materials has led manufacturers to develop innovative geosynthetics capable to give the maximum possible performance with the lowest possible weight. This paper provides an overview of the development of a biaxial geogrid characterized by a three-dimensional shape designed to improve the interaction with the granular aggregate. Multiple laboratory tests were run on various biaxial geogrid designs to evaluate the performance in pavement applications. Laboratory tests included pull-out, composite stiffness tests, cyclic plate load tests, and full-scale rolling wheel load tests using an accelerated pavement tester (APT). This paper summarizes the results of these tests, which showed the advantage of the three-dimensional biaxial geogrids over traditional planar geogrids.
