Finite Element Modeling of Coir Geotextiles Embedded Pavement Overlays

Theoretical analysis was conducted to determine the effects of natural material like coir geotextile in characteristics of asphalt overlays. The objective of this study was to evaluate the effects of coir geotextile inclusion and its position in stress strain behaviour. Flexible pavements are complex structures consisting of several layers of asphalt and granular materials. Non-linear mechanical behaviour of the pavement materials combined with the randomness in traffic and environmental conditions complicate the stress strain analysis of these type of structures. Stress–strain analysis done using software ABAQUS 6.9. Model, showed, introduction of coir geotextile in pavement overlays decreases stress and increases strain.

Introduction

One of the serious problems associated with the use of thin overlays is reflective cracking. Many pavements, which are considered to be structurally sound after the construction of an overlay, prematurely exhibit a cracking pattern similar to that which existed in the underlying pavement. This propagation of an existing crack pattern, from discontinuities in the old pavement, into and through a new overlay is known as reflective cracking.

Reflective cracks destroy surface continuity, decrease structural strength, and allow water to enter sub layers. Thus, the problems that weakened the old pavement are extended up into the new overlay. The cracking in the new overlay surface is due to the inability of the overlay to withstand shear and tensile stresses created by movements of the underlying pavement. This movement may be caused by either traffic loading (tire pressure) or by thermal loading (expansion and contraction).

Because a number of variables are involved in the nature of reflection cracking, no solution for the complete prevention of crack propagation has yet been suggested. Only retardation of crack progress is the best solution strategy adopted so far.

In this paper, an attempt has been made to study the interaction of coir geotextiles reinforcement in asphalt overlays. Objectives of the present study was to conduct theoretical analysis in order to determine the effects of coir geotextile, and finally to model the behavior of pavement structure with geotextile as intermediate layer between existing pavement layer and overlay using ABAQUS software.