Geosynthetics - from product to technology in road rehabilitation : geotechnical engineering

Before the launch of the new South African Pavement Design Method (at the time of writing), extensive research was undertaken to evaluate current road pavement material performance (design versus long-term actual performance) in the development of new materials. However, very little interest was shown in a technology which has been proven to benefit pavements by an unequalled value of up to 10 times normal traffic load, thereby allowing a reduction in layer thickness of up to 50%. This means a Category C (ES-0.01 to 0.1) road becomes a Category B road. Applying this technology greatly reduces the cost of construction where a G1 or a cement-stabilised material would have been used. This technology, which is known as geosynthetics, has a record of more than 30 years of proven results and efficiency in practice. Some new materials currently used in roadworks do not have proven records over such a time span. Although currently classified as materials or products, it is increasingly believed that geosynthetics in fact represent a new technology. Geosynthetics technology is the result of thorough research, field tests and calibration towards the development of a strongly-based formulation for designing. Geosynthetics technology was recently successfully used in a road rehabilitation project currently under construction near Glentana in the Southern Cape.