Test methods for evaluation of benefits of geosynthetic reinforcements for flexible pavement design - a critical appraisal for Indian scenario

Abstract

The Indian roadway construction has been in a golden period in the present decade. To optimize the cost of projects, Geosynthetics are widely used to save quantity of conventional flexible pavement materials and enhance the life of pavements. The cost optimization is majorly obtained by using Geosynthetic reinforcement products in granular layers in new pavement construction. In overlays, the asphalt reinforcement is in use to enhance the life of pavement by delaying the reflective cracking. For proper design and application of reinforcement materials in pavement sections, the design parameters that define the performance benefits in the overall system need to be obtained from proper testing. The basic material testing of Geosynthetic is carried out routinely in a few laboratories for quality control, but performance tests are not widely adapted in the country. However, the need and application of these materials are at a rush. The present performance test methods adapted in projects till now appear to be generally not as per specified protocols. This paper summarises test methods to quantify the benefits of reinforcements for each type of application and elaborates the important aspects not discussed directly in the relevant Indian Guidelines/Manuals. A general discussion on the present practice of test methods, analysis and design of reinforcements for flexible pavement along with recommendations is brought forth.