Kolkata airport runway

India, Kolkata
Nonwoven geotextiles for runway base stabilization

Problem:
when it comes to airport upgrade, one of the mostly commonly encountered situations is the extension of the runway or apron. From a technical point of view, there is an extensive array of solutions to choose from using geosynthetics to deliver reliability and long-lasting service life.
At Kolkata airport, the substrate was constituted of mixed materials (clays and sands) featuring good compression resistance.
The main problem was the rainfall drainage associated with the monsoonal climate. At the same time, there was a need to minimize the erosive effect of water flowing under the pavement. In addition, the required material had to guarantee long-lasting life and service.

Solution:
to meet technical requirements was chosen Geodren® PPST 450, a nonwoven geotextile capable of simultaneously serving three functions: separation, filtration and drainage.
To achieve superior permeability performance on the geotextile surface, a blend of fibres of a specific linear density was used: this resulted in a considerable increase in Geodren® PPST 450 drainage capacity.
In addition, the thicker fibres ensured improved durability in terms of both chemical aging and microbiological resistance.
Geodren® PPST 450 was laid on top of the soil on site, which is mainly made up of clay and sand. A layer of 10 cm of sandy soil and plus a layer of 30 cm of clayey soil were spread on top.
Drainage pipes were installed every 20 m to increase drainage capacity of the system considering the huge volume of rainfalls during monsoon season.