GEOSYNTHETICS IN ROADS AND PAVEMENTS

GEOSYNTHETICS IN ROADS AND PAVEMENTS

J.Thomas Britto

Dept of civil engineering

Thomasbritto3@gmail.com

ABSTARCT

A large variety of detrimental factors affect the service life of roads and pavements including environmental factors, subgrade conditions,traffic loading, utility cuts, road widenings, and ageing. These factors contribute to an equally wide variety of pavement conditions and problems which must be addressed in the maintenance or rehabilitation of the pavements, if not dealt with during initial construction.Existing pavement distress such as surface cracks,rocking joints, and subgrade failures cause the rapid reflection of cracking up through the maintenance treatment.Therefore, the preferred strategy for long-term road and pavement performance is to build in safeguards during initial construction. These performance safeguards include stabilizing the subgrade against moisture intrusion and associated weakening; strengthening road base aggregate without preventing efficient drainage of infiltrated water; and, as a last resort, enhancing the stress absorption and moisture proofing capabilities of selected maintenance treatments. Geosynthetics are the most costeffective tools for safeguarding roads and pavements in these ways.The four main applications for geosynthetics in roads are subgrade separation and stabilization, base reinforcement, overlay stress absorption, and overlay reinforcement. Subgrade

stabilization and base reinforcement involve improving the road structure as it is constructedby inserting an appropriate geosynthetic layer. Subgrade separation and stabilization applies geosynthetics to both unpaved and paved roads. Base reinforcement is the use of geosynthetics

to improve the structure of a paved road.Geosynthetics are also helpful in rehabilitating distressed road surfaces. The application of a layer of asphalt concrete called an overlay is often the solution for damaged pavement. Geosynthetics can be used as interlayers by placing them below or within the overlay. Some geosynthetics relieve stress and others are able to reinforce the overlay. The products may also provide a moisture barrier.