A SYNTHESIS AND EVALUATION OF GEOSYNTHETIC-REINFORCED BASE LAYERS IN FLEXIBLE PAVEMENTS - PART-I

In recent years, geosynthetics have been proposed and used as reinforc ement in the base course layer of flexible pavements for the purpose o f improving performance and/or to allow for the reduction of base cour se thickness. Much of the pioneering work with geosynthetic-reinforced unpaved roads on very soft subgrades has indicated that appreciable d eformation of the roadway surface is necessary before the reinforcemen t qualities of the geosynthetic can be realized. It may be expected th at this same condition is necessary in a paved road, thereby obviating the practical use of geosynthetics as reinforcement. It appears that this view has gained acceptance in the research and practice oriented engineering communities. The purpose of this paper is to provide a syn thesis and evaluation of the literature focusing on this application. The paper focuses on studies involving laboratory-scale experiments us ing stationary cyclic loads or moving wheel loads and field studies us ing controlled vehicle loads or random traffic loads. The majority of the studies reviewed indicate that appreciable improvement can be real ized by proper placement of a geosynthetic in the base course of a fle xible pavement and that improvement is seen over the entire service li fe of the pavement and not only for conditions of excessive surface de formation.