Overview of geosynthetic included pavement overlays: Fid-Bau Portal

Overview of geosynthetic included pavement overlays

Mhaiskar, S.Y.

Geotextiles are used for controlling surface moisture infiltration and retarding reflection cracks in pavement overlays. Once the geotextile is properly installed it functions as a moisture barrier that protects the pavement components, which degrade due to ingress of water. The geotextile also provides a cushioning for the overlay as a stress-relieving layer. These two functions combine to extend the life of the overlay. Pavement rehabilitation is required where structural deficiency in the existing pavement adversely affects the load carrying capability of the pavement. Impregnated geotextiles are used beneath asphalt concrete overlays for rehabilitation and as a means to retard the deterioration of existing roadways. Such measures prove to be economical when life cycle costs are compared. Geotextiles are used in Asphalt Concrete Overlays (AC overlays) and over Portland Cement Concrete (PCC) pavements. This is the second largest application of geotextiles worldwide. In spite of the magnitude of geosynthetic usage in this field the beneficial effects are not well understood. This paper presents an overview of the geosynthetic functions, applications in different types of pavements, design outline, cost considerations and advantages and disadvantages of geosynthetic included overlays. The paper also gives specifications of geotextiles as given by AASHTO and MOST.