A CONCEPTUAL APPROACH FOR REDESIGN OF GEOTEXTILE REINFORCED FLEXIBLE PAVEMENTS

The design of flexible pavements in India is usually based on the strength of subgrade soil as measured by the California Bearing Ratio (CBR). In this method, the total pavement thickness increases exponentially with decrease of the subgrade soil's CBR. The use of synthetic fabrics like geotextiles at the interface between the pavement and a poor subgrade can considerably reduce the required pavement thickness. Therefore, low-strength soils are prime targets for geotextile reinforcement. This paper presents a study of the functional and structural properties of a geotextile material, when used in a two-layer flexible pavement over poor subgrade soil. The study's objectives were to: (1) conduct repetitive static plate load tests on two semi-full-scale pavements with and without geotextile; (2) evolve a design curve for the pavement reinforced by geotextile; and (3) conduct economic analyses of the pavements with and without geotextile. Nonwoven needle-punched fabric was used, as it was the only geotextile readily available. The clayey subgrade soil and aggregates were obtained locally. The paper discusses the experimental programme, the development of the design curves, the application of the research, economic evaluation, and scope for future research. It presents several conclusions.