Terram FSB (Frost and Salt Barrier) has been successfully used to mitigate the effects of frost heave and salt damage for a
road and rail project in the wetlands of western Kazakhstan.
In the wetlands of western Kazakhstan the weather is characterised by very low temperatures in the winter (down to -400C) and high temperatures in the summer (up to +400C). The nature of the wetlands is that the water table is high and the geology is generally desert in character but with cohesive sub-soils in common with other great river deltas in the world. As with most deserts the water is saline. In the winter the combination of the very low temperature, high water table and cohesive soils creates the ideal conditions for frost heave of the ground by classic capillary rise of the ground water. Roads are destroyed in single winters. In the summer the high temperature draws up the salt laden water to the surface and concrete and steel structures are quickly damaged by corrosion. Railways are vulnerable to such phenomena as are many other civil engineering structures.
Terram Frost and Salt Barrier has been specially designed to eliminate entirely the effects of frost heave and salt damage. Research done by the USA Corps of Engineers in the late 1970’s showed that the unique combination of polyethylene and polypropylene which make up the component fibres of Terram nonwoven geotextiles are very effective compared with other constructions in reducing frost heave. This has been further enhanced by the inclusion of hydrophobic additives in the fibres to give the Terram unrivalled capability in this application. In combination with a drainage net core in the final product it has all the characteristics required to eliminate capillary rise and to deal with the drainage of water in the embankment above the water table which collects during times of rainfall.
Terram Frost and Salt Barrier was installed on the main access road and railway to the oil production area for the new Kashagan Oil Field in Kazakhstan in the summer of 2003. It has now performed its function perfectly as anticipated for two summers and two winters thus demonstrating its unique ability to deal with these challenging problems in this harsh environment.