Author(s)

A. Athanasopoulou & G. Kollaros

Abstract

Highway construction engineers often face the need for more stable, durable and, at the same time, more economic road structures. This is nowadays true because of increased traffic volumes and heavier loads on the roadways. As a consequence, enhanced pavement structures and improved subgrades is a necessity. The international highway \“New Egnatia” crosses areas in Thrace, Northern Greece with abundant clayey soils having poor technical properties. The treatment of physical soils with some substances could bring up new materials, which would operate better under the traffic and environmental conditions. This has led to the decision to investigate the possibilities of improving the existing soil materials using chemical additives. Soil samples were collected from the abovementioned area and mixed with lime and fly ash, in various proportions. The modification of the soil properties with special emphasis on their strength has been examined in the laboratory after different curing periods. The experimental results have shown that the unconfined compressive strength increased as a function of both the percentage of additive in the mixture and the time of curing. The improvement depended upon the soil mineralogy and the kind and quantity of exchangeable cations. This holds true when the influence of the kind and quantity of the additive is taken into account. The effects of lime on the swelling clayey soils tested were more beneficial than those of fly ash. The soils after their treatment could be used as a subgrade or even as a subbase layer in roadway pavements. Keywords: stabilization, lime, fly ash, engineering properties, unconfined compressive strength, optimum moisture.

Keywords

stabilization, lime, fly ash, engineering properties, unconfined compressive strength, optimum moisture